odurandina

depends on how much you plan to ignore the speed limit. big brakes are bigger and better.

Photodan

So what sort of performance gains are people getting? As with forced induction with a turbo, doesn't the CR need to be lowered as well for a supercharger? The whole idea sounds really appealing.

Damian in NJ

35 pages is a lot to read, but it's all discussed in the thread.

rgs944

I believe the gains are about 75HP and you can keep everything stock. It was designed with very modest boost so it would be safe without major engine modification.

RajDatta

Try the standard clutch setup unless it starts to slip. If it does, change to a higher clamping pressure plate.
Raj

mikey_audiogeek

Big brakes are bigger and brakier!

phil0618

+1 on the brakier

Todd951968

What kind of acceleration should a 968SC have? In Carl's video earlier in this thread, he accelerates from zero to 60 mph in about 6 seconds and to 100 in about 15.5 seconds. That is pretty much stock time, isn't it? I expected at least a second off those times, maybe more.

phil0618

I think the reviews of the 968 put the 0 - 60 time at about 6.5 seconds. Not sure about the 1/4 mile.

I'd be surprised if the super charged version didn't perform considerably better because of the significant boost in torque.

Phil

Todd951968

I think the factory (conservative) rating was 6.5 to 60mph. I saw a Car & Driver number at 5.9 seconds and I think in the high 14's in the quarer mile, just under 100mph.

Carl's video does not show improvement on those numbers. I am hoping he will chime in. I know these cars aren't drag stip cars but those acceleration tests do show what kind of street performance the cars are putting out.

RajDatta

What most magazine do is dump the clutch at high rpm to get the lowest 0-60 and 1/4 mile times. I doubt many of us would subject our cars to that kind of abuse. The proper indicator would be maybe 30mph-100mph to see the delta in acceleration.
It's almost impossible to match magazine 0-60 and 1/4 mile times.
Raj

Jason Judd

Raj wrote: "What most magazine do is dump the clutch at high rpm to get the lowest 0-60 and 1/4 mile times..."
________________

Ouch! It must be nice not having to worry about maintenance costs...and just aiming for the lowest 0-60 numbers!!

I like Raj's idea of a rolling start (from either 20mph or 30 mph) and the elapsed time to 100mph...which, in my view, is more 'real world' anyway!

Just my $.02

Fox944

C&D ran a 5.6sec to 60, R&T did 5.9. Both were in the low 14's for 1/4. typically, magazines will do several 1/4 & 0-60 tests and then post their average time ( i know road and track used to). A Supercharged car with 75BHP over stock should be significantly quicker. The Video's does not show this because Carl was not attempting to do a drag like start. If you have decent experiance, the right tires, weather, etc a stock 968 may be able to dip into a high 13sec 1/4.

People have run 12.9 in stock E46 M3's & 13.9 in stock S2000's. Magazine results for both cars were low 13's & low 14's. A near perfect launch, healthy motor & powershifting will do the trick.


Lastly, magazines do not dump the clutch at high rpm. Every car is different and they all have a sweet spot. With some cars you need to bleed the clutch rather then dump it for the best times. Unless you are in an economy car, dumping the cluth from high rpm would generate too much wheelspin and hurt your 1/4 & 0-60 times. But is all relative. I dont consider 3500-4500RPM a high rpm dump. And for most 968's (depending on mods & tires)...the sweet spot is somewhere in that area.

Carl Fausett

Your missing the obvious. Two men in the car.

Trying to measure my times off my video means that you need to compare them to YOUR times in your 968 with two men aboard. Driver and the passenger that is holding the camera. My guy is big.

The weight you are accelerating does matter and does affect times measureably.

Lastly, I wasnt trying to put down great 0-60 times, or i would have thrown him out, and the spare tires and tools, and warmed the tires. You can see I was fairly gentle on the clutch and had quite a bit of wheel spin in the first 10 feet.

But no matter - look at the dyno charts. The improvement is HP and Torque is real. There is no way that CANT produce shorter 0-60 times in real life.

Jfrahm

The car makes lots of power pretty low down. It really feels like a V8. It muscles around like my other cars (Audi A8 with 40v V8, 928S4) with the supercharger. The stock 968 I describe as quick, the SC 968 is *fast.* There might not be much improvement below 2K RPM but with the six speed you don't notice it as you are only below 2k for an eyeblink when leaving a light A tippy might feel it more? I don't know.

I have not put a boost gauge on yet for testing, been kinda busy with other stuff. I have run it with the intake tube off and this supercharger will blow your hat off at idle speed.

This car I am pretty sure has the stock pressure plate as the pedal pressure is quite light. It does not slip the clutch that I have seen and this car has S02's on it so the tires are not giving up first.
Personally if the clutch did slip I would get a plate made up with better friction material rather than use the 964 PP or whichever one it is that fits, that one can cause the firewall to crack. I suppose you could reinforce the firewall and use it though. I would not fret about the clutch until it slips.

-Joel.