pcguy760

My setup is basically going to be low boost less than 7 PSI on a H22A and I am kinda confused as to what DP Size I should go with and honestly, 2.5" would fit so much easier although I could get the 3" to work.

If 3" would gain me some power benifits or is better for the turbo then I would go with it but if it really is nothing too much I would just go with 2.5" - what do you turbo guys think - 2.5 or 3 Inch ?

boostedcivicsir

you can do a 2.5, but with the 2.2, a 3 would be much more happier.

hotimportcrx

I would do a 3. Chances are, no matter what you say now, you will want more horsepower when you get boost happy. Its like a drug and we are the fiends. Better to get a 3 inch now, instead of getting a 2.5 then wanting a 3 inch.

pcguy760

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hotimportcrx &raquo;</TD></TR><TR><TD CLASS="quote">I would do a 3. Chances are, no matter what you say now, you will want more horsepower when you get boost happy. Its like a drug and we are the fiends. Better to get a 3 inch now, instead of getting a 2.5 then wanting a 3 inch.</TD></TR></TABLE>

Yeah I think I might as well call it a day and go for 3 Inches DP - gonna go measure it up and see how it all fits in a little bit...

Lol I have the cure to avoid becoming a boost fiend - seeing that my tuner is very far away and there are NO tuners near my town, I will be having boost cut set pretty close to my tuned PSI so then even if I got boost happy (LOL) I could not get that much out of it haha. You're right about the boost addiction though

pcguy760

Update : Well after test fittingg the manifold, turbo, charge pipe to intercooler, wastgate and dumptube, sadly I see there is virtually no room for a 3 inch downpipe so now I kinda have no choice but to go with a 2.5 inch so, for my setup (H22A at 7 PSI or less), do you guys think I would lose alot of power or have a noticable difference if I just went with a 2.5 inch downpipe???

Besides, my entire exhaust system is 2.5 inches with a free flowing / gutted cat...

AdamB18C1EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pcguy760 &raquo;</TD></TR><TR><TD CLASS="quote">Update : Well after test fittingg the manifold, turbo, charge pipe to intercooler, wastgate and dumptube, sadly I see there is virtually no room for a 3 inch downpipe so now I kinda have no choice but to go with a 2.5 inch so, for my setup (H22A at 7 PSI or less), do you guys think I would lose alot of power or have a noticable difference if I just went with a 2.5 inch downpipe???

Besides, my entire exhaust system is 2.5 inches with a free flowing / gutted cat...
</TD></TR></TABLE>

well. youre going to see considerable gains by taking off and or buying a larger diameter exhaust. and i personally would do everything possible to fit a 3'' dp in there. i have a log manifold and a 4''dp. put your mind to it. you'll find a way.

reactone

I think your 2.5" downpipe is fine, especially for low boost. Until I see numbers clearly showing that a 3.0" downpipe will increase HP on a Low HP setup I'm skeptical.

pcguy760

Can anyone else confirm that a 2.5 inch would be fine? I am gonna try a 3 inch bend from the turbo and see how it all fits during the week. Seems like its gonna be too close to the alternator though... manifold is a Lovefab shorty btw...

KeyserSoze

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by reactone &raquo;</TD></TR><TR><TD CLASS="quote">I think your 2.5" downpipe is fine, especially for low boost. Until I see numbers clearly showing that a 3.0" downpipe will increase HP on a Low HP setup I'm skeptical.</TD></TR></TABLE>

I don't think anyone is saying that a 2.5" dp wouldn't work. People are saying that down the road he will most likely want more power and because of this he should just get the 3" and be done with it so he won't have to make another dp later.

2point2

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by reactone &raquo;</TD></TR><TR><TD CLASS="quote">Until I see numbers clearly showing that a 3.0" downpipe will increase HP on a Low HP setup I'm skeptical.</TD></TR></TABLE>

I'll put money on it.

You will see hp gains in the 300-400hp range going from 2.5" exhaust to 3.0" exhaust on a turbo H22 from my experience....

however, you will be fine.. just make sure you are running an open dump tube. I ran 11 second 1/4's with a 2.5" exhaust.

pcguy760

Since this is not really an extreme hp turbo setup, and I have NO plans what so ever of boosting more, do you guys think I will be just fine with a 2.5 incher?


Modified by pcguy760 at 2:19 AM 8/5/2008

2point2

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2point2 &raquo;</TD></TR><TR><TD CLASS="quote">just make sure you are running an open dump tube.</TD></TR></TABLE>

pcguy760

Yeah I am running an open dump tube - So on the original subject, I was wondering, do you guys think I will lose any power (for my setup) because of the 2.5 inch dp? Thx.

2point2

My guess would be that you will lose a small amount of power running a 2.5" exhaust/dp vs 3". Power potential will also go down with a smaller dp and exhaust. You're not too bad because you're running an open dump - this makes a huge difference but is not often discussed. People can only go by their experiences.. you're not going to get a yes/no answer.

It's up to you. Is the extra trouble of going 3" for a handful of WHP worth it?

I personally wouldn't nit pick over this if I was aiming for ~300 whp - 2.5" with a an open dumptube would be perfect.

Turbo-charged

here i'll make your decision easy!


2.2 H22 turbo.....before and after with 2.5 inch dp/ex and then a 3 inch dp/ex






both exhausts were the same style "dual" exit

90blackcrx

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pcguy760 &raquo;</TD></TR><TR><TD CLASS="quote">Since this is not really an extreme hp turbo setup, and I have NO plans what so ever of boosting more, do you guys think I will be just fine with a 2.5 incher?


Modified by pcguy760 at 2:19 AM 8/5/2008</TD></TR></TABLE>

2.5 will cause the motor blow up..... of course it will be fine. 3 inch would be better. Go from 2.5 to 3 inch under the pan.

EASY101

I wouldnt go any smaller then 3" all the way back on any boosted honda, but thats just me.

pcguy760

Dammit this is peer pressure!! LOL just kiddin - well this weekend we gonna try again and see if there is any way without raising the car, the 3" dp would fit...

Thanks for all the advice guys!!

90blackcrx

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pcguy760 &raquo;</TD></TR><TR><TD CLASS="quote">Dammit this is peer pressure!! LOL just kiddin - well this weekend we gonna try again and see if there is any way without raising the car, the 3" dp would fit...

Thanks for all the advice guys!!</TD></TR></TABLE>

I'd love to post pics of the car ( h22 ) we just did, but unfortunately I will get banned. It was a 2.5 to 3 inch setup. Very nice. Tuck 3 under the oil pan, it can be done.

pcguy760

Well I decided to take a picture and post it because today I decided to exactly measure how much clearance I would have instead of estimating - seems like I can only get about 4 Inches (with a 5 bolt flange of half inch) for the downpipe bend. NOW do you guys think a 3" downpipe would fit - honestly I personally think it might be too close to my alternator... but I thought I would let you guys who have done this see and let me know what are your opinions. Thanks Guys!!

NeKe1point0

There is plenty of room in there !!

I wouldnt even think about doing 2.5" DP.
No matter what you think now, your gonna want more power...


3" pie cut/heat wrap &gt;&gt;&gt; done

pcguy760

LOL, I hope so because I just took the pics to a local muffler shop who does custom work and he said he did not think he could fit 3 inches in there - Guess I could give it a shot by myself and just get the pieces welded there... I will see what happens - like your signature btw, sounds like something I would hear around in this part of IL

Anyone else care to chime in?? Thx!

NeKe1point0

i went to get mine done at a local shop and they told me the same thing so i just bought my own welder and went to a local shop for some scrap and just cut it up and put it back together... finally i said what the hell and gave downpipe fab a shot !

basically im sayin ... dont look at the welds ! ha ha ! (still a beginner welder) but this is how i did my Accord, and i have a full sized radiator and A/C. this pic was while i was mocking it up. maybe now that will help ur decision.

90blackcrx

You're really gonna regret that log manifold on an h series.

pcguy760

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 90blackcrx &raquo;</TD></TR><TR><TD CLASS="quote">You're really gonna regret that log manifold on an h series. </TD></TR></TABLE>

Are u talkin about the guy above?