jleev

Good morning all,
I am contemplating some performance mods for my 996TT '02 and am amazed at just how reasonably and cost effectively we can get massive horsepower gains with minor after market tweaks out of our TT's. ECU, upgraded K16's, exhaust etc
What I would like to understand is wether other stock systems left factory combined with mods can actually handle this kind of increase in output with incurring premature wear & tear and/or failure? Fuel system, clutch/transmission, engine internals such as rods, valves etc....

Is there a broadly defined HP scale that for example would dictate when other components would need to upgraded to handle increased HP?

All thoughts most appreciated.

Cheers,

J

Joe Weinstein

yes, there's a broad rule of thumb, that the stock clutch is marginal and
any power added will want a better clutch. Beyond that, the feeling is that
the stock motor will bear up to 600hp without strengthening. Beyond that
the rods are vulnerable, and maybe other stuff too.

manny_g

j...i had a simiar question on a previous post. here is what alex from shark werks had to say...

Quote:
Originally Posted by manny_g
alex...with that type of horsepower increase don't you really need to also upgrade some of the engine/transmission internals....how much horsepower increase can the stock engine safely handle...and i mean for street and not track use..? this has always been a concern of mine. one thing is the cost of the kit, but most importantly what would it cost to improve basic engin internals.

hi manny, other than the clutch itself there's nothing "needed" for the tranny. We generally build motors from the 700hp and up range depending upon the desired usage. Since yours is for the street whatever kit you do I'd say 640-660 should and has always proven to be asbolutely fine on stock internals.

Building the engine would really vary on the parts used and who does it (labor rates). Most of the engines we've build have had Carrillo rods, ARP head studs, EVO head gasket, GT3R oil pump and misc stock replacement parts obviously. No doubt it's expensive but unless you had 70K miles on the odo I wouldn't see the need for it at 660hp (crank).
__________________
Alex "Sharky" Ross
Shark Werks: www.sharkwerks.com
Phone: 510-651-0300
Email: sharky@sharkwerks.com
Northern California's Porsche Performance, & authorized Evolution Motorsports/GIAC dealer and installation center
Tech Art, HRE, Fikse, Brembo, Bilstein and more.

1AS

Is the clutch issue related to "off the line" use, or "rolling, in-gear" use, or both? Always seemed to me that our clutch components are much more vuilnerable on launch, as the absence of wheel spin transmits all that shock into the driveline.
So, is the stock clutch good enough if you don't try all-out standing starts? AS

04s4_nc

I'm running A Proto K24/18G setup and you go through tires rather quickly.

Turbohead

I found that the stock clutch would slip on hard 3rd gear pull on my car when it went to a stage 2.

Now a stage 4 with a LWFW and IA sachs upgrade clutch......no problems .
BTW I love the lwfw.
Elliot

John D II

My stock clutch went over 50,000 miles at stage 2, then another 12,000 miles at stage 4 before it began to slip. At this point, I went to the Protomotive 700 package and installed a new Sachs Motorsport HD pressure plate and new GT2 disc. It lasted one season and was slipping in the fall...from my experience, 700 HP requires some serious clamping force and a marginal clutch application will not last long...

Alexander, the clutch behaves fine on an aggressive launch, even if it is going. For example, when my OEM clutch was beginning to go, I first noticed it in a 1/4 mile run, when I shifted to 4th and there was high load on the motor, it just zinged to redline. I did a couple more runs and everything was fine until top of 3rd and 4th gear. Same on the street, fully driveable, even on an agressive launch, but it would slip on a hard load, upper gear highway pull.

markski

My tuner told me that Porsche over engineers by 30%... with that said, you can add that to the base figure and know where to stop...
markski

manny_g

that appears just about right...with a base of 420 hp a 30% increase will put you at 550hp. at 600hp your are approx. at 43% over base. would probably not want to go more than that...thank for posting markski.