mirko_tripic

I am posting this for those of you who are contemplating this upgrade but having doubts about performance gains.
I was one of doubters before this installation who spent a lot of time reading reviews and talking to people who have in depth knowledge on mechanic of fluids and generally who have experience with racing and tuning.

To sum it in one sentence: "This is one of the best upgrades you can do for your naturally aspirated flat six engine provided that you already have a less restrictive exhaust system than stock".

I have the following upgrades on my 2002 C4 Cab:
The upgrades were done in the following order:

1. FVD Brombacher Sport exhaust Sound Version
2. FVD 200 Cell sport catalytic converter.
3. FVD Race tune
4. BMC Flat filter
5. IPD Competition Plenum with GT3 Throttle body (82mm) and straight hose.

The car now has loads of low and mid range torque and pulls strongly to the red line (7500 RPM with this tune).

The sound is as close as it gets to GT3 sound. It sounds like a race car.

I have recently driven a stock 996 V2 and compared it with my car.
Throttle response is improved by 20 to 30% compared to the stock car.
The car is way faster than the stock. It is not comparable.

Additionally, I have compared both cars to BMW M240i (my daily driver) which has a 3.0l turbo charged engine capable of making 369 lbf at 1500 RPM. This car does 0-60 in 4.5 seconds.
The stock car is significantly slower than the Bimmer.
My upgraded C4, although it doesn't have this amount of torque, does not lag behind the Bimmer. Torque distribution is more linear and in my humble opinion natural all the way to 6K.
Torque is there all the time at any RPM and any gear.

Before doing this upgrade I was a little skeptical about the gains having read various posts and comments from people who installed it. However after some analysis I have come to conclusion that most people who didn't experience any gains were the ones who have the stock exhaust and no software tune.

So in order to enable the engine to breathe faster you need to open it up at the exhaust.
Also, new mapping is required to take advantage of larger amount of air coming into the engine.

That's my two cents.

I will post the video with the sound of the car when I get a chance to make it.

Let me know your experiences.

AnthonyGS

I’m real curious to know how you measured the improvement in throttle response.

DGI

I appreciate this feedback.

I'd be looking for improved throttle response over any power increases. I figured not much would be had.

What other tunes are available that would take advantage of this setup? Would Fabspeed work just as well?

jaycm3

could the throttle response be a result of the tune mapping? Thats all it seemed to do for me.

mirko_tripic

You will get both the torque and high end HP.
Throttle response is amazing.
Yes, Fabspeed will work too. All top brands products are similar in terms of sound and quality.
But, you have to do the exhaust first and the tune to capitalize on performance gains. Otherwise, you probably won't see much difference, like all those people who complained about IPD plenum gains.

mirko_tripic

Yes and no.
I had the mapping done before the IPD and TB installation, along with the muffler and 200 Cell cats.
That was a good improvement over the stock throttle response.

However, it was only after IPD and TB installation, when I couldn't recognize my car anymore.

Guys, we are not talking 5-10 HP and 10 lbf of torque. That is difficult to notice.

We are talking about 50 HP and 20-30 lbf of torque of improvement. The throttle response is instantaneous at any RPM.

Of course, I didn't do Dyno to back it up, but I don't need to do it because it is so obvious that even a layman would see the difference between the stock 996 and my car.

mirko_tripic

Start the stopwatch and floor the gas pedal in the first gear at the same time.
Stop the stopwatch when you reach 60 mph speed. Record the time. Do this 3 times.
Do the same from the rolling start and the second gear.
Do the same in the third gear.
The goal is to measure the time required to get from one speed to another. For instance; from 20 mph to 110 mph.
Compare the results with the stock car.

Imo000

Too bad after spending all this money you didn't bother to do before and after dynos to see what exactly were the performance changes.

mirko_tripic

I agree.
However, all these updates were done in stages. One after another.

When I first started doing it, I remember my mechanic telling me to lay off a bit from spending too much money.
Enjoy your car a bit instead of rushing from one upgrade to another, he said to me.

I can still Dyno it. I am just worried about it. Don't want to do any damage to the car.
I don't have any experience with it.
Any thoughts?

Prelude Guy

Not a fan of butt-dyno threads. Subjective analysis has never been a reliable way to measure anything.

On engines with larger displacements like our csrs, increases in HP and TQ have to be more significant to actually feel. Without a before and after dyno, it's just speculation.

It would be nice to see a dyno of your car the way it is now though.

mirko_tripic

That is exactly what I am trying to tell you.
This is a very significant difference from the stock car. I don't know the actual figures but it is day and night in terms of acceleration.
It is up to everyone to decide whether they will trust my judgement or not.
However, there are lots of people on these forums who have installed this product and are very happy with the gains.
I am one of them.
I understand that there are some who are not impressed with it too. But from what I have read, most people who didn't feel any gains did not install the throttle body and less restrictive exhaust system.

Imo000

Increased noise can easily be confused with more power and better throttle response. No saying your modifications didn't increase the power of your engine but maybe those number are skewed by how things now sound. Also, did the power just shift in the power band or was there an increase under all rpms? It's difficult to gauge this when the car sounds like a race car. A race tune usually concentrates on near redline performance because that's where those engines spend most of there time and that's where they need the most power. How does this translate to daily driving? Race cars are terrible daily drivers.

Porschetech3

Record your max-MAF value display and post to this thread. https://rennlist.com/forums/996-foru...potential.html

mirko_tripic

I agree with your statement about higher noise levels making is feel like the car is moving faster. There is a little bit of that too.
The increase in torque all across the range, at all rpms and at any gear. Yes it is difficult to gauge the car when it sounds like race car. However, this sound can be easily modulated with the throttle. If you want it to sound like race car, you just step on the gas pedal. If you want it to sound tame, you just accelerate at a normal pace and car doesn't sound like a race engine. That is the beauty of this exhaust system. It is the sound on demand.
I hardly ever rev the car beyond 6K since I am not racing or driving it on the track. However, I have noticed a brutal acceleration past 5 K in 2, 3 and 4 gears.
What makes it more impressive is that you don't have to rev it high to be fast in daily driving. You can stay below 4K and still be faster than most cars on the road. Do your overtaking and lane changing between 3 and 4K.
The torque is available as low as 2K.
With the stock engine, you need to past 3K to feel any torque. For the stock engine you need to do daily driving between 3 and 5 k to be able to pass comfortably.
This one is between 2 and 4k.

mirko_tripic

Is this any accurate?
Where do I buy this and how does it connect to the car?