Well torque is what breaks things... peak forces...

What sort of clutch setups are you guys running? Anybody have any data on how much steady state torque the stock clutch can handle?

 

I run an ACT triple plate (over 2700 lb clamp load pressure plate) hard as a **** to push in the pedal but it grabs like a biatch. I think the stock will hold until like 320 to 350 wheel. After that the break down on the surface will be very significant and you will start to see a lot of slippage.

And yeah, torqu breaks things, but what i was getting at is going from 0 lb/ft to 350 lb/ft very quickly will not make your engine happy. A good example of this is a top of third gear pull on the highway. Sitting idly by at 4800 rpm and then mashing it and spooling almost instantly and having that kind of load transfered is really rough on your drivetrain.

 

No, turbo will be less stressful since you are not running boost all the time. In addition you do not have the stress placed on the crank(side loading) from the supercharger belt. Plus right off the bat you are running 2.5psi less boost so less stress on the motor for the same given hp.

 

We're talking about single turbo versus twin turbo, not supercharger versus turbo. But if you think a centrifugal blower that's putting out the same peak horsepower as a twin turbo but 80+ fewer ft-lbs of torque is less stress, you're smoking something. You're talking about the tortional load from the supercharger belt, but what about the steady tortional load on the crank through the flywheel from accelerating your car with 400 ft-lbs compared to 320 ft-lbs? You're dreaming. Now if either one is knocking it's a different story...

 

Stock clutch since the TT install, 6 months and 5K miles ago.

 

"In addition you do not have the stress placed on the crank(side loading) from the supercharger belt."

What people forget is that the engine needs to make 17-40 [sometimes more]EXTRA HP to turn the supercharger, that never shows up at the flywheel..wheels.

 

+1 ^^^ In reality, the supercharger is just as stressful if not more because of where it derives its power from. A TT setup is obviously using spent exhaust gases to create power (which doesn't take anything to use....you just re-route the exhaust into a turbine.) The SC has to use the power to make the power. It is engine power so turning that belt off of the engine takes away some of the power created and through smaller gears/pulleys will generate more power than it takes from the motor initially. I would have to say that a TT setup is less stressful on the engine for a ton of reasons.

 

So will you also venture to say that TT is less stressful than a ST with the same Whp/ft-Lbs or the other way around?

 

I would probably say that a TT is slightly less stressful on the engine than an ST setup. They both work on the same physics so the only difference would lie in the turbo and piping. I know there is some re-routing of one side of headers to the other etc. But I think with all things being equal the most difference in terms of wear would be on the turbo itself. With a TT the turbos share the work and with an ST the turbo is taking the whole load. Long story short, the stress is more on an ST but the recipient of the stress is not the motor, instead it is the turbo.

 

I guess both have their pros & Cons, what kit do you have and how many mile's you've been running with Turbo. Looking at your power I would say you're running on stock internal and just a thicker gasket.?! If you went through replacing the head gasket why not just go the extra mile since replacing it is already a pain in the b*tt to replace it .

 

I've been running a Greddy TT for about 12,000 miles. And yeah I have the low compression head gasket and ARP head studs. The extra 8 to 10K to build the motor was on my mind for a while, but I decided to put a stereo in it with that money. Additionally, once you replace the internals, you just increase the risk of things like blowing an O-ring, piston ring, oil seal, leak down, dropped compression. The internals from the factory have gone through thousands of tests and milage and stuff before it went into production, so the factory bottom end IS going to work without problems. Whether or not I detonate the rods or not is my problem, but I have a conservative tune and safety precautions to prevent that. Lastly, I have the Skyline to build on now and the additional money I would spend on the G is most liekly going to the Skyline for now. The G is now my show car anyway, so the Power it makes is nice, but it really doesn't do it a lot.

 

For me it doesn't get any better than the burst of power in second and 3rd gear with a turbo. The power curve a turbo provides makes for an awesome driving experience. After having driven Randys_G with his Vortech I was impressed but the burst of acceleration is what makes me happy everyday that I have a TT setup.

 

Yes, and the added backpressure of the turbine in the exhaust path reduces the pressure differential across the intake to exhaust port, reducing the amount of airflow for a set intake pressure and therefore power. Nothing is free.

You guys are crazy if you think the extra 15-30 hp drag from the blower represents a stressful load compared to the huge delta in peak torque and jerk rate with the TT.

 

there are a few 350s running stock internals with the aps tt making 500+ at the wheels, there is one making 550 rwhp on stocks, been for quite a while now. its all in the tune.

 

Are they running spacers for lower compression? The problem is you're fighting the 10.3:1 all the time... water injection is the key, in my opinion, and I wouldn't run FI on stock compression without it.