turboed350z

Ok so im having a debate with a few friends. And i brough up the fact that F/I, when built and tuned well does not add any extra stress on the engine.

Let me explain. Stock from factory, the engine is NA. I slap a supercharger or turbo on it, get a professional tune, and stay in a safe ball park. Lets say 375whp for a vq35de.

Here the thing, i cant find ANYWHERE where it says that boost stresses an engine. Yes the extra power *CAN* potentially be dangerous, but does that really mean its stressing an engine?

Yes i understand the explosion is bigger for more power, but the engine cant tell the difference between air being sucked in and air being forced in. To the engine air is air. If an NA engine makes 375hp and a boosted one makes the same hp, does the boosted one see more stress?

I have always understand that building an NA engine to see the same power as a boosted engine is more stressful on the engine than just boosting the engine. And by that, i mean changing compression ratio, cams, head works and so on.

So bottom line is, is boost stressful in the engine?

CK_32

iTrader: (1)

F/I and any major mods don't aid the car.


Your adding several thousands of PSI per cylinder. Which over time has more applied forces against the support, moving and static parts and materials. Yes a proper tune determines the over all quality and outcome of the motor. But yes in a technical way it does do more damage aka wear to the engine.


Move stress and forces on the drive line, the inner parts. For ever action there is a reaction. So think that now you have added much more heat, and forces given off by the higher power numbers then think of every part that needs to now take and process that added force and heat.


Its 100% technicality and what angle you are trying to get at. In a way both of you are wrong. But both can be right at the same time.


I say yes much more stressful on the engine. How stressful is determined by many factors. But it sure as hell wont help it in any way structurally anyways.

Cux350z

iTrader: (162)

is this for real? i was clicking in hopes of a troll thread. but you're serious?

turboed350z

Its a serious thread.

If it was stressfull on the engine, the why do oem turboed car can last much longer than NA cars.

Many car comes from the factory turbo. If FI stresses tge engine and affect reliability, surely manufacturer wouldnt have thoseon their economy cars

dkmura

iTrader: (64)

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.

turboed350z

So which eould last longer? A fully built NA block, with highere compression, cams, head work and so on, or a turbo block on low compression?

Thats the main question. I understand in the 80s, turbo and supercharged car had bad reps due to technology being so inefficient. But it is now 2016 and we have advance so much. So is the same thinking true?

Main issue with turbo cars are, too much power, too hot, and tune is off. So let knock all those factors out and focus soko on the boost itself. 1psi from a small turbo netting 10hp gain, is that more stressful than a new air intake, new headers and same 10hp gain?

Thats the main question i have. Is a turbo car and an NA car both making the SAME power, is the turbo car being stressed more? All things equal.

dcains

iTrader: (15)

Threads here just keep getting more stupid and useless as our Z33's get less expensive and more accessible.

turboed350z

Been here for years. And this isnt a stupid thread at all as no one has answer the question completely. So excuse me for starting an educated debate. Not my fault you cant chime in...

dcains

iTrader: (15)

If I weigh 800 pounds does it increase the stress on my bones, joints, heart, circulatory system, etc? Totally stupid thread and question. You should know better.

turboed350z

If you weight 200 lbs and hold 600 lbs would it not have the same effect on your joints, heart, circulatory system, etc?

Again if it was so unreliable and stresses the engine, why are manufacturers using turbo more now than ever?

Back to the question. Whats the difference between 1psi with 10hp gain and a polished heads and ibtake with the same hp gain.

Edit: this is my point, how can your body tell if you weight 800lbs or you weighting 200lbs and holding 600lbs of weights? Minus the cholesterol in your arteries(a factor). Just like how can the engine tell the difference between the amount of air sucked in and being forced in? Once it explodes, air is air is it not? Minus other factors.

An engine is a giant vacuum is it not? Its all about air flow. So does it matter how it gets more air as long as its getting more air its stressing the engine is it not? So wouldnt an air intake technology stressing the engine if it offers more air flow?

Cux350z

iTrader: (162)

Yes FI stresses an engine.

A na 2L is not going to make the same power as the same motor with a Turbo on it.
Cylinder pressures increase net an increase in power. also comes with the use of more fuel and generation of more heat.

OEM's are going FI now more often because of the MPG benefits. They can build a 200hp 1.xL motor that gets 35+mpg. You have power when you need it and MPG when you don't. Its all due to legislation. OEM's are building the motors to last the life of the warranty with stock FI considerations.

Ever wonder why the 2jz was popular? Easy HP gain since the engine was overbuilt for stock power levels.

FI also helps in higher altitudes since they still compress the air, where a NA motor will struggle.

FI to NA will never be a direct comparison since the TQ curves will be different. Don't just look at peak numbers.

turboed350z

Youre right, a 2L wont make the same power. However lets look at the bigger engines. Let say an ls3.

Those can make well over 400whp with minor engine work while still staying NA. You can take an identical ls3 and turbo/supercharged it to make 400whp.

Not minus the heat factor the cars are both making the same power. One NA one FI. My question how exactly is the FI one more stressed than the NA. Sure you have pressure, but is that consider stress? Since i can argue going uphill in an NA stresses it out also

Cux350z

iTrader: (162)

400whp NA is not the same as 400whp FI...already said that.

I think the problem you have is you do not know what you are asking.

Sounds like you want to know whether 400whp on a 2L I4 TURBO is more stressful than a 6.3L V8 making 400whp?

It is easy to see that adding a turbo to a NA engine and making more power than the NA variant is more stressful on the motor.

400whp on a Turbo v8 sounds weak, like a waste of effort.

turboed350z

What im asking is, all factors aside. Soly focusong on FI vs NA. And air flow from both. How is FI more stressful than NA if they have the SAME, keyword, Air flow and making the same power because of it. How can the engine tell the difference between air being forced in or air being sucked in.

Yes 400whp on a v8 is weak, but i was just using that as an example. Like basically, your job requires you to make 500 bucks a day for the company, does it matter how you make the 500 as long as quota is met?

Cux350z

iTrader: (162)

Stop asking questions about scenarios that don't exist. FFS dude.

Higher cylinder Pressure = more stress

NA will never make the same power on an identical engine that has a turbo added.

turboed350z

Thats what debates are for... were talking about boost being stressful. Boost by itself, bot the consequences of other factors that comes with it just the boost.

We are talking about air flow. And if both engine has the same air flow if one is more stressed than the other or not.

I find it funny how everyone says "when built properly, an FI car will be plenty reliable." But yet when i question whether boost is really stressing the engine compare to an NA build, everyone goes nuts. Stress has a role to play with engine reliability does it not?

Edit: obviously 99% of the time these scenarios does not exist. However, im question if boost stresses an engine same as alot of people who seems to think nitrous blows engines.

Edit 2: you say no NA will make the same power as an identical turbo charged engine. Nascar uses NA engine producing 750hp+ they are 340ci v8. So i would think that is similar to a turbo charged street 340ci engine. Just saying. At this point, reliability flys out the window and the question becomes more relevant. Does boost stresses an engine more than NA or no?

CK_32

iTrader: (1)

Lets KISS this....




Blanket statement: Nothing comes for free, and with the good. Come the bad.


Now lets go to the basics. Power aka a combustible engine is and needs 3 things.


Air, Fuel and spark.


How do you get more power? Make a bigger boom. to make a bigger boom you need more air and fuel.


N/A power mods, and FI power mods are ways of getting more air into the engine. To counter it, you add more fuel. Ok all together class?


Makes more boom which = more zoom.


They do the same thing, just in totally different deliver systems. And for anyone who says a high HP car equivalent to a high HP F/I car is easier to work on..... Not true at all.

CK_32

iTrader: (1)

This is pretty much how this thread is going right now..

turboed350z

If i remember correctly, the 2jz has 2 form right? One is tt, in the supra, and on in the lexus.

Will the lexus see more mileage than the supra since the engine was design with TT in mind? If FI is stressful on all engine, even the ones engineered to be boosted, then are you saying if i take the turbos out of an r35 the engine will last longer?

Can i take the turbo out of the r35, built it NA to match a stock r35 power output, will it be more reliable than a stock r35?

turboed350z

Thats what im asking, more air=bigger boom=more zoom. So whats the stress factor behind FI and an NA build