Has anyone tried these?
Should I go for the 74mm or the 82mm?
I am waiting for the GT2RS intercoolers to arrive and I was thinking whether these make any difference, especially if I flash the ECU.
Any advice will be welcome guys!

 

I have the 74mm plenum installed. I honestly have not felt any difference what so ever with the car but that is my own personal experience.

My advice is go for:

1- Exhaust (Catless)
2- Tune (if I could recommend a tuner I would go with Emre, once against personal opinion)
3- BMC Filter (I have tried the cold air intake and actually made my times worse, other than the kool sounds of the turbo it's useless, once again my own personal opinion)
4- 997.2 Intercoolers (Best Mod I have done and best Performace improvement for $ I improved 1 full second after installing these)
5- If you want more power then you can get a meth kit..
6- If your not a tiptronic you can consider upgraded VTG's (67 or 68 / Proto or CHampion)

Exterior mods:
1- 997.2 facelift very inexpensive but makes a huge difference
2- Stick to stock wing
3- Rims only if they are lighter than stock

Once again the above is based on my own experience and opinion

Goodluck

 

fortunately, I have done many of these!
I have Kline Innovation exhaust, soon to be catless
I have a tune from the guys who installed the Exhaust but will soon go for APR.
I just bought the GT2RS intercoolers, will be installed next week.
I will install the GT2 rear wing and front fender.
What you are saying is that th eplenum is useless?
what about the throttle body?

 

Talk to you tuner, so far I asked a few and the plenum and throttle body don't get high reviews.

If you are planning for larger turbo's then maybe but why spend cash on something until you need it?

We have similar mods, I have a catless Kline, gr2rs IC's and a custom Cobb tune. Next mod I will do is injectors and clutch and a E85 tune.

I think I will stop there and focus on handling since the turbo needs some love in that department.

 

Plenum/TB are only things you should replace when going all out on a build. They're the last things to go really once all other options have been exhausted. They do produce measurable gains, but not compared to other, cheaper options.
Advice given here so far is spot on.

 

Yasou ti kanis......if you going in there for intercoolers save your money and go for turbo in and out turbo plumbing....I'm going 3 inch maf less with proto intercoolers and dialed in proto tune.....

 

Go that route and you'll pick up a nice gain...I remember seeing a post with 50-60 whp

 

With a tune, yes a plenum is recommended. You can look at the OEM plenum and see where it leaves a lot to be desired. For stock turbo, I would stick with the 74mm option.

If you upgrade the plenum without a tune, yes it will have minimal gains. Due to the ECU adapting, you certainly would not meet the advertised numbers. From what we have seen when the plenum is added to a tuned vehicle, the claimed numbers are pretty accurate.

 

I just put the plenum and TB in last week and didn't notice much difference, however thanks to info from GIAC (my tune), they have a modified tune which takes advantage of the plenum which I'm going to have updated in the next week or two. I'll post updated results on the 1/4 mile once I have some numbers.

 

Looking forward to it! GIAC has done a fair amount of testing with the plenum and it is certainly one of the upgrades they recommend.

 

I agree, and the more I think about it the more it makes sense. The ecu can only make adjustments within a certain threshold. When I add race gas, the ecu can't advance timing enough to really make a difference unless I load the race gas tune. I suspect the plenum is the same way. Increased airflow can help, but the ecu by itself can't take full advantage of the change without an update to the software.

 

I have tune, Kline exhaust and I installed the plenum and yes I felt a difference and can attest it works

 

I did the plenum and the TB and it did nothing for me. If anything it made my car feel flat and lose response.

I have a near enough TB sitting here if any one chooses this route.

 

I think this wrong, the DME dont know what fuel you use thus the timing needs to change ie new map needed. But the DME knows if the airflow changes via the maf sensors and adjusts to it (it does this all the time).

 

The MAF signal is used mainly as a means of adjusting fuel delivery. You will still run into the factory torque limiters even though the MAF is sensing more airflow.