New here and to the Porsche world. I have a 2003 996TT, stock.

I see some of the perfomance kits and upgrades getting 500+ hp. My question is what is allowing the stock parts to survive at those levels (maybe 500-520 HP, I assume much higher and stock parts won't survive much longer) assuming the right fuel and tune?

I come from tuning and running STi, 350Z, EVO, etc, where the stock internals could not take that kind of power. Just wondering what makes the Porsche engine different? Is it just higher performance stock parts - seems reasonable I suppose. Interested to here some thoughts from the gurus...

Thanks.

 

Most seem to think the limit is 700 crank hp...

 

Is this documented as I would think that there are many other variables that come into play such as fuel, boost, how hard you drive, miss shifts etc.? On a related topic why would one upgrade internals when our cars are depreciating so fast that one might just be able to go buy another 996TT if the engine blows as opposed to paying for the labor and parts of upgrading internals.

 

You have a stock turbo? Not for long. BTW, welcome. I'm sure others will chime in.

 

Ok, under the right conditions, and generally, most would agree around 700 crank hp.

Building the internals can yield 700+ hp. Buying another 966t gives you a stock 996t, enjoy!

 

I would say it is documented in the fact that there are loads of 500+ and 600+ HP 996tt's on this board and I do not know of any in this range that have had internal problems. The problems seem to begin at over 650 HP and for all the stock internal cars running around at the 640-700 HP level, there are very few incidents. Of these few incidents, a few seem to be due to abuse/over-boosting and a few seem to be the motor just gave up. I would say you can safely go to 650HP and after that you should be aware that the motor may decide it's too much at some point. The reason to upgrade the stock internals is that you can easily get used to 650-700HP and want more. If you want more, you really need to do the internals. It's worth it for the car you will have in the end and much less expensive than a new (used) 996tt (if you do just rods and studs), unless you do a complete internals rebuild and then you can easily spend more than another used 996TT. I ran a 700HP stock internal car this year for 15,000 miles, including a few 1/4 mile days, without incident. As have many others. However, I would feel better with a built motor at 700HP, even though it feels fine while driving.

 

I think the real issue is that at 650HP the fuel system is at the ragged edge. A 5 BAR FPR helps you get there, but the fuel system is 100% maxed out. Some very cold weather or bad fuel and you're playing with fire IMO.

Given these facts, one could argue that the 700 HP kits which have upgraded injectors may be more reliable due to a larger latitude.

 

I have seen 700 rwhp on a stock engine but that was minimum C16 and higher...
I do not recommend this by any means....

 

Ebc Ftw!

 

I'd give a little more conservative HP limit of 600 crank HP.

 

I guess my question was more focused on the physical limits of parts (assuming the right fuel pressure and flow, timing, etc.). I don't know much about the Porsche 3.6 internal components and how they are made (cast vs forged pistons and billet vs forged rods for example). I assume the 996TT OEM pistons are forged, they'd have to be to survive those HP levels. Usually ring lands give up in a cast piston.

 

I would say 650 crank is about it, gives you a little margin just in case.

 

i had a 600-650hp kit and my engine blew - bad gas, boost leak, it's hard to say. you're always risking something at those levels. as others have said, many people have run up to 640hp kits w/o issue. beyond that, it's time for internals imo.

it doesn't cost that much to upgrade the internals - $10-15k to get the basics and you're done.

- chuck

 

Yes, I agree with markski! I have also seen 700 rwhp on stock internals. Also I do not recommend this . We also have done many evoms GT700 kits with no problems.
Tim