Vr6 exhaust dyno: 2.5" vs 3" back to back.

[root beer]

First off, Kurtis@MBSP sponsored this test. He is deserving of the credit here. I am merely reporting because i am a superstar.

We went to Charm City Tuning this afternoon, super hot and humid. They've got a dynojet in house there. Strapped it down.

Setup:
170k block
mk4 hg
7lb flywheel and light crank pulley
home ported head, and competition valve job
2.9 clone upper intake
Autotech intake
Schrick 268's
Ported exhaust manfolds
2. 5" TT with Borla with 42dd testpipe

The best pull was 197whp

Next, we backed the car off the dyno, and Kurtis threw on the 3" setup that is available in the classifieds. Kurtis@MBSP

The best pull with this exhaust was 204whp. This gain was the whole powerband, and 7whp at peak. It also helped churn a couple lbs of torque across the entire powerband, and 5ft/lbs at peak.

I now run a 3" aluminum, single muffler system made by Kurtis

Cliffs:
-A mildly modified VR will see mild gains from a 2.5" to 3" exhaust. If you're planning on modding the motor to anything more than bone stock, it might make sense to just buy the 3" system off the bat.
-You 2.25" lovers are wrong. I just pooped on your 'low end torque'.
-Don't be scared.

[rlsib16]

[root beer]

[son of planrforrobert]

SUPERSTARRRRRRRRRRR

Get well soon cutie

[yellowrocco87]

Super big thanks to Tim (aka Rootbeer) for letting us use his car for this test. With out him none of this would even be possible. So i can't thank you enough man. Also i'd like to thank all the guys up at Charm City Tuning for letting us use the dyno after hours. Mike, Jeff, Beavis, John thanks again guys

To say we're happy with the results would be an exact understatement of how i feel right now. it was great. I'm just so glad that now There is with out a doubt proof that a 3" system on a mildly modded N/A VR6 picks up power over your more common 2.5" TT system. Like tim had posted dyno graphs will be available for posting tomorrow.

[Sandlock]

good stuff gents.

[dawgpound]

sweet. im running a 3in in my set up and love it. good to see the proof.

[dubsnmotion]

thank you

[ruck]

good stuff

[root beer]

sweet. im running a 3in in my set up and love it. good to see the proof.

Yea man. Now i'm getting my aluminum system built

[DUBZAK]

This is good news.

Can't wait for the graphs.

[root beer]

videos are up. Not the final pulls, but they're videos.

I'm the sexy one with the hand splint.

[VR JC]

for our black all motor vr's

[rlsib16]

nice sound there. what you do to your hand bud?

[root beer]

I was taking the trans out of my new tacoma last night, and a bolt let loose, banged my thumb knuckle open on it. Went right to bone. I looked at it, and ****ing passed out in the shop in a puddle of water.

Partially cut tendon, hand surgeon tomorrow.

This is so amazingly inconvenient. I was ready to go run a ****in number tomorrow.

[Grits 'n gravy]

Man you had that thing screaming.

[BHCfarkas]

Much appreciate the useful information.. now the 2.5 an 3" debate can be put to rest.

[Andras.R]

Once again, nice work What are your impressions about the difference in exhaust note?
ps. its was hard to tell with the sound quality of the video..

[root beer]

The 3" def has more bite to it.

[Harris_Teeter]

Good to know.

[vdubxcrew]

What exactly was included in the MBS kit when you dyno'd? Test pipe, no resonator to magnaflow muffler?

[skydaman]

I'm just so glad that now There is with out a doubt proof that a 3" system on a mildly modded N/A VR6 picks up power over your more common 2.5" TT system

Joe @ Tempest did this test years ago...

Cool you guys backed up the results though.

[root beer]

What exactly was included in the MBS kit when you dyno'd? Test pipe, no resonator to magnaflow muffler?

Yea, just a magnaflow.

[LA7VJetta]

Schweet

[976-RADD]

It seems unrealistic that a car with 199whp would benifit from the same size exhaust you'd run on a 400whp vrt car.

[yellowrocco87]

Joe @ Tempest did this test years ago...

Cool you guys backed up the results though.

well no one ever saw the results of his test except for a very few people skyle so we took it upon our selves to see what would happen if we did this.

[V-dubbulyuh]

This is good stuff.

[root beer]

It seems unrealistic that a car with 199whp would benifit from the same size exhaust you'd run on a 400whp vrt car.

Even when my car making 199whp busts ass on 400hp vrt's?

Really though, this is pretty typical of other makes.

[skydaman]

It seems unrealistic that a car with 199whp would benifit from the same size exhaust you'd run on a 400whp vrt car.

This is whats wrong with import drag racing...

well no one ever saw the results of his test except for a very few people skyle so we took it upon our selves to see what would happen if we did this.

True it was on the DSD site that is long gone.

[root beer]

It might be what's wrong with import modification as a whole. Too much internet, too much unfound logic, too much bench racing. No real world testing.

Things like:
-small cams are good for boost
-restrictive exhaust systems are needed for "back pressure"
-cai's don't make power
-20w50 is good for a vw

[son of planrforrobert]

-20w50 is good for a vw

[LA7VJetta]

It might be what's wrong with import modification as a whole. Too much internet, too much unfound logic, too much bench racing. No real world testing.

Things like:
-small cams are good for boost
-restrictive exhaust systems are needed for "back pressure"
-cai's don't make power
-20w50 is good for a vw

when in reality

Big cams> small cams
wide open large exhaust is good for power
CAIs make a decent boost in power


but that is true about the oil, for a 8V anyway.

[root beer]

My 8v runs on piss and vinegar.

[son of planrforrobert]

I thought it ran on wailing guitar solos and Star Wars references?

[976-RADD]

It seems unrealistic that a car with 199whp would benifit from the same size exhaust you'd run on a 400whp vrt car.

This is whats wrong with import drag racing...

Care to elaborate?