I've never seen a true Dyno Comparison.

So here it is:

First Run:
WSP Y-Pipe
WSP Straight Pipe
WSP B-Pipe "fix"
Stillen Muffler



(The Blue run is with the MEVI opening, the red is without)

Second Run:
Cattman 3" Y-Pipe
Carsound 3" Cat
Mandrel Bent custom 3" B-pipe
Magnaflow 3" open muffler

Pay attention to the blue run on this one. I had just reset my ECU in the red run, causing it to be rich.




I am lean up top because I need a Z32 MAF.....but that's another thread.

No other varibales were changed between these 2 runs. Both done on the same dyno.

All runs were done in 4th Gear.

IanS

 

Damn! Look at the torque!

 

.............

 

No doubt, can't wait till you get a Z32 MAF. Then it's on to Aquamist.

S

 

nice gains

 

Hopefully this will help to quell the "backpressure" uprising. It still amazes me to this day that people think that our engines somehow use backpressure in the exhaust system

Those are some VERY nice numbers iansw. Keep up the good work...

 

I dont have $500 to upgrade my exhaust
nice numbers. I love that torque.
do you have a air to air ICer by any chance?

 

No - no charge cooling of any kind.

I was considering trying Aquamist after I get the Z32 MAF set up and a BBK (I really need one now).

IanS

 

awsome numbers. How many psi of boost are you running, and how does the 3" exhaust sound compared to the 2.5"? Does it sound ricey at all?

 

very good question. How many resonators do you have BTW?

 

Good stuff!
Is it still backfiring?

 

Back pressure on any vehicle is not a good thing. The only thing back pressure will do is increase your EGT's. The less back pressure a exhaust system will have the better the system is. Even on a vehicle equipt with a turbo back pressure is not needed, however it is unavoidable that there will be some back pressure when using a turbo due to having to get the turbine spooling (turbo lag). I'm positive if there was a company out there that could produce a turbo that would have 100% no turbo lag, no matter how big the turbo is everyone would buy that one instead of the others. So for that matter on all variences of spark ignited combustion engines back pressure is unwanted.

Great numbers!!!
Keep up the good work!!!

 

No resonators anywhere unless you count the muffler itslef as a resonator. Just a straight 3" mandrel B-Pipe.

It's loud as hell, and on a 1st gear run at high RPM, sounds pretty ricey, but in a nice deep tone kind of way.

But I don't like how loud it is. I'll probably go to another muffler soon and see if that helps (Dynomax Super Turbo, per Mardi's suggestion.)

IanS

 

See, that's what I'm talking about. In a 4 stroke motor, there is no exhaust backpressure...

YYou can have backpressure on the crossover pipe for the turbo/SC'er setup (IIRC...and only under certain conditions), but the actual exhaust from the manifolds back have no backpressure of any kind...ever...never will (unless you're falling off a cliff backwards with the engine turned off...maybe)...

 

Did you tune that beast?

 

Not yet. AFR looks pretty good when I haven't just reset my ECU - except for up-top where I'm leaning out due to maxing out my A32 MAF.

Z32 MAF and ECU Reprogram shortly should fix that.

But I understand the Z32 MAF must be 18" from the blower inlet, and I'm not sure how that can be done with the limited space up there.

I could risk it like Stephen Max is however and just run it on the charged side.

 

Oh - and yes, it still backfires when engine braking. Although it didn't get any worse when I went to 3" exhaust.

Maybe because having a Cat again is offsetting any change for the worse?

 

I am getting estmates to have an 18 inch intake pipe made.
One way would be to run the intake paralell to the charger pipe and put the actual k an N where the NA stock one is. Or maybe relocate the battery too.
Similar to the 5th gen setup.

Want me to see about having a second one made for you? I guess I will be the guinea pig and we can see how it goes. IF people like we can prolly have more made?

One guy I spoke with was very familiar with what needed done and how we need to keep the recirc hose small as possible. With the pipes paralell, this will be quite optimal.

 

Depending on cost, of course, I would totally be down to do that.

At the Dyno/Tune shop I tried to discuss this with them and they just stared at me blankly.

IanS

 

Not bad.. looks about like 10-20whp and 20-25tq just from switching the exhaust.

Looks like when I was told that I would gain 10-20whp from just changing the exhaust after going turbo that it was correct. I am glad that there are some general dyno numbers to back this theory up since I couldn't redyno myself.

Nice numbers.

 

Actually - I got the Dyno Files uploaded to my machine today so I could graph a closer comparison...side by side on the same graph and all.....

The Exhaust adds alot of meat to the curve through the powerband.

 

Z32 MAF and such is on the way now.

Will Dyno again at that time.

Thank god I'm taking her to the track May 1st - I'm starting to feel like she's just a Dyno Queen.

IanS

 

It's really strange (to me) that the gains from the larger exhaust diminish to nothing at high rpm, where you would expect the gains to be maximized. The gains all through the low and mid range are fabulous, but very counterintuitive.

 

..............

 

I believe that's from his leaning AFR.

Look at the gains he made after he supposedly reset the ECU and it took a richer AFR.

At least that's my guess, since you're right, that wouldn't make sense.

 

I also am sure that's the AFR issue.

We'll find out in a few weeks when I get the Z32 MAF going.

IanS

 

Thanks for sharing Ian. NICE TQ

Your at 11 psi correct?

And I hope alex and stephen and you are correct about the upper rpm. I thought it would be MORE WHP at max boost.

 

Oh, I bet you're right. I had forgotten about that.

 

hitting about 11.5PSI on average.

(Depending on temps, phase of the moon, my wife's anger at me, etc....I get 11PSI or 12PSI...)

 

I understand

Thanks