I am nooby when it comes to 997T upgrades.

I've been reading about these plenums, in particular about IPD Race Plenum, which is sold by Suncoast.

http://www.suncoastparts.com/product..._Code=997TURBO

The following is written:


"Adding bolt-on horsepower to the 997 Turbo is a continuous quest by many enthusiasts looking for more power. Reverting back to old tuning technologies, Agency Power has developed a larger throttle body and plenum kit for the Porsche 997 Turbo to gain added performance. The point of a larger throttle body is to get in more air. The more air you bring in, the more power you make. The 997 Turbo's engine intake system works off pulses, so how that air is diverted to either side of the engine is not as important as the volume incoming. The plenum kit includes an OEM Porsche Cayenne Turbo throttle body (part# 94860511503) which is a direct bolt on and plug in for the electronic throttle control with no modifications needed. This throttle body has a 77.64mm inner diameter compared to the stock one of 75.64mm. We chose to go with this smaller diameter throttle body to give the car more low end horsepower and torque. If the diameter of the throttle body is to big, it will increase turbo lag and performance gains will only be made at the mid to top end RPM range. Since most 997 Turbo users drive their car on the street and track, we developed this product to substantially increase throttle response and improve "usable" power.
The Agency Power plenum kit is made using high quality 6061 aluminum that has been TIG welded and pressure tested in a T shape to mimic the OEM design. The CNC machined 4 bolt throttle body flange features a groove to accompany a rubber o-ring to ensure a secure and sealed fit with the OEM Porsche Cayenne throttle body. The T plenum features the necessary fittings for stock vacuum hoses and breather lines and includes a 1 way check valve needed. Each T plenum is powder coated gloss black for an OEM look and includes new silicone couplers in black and worm clamps to secure it to the factory intake manifolds. The installation of the plenum requires removal of the factory airbox and Y pipe to access the component. Recommended installation time is approximately 3 hours. Installation of the Agency Power plenum kit DOES NOT require the ECU to be flashed. The factory ECU will adjust accordingly to the change in throttle body diameter. However, corresponding mods including an ECU flash will only bring out additional power. As it stands alone, the plenum kit will add a bolt on 20 wheel horsepower to your Porsche 997 Turbo. As tested on a VR700 kit, the plenum added nearly 45 horsepower and 60 ft/lbs of torque. This product features the Agency Power 90 day warranty and is Made in the USA."

My car is 6-speed 997.1 2007 Turbo with 200cell cats and ECU flash, producing peak 565bhp and 560lbft. Stock clutch. H&R springs.

I have questions:

1) Would addition of just Plenum (without reflash) improve the performance (power and response)?

2) Is concurrent installation of improved Y-pipe necessary or more like "icing on a cake" (=even more added performance)?

3) The diameter increase for this particular plenum is only 2mm, but the promissed power increase on stock car with no ECU flash is 20hp (45hp on a VR700). Is it realistic or just a marketing trick?

4) What is a better performance upgrade: improved exhaust manifolds or plenum?

Thanks for your thoughts, ideas, and suggestions!

 

I have the IPD plenum installed, solid product. It was worth it to me as it stopped the stock ****ty hose from blowing off every couple months. The added performance (assuming its accurate, but dyno cannot tell) is just an added benefit.

I would not make this your first mod. Do a flash and exhaust at the same time first.

 

I agree and have been pleased with the plenum. It's not a measurable but gives greatly improved air flow and comes highly recommended by lots of drivers and tuners. If you plan to jump up to a kit with a larger throttle body the plenum will not work. Just a heads up.
K

 

I see these strong claims from this product, while it looks like it would work well. I run the stock plenum/TB/Y-pipe/Manifolds and have run numerous mid 10 pass's.

Will the upgrade to this plenum get me in the 9's. Highly doubtful.

 

I would put the $979 on something else!
Plenum not worth it.
headers not worth it and it will crack sooner or later.
Gut the cats and install Forge DV's

 

I'm a fan. Been able to see gains on all of my own cars as well as costumers. Especially TT's. It's not so much that you will shave time (and you will with any good upgrade). The feel is improved. Boost response is greatly improved, more mid-range punch and most importantly (to me) you can install a larger throttle body which really helps the car open up in the higher rpm's. Most respected tuners like 'em.

Best,
Sam

 

That may be true but they don't all recommend them. Mine didn't fwiw, at least not for me.