I see all kinds of posts on turbo setups in this forum so I am going to ask. I already posted in FI section but no one answered. I have done a search and do see an answer to this question because its specific to a prelude.

I have a built supercharger by Endyn, port and polished job on my head, and a kamikaze header that has a modified collector at 2.5 in. on my built H22A. I am about to purchase mandrel bent piping for a custom exhaust but am not sure which diameter I will benefit more.

I hear it is good to have 2.5 because it provides some back pressure as to where 3 in is too free flowing. I also here the opposite at where you want a free flowing as possible.

So far I am pushing 242 hp and 222 tq with NO bolt ons and a hondata with 550cc injectors. When I dynoed it, the guy said that the stock header and stock exhaust wasn't free flowing enough which I understand. I just want the most power out of the car. It IS a fatass prelude but I still love her.

I would appreciate any comments or insight. Thanks

 

i say go 2.5 all the way back
if you had a monster turbo or something,
i would say 3

 

SMSP makes his NA exhaust 2.5". I'd say go 3" or just run a cutout and see how that works. If the cutout works, then go for 3" all the way back.

 

Anyone else?

 

3"

 

Well they say to go 2.5" on bigger n/a builds, so I would say that a supercharged motor will flow a good deal more exhaust than that.

BUT 3" is a huge jump, as far as flow goes......so I would see if I could get ahold of a 2.75" exhaust.

 

I have looked around and I have never seen anyplace that offers a 2.75in piping. All I have seen is 2.5 and 3. SO you recommend 3?

 

3

 

HAHAHAAHA OMG 2.75 in piping. What did you make that size your-self.

 

2.5 unless you plan on making 500+ HP then you dont need 3 inch piping.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kryptic &raquo;</TD></TR><TR><TD CLASS="quote">2.5 unless you plan on making 500+ HP then you dont need 3 inch piping.</TD></TR></TABLE>

I disagree, I think 3" exhaust is beneficial to applications making much less than 500+ hp...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jrwingate6 &raquo;</TD></TR><TR><TD CLASS="quote">HAHAHAAHA OMG 2.75 in piping. What did you make that size your-self.</TD></TR></TABLE>

actually ive seen 2.75 before jack ***, its just not as common,


and to answer the question ithink the size of the exhaust depends on your target HP, there is a point where 3 inch is just too big and 2.5 is better and vice versa, it is dependent on you hp goals

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sam1am26 &raquo;</TD></TR><TR><TD CLASS="quote">

I disagree, I think 3" exhaust is beneficial to applications making much less than 500+ hp...</TD></TR></TABLE>

explain please.

 

yes i second.. ^^

2.5 is optimum for N/A..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Initial Lude &raquo;</TD></TR><TR><TD CLASS="quote">yes i second.. ^^

2.5 is optimum for N/A.. </TD></TR></TABLE>

If only we were talking about n/a cars....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">So far I am pushing 242 hp and 222 tq with NO bolt ons and a hondata with 550cc injectors.</TD></TR></TABLE>Looking at it as just a matter of area. A 2.5" exhaust has 1.5x the flow area of a stock 2" exhaust. A 2.5" exhaust would probably be optimal at this point.

If you want to go 3", just realize, that it's pretty loud. If you have any police issues in your area, you might want to keep it at 2.5". You're not going to gain very much by upping it to 3". Turbo guys can get away with it, since the turbo dampens the sound significantly.

Personally, I don't like advertising.