Do what makes you happy. Whatever you do the gains will be modest. And the ipd plenum is pricey. I did a tune, headers, cats and valved exhaust and my 3.4 is more exciting, but it's not been Dyno tested so it could all be in my head. But it sounds like an old F1 car and I love that. The tune was done after the exhaust was, and really improved the mid range torque, but the most awesome thing is the throttle response. That, to me, it's the best thing about the tune, because you can feel it and use it. If you have a 99 or other cable throttle car, you will already be golden. But anyone with a 6mt and e-throttle who does not fix the response lag is very much missing out. Hard to heel and toe and double declutch until the fix is done. With it, is like shifting my old fiat spider, instant blips. But with horsepowers 😎.
you could try something like this https://www.ecstuning.com/b-sprint-b...sbpo0033s~spb/ but honestly a tune is only 350 more. Or mine was, and was needed to fix the loss in torque the exhaust change caused.

 

Appreciate you sharing that. Good insights all. Life is all in our head anyway!

 

I’ve installed a few IPD plenums.
Only once did I break the plastic coolant connector.
But I keep at least 1 aluminum connector in stock at all times and was able to fix it in about 5 minutes.

 

Holy cow! Finally someone talks about the lagging throttle response! What tune do you have?

 

Holy cow! Finally someone talks about the lagging throttle response! What tune do you have?

 

I’m my opinion the ipd works in my car. It’s a 3.4 cable throttle. Now the throttle has been bored, I’m running the Carrera 3.8 s airbox with a kN panel, I had soul headers but I sold them to squirrel and got his agency power headers, I also have a fab speed catless x pipe, and the fabspeed max flow exhaust. My car has an apr tune. Yes the plenum made a difference I’m happy. Another observation the agency power headers are 2 plus pounds per side lighter in weight than the soul headers, also the car sounds a bit louder with the agency power headers compared to the soul headers. I drove it Saturday to a performance shop anniversary event and I got compliments on how it sounds. A big thing is the weight removal, the factory mufflers weight a lot, so do the cats. I have removed the back seats and spare tire so Car has gone thru a diet. I really like the apr tune. Cost wise is probably the best bang for the buck performance enhancement. I’m happy with the plenum but look at all the other mods. Only way I can make my car faster is to get a bigger engine.

 

Would love to hear a sound clip. Sounds like you did a lot. Like so many, seems the plenum isn't that cost effective (if at all) unless it's done in the context of a larger series of upgrades. Still scratch my head on the PCA review of the stock 996 getting 10HP and increased torque. I love how IPD's ad in Panorama claims a 28HP gain. All things being said, passionately drove mine yesterday on PCH with the top down asis and smiled all the way to the beach. These 996 cars don't disappoint. Thanks!

 

IPD plenum "works" in the context of other upgrades because it isn't doing anything.

If the plenum had a reproducible effect it would be extremely easy to prove it. You would see an immediate shift in the fuel trims. VE would increase, etc.

I'd love another 20hp with no downside for a couple hundred bucks but it doesn't exist.

 

I’ve watched 2 videos ( PCA/9Werks) that show a 10 hp gain across the rev range on 1999 C2s.
Both were done the right way.
Same car, same dyno and the same day.

I’d call that something

 

Sure. Those 2 videos prompted this thread. The PCA one is the most puzzling in that it was a stocker that pulled 10HP on its own. I'm only looking for more fun/torque in the lower range, so that's what's most important to me. The tech in the shop I go to encouraged me to look at the IPD plenum as a single mod to do that, so.....that Intrigued me enough to ask all of you, and thanks for the breadth of opinion!

 

@dougn Vivid Racing VRTune. They asked which aftermarket intake and exhaust bits I had, I'm very pleased with the result. Easy procedure to back up stock ecu and apply vrtune.

 

Again I refer to this video which shows why these may not work as well as some believe. It's all in the intake temps and flow rates.


Edit, I think the plenums work on the right engines. They seem to not do so well with stock to engines with basic modes.

 

Haven't found a test yet on yutube for a 3.6 m96 that benefits. Only the 3.4. The question is why?

What's so different about the engineering of a 3.6 that it doesn't work?

And what's so different about the 3.4's engineering that it does?

 

Is the exhaust airflow on the 3.4 greater than 3.6? If yes, and airflow through the stock plenum is the overall flow constraint, the higher volume plenum will help. WAG.

 

Your first assumption is that an engine that makes less power is flowing more air than one that makes more?