Same Dyno Month Apart, Similar Weather. I would have loved to do it back to back but **** happens

Previous Dyno Run.

JDM H22A, SRI, DC Crap 4-2-1, Skunk2 Mega Power Exhaust, SKunk2 Cam Gears, Removed Butterflies in the Intake Manifold, Tuned on Crome

Same Setup now with 3" Catback Crush bent with Resonator and Vibrant Flat Black Muffler

NO ECU ADJUSTMENTS MADE AT ALL!!!!!!!!!

Overlaid 3" Exhaust is thin line, previous setup in bold line

Found a cold air intake laying around

Cold air intake with 3" (thinner lines) Vs Just 3" and Short Ram intake (bold lines)

Untuned 3" vs Tuned 3"

Tuned 2.25" Vs Tuned 3"

Vtec Powa

Modified by EG8 at 3:39 PM 2/29/2008

Nice to see another graph that shows people that a CAI will out perform SRI's in both the bottom and top end of the graph and no reall loss in the midrange either.

Quote, originally posted by PatrickGSR94 »

lol there is no "mileage" on a JDM cluster. It would have to be umm... kilometerage

DC Squad member #0492

it's just an LS...i swear

Quote, originally posted by boots »

you gained 19 ft. lbs. of torque off an exhaust?

i dont doubt it at all

Great comparison

My tuner told me the samething when I went up to get it tuned with mandrel bent 2.5" exhaust system. I was worried about loosing torque but darn you didn't loose anything. I think I'll go for 3" next season

H-deuce's like large exhausts...

Nobody local does 3" but overall i am very very happy with it. VIbrant makes an awesome product with their muffler.

I just need to ditch this broke ass DC Sports header.

What numbers did you make after you tuned?

1997 ITR #110 -- 227whp/156tq 2.0L

2007/2008 WWU Formula-SAE Engine/Drivetrain Captain

X2.

My first impression was going from a larger exhaust possible your peak hp will change will be gained, your curve will look a tiny bit different little torque would be loss downlow... but this isn't the case... collector size I think is crucial...

I'm not sure but could the crushed part cancel out the increase in size?

This is true, which may give you the gains without any losses... replace the bends with mandrel if possible. Crush bend bents can have as much as 1/2" loss in the bends.

Cheers for posting this up, you've helped me make my mind up on exhaust size aswell

2.5" collector to 2.5" cat (or test pipe) to 3" mandrel bent catback
or
2.5" collector to 3" cat (or test pipe) to 3" mandrel bent catback

I will need to figure out to do with my build coming up soon, which will use Type-S pistons (11:1 c/r) and some goodies for the head.

One thing that the dyno doesn't measure is part-throttle power and acceleration. So I want that to be acceptable as well.

I would probably say go with 2.5" collector... take a 2.5" piece of pipe with the correct flange on it for the header 2.5" come out from it 4-5" flare the 2.5" out to 3" run a 3" high flow cat and 3" exhaust system...

Or if you have a cheesy flange depending on the header and are knit pickin to the tenth degree, if the header has a flex pipe id think id cut the flange use a clamp flare the exahust side to overlap the header outlet and clamp away...