401whp
 

Can't wait for the runners to ship! BTW, is the tune optimized for the V3 ready to go as well?

Car comes off the dyno on Monday/Tuesday and we check part throttle and around town.

We're also going to go backwards and put the stock muffler back on and run with stock tune, just to have all the data for as many of the combinations we might get asked about...

We had to throw everything at it, at 390+whp the CarreraS Plenum and TB and the GT3 muffler both combined for some big gains past 7000rpm... The combination is really quite crazy... We were at 396whp for a while peak and Charles decided to put the Carrera S plenum in the car and the GT3 TB, and wham, 401whp peak... So it's necessary now... and we were off by 5whp or so where it was necessary...

We set a goal of 400whp when we started the intake runner project and we nailed it... Honestly super proud of the entire team, doing the math and understanding the science, no bullish*t just real engineering.

So here's a few things that we learned, and why we approach everything with curiosity and a thirst for learning.

Below is the difference between the 981 Center Plenum and TB and the 991 Carrera S Plenum and TB. Starting at 390whp and 7000rpm the car needs more... The Plenum and TB give it more...
https://cimg6.ibsrv.net/gimg/rennlis...31af624a5b.png
Dundon D3 with 991 Carrera S Center Plenum




Below you see the D3 kit with 981 Center Plenum and Stock Muffler vs D3 kit with 991 Carrera S Plenum/TB and GT3 Muffler
The difference is a big deal... 15lbft at the wheels at peak torque and 24whp at 7600rpm.
https://cimg2.ibsrv.net/gimg/rennlis...9e13376be1.png
Dundon D3 with GT3 Muffler and 991 Carrera S Plenum

The GT3 muffler really makes the engine happy, the PSE is a restriction at this power level. We get more power with less ignition advance and very low knock signature. For those tracking this is a big deal. Means the engine is actually happier, not struggling, just cranking out the ponies easily...

This is why we test everything and verify that it all works the way we expected.

We have a few things to finish for our GT3 muffler kit and the adapters for the CarreraS Plenum. But we're real happy with where this landed. Can have the plenums out just after new year (now that we have confirmed which of the 3 evolutions we wanted to bring to market!)

Question...

Isn't the 991S and GT3 (not sure which you are using, prolly 991.1) TB the same at 82mm?

Or do they differ in mounting surface / bolt ports?

Since the T shaped Carrera S plenum shows gains, the IPD dimpled Y shaped plenum would be even better?
Would like to see data with DMS race exhaust as well, unless mine is one of one. ;)

Thanks Jamie! Think for most of us who are asking the questions of IPD and larger TBs is that we already have those mods and prefer not to swap'em out. If we have to do it all over from scratch, definitely follow this new formula.

Excellent work!
Compared to X51 (heads, camshafts, intake) this gains substantially more TQ over the entire range, and substantially more HP through most of the range.
Different dynamometer and day, but X51 doesn't catch up to it's 6730 RPM peak HP until around 7375 RPM, and even though it starts to taper off sooner it's still fairly close;
https://rennlist.com/forums/gt4/1049...l#post14825598

Yes! Shocked how big a difference the GT3 exhaust made! I've decided keep the stock RS and DMS lifetime exhaust (quiet) and swap them whenever I need to pass sound at the track. Can't go back to the stock PSE after feeling the power :p

As the power goes up, the restrictions show... ;)

And ours is about $25,000 cheaper and no internal mods required...

Yes, less expensive than the $20K for X51, LWF and LSD installed.