Who says 3" Exhaust is to much for N/A?

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

 

I've often heard that a 3" exhaust was a good choice for the H22, it's the 1.8L's that most people fint it to be too big.

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.

 

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

 

i have a 3 inch exhaust kit from kteller and cant wait to install it.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boots &raquo;</TD></TR><TR><TD CLASS="quote">you gained 19 ft. lbs. of torque off an exhaust?</TD></TR></TABLE>

i dont doubt it at all

 

If your refering to the 125lb-ft in the first picture thats at 7363rpms with the red dotted line. I gained MAX 4.5lb-ft of torque at my peak. But as you can tell it gained completely across the board in HP and TQ

 

Great results, this is exactly what i've been looking for

 

"Who says 3" Exhaust is to much for N/A?"

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...

 

i appreciate it, i wonder if mandrel bent would have done better, but all i could get was crushed bent.

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 *** DC Sports header.

 

You would probably pick up a bit with a mandrel bent system.

What numbers did you make after you tuned?

 

I havnt tuned yet, I need to sit down and check the Air Fuels and just make some pulls, But the fuel table has changed to what it was tuned from before.

 

Nice work

 

that coming from big tuna means alot!!!!

 

Despite what I've heard, I have never once seen any sort of proof that you can lose power by changing to a larger exhaust. From reading SAE papers and textbooks, the general consensus is everything after the last merge collector is a restriction.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92TypeR &raquo;</TD></TR><TR><TD CLASS="quote">Despite what I've heard, I have never once seen any sort of proof that you can lose power by changing to a larger exhaust. From reading SAE papers and textbooks, the general consensus is everything after the last merge collector is a restriction. </TD></TR></TABLE>

X2.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 92TypeR &raquo;</TD></TR><TR><TD CLASS="quote">Despite what I've heard, I have never once seen any sort of proof that you can lose power by changing to a larger exhaust. From reading SAE papers and textbooks, the general consensus is everything after the last merge collector is a restriction. </TD></TR></TABLE>

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...

 

at this point i have stock collector on my DC sports!!!! I really need to update that and get a light weight flywheel

 

I'd predict with a better header larger runners and true 2.5" collector you should be able to hit 190+ whp on a good tune... you should also see an increase of atleast 3-5 ft lbs of torque...

 

Just had a thought, how crushed are the bends in your system?

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

 

ha looks like u answer my question on my other thread

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybrid2007 &raquo;</TD></TR><TR><TD CLASS="quote">Just had a thought, how crushed are the bends in your system?

I'm not sure but could the crushed part cancel out the increase in size?</TD></TR></TABLE>

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.

 

I have an RMF header with a 3" collecter and i was going towards a 2.5 but since i saw this thread in going 3" now

 

It would be interesting to see what size your system is at the bends. You should stop by your muffler shop and get them to put a 90 degree bend in a bit of scrap and then cut it in half.

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

 

I wonder what would be most optimal for a stock bottom-end H22 then?

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'll be running an SMSP header with 2.5" collector, 3" outlet to a 3" high flow cat to a 3" mandrel bent catback

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mike95lude &raquo;</TD></TR><TR><TD CLASS="quote">I wonder what would be most optimal for a stock bottom-end H22 then?

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.</TD></TR></TABLE>

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...