Purekoryo

Does anyone know what the major differences are in the engine components? I wonder if it's just the exhaust difference much like how 992 has a better exhaust manifold design than 991.2 to get some extra power and turbo response. Although Porsche rates the power differently, I wonder if the delta is a lot closer on the dyno. Is it really the programming in the ECU that's different? I also realize that the redline is different but on the GT4 the power level drops off several hundred rpm's before redline.

Would be interesting to see what the dyno shows with GTS and GT4 on aftermarket full exhaust.

HooosierDaddy

It’s all programming, can’t remember which video I watched where it was confirmed. Start scouring YouTube is my best suggestion

rjag2034

Henry Catchpole talked about it on his review. go to 1:10


Heres his Youtube channel that has a bunch of great reviews Carfection - YouTube

GrantG

Porsche made the same mechanical internal upgrades to the GT4 engine to make 20hp more than the GTS 4.0 as they did to the GT3 RS to make 20hp (and 7 ft-lbs) more than the GT3, Nothing...

c1pher

My question would be what do you have to do to the GT4 4.0 to get GT3 power. A lot I guess.

Purekoryo

Check out JCR. They got it up to 475 hp, although I think it’s more like 485hp if you do the math on their dyno. This is will full exhaust but STOCK tune. So with a tune entirely possible to reach GT3 level. If the fuel system has the capacity then Ethanol tune may even allow it to surpass stock GT3 power level.

Making me REALLY consider trading my 991.2 GTS in for a GT4. Perhaps next year when used ones become more available...

Avaley

Is there a well adopted aftermarket tune for the GT4 or GTS 4.0 yet? Fairly certain the engines have no differences other than factory ECU tune limitations.

Purekoryo

I think you’re right. Looks like softronic has one out with same power figures for both.

https://soulpp.com/product/porsche-7...onic-ecu-tune/