So I'm already running GIAC Stage 2 with 200 cell cats and exhaust, diverter valves and BMC air filter.

I have the new Champion ICs on order and will be upgrading to the Stage 2+ tune at the same time next week.

I was trying to think of any other bolt ons to do while the car is already opened up.

Don't get me started on the IPD plenum, but I was thinking maybe the FVD headers would be a good addition.

Anything else?

I'm also looking at switching to the Sport Cup 2s and really hoping to near the 9s in the 1/4.

 

you don't like the IPD plenum?

 

no, they've yet to release any solid proof it does anything


and it's a 997 part that wasn't properly redesigned for the 991 platform.

 

how about the Y pipe?

 

yeah, the issue there is Champion is doing some further tests on that in their shop to a) ensure no compatibility issues with the new ICs and b) run the dyno to see if there's any increase in performance.


so I was recommended to wait on that for now.

 

Probably the single biggest gain you could do is go catless exhaust. Of course Tubi catless is A good deal louder than high flow cats especially on cold start up and respect to the popping sound when you let off the gas. And it would be tough to pass inspection in NY where I live.

You can get a big boost from water/meth injection from a leading company like Aquamist. Of Course that will consume a good bit of your front trunk and carries a bunch of risks that I would never take. I have zero interest in carrying methane in my car and do not want to risk blowing up the engine if the system fails or if I run out of water/meth.

You could do nitrous but again I would never do that.

I am doing FVD headers because I got a sick deal on some lightly used ones (as in a cost of $1000). Had I been buying new I would have gotten the GMG ones. Those are like $3k. GMG is known for solid quality and GMG has so much success in modding and racing our cars. Headers appear to give a small gain but certainly nothing dramatic.

If you are getting the Stage 2 plus tune at Champion Motorsports you could ask champion to Dyno and datalog your car and work with GIAC which might enable them to do a little custom tuning for a bit more power than the canned version of the stage 2+ tune.

If you haven't gotten the race gas tune subfile you should certainly have them add it. I found there was a huge performance difference in using race gas with the race gas tune subfile as opposed to pump.

Any R compound tire such as the MPSC2, Dunlop Racemax, Trofeo R or R888 will give you a big traction advantage over regular summer rubber which will lead to better ETs. Of course, you really cannot drive an r compound tire safely in the rain so you can't really daily drive one unless you live in the desert.

The IPD Y pipe may give you a small gain. Champion will only sell it if it helps performance.

Happy hunting!

 

Stock headers are fully double walled so all the heat remains inside the tubes. High temperature inside the header tubes = big air volume = higher airspeed = faster spinning turbos = higher output.

Aftermarket headers are never double walled and on the 991 Turbo they won't be equal lenght either. The gain you might see on the dyno is measured while standing still so without the proper airflow underneath the car. Doing 125 mph will realy cool down the headers and the gains are gone. I've tried them and it they didn't improved my 0-200 kmh at all.

 

Great info here.

 

Stef is always a wealth of information. And it is reflected in the quality of his exhausts.

 

that's exactly what I was looking for.


great info!


saved me about 3k.

 

people that already bought headers are like

 

Time to come out with a header heater mod.

 

Hi, Great set-up thus far!

Proper headers are always a nice enhancement. Perhaps one of the more subtle, but definitely an always present part of any fully tuned performance suite. Porsche has applied thermal retention enhancing techniques for years on it's manifolds mainly using double walls. Some models are even less efficient than others. This however is just one part of the equation. Kline has put lots of effort in the manifolds they designed and considered all parts of the equation. Things like material (offering F1 grade inconel), runner length, merge, diameter, added flow/horsepower and over-all design/fitment. The most important feature being equal length design to flow the most efficient pulses to the turbocharger providing consistent fast spool. You will need is the manifolds are also low profile and do not hang down. Special ceramic coating, wrapping and even had her blankets are also ways that race teams retain heat when deemed necessary. I am willing to stand behind the Kline Innovation Equal Length 991TT Exhaust Manifolds 100% for you. We will confidently respect/embrace your independent results/opinion and support you A-Z on it! You have my SamboTT guarantee! That goes for the IPD parts as well (including header blankets ). Let me know if you are interested at all and how I can be of assistance or earn your business.

Cheers,
Sam
By Design