Since there are currently a lot of conversations about what HP can a 996TT engine handle realiably long term, I wanted to open up a conversation about the engine differences between the 996 Turbo and 997GT2 RS. For reference, 7GT2 RS is pushing 620hp stock in a same displacement (3.6L) engine as 996 Turbo @ only 415-480hp (base-GT2 range).

NOTE, by "reliably and long term", I mean STOCK reliability, so this is not yet another "my engine makes 750hp reliably for X months" thread, but rather trying to get to the bottom of mechanical engine differences between the two. Also, not looking for HOW GT2 RS makes the power (bigger turbos, more fuel, etc), but WHY it can handle the 620hp stock (internals? head design? block differences?).

So, what is mechanically different about the 3.6L in a GT2 RS vs. the 3.6L in a 996 Turbo?

Discuss!

 

From my understanding the 996 block can handle 700 whp with out cracking it open to change rods. So the whole why can the 997 gt2 rs handle the power and not the 996 doesnt really matter since 996 owners are well above the 620hp on there stock blocks.

I dont know the differences though, maybe a company can chime in and let us know.

 

interesting thread!

 

No factual data but i do have a hypothesis.

The general consensus is that the rods are the weak link above 700 HP on the 996. The. 997.1 uses the same block as the 996T. In fact if you buy a new 996 engine from the factory you will receive a 997T lower end with 996T heads, manifold, turbos, etc...

I imagine the GT2 RS comes with stronger rods, improved oiling system and more cooling capacity. If anything I assume the GT2 RS probably uses an evolution of the 997 engine which is generally accepted to have stronger rods and better air measurement and fueling.

I recall reading an article once where a Porsche engineer was quoted saying something to this effect: "the 996T engine can handle 700 HP but would need a cooling system upgrade"

Of course we all know Porsche overengineers their top end models by a significant margin. What Porsche considers needing upgraded cooling will likely never overheat

 

Interesting, that's exactly the type of info I'm poking at - just like a stock 996T engine can handle more than factory HP output, I'm sure whatever is in 7GT2 RS can handle more than stock 620hp.

If we can nail down the differences and the parts were interchangeable, this could be a great upgrade venue for 996T platform in the future using stock parts..... not sure how cost effective this would be vs. aftermarket parts, but a thought worth exploring.

Either way, even if nothing comes out of it, would love to know out of pure curiosity. :-)

 

Well, from I have seen OEM Porsche parts are more $ than aftermarket regardless of strength, quality etc. Minus the oiling or cooling system components I can't imagine using OEM 997 GT2RS parts would be any better than what is already out there aftermarket to be honest.

As far as the 996TT engine strength goes I find it to be an interesting subject. I have been researching it alot lately and it seems to be that these engines hold up quite well unless you over rev them or run lean or use an EBC that ignores the safety intervention portions of the Motronic system. This is not to say that every engine can safely handle 700 HP, but I would be surprised to hear about one that is tuned correctly and has not been bounced off the rev limiter alot grenading. I am not an expert on this, so this is purely based on my own research and theories. Take it for what it is worth.

 

Just look at Powell's car....more than 800WHP on a stock engine...that could be the exception but if 700hp was "the edge" for the tt engine then it should have been destroyed in a few seconds at roughly 950HP..

From what I learned here on 6speed, with some good rods and a stockish rev limiter, the 996tt engine can safely handle lots and lots of power..

 

Agree, no way the internals from a limited production (250 in the US?) car would be cheaper than aftermarket, however, if the shotblock (inlc. pistons/rods/crank) is the same, there may be an opportunity in oiling/cooling/head design that can be applied to 996T - once we know what the differences, we can figure out if 7T and 7GT2 RS use the same engine, making the parts more readily available.

Also agree with you 100% on tuning/rev limits.

Yes, I agree, but note my origninal post specifically asked for a discussion about engine differences, not "this car makes XX hp safely" as we already have 20 threads about this.

Not trying to be a dick, just want to have a technical discussion about engine differences

Some good stuff so far, let's keep it going!!

 

The new Excellence stated different pistons, intercoolers, turbos and an ECU tuned to 23 psi. 0-100 in 6.8 sec with a 6-speed.

 

Sorry..

 

I'm sorry buddy , didn't mean it like that!

 

Anything about rods/crank or piston specs? Head differences?

 

Sorry, but the Excellence article was little more than a Porsche advertisement with some quotes from some P engineers. Things like the "fastest and best 911 ever". However, an alleged 7 min 18 sec Nurburgring lap. Holy SH** Batman, that's absurd if true.

 

3,021 lbs wet, 0-186 in 28.9 sec

 

Seriously ??