F/I strains engine?
06-24-2016, 12:34 PM
#81
Registered User
Thread Starter
Not necessarily. Building that much torque - required for towing - in a turbo engine takes more boost and there's a point of diminished returns when the turbo is spooling at it's maximum speed design point.
Add in other things like torque curves, more heat everywhere, more mechanical chaos is likely.
Turbo engines (except diesel) are not as good for towing due to this. You want to tow, get a V8 or diesel with a torque curve as flat as Kansas.
Gee, we haven't even started to talk about hybrid/electric power at elevation.... hahahahahahaha.
Add in other things like torque curves, more heat everywhere, more mechanical chaos is likely.
Turbo engines (except diesel) are not as good for towing due to this. You want to tow, get a V8 or diesel with a torque curve as flat as Kansas.
Gee, we haven't even started to talk about hybrid/electric power at elevation.... hahahahahahaha.
So v8 vs turboed deisel, both same towing capacity, which would be more stressed while towing?
06-24-2016, 12:55 PM
#85
I think you also need to look a bit at the basic definition of stress. and the basics of a gasoline vs a diesel engine. A diesel engine is built many many many times more durably than a gas v8 of near equal power, but only because the diesel will see many times more forces internally. since the diesel is built more robustly, it can handle the harsher forces.
The stresses would be nearly the same.
The differences in options with this do come into play with altitude, gas milage towing vs unloaded, fuel price, tunability.. and many other facters, which is why you can still get a gas chevy 2500 etc.
The stresses would be nearly the same.
The differences in options with this do come into play with altitude, gas milage towing vs unloaded, fuel price, tunability.. and many other facters, which is why you can still get a gas chevy 2500 etc.
06-24-2016, 05:28 PM
#86
Registered User
Thread Starter
I think you also need to look a bit at the basic definition of stress. and the basics of a gasoline vs a diesel engine. A diesel engine is built many many many times more durably than a gas v8 of near equal power, but only because the diesel will see many times more forces internally. since the diesel is built more robustly, it can handle the harsher forces.
The stresses would be nearly the same.
The differences in options with this do come into play with altitude, gas milage towing vs unloaded, fuel price, tunability.. and many other facters, which is why you can still get a gas chevy 2500 etc.
The stresses would be nearly the same.
The differences in options with this do come into play with altitude, gas milage towing vs unloaded, fuel price, tunability.. and many other facters, which is why you can still get a gas chevy 2500 etc.
So towing, the stress level will be similar? I always thought since turbo uses load to make power, i would figure the strain would be on the turbo rather than the engine.
06-24-2016, 05:29 PM
#87
Registered User
Thread Starter
To anyone who want to flame, continue flaming as it doesnt bother me, im actually learning by asking "stupid" question so in the end, im benefitting from this.
A day without learning something new is a day wasted.
A day without learning something new is a day wasted.
06-24-2016, 06:19 PM
#88
So let's be serious here: each engine from Nissan is designed around certain parameters. Will it be primarily a NA or FI is one of the bigger considerations. It's why the VG engine blocks were built from cast iron and the 300ZX TT could make huge power. Same for the newest VR38DTT engines built from compacted iron. Can we modify a VQ to handle the heat and stress of a FI application? Sure, but that means lots of time and effort spent towards building the short block and tuning the engine for FI.
So, bottom line, FI on any engine is stressful. Nissan uses FI in certain applications, but a VQ--with its all aluminum block-- is not one of them. It will last longer and see more miles in NA form if maintained properly.
So, bottom line, FI on any engine is stressful. Nissan uses FI in certain applications, but a VQ--with its all aluminum block-- is not one of them. It will last longer and see more miles in NA form if maintained properly.
moving on i didnt even read this entire thing what i read however is you want to compare airflow thats stupid because just airflow means absolutely nothing, stroke, piston speeds, timing all affect power which affects the stress on the engine. the stress on parts is going to be a function of the mass pushing on them and the speed of acceleration. To that end NA, Turbo, or nitrous will all be the same assuming a perfect tune. sometimes na may be more stressful due to acceleration(F=MA). The mass is going to come from the force of the explosion pushing down, acceleration will come essentially from the RPMS thats as dumbed down as you can get. Turbos will be slightly more sometimes due to back pressure but its all negligible. Nitrous theoretically is the same as NA of the same power but tends to go through pistons more often due to jets not being that precise for fueling.
NOW WITH THAT SAID supercharged cars at the same power level will have MUCH greater stress, how much is determined by the amount of boost being ran, the parasitic loss is exponential with boost increases. The rule of thumb is about 50 hp up to 10 psi, about 125-150 at 20 psi, and hits about 500 at 40 psi. Also the upper portion of bearings are worn more due to the upward force from the belt, which also causes additional harmonics and flexation on the crank all leading to a less reliable setup.
for SPECIFIC engines that would need the exact specs of the engine, bearing width, bearing diameter, power per bearing surface, power per cylinder, ect. all of that matters A LOT. however in general n2o, na, and turbo will all be similar at a given power level on the same engine with the same power.
i noticed a comment about closed deck having stronger sleeves, thats not true either, closed deck run a more rigid block which prevents cylinder movement. open decks have handled power easily in most cases outside of a all out max effort engine its completely irrelevant. the vq for instance has shown it can handle 800 ish on stock sleeves on a open deck block and even more on factory sleeves, dosnt have issues till around 45 psi, the sleeves dont make it anything other than a sleeved engine even with MID since block deflection still happens and cylinders shift around thats why need billet around 45 psi( ~1600-1700 ish hp)
06-24-2016, 06:44 PM
#89
I can tell you this is a bit wrong unless its a PD blower car all the things that matter on a NA engine STILL matter on a FI engine because that's what helps shape the power curve, its ESPECIALLY important on turbo cars whose turbo spool depends directly on off boost power production. The cars that i produce still get custom designed intakes and exhausts to match heads and cams ill admit i do HIGH power stuff almost exclusively now that every bit helps but for instance the pro mod im currently building is a 416 that will spin to 9k rpms and will be using 440 cfm heads(highest flowing small block heads available.) otherwise ill be trying to run the turbos outside the efficiency range and leave power on the table.(its a fine balancing act and why most high end shops have engineers on staff now and im currently getting my own engineering degree.)
Blower cars dont care about any of that for the most part because the PD blowers will move the same amount of air every revolution regardless of anything else they dont spool up like turbos or centri blowers do.
As i said in my previous post, turbo and NA dont generate more stress only superchargers do, heat is going to be the same, the engine produces the same btu's of heat give or take a few thousand(read not much at all) for a specific output.(thats all power is, btu's of heat converted to kinetic energy.) Pressure in NA will be lower but speed will be higher going back to F=MA.
Your comment on head gaskets, Yes NA will have less pressure, but again more acceleration in the engine means they experience more cycles, its not static pressure that kills anything in a engine its dynamic so at a given power the total force over time applied to a cylinder head trying to lift it will be the same.
As far as valve train your actually 100% wrong a NA engine for a given power will ALWAYS have more valvetrain stress. Again dynamic loads, the only thing is harmonics are also HUGE which affect the strength of a metal(nascar fills the valve covers with oil to dampen harmonics, f1 cant find a spring strong enough so they use pneumatics). say on a 1k whp engine NA vs turbo, the NA engine will usually see about 20% higher seat and open pressure because of harmonics, not to mention as speed goes up the effect of weight goes up since its multiplied not added. meanwhile FI engines see paltry increases since they will generally have a much lower rpm limit and the only extra force they deal with is intake side charge air trying to press the valve open more. exhaust side trying to open with a bigger charge is harder but again NA sees more cycles so its a wash. In MOST engines(not the VQ) they have some sort of rocker(yes even ohc engines have finger followers that act as rockers) which increase the force springs have pre spring. this again is made worse by what is needed in a NA engine for a given power level.
Again the iron vs aluminum block is pretty much completely irrelevant the biggest issue is price. almost all aluminum blocks have iron liners, what type of iron will vary some have steel and some have plasma sprayed liners. aluminum blocks and connecting rods are used in 10k hp top fuel engines, stock 200 hp 4 bangers and everything in between my pro mod im working on is only getting a iron block because i need a raised cam and i dont want to spend 6k on a bare block when iron is half that and ill just up the boost 4-5 psi. it seems your speaking on limited experience which is fine but frankly, any aluminum block will perform just fine, l33's run 1400 hp on completely stock components just opening ring gaps a little.
as far as upgrading ignition meh generally your going to need something pretty wicked to need to upgrade modern stuff and usually just throw GM coils on it and its fine. these 1k coils are retarded that people actually pay that. IGN-1A coils are $70 and can handle up to 8 hp per cubic inch. in most cases drop the plug gap down a little and your fine thats about it. you need to be pushing some major power over stock to really need to upgrade that. high rpm on a distributor vehicle however its a good idea to go to some sort of aftermarket preferably individual or at least wasted spark setup.
Blower cars dont care about any of that for the most part because the PD blowers will move the same amount of air every revolution regardless of anything else they dont spool up like turbos or centri blowers do.
As i said in my previous post, turbo and NA dont generate more stress only superchargers do, heat is going to be the same, the engine produces the same btu's of heat give or take a few thousand(read not much at all) for a specific output.(thats all power is, btu's of heat converted to kinetic energy.) Pressure in NA will be lower but speed will be higher going back to F=MA.
Your comment on head gaskets, Yes NA will have less pressure, but again more acceleration in the engine means they experience more cycles, its not static pressure that kills anything in a engine its dynamic so at a given power the total force over time applied to a cylinder head trying to lift it will be the same.
As far as valve train your actually 100% wrong a NA engine for a given power will ALWAYS have more valvetrain stress. Again dynamic loads, the only thing is harmonics are also HUGE which affect the strength of a metal(nascar fills the valve covers with oil to dampen harmonics, f1 cant find a spring strong enough so they use pneumatics). say on a 1k whp engine NA vs turbo, the NA engine will usually see about 20% higher seat and open pressure because of harmonics, not to mention as speed goes up the effect of weight goes up since its multiplied not added. meanwhile FI engines see paltry increases since they will generally have a much lower rpm limit and the only extra force they deal with is intake side charge air trying to press the valve open more. exhaust side trying to open with a bigger charge is harder but again NA sees more cycles so its a wash. In MOST engines(not the VQ) they have some sort of rocker(yes even ohc engines have finger followers that act as rockers) which increase the force springs have pre spring. this again is made worse by what is needed in a NA engine for a given power level.
Again the iron vs aluminum block is pretty much completely irrelevant the biggest issue is price. almost all aluminum blocks have iron liners, what type of iron will vary some have steel and some have plasma sprayed liners. aluminum blocks and connecting rods are used in 10k hp top fuel engines, stock 200 hp 4 bangers and everything in between my pro mod im working on is only getting a iron block because i need a raised cam and i dont want to spend 6k on a bare block when iron is half that and ill just up the boost 4-5 psi. it seems your speaking on limited experience which is fine but frankly, any aluminum block will perform just fine, l33's run 1400 hp on completely stock components just opening ring gaps a little.
as far as upgrading ignition meh generally your going to need something pretty wicked to need to upgrade modern stuff and usually just throw GM coils on it and its fine. these 1k coils are retarded that people actually pay that. IGN-1A coils are $70 and can handle up to 8 hp per cubic inch. in most cases drop the plug gap down a little and your fine thats about it. you need to be pushing some major power over stock to really need to upgrade that. high rpm on a distributor vehicle however its a good idea to go to some sort of aftermarket preferably individual or at least wasted spark setup.
Well, the main point here is that everything is NOT equal between the two so I'll weigh in here.
I find this a VERY interesting topic because of my own experiences with turbocharging, both from a factory and an aftermarket standpoint. FTR, I've owned something like 8-10 turbo cars, two built with aftermarket components and the rest factory FI cars - including two in my stable currently.
So here's my as-close-to-a-Reader's-Digest-style assessment as I can make it. (But it's still way lonnnnnnng as this is a complex topic.) - You are warned.
________________________________________
Number one, fact versus fallacy:
Wear and tear between a 400bhp normally aspirated engine and a 400bhp forced induction engine are NOT the same. Fact.
Start by examining the basic principles of a normally aspirated engine:
An NA engine producing that much power relies on many components but the one area that is primarily being discussed here is how said engine gets it's air in and out of the engine - how it "breathes" as it were.
NA relies on a number of different-from-FI aspects: compression ratio, valve sizing, intake path design, cylinder size/volume, camshaft lift and duration, combustion chamber size, and overall displacement. And so on.... The bottom line here is that it relies on the engines "natural breathing" (no external help) to move air in and out.
Like an olympic runner or swimmer, big, highly conditioned lungs can move air in/out more effectively and efficiently than "mere mortals". So, to bring out more efficiency and effectiveness (mo' power) from your engine, increasing the size, design, specifications, of any of the above mentioned components can yield higher breathing capabilities. (Should be noted that a properly designed combination of all of the above are required to make the most effective changes throughout the engine's operating cycle.)
In order for a NA engine to take in an amount of air equal to what a turbo or supercharger does - to keep things "equal", it would require increases in all of the above.
So, the initial question of "How does the engine know if the air is sucked in by piston action or if it's mechanically forced in?" is actually a very astute question.
With a simple answer...
It doesn't.
However....
The NA engine, due to its generally more sizable displacement and upsized/tuned components will generally have a lower specific output (the engine size to power ratio; say, "one hp per cubic inch" or "82 hp per liter") than a forced induction engine.
But it is also designed to not exceed it's physical limitations. And, any changes to any of the components referenced merely help it breath better ON IT'S OWN and NOT with the use of an external charge mechanism.
In other words, the NA engine does not, can not exceed it's own natural breathing limitations. Hence, the engine works under a "designed stress load" - generally speaking at a much lower or tempermental level than an FI motor. Not to say it can't break, of course it can; but not to the type and extent of damage generally, of a forced induction engine. Read on....
________________________________________
Now, let's examine what happens when you put a blower on an engine.
But we need to confirm another thing (myth or fact) first:
Turbocharging and Supercharging (forced induction) both induce more stresses on an engine than a like-for-like (powered) normally aspirated engine. We can all agree on that.
But why?
1. Heat
2. Pressure
3. Components and algorithms not designed to handle #1 and #2.
That's pretty much it.
T'bo, you likened the engine to an air pump. That's essentially true. More in, more out.
But an engine, like any pump, is a mechanical device and as anyone knows (and Dean likened this to a weightlifter in his excellent example earlier), you push said device - be it an engine or a human) past its physical limits and stuff is going to break.
Let's examine what can go funky in a blown engine:
Gaskets - rudimentary, right?
Let's use head gaskets, amongst the many, as an example. They're there to seal the surfaces between the heads and the block and keep stuff that needs to be inside on the inside. What happens when you add pressure (due to a higher concentration of air/fuel resulting in a larger explosion inside the cylinder).
You exert many times the pressure it may have been designed for. Simple, obvious result: blown head gasket - which can lead to every kind of failure known to an internal combustion engine....cooling failure, oil starvation from loss of oil pressure, combustion gasses blowing out the side of the motor, etc.
I don't think I need to expand on the resulting mechanical chaos in the event of oil starvation or overheating do I?
Valvetrain stress - every component of the valve train has to work harder to maintain valve sealing AND there's even more undue stress on the cam(s), followers, springs, etc. in opening and closing of the valves going against the increased cylinder pressures.
In a heavy boost, high rpm incidence, valves may start to float, springs get overworked trying to keep the valves closed, opening them becomes a chore and strain on the cam actuators and this can lead to premature failure of the cam - and any of cam followers componentry.
Cylinder wall, piston, damage- Think of these items as if they were balloons. Fill them with something - water, air, or in this case a very dense air/fuel mix leading to higher cylinder pressures upon ignition, well, it's plain to see that these items (and all surrounding components) may suffer a similar fate as the balloon. They can stress and ultimately crack or break if forced to work beyond their design.
As David (dkmura) pointed out earlier, the VG series engines in the Z32 (and other non-US-spec cars) are built much more stout being designed specifically for forced induction (times two). How? Through thicker cylinder walls, more internal block webbing, better main bearing caps, stronger bearings. And perhaps, no, make that for sure, the biggest difference, the construction material of the block itself, cast iron (VG) versus aluminum (VQ).
While aluminum is lighter and very strong, it doesn't have the heat resistance properties that cast iron does and to make an aluminum block last as long as cast iron in an FI application, the addition of iron sleeve liners are sometimes recommended to resist the higher heat generated within the cylinder.
Note: This is NOT saying aluminum is unsuitable for FI applications at all. However, contemporary all-aluminum engines that are designed to be turbocharged are engineered from the design phase through production with higher grade aluminum, different sizing and densities, and in general, designed to withstand turbo/supercharged applications.
Saved the "best" for last.... THE biggest enemy of an FI engine (any engine actually but many fold worse in an FI engine) and perhaps the most highly overlooked when building a forced induction engine is DETONATION.
This can come from many things; but the two biggest culprits are:
- Insufficient fuel to properly match the incoming pressurized air charge ("lean out" or, slightly more scientifically, the stoichiometric A/F mix is askew... higher than 14.7:1) and...
- Insufficient or mistimed spark.
So you have this engine that is now receiving a super dense air entering the engine thanks to the air-charger(s). The resulting what-ifs that can lead to premature failure or outright destruction:
- What if the spark isn't hot enough to ignite it properly and fully?
- What if said spark occurs during the wrong portion of the combustion cycle, e.g., too early, too late?
- What if there's more air than fuel? (Meaning, the builder hasn't upsized the volume of fuel delivery or it's not functioning properly.... higher capacity pump, larger injectors.)
Disaster happens.
Any/all of these lead to detonation, which, I don't need to tell anyone who's taken Auto Shop 101, is deadly and will likely cause massive engine failure from these mini-hand-grenades going off in rapid sequence internally if left unchecked.
To properly prevent this, ALL of the mechanical ignition components (coilpacks, wiring, distributor/magneto (in such applications), plugs, etc.) ALL need to be upgraded to match the new parameters the engine is forced (no pun intended) to run under.
Generally speaking, when factories design their cars with factory turbo engines, you can bet these components are all upgraded (and often carried "down" to their normally aspirated brethren to cut overall costs by keeping the components consistent) before testing.
AND, more importantly, in addition to the hardware, the brain mapping (ECU parameters) - the software side - is all different. Timing curves (advance and retard points - and all facets of spark control) need to be mated to all of the engine's new different-from-stock operating conditions: boost pressure, engine speed, fuel pressure, MAF readings, knock sensor(s), O2 readings, all happening simultaneously to interpret and maintain what's going on inside the engine.
--------------------------------------
I could go on and on and on but this is a cursory look at why a turbo or supercharged engine - especially one done after the fact like any/all aftermarket systems - are more stressful to an engine.
Hope this helps to answer the question, T'bo (and any other interested parties).
I find this a VERY interesting topic because of my own experiences with turbocharging, both from a factory and an aftermarket standpoint. FTR, I've owned something like 8-10 turbo cars, two built with aftermarket components and the rest factory FI cars - including two in my stable currently.
So here's my as-close-to-a-Reader's-Digest-style assessment as I can make it. (But it's still way lonnnnnnng as this is a complex topic.) - You are warned.
________________________________________
Number one, fact versus fallacy:
Wear and tear between a 400bhp normally aspirated engine and a 400bhp forced induction engine are NOT the same. Fact.
Start by examining the basic principles of a normally aspirated engine:
An NA engine producing that much power relies on many components but the one area that is primarily being discussed here is how said engine gets it's air in and out of the engine - how it "breathes" as it were.
NA relies on a number of different-from-FI aspects: compression ratio, valve sizing, intake path design, cylinder size/volume, camshaft lift and duration, combustion chamber size, and overall displacement. And so on.... The bottom line here is that it relies on the engines "natural breathing" (no external help) to move air in and out.
Like an olympic runner or swimmer, big, highly conditioned lungs can move air in/out more effectively and efficiently than "mere mortals". So, to bring out more efficiency and effectiveness (mo' power) from your engine, increasing the size, design, specifications, of any of the above mentioned components can yield higher breathing capabilities. (Should be noted that a properly designed combination of all of the above are required to make the most effective changes throughout the engine's operating cycle.)
In order for a NA engine to take in an amount of air equal to what a turbo or supercharger does - to keep things "equal", it would require increases in all of the above.
So, the initial question of "How does the engine know if the air is sucked in by piston action or if it's mechanically forced in?" is actually a very astute question.
With a simple answer...
It doesn't.
However....
The NA engine, due to its generally more sizable displacement and upsized/tuned components will generally have a lower specific output (the engine size to power ratio; say, "one hp per cubic inch" or "82 hp per liter") than a forced induction engine.
But it is also designed to not exceed it's physical limitations. And, any changes to any of the components referenced merely help it breath better ON IT'S OWN and NOT with the use of an external charge mechanism.
In other words, the NA engine does not, can not exceed it's own natural breathing limitations. Hence, the engine works under a "designed stress load" - generally speaking at a much lower or tempermental level than an FI motor. Not to say it can't break, of course it can; but not to the type and extent of damage generally, of a forced induction engine. Read on....
________________________________________
Now, let's examine what happens when you put a blower on an engine.
But we need to confirm another thing (myth or fact) first:
Turbocharging and Supercharging (forced induction) both induce more stresses on an engine than a like-for-like (powered) normally aspirated engine. We can all agree on that.
But why?
1. Heat
2. Pressure
3. Components and algorithms not designed to handle #1 and #2.
That's pretty much it.
T'bo, you likened the engine to an air pump. That's essentially true. More in, more out.
But an engine, like any pump, is a mechanical device and as anyone knows (and Dean likened this to a weightlifter in his excellent example earlier), you push said device - be it an engine or a human) past its physical limits and stuff is going to break.
Let's examine what can go funky in a blown engine:
Gaskets - rudimentary, right?
Let's use head gaskets, amongst the many, as an example. They're there to seal the surfaces between the heads and the block and keep stuff that needs to be inside on the inside. What happens when you add pressure (due to a higher concentration of air/fuel resulting in a larger explosion inside the cylinder).
You exert many times the pressure it may have been designed for. Simple, obvious result: blown head gasket - which can lead to every kind of failure known to an internal combustion engine....cooling failure, oil starvation from loss of oil pressure, combustion gasses blowing out the side of the motor, etc.
I don't think I need to expand on the resulting mechanical chaos in the event of oil starvation or overheating do I?
Valvetrain stress - every component of the valve train has to work harder to maintain valve sealing AND there's even more undue stress on the cam(s), followers, springs, etc. in opening and closing of the valves going against the increased cylinder pressures.
In a heavy boost, high rpm incidence, valves may start to float, springs get overworked trying to keep the valves closed, opening them becomes a chore and strain on the cam actuators and this can lead to premature failure of the cam - and any of cam followers componentry.
Cylinder wall, piston, damage- Think of these items as if they were balloons. Fill them with something - water, air, or in this case a very dense air/fuel mix leading to higher cylinder pressures upon ignition, well, it's plain to see that these items (and all surrounding components) may suffer a similar fate as the balloon. They can stress and ultimately crack or break if forced to work beyond their design.
As David (dkmura) pointed out earlier, the VG series engines in the Z32 (and other non-US-spec cars) are built much more stout being designed specifically for forced induction (times two). How? Through thicker cylinder walls, more internal block webbing, better main bearing caps, stronger bearings. And perhaps, no, make that for sure, the biggest difference, the construction material of the block itself, cast iron (VG) versus aluminum (VQ).
While aluminum is lighter and very strong, it doesn't have the heat resistance properties that cast iron does and to make an aluminum block last as long as cast iron in an FI application, the addition of iron sleeve liners are sometimes recommended to resist the higher heat generated within the cylinder.
Note: This is NOT saying aluminum is unsuitable for FI applications at all. However, contemporary all-aluminum engines that are designed to be turbocharged are engineered from the design phase through production with higher grade aluminum, different sizing and densities, and in general, designed to withstand turbo/supercharged applications.
Saved the "best" for last.... THE biggest enemy of an FI engine (any engine actually but many fold worse in an FI engine) and perhaps the most highly overlooked when building a forced induction engine is DETONATION.
This can come from many things; but the two biggest culprits are:
- Insufficient fuel to properly match the incoming pressurized air charge ("lean out" or, slightly more scientifically, the stoichiometric A/F mix is askew... higher than 14.7:1) and...
- Insufficient or mistimed spark.
So you have this engine that is now receiving a super dense air entering the engine thanks to the air-charger(s). The resulting what-ifs that can lead to premature failure or outright destruction:
- What if the spark isn't hot enough to ignite it properly and fully?
- What if said spark occurs during the wrong portion of the combustion cycle, e.g., too early, too late?
- What if there's more air than fuel? (Meaning, the builder hasn't upsized the volume of fuel delivery or it's not functioning properly.... higher capacity pump, larger injectors.)
Disaster happens.
Any/all of these lead to detonation, which, I don't need to tell anyone who's taken Auto Shop 101, is deadly and will likely cause massive engine failure from these mini-hand-grenades going off in rapid sequence internally if left unchecked.
To properly prevent this, ALL of the mechanical ignition components (coilpacks, wiring, distributor/magneto (in such applications), plugs, etc.) ALL need to be upgraded to match the new parameters the engine is forced (no pun intended) to run under.
Generally speaking, when factories design their cars with factory turbo engines, you can bet these components are all upgraded (and often carried "down" to their normally aspirated brethren to cut overall costs by keeping the components consistent) before testing.
AND, more importantly, in addition to the hardware, the brain mapping (ECU parameters) - the software side - is all different. Timing curves (advance and retard points - and all facets of spark control) need to be mated to all of the engine's new different-from-stock operating conditions: boost pressure, engine speed, fuel pressure, MAF readings, knock sensor(s), O2 readings, all happening simultaneously to interpret and maintain what's going on inside the engine.
--------------------------------------
I could go on and on and on but this is a cursory look at why a turbo or supercharged engine - especially one done after the fact like any/all aftermarket systems - are more stressful to an engine.
Hope this helps to answer the question, T'bo (and any other interested parties).
06-24-2016, 06:52 PM
#90
Registered User
Thread Starter
Now im conflicted. And confuse and not sure which to follow along.
I thought that air to fuel has to do with how big of a boom the explosion is. So wouldnt more air cause a bigger boom therefor wouldnt more air=more stress whether NA or FI?
I thought that air to fuel has to do with how big of a boom the explosion is. So wouldnt more air cause a bigger boom therefor wouldnt more air=more stress whether NA or FI?
06-24-2016, 08:42 PM
#91
your not understanding how this things work, gas engines throttle off air(meaning they need air to rev up add more air they increase rpms till something limits it or boom), diesel engines throttle off fuel so more fuel means more revs(this is how they roll coal, they inject way more fuel than normal for a given airflow). HOWEVER BOTH make power(aka boom) off of the fuel injected, each molecule of fuel puts out a specific amount of heat, that heat converted into kinetic energy is what we measure as horsepower and torque.
with gas engines you add air to throttle the engine and then add fuel to the correct ratio to ensure proper combustion. so no more air dosnt mean a bigger boom unless you add more fuel as well.
with that said its not just about the size of the boom, its about BOTH the size of the boom as well as how often that occurs. all power is, is a measurement of potential power(torque) and work done(horsepower) this is why horsepower is what breaks things, not rpms, not torque, a combination of both(again F=MA). if you have an explosion with 1000 psi but only see it once in one second or 800 psi but see it four times in a second which do you think causes more stress on components?
and example look up a f1 cars connecting rods they are massive billet aluminum piece, yet those only make 240 lb ft of toque, even if you double the stroke so its comparable to what most engines run thats still only 480 lb ft so thats all the "boom" its making and all the connecting rod is subject to(need to remember what is measurable is a function of the boom and the lever rod aka the stroke of the crank), yet they run just as beefy rods as what pro stocks run which have almost double the torque. both engines put out similar horsepower figures however because one revs to 10k5 and the other 18k
with gas engines you add air to throttle the engine and then add fuel to the correct ratio to ensure proper combustion. so no more air dosnt mean a bigger boom unless you add more fuel as well.
with that said its not just about the size of the boom, its about BOTH the size of the boom as well as how often that occurs. all power is, is a measurement of potential power(torque) and work done(horsepower) this is why horsepower is what breaks things, not rpms, not torque, a combination of both(again F=MA). if you have an explosion with 1000 psi but only see it once in one second or 800 psi but see it four times in a second which do you think causes more stress on components?
and example look up a f1 cars connecting rods they are massive billet aluminum piece, yet those only make 240 lb ft of toque, even if you double the stroke so its comparable to what most engines run thats still only 480 lb ft so thats all the "boom" its making and all the connecting rod is subject to(need to remember what is measurable is a function of the boom and the lever rod aka the stroke of the crank), yet they run just as beefy rods as what pro stocks run which have almost double the torque. both engines put out similar horsepower figures however because one revs to 10k5 and the other 18k
06-24-2016, 08:48 PM
#92
he said his comment a little wrong, the stresses for a given horsepower will be the same because diesels while they have huge torque run low rpms unless its some four banger like VW uses. a $500 tuner can get you a 500 hp nowadays on a diesel though with the new ones out there that are already lowto mid 400's from the factory. however they see maximum stress more often than a gas engine due to the smaller operating range and the typically greater load on the engine. because of that the total stress imparted on the engines is greater and so they build the parts beefier. turbos have almost no load on them outside thrust load. they build power off load because of greater exhaust volume and heat which spins the wheel faster. turbos are all about getting that turbo to 50k+ rpm's but there is hardly any mechanical load on the turbo itself.
06-25-2016, 11:28 AM
#93
Lol AMS tears through vr38's pretty regularly. Aluminum blocks aren't that strong, period. Hence why AMS sleeves their big HP Vr38's. They talk about in videos and in posts online, at their 2khp level they flex the engine, because it's aluminum.
Coyotes are weak past 900hp just the same; the cylinders are just not strong enough. And the infrastructure on a new 5.0 is awesome.
06-25-2016, 12:04 PM
#94
has nothing to do with it being aluminum, the vr38 has thin plasma lined bores from the factory it dosnt have true sleeves. RHS aluminum lsx, fine to 1800 hp, ERL performance uses factory honda blocks to 1400 in their setups, factory ls blocks they modify all the way up to 2500 hp, dart ls next and billet aluminum blocks handle 2500-3k hp. ALL the fastest pro mod guys are running aluminum blocks and they run 3500-4000 hp. most of those 2500+ hp pro mods also run aluminum rods, steel you get a extra 1 or 2 passes out of thats it because while steel is technically stronger its also heavier putting additional stress on rods. top fuel dragsters and funny cars? all aluminum engines that run 10k hp now, top alcohol all run aluminum blocks. pretty much you have to drop down to the budget pro mod guys like me or super comp dragsters to start seeing iron block(hell even the super comp 632 big block i was just looking at to possibly run the next two years while waiting to finish the pro mod was aluminum block, 1k hp NA in a 1400 lb chassis) and ALL of us run iron for because of cost not because its better, if i could afford 6k for the aluminum dart ls next2 i would have it hands down but that extra 3k is a little over half one of my turbos or almost half what my heads are costing me. ALL the high end drag cars which see the most abuse run aluminum for the weight savings, its just as strong. l33 is a factory aluminum 5.3L and has no problem handling 1400 hp, past that they push water due to not enough clamping force on the heads, but the iron blocks fare no better you simply have to start o ringing the block or going 6 bolt at that point. the larger bore blocks push water sooner due to less surface area but has nothing to do with strength of the block, the ls7 is the only one in the ls family to have issues and its not the block its thin factory sleeves that is the issue. Sleeves dont count as aluminum blocks being weak because no engines run a aluminum sleeve from the factory(unless we are talking like jet skis, snomobiles, and four wheelers) so an iron or plasma moly sleeve failing in a aluminum block isnt the block being weak its the sleeve being weak.
What the ****?
Lol AMS tears through vr38's pretty regularly. Aluminum blocks aren't that strong, period. Hence why AMS sleeves their big HP Vr38's. They talk about in videos and in posts online, at their 2khp level they flex the engine, because it's aluminum.
Coyotes are weak past 900hp just the same; the cylinders are just not strong enough. And the infrastructure on a new 5.0 is awesome.
Lol AMS tears through vr38's pretty regularly. Aluminum blocks aren't that strong, period. Hence why AMS sleeves their big HP Vr38's. They talk about in videos and in posts online, at their 2khp level they flex the engine, because it's aluminum.
Coyotes are weak past 900hp just the same; the cylinders are just not strong enough. And the infrastructure on a new 5.0 is awesome.
Last edited by jerryd87; 06-25-2016 at 12:08 PM.
06-25-2016, 12:15 PM
#95
also ams actually uses a billet block now, the point is all the highest end vehicles use some form of aluminum block now, iron is simply for the poor people like me, e kanoo even uses mostly billet aluminum blocks in their drag cars because of how often they where splitting the factory iron blocks apart. with modern metallurgy and block designs your not going to find the limit of aluminum, maybe factory blocks(btw ive known quite a few both 4.6 mod motors and 5.0 coyotes well above 800) run into issues but some modifications and they can easily be taken further. once you start dealing with the stuff i deal with now nothing fresh from the manufacturer is ready to race, even my iron block needs machining for larger lifters, roller cam bearings, and o rings, heck even my heads im going with are $8000 and need additional machining for 9/16 pushrods and o rings.
Last edited by jerryd87; 06-25-2016 at 12:25 PM.
06-25-2016, 12:33 PM
#97
friggin ridiculous the faster you wanna go..... Im going to napa about sponsorship and thinking of getting a 9 inch jig to start manufacturing chromoly 9 inchs, when your dropping 17-19k on a engine, 5k on a dry sump, 8k on a transmission, 3k on a torque converter, 11k on turbos, 3500 on ECU, and 5700 on rearend it gets absurd lol and im a "budget build"
supposed to have a car coming into the shop soon for either a built engine or LS swap but the guy has a 5AT so i told him he needs to sell and get a 6MT or go GM transmission for his goals.
Dont forget about girlfriend/wife strains too(in general with any car project), i wanted to get some work done on the chassis today but i was over ruled and had to cut up a cherry tree and drag it to the burn pit and cut some bushs down.
supposed to have a car coming into the shop soon for either a built engine or LS swap but the guy has a 5AT so i told him he needs to sell and get a 6MT or go GM transmission for his goals.
Dont forget about girlfriend/wife strains too(in general with any car project), i wanted to get some work done on the chassis today but i was over ruled and had to cut up a cherry tree and drag it to the burn pit and cut some bushs down.
Last edited by jerryd87; 06-25-2016 at 12:39 PM.
06-25-2016, 03:19 PM
#98
has nothing to do with it being aluminum, the vr38 has thin plasma lined bores from the factory it dosnt have true sleeves. RHS aluminum lsx, fine to 1800 hp, ERL performance uses factory honda blocks to 1400 in their setups, factory ls blocks they modify all the way up to 2500 hp, dart ls next and billet aluminum blocks handle 2500-3k hp. ALL the fastest pro mod guys are running aluminum blocks and they run 3500-4000 hp. most of those 2500+ hp pro mods also run aluminum rods, steel you get a extra 1 or 2 passes out of thats it because while steel is technically stronger its also heavier putting additional stress on rods. top fuel dragsters and funny cars? all aluminum engines that run 10k hp now, top alcohol all run aluminum blocks. pretty much you have to drop down to the budget pro mod guys like me or super comp dragsters to start seeing iron block(hell even the super comp 632 big block i was just looking at to possibly run the next two years while waiting to finish the pro mod was aluminum block, 1k hp NA in a 1400 lb chassis) and ALL of us run iron for because of cost not because its better, if i could afford 6k for the aluminum dart ls next2 i would have it hands down but that extra 3k is a little over half one of my turbos or almost half what my heads are costing me. ALL the high end drag cars which see the most abuse run aluminum for the weight savings, its just as strong. l33 is a factory aluminum 5.3L and has no problem handling 1400 hp, past that they push water due to not enough clamping force on the heads, but the iron blocks fare no better you simply have to start o ringing the block or going 6 bolt at that point. the larger bore blocks push water sooner due to less surface area but has nothing to do with strength of the block, the ls7 is the only one in the ls family to have issues and its not the block its thin factory sleeves that is the issue. Sleeves dont count as aluminum blocks being weak because no engines run a aluminum sleeve from the factory(unless we are talking like jet skis, snomobiles, and four wheelers) so an iron or plasma moly sleeve failing in a aluminum block isnt the block being weak its the sleeve being weak.
My main point was that using the vr38 as proof of aluminum being up to par wasn't a good choice for 2k-4k engines.
As for your point about a sleeve failure not meaning a block is weak, I think we just disagree.
Aluminum can make the power, but for how long.
but here is a cool picture of a turbo vw motor we have at work..
06-25-2016, 05:18 PM
#100
No offense dude but you dont deal with ANY of the stuff i do now are you even done with your car yet? Have you ever seen ANY of those engines i listed? all blower cars get rebuilt ever run at that level because of how they are fueled. they are fueled with jets in the blower hat they dont have injectors or carburetors(alcohol pro mods are the same way or anything running hat injection. You have a lever that turns the fuel pump from 15-20% fuel to 100% by rotating the lever on the barrel valve.(thats the gurgle you tend to hear in staging. the rebuilds are because the over fueling floods the crankcase, mixs the fuel with the oil and trashs the bearings. Ever heard of birdman racing? he runs a 4000 hp street legal backhalf car, he checks lash, spring pressure, and plugs after each pass and then the data from the computer thats pretty common in all of the 2k-4k turbo v8's even the methanol engines because they arnt over fueling. No one runs aluminum rods on the street? LOL better call GRP, BME, and R&R and tell them they are lying then actually a lot of high power cars run them because they provide a cushion in compressive forces, thats ESPECIALLY useful if theres any detonation or pre ignition for any reason. The whole stretching deal is a myth they do elongate more from thermal expansion but thats it they just need a larger clearance and pinned bearing. who ever is telling you the blocks are flexing and pulling the mains out of line you need to go punch in the face because they are idiots and obviously dont have the slightest clue what they are talking about, lemme guess your going to throw your "sand rail" buddys out there right? none of them run the stuff i deal with nowadays. needs to be thicker huh? tell that to ERL all they do is reinforce the head stud mounting locations they dont thicken the aluminum at all. the cast iron used in most blocks is about on par with aluminum, they are iron blocks NOT steel iron isnt nearly as strong as you think it is unless its a CGI block which hardly any are unless its a diesel.
except your point on the VR38 isnt a good point because the issue isnt the block, the issue is the thin plasma spray liners, point out where i used the vr38 as proof of aluminum being up to par for 2k-4k hp engines? i stated that the vr38 was aluminum not iron like the person i quoted stated then i stated engines run 2k-4k on aluminum blocks and its pretty normal.
how long? well considering the failures i see are either detonation, or cranks snapping(most commonly with non ccw cranks), turbo failures, injector failures..... they last plenty long, hence why all the top teams run them its just expensive, granted the top pro mods and top alcohol dragsters for instance are spending 35k JUST for the superchargers, turbo teams are spending 8-13k for JUST turbos.
the reality is your just flat out wrong, which you would know if you watched any of the races i do and seen the guys i interact with now. this is why i left here in the first place a bunch of people who think they know something but at best have just scratched the surface.
except your point on the VR38 isnt a good point because the issue isnt the block, the issue is the thin plasma spray liners, point out where i used the vr38 as proof of aluminum being up to par for 2k-4k hp engines? i stated that the vr38 was aluminum not iron like the person i quoted stated then i stated engines run 2k-4k on aluminum blocks and its pretty normal.
how long? well considering the failures i see are either detonation, or cranks snapping(most commonly with non ccw cranks), turbo failures, injector failures..... they last plenty long, hence why all the top teams run them its just expensive, granted the top pro mods and top alcohol dragsters for instance are spending 35k JUST for the superchargers, turbo teams are spending 8-13k for JUST turbos.
the reality is your just flat out wrong, which you would know if you watched any of the races i do and seen the guys i interact with now. this is why i left here in the first place a bunch of people who think they know something but at best have just scratched the surface.
And top fuel dragsters get rebuilt every run? And nobody runs aluminum rods on a street car? The engine is flexing (not the cylinder walls) and pulling the mains out of line, because there isn't enough material... In order for the block to be strong enough with aluminum, it needs to be much thicker.
My main point was that using the vr38 as proof of aluminum being up to par wasn't a good choice for 2k-4k engines.
As for your point about a sleeve failure not meaning a block is weak, I think we just disagree.
Aluminum can make the power, but for how long.
My main point was that using the vr38 as proof of aluminum being up to par wasn't a good choice for 2k-4k engines.
As for your point about a sleeve failure not meaning a block is weak, I think we just disagree.
Aluminum can make the power, but for how long.
Last edited by jerryd87; 06-25-2016 at 05:25 PM.