I'm looking to be making about 350hp on my gsr and want to hopefully get 400-450 when i do some more upgrading.

I was 100% set on custom 3" dp and 3" exhaust. However, lately i have been hearing to stick with 2.5 dp and sometimes exhaust.

I'll let my setup so it would help

stock b18c1
precision sc61 turbo
precision FMIC
Tial wastegate
hks squential bov
720 or 770cc injectors
hondata s200b and other features later on.

what do you guys think i should get and why? thanks in advance.

 

I would say 3" as long as you can get away with it on the street. Its going to be loud to drive everyday and attract cops but you'll get the most performance out of it.

 

I thought so too, but the reason i asked because i have been hearling a lot lately, "don't get 3" dp, it's a waste of money" so i wanted to know estimates of hp that i would gain/lose.

If i end up with the 3" all the way, could i still get a sliencer so the noise wouldn't be as loud?

 

If you had a cat, resonator, and a good quiet muffler it would shut it up pretty good....

 

anymore comments on the performance ?

 

3 inch is not loud at all!
i have 3 inch dowpipe, no cat no resonator, 3 inch maderal bent piping from downpipe back, and a magnaflow fuffler. it is not nearly as lound as n/a cars with bolt ons. the turbine quiets the exhaust down alot. there is no reason not to go 3 inch, since its very hard to go too big with turbo exhaust. the only draw back is less out of boost power

 

3 inch isn't too loud, 2.5 can be restrictive, 3 inch

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98gsrTEG &raquo;</TD></TR><TR><TD CLASS="quote">3 inch is not loud at all!
i have 3 inch dowpipe, no cat no resonator, 3 inch maderal bent piping from downpipe back, and a magnaflow fuffler. it is not nearly as lound as n/a cars with bolt ons. the turbine quiets the exhaust down alot. there is no reason not to go 3 inch, since its very hard to go too big with turbo exhaust. the only draw back is less out of boost power</TD></TR></TABLE>

I disagree. I ran this setup and it was too damn loud...embarassing loud. I would not recommend 3inch on the street. If you're going to do 3inch at least get some resonators but even then its on you whether you like the droning or not when you're in the lower rpm range.

 

theres a few people running 3" dp to 4" exhaust and from what i can hear, its no louder than my 3" dp to 3" straight exhaust, and mine isnt that loud

 

Is it possible to lose power by using 3" dp and 3" exhaust over 2.5" setup?

 

Yes it's possible but it's not probable.

 

Would I be able to keep AC with 3" dp ?

 

If you go from 2.5" to 3.0" after the condenser, yes. If you go 3" from the turbine, not likely.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RNPoo7 &raquo;</TD></TR><TR><TD CLASS="quote">Would I be able to keep AC with 3" dp ?</TD></TR></TABLE>
I think i've seen a 3" downpipe that allowed you to keep A/C, and no it wasnt flared to 2.5" either. i'm pretty sure there's one out there...

 

Is there a lot or insignificant amout of power that you get from 3" dp ? I'm trying to see if it's worth the money or not.

 

Do you already have the 2.5" DP, if not, it's not gonna be a question of price, it would be a question of prefference.

 

I'm buying a turbo kit very soon and i can get the kit with or without the downpipe, that's why i was asking...I'm figuering $250 to custom make the 3" downpipe.

 

$250 is the most you should ever pay for a high quality Stainless DP. It doesn't involve that muck work. What turbo kit are you using, and how much is the downpipe that comes with it. The downpipe that comes with the kit could prove to be useless if you change other components like the turbo, or manifold anyway. And if you get a custom 3" pipe and change these things you will have to either modify your dp or get another one made.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FwdCivicHatch &raquo;</TD></TR><TR><TD CLASS="quote">$250 is the most you should ever pay for a high quality Stainless DP. It doesn't involve that muck work. What turbo kit are you using, and how much is the downpipe that comes with it. The downpipe that comes with the kit could prove to be useless if you change other components like the turbo, or manifold anyway. And if you get a custom 3" pipe and change these things you will have to either modify your dp or get another one made.</TD></TR></TABLE>

Thats not true at all... Stainless materials are not cheap. $250 is not a bad price at all and could even be a starting price. Depending on the quality of the welds and craftsmanship/time put into a DP. I would like to know how well you weld/tig... You get what you pay for, and alot of the time the money is spent on the craftsmanship of the work, not just hte grade of material, ask a few guys that make them on here, they will tell you so

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98gsrTEG &raquo;</TD></TR><TR><TD CLASS="quote">3 inch is not loud at all!
i have 3 inch dowpipe, no cat no resonator, 3 inch maderal bent piping from downpipe back, and a magnaflow fuffler. it is not nearly as lound as n/a cars with bolt ons. the turbine quiets the exhaust down alot. there is no reason not to go 3 inch, since its very hard to go too big with turbo exhaust. the only draw back is less out of boost power</TD></TR></TABLE>

So a 3" DP and exhaust would kill out of boost power? It would be a bad thing to do on our honda engines (by way of power)? Would a 2.5" be good up to 450-500whp?

A daily driven car with 3" would suck for power daily, but at the track would really utilize the extra flow the exhaust offers right? What would be the best recomendation for a daily driven track car with approx. 400whp?

 

Id suggest 3" downpipe. Corky Bell says "the best turbo exhaust, is no exhaust" which would give me reason to believe 3" would be better then 2.5 definately...

Now on the evos( i know we dont drive evo's but this is just a statement) HKS shows to not get a 3" downpipe for them unless ur over 400whp i think and to only use 2.75" downpipe.

There is information all over that shows to go one way then says to go another..I think its more of a matter of opinion and what YOU wanna do. My .02 worth.

 

So basically, i get the feeling that 3" downpipe will make more but not enough difference to notice with the amount of money spent on customizing a 3" dp instead of getting 2.5". right?

 

What about if your turbo exhaust housing ID is only 2.5? would it make a difference to flare the 2.5" to a 3" over just a straight 2.5" turbo back?

And does it matter where the flare is? Im running the revhard manifold on a GSR and Id like to keep the AC but also like to run a 3" DP.

 

i think i decided to go with 2.5" dp instead of paying all the money on the 3" for little hp difference.

 

ive read that 2.5 and 3" dp will make boost spike at high rpm.