How much horsepower am I going to gain with a 3" vs 2.5" exhaust on a t25 turbo? If going 2.5 inch isn't too big a loss, it would be a lot easier to control the noise..

<font face="Verdana, Arial" size="2">Originally posted by Doug H:
How much horsepower am I going to gain with a 3" vs 2.5" exhaust on a t25 turbo? If going 2.5 inch isn't too big a loss, it would be a lot easier to control the noise.. </font>

The only thing I can say is that open exaust (no cat back, 2.5 downpipe) was no traction in 2nd and 3 inch crush was traction in second..

BIGGER.. the better =) Go 3 inch or 2.5 mandrel if you have to. 3 inch crush through a dynomax muffler was pretty damn quiet on my sentra... was with BBDET
david

Yeah, I was going to get one for the 2.5 inch exhaust just to keep that quiet. So, you don't think a 3" exhaust with a Dynomax muffler and a bullet pre-muffler will be loud?

And a 3" exhaust can fit where the stock exhaust did?

3 inch exhaust will be louder than 2.5, do you want a little more power or less noise? I say go 3 inch if you were gonna run bigger than a T-25.

i'd go 3" mandrel all the way back if your going to go with turbo. a turbo motor loves that free flow. the less resistance the better off you are. i'm going to a BB setup next month, and the 3" is on my list of goodies to get... &gt;:^D


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http://www.sleepermotorsport.com/
kjopi@hotmail.com
http://www.sleepermotorsport.com/images/brandon01.jpg

That is pretty crazy. You said your 3" exhaust was "pretty quiet." Anything you could compare it to?

another thing you could do is add in a pre muffler, or resonator where your cat currently is. this will dramatically decrease the noise, without the loss in power.

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http://www.sleepermotorsport.com/
kjopi@hotmail.com
http://www.sleepermotorsport.com/images/brandon01.jpg

<font face="Verdana, Arial" size="2">Originally posted by Doug H:
That is pretty crazy. You said your 3" exhaust was "pretty quiet." Anything you could compare it to? </font>


Stock )
It was that damn quiet!

David

<font face="Verdana, Arial" size="2">Originally posted by Doug H:
Yeah, I was going to get one for the 2.5 inch exhaust just to keep that quiet. So, you don't think a 3" exhaust with a Dynomax muffler and a bullet pre-muffler will be loud?

And a 3" exhaust can fit where the stock exhaust did? </font>

it's more deep than loud...i personally like the way it sounds....just as long as you have the premuffler it'll be nice-n quiet. also, the 3" will fit just fine.



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http://www.sleepermotorsport.com/
kjopi@hotmail.com
http://www.sleepermotorsport.com/images/brandon01.jpg

CHECK OUT "TURBO", this months issue for a comparison on 2.5 and 3 inch exhausts!!!

3 mandrel. Jay hass was actually considering experimenting with larger than 3" for his car.

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97 Super Black 200sx SE-R
Hotshot CAI, custom 2.5" catback with dynomax super turbo muffler, Hotshot header, UR pulleys (2 set), JWT ECU, Stillen FSB, Courtesy RSB, V-Racing Buzz seat with custom seat bracket

the turbo actually quiets down the car quite a bit, unless you are running just a downpipe. I have a good friend running a Minam II kit on his 2k 2.5 rs and he can have the exhaust rigged up so it looks like it is there, but he is only running a 1' long 3" downpipe off of the turbo, and that is loud, but normally it is quiet at idle.

PNW's car *was* very quiet... I will attest to that, kinda strange considering it was a Dynomax muffler (gag!) http://laf.cioe.com/~benbobbo/NonCGI/wink.gif

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Brian
AIM: pdxs2000
91 se-r 12.31 @ 117.8mph
00 s2000 14.1 @ 98.6 mph

<font face="Verdana, Arial" size="2">Originally posted by PDX S2000:
PNW's car *was* very quiet... I will attest to that, kinda strange considering it was a Dynomax muffler (gag!) http://laf.cioe.com/~benbobbo/NonCGI/wink.gif

</font>


Ya... but it was free =)

I'll let ya guys know how a 2.5 downpipe to 3 inch crush cat back (stock cat, no resonator) with a walker race muffler sounds tomorrow =)
David
92NX2kT