this seems to confuse me even more

maybe because i am unsure of the future of what i want my z for


i think most likely i want to do roadcourse racing (same as autox?)

but i alwo would like to spank most cars on the highway

 

The BMW engine I believe is the M12/13TC 1.5L F1 motor. It was rumoured to put out 1200hp in qualifying trim, but most people concur that it ran from 550-850 depending on the year and tune -
Awesome for 1981 and a tiny motor, but still not up to Top Fuel par - ~6000hp out of 500CID is pretty sick

I am not aware of the Porsche engine, but the Acura motor hes referring to is most likely a fully custom funny car and totally billet engine built by Bob Norwood - Half a top fuel block basically





Heres a link to a story on the "Acura"

http://www.turbomagazine.com/tech/0202tur_extremeedge/

 

That is true, and some setups do come with an intercooler. For example, one way is done via a funnel to pipe adapter like those from Jackson Racing specifically for the Miata. You can get that setup with an optional intercooler. Another way is to build the intercooler directly into the intake manifold with the supercharger mounted on top like the '03 Mustang Cobra.

Miata:
http://www.jacksonracing.com/pages/c...g_componts.pdf

Cobra:
http://www.svt.ford.com/flash/bottom1cobra03.html

 

As much as i love turbos, and despite all that was said still think they're superior to SC's... adding a turbo to a naturally aspirated car is SOOO much more work than bolting on a SC... and for the 5-8psi you can run (without major engine modifications) it's probably the best $/buck.

 

I wasn't looking to generalize that much. I'd be willing to bet a SC'ed 350z @ 8psi would dyno LESS than a TT 350z at the same boost.... and i'm not talking +/-5hp.

 

i believe our engine is a lower reving one than previous supras, skylines, 300z, so would this affect the spool of the turbos?

 

No, you pick the size of your turbos according to Pressure ratio and Air Flow. So, as long as your turbo's were sized according to your engine characteristics then it won't matter.


Pressure Ratio: (boost pressure + atmospheric pressure)/atmospheric pressure


Air Flow(lbs/min): This is the air flow you calculate based on engine displacement, boost level, volumetric efficiency(VE), RPM

 

check out

http://exvitermini.com/

rb26dett from a r33 modded to 1350 bhp ......nice
(edit: did i mention it revs over 10,000 rpms....damn, great motor )

But please guys, did we really need another tc vs. sc thread? For those members that have been here for a while, it's really old .

 

sorry man.. i have actually started alot of the tt vs sc threads.. i just am trying to learn.. give me a break

 

Road course racing is driving on a full track like Laguna Seca, Sears Point, etc. Depending on the track you can easily see 100+ MPH in the stock Z, and you will quickly eat through tires and brakes. It's DAMN fun though!!!

AutoX is done in parking lots around cones. Typically you see about 60 MPH max and go through a much tighter course. This will wear tires, since you are almost always turning, but the speeds are relatively low so the brakes don't wear out too fast.

When I was at Laguna, I drove in 2nd, 3rd, and 4th gears, depending on the corner. At an AutoX, I have not yet needed to leave 2nd gear. I think the Z will not benefit much at AutoX from extra power, because the ability to get through corners is of primary importance. Therefore, for an AutoX, I would focus on suspension work to balance the handling of the car. Also, it's already pretty easy to break the tires loose in second gear, so unless you went to some massive tires, it would be difficult to take advantage of that power. On the track however, extra power will make a much greater difference. This is because you are in the taller gears more often and because there are usually a couple long straights where you can use the power to get much higher speeds. Of course, suspension work here is critical as well, but the engine plays a much larger role here than it would in an AutoX.

Of course, this is just based on my limited experience so far.

I would say that if you unsure what you want to do in the engine, then go for some suspension work first, since that will help you no matter what you do with the car. Also, if you do frequent track days and autoX's, then a set of race tires will be very nice. After all that, you'll probably have a better idea of where you want to go with the power mods.

As far as spanking cars on the HWY, just be sure to drive twisty ones and you'll be fine .

As far as the Turbo VS SC debate goes, as an engineer I have become a very firm believer in the KISS principle (Keep It Simple Stupid). Any time you add more components to a system, the liklihood of failure increases. If I were running a race program, or had the luxury of rebuilding engines all the time, then performance would be of prime importance, but for a daily driver I'd want to do my mods a simple as possible. For this reason the SC idea appeals to me, since it is definitely less complicated in many ways. While it is also less tunable, that may not be an issue if it can reach the power levels you want.

Personally though, I would go N/A rather than F/I, primarily because my power requirements are fairly modest (which may be another reason that I prefer the SC idea over the TC) and because most N/A mods are even simpler than an SC (other than completely overhauling the engine).

-D'oh!

 

Yes, that is the BMW -- wasn't rumored to put out 1200hp, it did it twice in quals.

Yes, that is the acura drag car. Call it half a V8 if you will, but it is a DOHC turbo'd I-4.... I have no idea if any top fuel cars use any type of multiple (more than 2) valve DOHC config???? Intersting the article that was pointed to finishes with ""The big question mark, Is that nobody knows what happens when you take a Fuel motor and get rid of the blower. People think blowers take away 1,000 hp from a Top Fuel crankshaft. I don't have to pay that penalty."

BTW, Kenny Bernsteins car is a 6000HP plant, but remember that it uses 1100 of that to turn his 6-71 blower strapped to his crankshaft. so his 8.3 liter engine is actually making roughly 590 HP/liter.

The porsches.... well your numbers on the best 935's right up there just shy of Kenny B's current output, but remember this was in the 70's and these cars consistently ran for 24 hours straight. Not to mention the 917's putting out 1450HP....now that is quite a turbo set up.

Again, I only quoted those cars as examples of extremely powerful turbo setups (as powerful as a top fueler) that can be very reliable.

Qirex:

I may be a n00b here, but you have a lot to learn. I am "chilled out". I am not quoting a book, only myself.

you said:
"Personally, I prefer the low rpm pull of a Sc vs a turbo (for thsi application)."

Do you realize that your supercharger does/did not make its full power at low rpms? A properly sized turbo will make full boost at a lower RPM than that supercharger. Your blower will make its max boost at the engines max rpm (more or less depending on pully size). A JR supercharger (it is a better roots type) on a prelude (as per their dyno sheets) makes max power at like 6600 rpm...the gains at "low rpm" are small (18 hp at 1500, 30 hp at 2500, etc.) That prelude doesnt start making real power until after the v-tec kicks in at 5K rpm or so. The stock turbos on my z32TT make full boost (up to 14 psi if I want) at around 2500 rpm. Where did you get this magical low rpm pull that doesn't show in Jacksons own dyno sheets? If you're ever in Atlanta, let me know -- I'll let you drive my z32TT and set it up so you can drive a friends supercharged mustang -- This way, you'll have a basis in reality for what you talk about. Both of these cars will be a better definition of "low rpm pull" than your prelude was.



Again gents, what most of you chose to bash me on were my opinions. I'm actually okay with that -- but I am really suprised at how you let people get away with fiction over here.

 

D'oh:

You nailed it right on the head. Nissan has a 450HP NA version of this VQ engine -- let's hope we see some of that as the Z33 develops. with 400 or so NA hp, none of us would be begging for a good FI solution. I also agree the first things that should be addressed on a performance car are the brakes, suspension, and lighter wheels.

GaryK:

I've enjoyed the debate. Just tryin' real hard to keep people HONEST when it comes to sc vs. turbos. This board is full of people who are going to try to be selling these kits to us and some of them are already hinting at inflated prices (like the early Nissan dealerships with the z33). Look at all the posts about the magic waxes and the plethora of "performance grounding kits" -- almost all inflated claims by the many sellers.

As I've said, it is only MY OPINION that the Z should be twin turbo'd. I actually have no problem with slapping a lt1 into a 240 or puttin a buick GN engine in an rx7, etc...

Maybe my real problem is with all these questionable reliability/service companies that churn out $CHEAP$ superchargers for the 10 billion mustang & camaros out there porting a kit over to the 350Z and jacking the price waaaay up....Then popping up on forums and slamming any other alternative. Maybe I'de rather see our $$$ going to companies who have supported the z (and other import) owners all along (greddy, jun, stillen, jwt, sgp, etc...).

Yeah, that's probably it.

Time to shut my mouth. Feel free to tear me apart, but make it factual.

You all have free shots, because I'm letting this thread die.

/lurkmode: back on

 

Me too

 

I think one of the confusing issues here is "power" VS "torque". Since power is simply torque X RPM, it is well known that practially every vehicle makes power at the top end. However, when you press on the gass and accelerate through the RPM range, the torque curve is what you feel. So when you say that your Z32 makes full boost at 2500 RPM, it still is only making half the extra power it would be at 5000 RPM, and would therefore mirror your SC example. You can't compare the low RPM boost of the turbo to the low power a SC makes at low RPM. You can compare power to power, torque to torque, or boost to boost, but when you start mixing and matching its like that other well known comparison....what's its called....oh yeah, apples to oranges.

Also, "turbo lag" is evident even on cars that boost at low RPM. Lag does not mean the RPM that the turbos produce boos (although that is a sign of how much lag there will be). Instead it is the time it takes for the engine to reach boost when going from light throttle to heavy throttle. Since turbo's are driven by the heated exhaust gasses (not just airflow) you need to lay into the throttle to get the turbos spinning. Just cruising along at a higher RPM won't necessarily get rid of lag beacuse there is not enough energy in the exhaust gas to spin the turbos. The super charger on the other hand is always creating boost as the engine is spinning. Therefore, it will not have that split second of lag. Even though the torque/boost output of turbos can be tuned more flexibly than a supercharger, the supercharger will have less lag.

In the latest C&D, where they reviewed the TT, Z, S2000, Boxster, and Z4, they complained about lag on the TT, which I think has its torque peak at an insanely low RPM (less than 50% redline). So even in this car, with two small turbos, with a low RPM boost and torque peak, there is still some lag.

Which you prefer should depend on what you want to do with your car and of course the quality of the components.

Hopefully both the TC's and SC's for the Z end up being high quality and reliable.

-D'oh!

 

here i am, fussing over your comments

superchargers (at least on the S2000) provide MOST of their gains in the 6000-8900 rpm range. there isn't much difference down low. superchargers on the S2000 usually dyno higher to the wheel horsepower than turbos.. but turbo's, on the other hand, gives you more low end to mid end power but less upper rpm power than superchargers. it's kind of like that cable vs. dsl debate. DSL is all-around more quick but at some times, cable can be faster than DSL. plus, a turbocharger is "easier" to add boost to get more power, if you wanted to, of course. there are a select few of S2000s running 400+hp on turbos, a number that supercharger owners can only dream of. but yeah, this is a 350z forum, i know i know just wanted to help

 

The're not all turbocharged, remember AMG and Mercedes? All of their FIs are S/Cs and having owned a turbo for 7 years, I would be looking closely at S/Cs now because of the heat factor. Any turbo aftermarket kit is suspect to me because they are not factory units. I would not put one on my Z, but I would consider the ATI Procharger S/C because it is much simpler, intercooled and probably less money than a turbo. I loved my MR2T, but I am realistic, my Factory turbo engine had a 8.8:1 CR and the Z has 10.3:1. I'm not putting a turbo on with that CR, because my turbo was running only 7psi. The odds are against it for reliability and long life, IMO.

Boomer--use it or lose it, I don't care.