Dear Rennlisters

I have a 997.1 C2S Coupe with full stainless from the headers back M&M exhaust with 200 cell cats and a EVOMS CAI.

It sounds absolutely gorgeous, particularly when you open the throttle.

82mm TB's and Plenums have done the rounds on various internet forums including this one.

I don't want to open a debate, I want first hand experience of yours specifically in relation to sound...

I have a service scheduled in April and I am considering the installation of the TB + Plenum - not really interested in extra horses but it would be nice. I'll be sold on it if it has increases the sound (both at idle and with open throttle).

Let know about what you know about how the TB + Plenum enhances this aspect of the intake.

If you think its a bad idea... say so - honesty is the best policy.

Nayg.

 

Just did the IPD plenum for the stock throttle body.
Have headers/xpipe/exhaust and the EVO MS intake.

TO ME...the sound is the same but could be more with the plenum with the bigger throttle body.
What I did notice is the smoother power and harder pull in the mid-range/higher rpms.

 

Do you have an aftermarket air intake? Sounds like that would be more bang for the buck of what your hoping to achieve.

 

I have an 07 C2S and I added the Fabspeed Performance Pkg. which includes intake, headers, full exhaust, and ECU Tune. Also upgraded the intake with an 82mm IPD Competition Plenum with the GT3 82mm Throttle Body. Since everything I changed resides in the rear of the car it's hard to differentiate exactly what is making that beautiful sound, the exhaust or the intake. Driving the car is amazing and the engine pulls much harder above 4k than before. The car dyno'd over 400hp so I'm plenty satisfied without the setup. Only downside is the cost!

 

Dont notice any increased sound but youre not likely to if you have 200 cell cats etc like me. The exhaust itself makes the biggest difference by far

 

I have the IPD competition plenum , GT3 82mm throttle body and Evoms V-Flow cold air Intake.... Plenum and GT3 throttle body alone will not add much sound... better throttle response and hp mid range... yes. The biggest bang for the buck intake sound wise are any of the cone filter type intakes, such as EVoms, Fabspeed, K&N, AFE.... Those are night and day difference sound wise above 5k rpm... sceamers all the way to redline. Since you already have the Evoms intake you pretty much already have all the biggest intake sound benefits.

 

Thank you to all of your for your feedback - not completely sold but most likely will do it anyway.

If anyone else has further information related to this topic please contribute.

Nayg

 

Question, speaking to my mechanic, his opinion on aftermarket cold air intake is that the best concept is the stock intake because it is sealed from the heat of the engine compartment, I live in Florida so trying to get cold air is rough. Your thoughts on that?

 

Chuck, I tend to agree with your mechanic. Off the shelf aftermarket parts typically do not hold as tight as tolerances as OEM and this is particularly bad with cold air intakes with 911s because of the location. I have read a lot of reviews stating a noticeable difference in power once the engine is up to temp due to heat soak.

I have had aftermarket intakes in the past and really enjoy the noise but wouldn't personally add one to my 911. Not to mention the cost of these parts.

 

Florida in the summer time.... Oh man, that is a tough place to be. I am Cuban, so I have spent lots of time in Miami visiting relatives and so I understand your dilemna. I have used all three of the intake mods below. For very hot climates like Florida, your safest bet for "cold air" , if you can call summer air in Florida that, is to use the OEM air box with a high flow K&N/BMC air filter replacement along with better flowing intake tube and resonator helmholtz block off cap. This will give you 75% of the sound of the "cone filter style" intake kits. I am torn between the K&N and EVOMS kit. Both of those sound amazing and offer the same volume increase and wailing sound from 5000-7000 rpm. It's a GT3 like wail at high rpms. The K&N sits right below the fan so it gets plenty of air flow while moving, but not so good while sitting in traffic. The EVOMS is my current intake setup and offer a bit more isolation from engine air than the K&N, but still not 100% closed off like the OEM air box... So it is really up to you. On the hottest days in Florida are you willing to give up a few horsepower in order to enjoy a GT3 wail at high rpms??? For me it's worth it, but that is your call..

 

I just did this last week, so I have a BMC filter, IPD Competition Plenum/Intake hose/helmholtz cap/GT3 TB + Fister exhaust mod.
As mentioned above, I noticed a lot more noise 5k to redline. It is a much more intense GT3 like induction howl from right around 5k to redline.
There is a bit more noise before that at WOT but in normal circumstances, until you get on it and start revving up the motor, the sound is not much changed.
I really like the feel with the kit more in regards to normal driving (off the line starts and in normal traffic + freeway driving).
TBH, IDK how much of that is HP/TQ or how much is the TB being better at it's job (response/intake of air...) but I am happy with the mod.
For me, my only goals with this car is to eventually have:
BMC filter
IPD Competition plenum...
X51 headers
200 cell cats
Fister exhaust
Tune.
This has been my basic formula with NA cars since around 1995.
It has always resulted in OK power gains and nice aural gains.
Once I go beyond that with an NA car, I feel like it degrades driveability and reliability.
I have done cams and headwork on NA cars but that seems like it would be stratospherically expensive on a 911 for what you'd gain.
I really just want to tune the car to where I feel the Porsche engineers designed it before having to scale it back for various reasons.

As for today's discussion, when I look at the stock boxes (OEM S and the X51), I do not really see how they can improve on them. I found this to be the case with my EVO as well. I just had a drop in filter even when running a stroker motor with 465hp/tq.

 

https://rennlist.com/forums/997-foru...surements.html

A bit of a read, but the general conclusion is the aftermarket Cold-Air-Intakes for our cars, e.g. Fabspeed Competition CAI, are indeed "hot-air intakes."

This reduces low-speed torque, since the engine is sucking in hot air.

BUT!! Since they tend to flow better (marginally) once you are moving, that hot air has already been sucked in, and new fresh air is rapidly replacing the hot air in the engine compartment. This creates the potential for more power once you're actually going fast. And they sound good.

Edit: I had Fabspeeds Carbon Fiber Competition Intake on my 996.2, and it sound amazing. It didn't fit well, but it sounded great.