how big of a difference will 3" piping make instead of 2.5"
09-20-2004, 10:54 AM
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how big of a difference will 3" piping make instead of 2.5"
i'm thinking about upgrading my exhaust(catBACK) including DP from 2.5" to 3" will the difference be worth the $$$? my turbo setup is the inline pro mani, gt35r presicion turbo.... 
09-20-2004, 11:16 AM
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Re: how big of a difference will 3" piping make instead of 2.5" (PIFFSTAR)
Well, I have a 3" E-cutout, and with it closed (so that means It ran through 2.5" piping all the way back) it made 24x whp, with it open it made 263whp, so it gained about 20whp with a 3" open downpipe. This is just to give you an idea. . .
09-20-2004, 11:44 AM
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Re: how big of a difference will 3" piping make instead of 2.5" (PIFFSTAR)
It depends on how much power you want to make.
Most people say that for around 250 whp, 2.5" is fine, but if you start making more power, a 3" exhaust will net you more power.
Most people say that for around 250 whp, 2.5" is fine, but if you start making more power, a 3" exhaust will net you more power.
09-20-2004, 12:01 PM
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Re: how big of a difference will 3" piping make instead of 2.5" (2000GSRT)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2000GSRT »</TD></TR><TR><TD CLASS="quote">It depends on how much power you want to make.
Most people say that for around 250 whp, 2.5" is fine, but if you start making more power, a 3" exhaust will net you more power.</TD></TR></TABLE>
That's about right I'd even say to about 300whp the difference is minimal. The bigger DP also allows the turbo to spool faster. Again an exact answer isn't possible but probably between 200-400rpms , maybe more, maybe less. I'd stick with your 2.5in. That's not a bad size at all. Just remember if you are upgrading to do the entire system at 3"...that means DP, cat(if you have one), and catback
Most people say that for around 250 whp, 2.5" is fine, but if you start making more power, a 3" exhaust will net you more power.</TD></TR></TABLE>
That's about right I'd even say to about 300whp the difference is minimal. The bigger DP also allows the turbo to spool faster. Again an exact answer isn't possible but probably between 200-400rpms , maybe more, maybe less. I'd stick with your 2.5in. That's not a bad size at all. Just remember if you are upgrading to do the entire system at 3"...that means DP, cat(if you have one), and catback
09-21-2004, 07:41 AM
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Re: how big of a difference will 3" piping make instead of 2.5" (adseguy)
thanks for the input i'm going to upgrade since i'm looking to make about 500whp.......
09-21-2004, 08:15 AM
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Re: how big of a difference will 3" piping make instead of 2.5" (PIFFSTAR)
Why are so many people on here talking about making 500whp. I don't think you peeps know what 500whp will do in a fwd car. It's pretty much pointless.
09-21-2004, 08:24 AM
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Re: how big of a difference will 3" piping make instead of 2.5" (silverb18)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by silverb18 »</TD></TR><TR><TD CLASS="quote">Why are so many people on here talking about making 500whp. I don't think you peeps know what 500whp will do in a fwd car. It's pretty much pointless.</TD></TR></TABLE>
Bragging rights. Just kidding...I wonder the same. 
Bragging rights.
Just kidding...I wonder the same.
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09-21-2004, 09:14 AM
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Re: how big of a difference will 3" piping make instead of 2.5" (silverb18)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by silverb18 »</TD></TR><TR><TD CLASS="quote">Why are so many people on here talking about making 500whp. I don't think you peeps know what 500whp will do in a fwd car. It's pretty much pointless.</TD></TR></TABLE>
It's pointless on the street, but like me, I'm going to de-tune for the street (about 350) and I want 600+ for the track. And with some big *** slicks, traction bars, and a good suspension setup, you can put the 500+ to use very easily.
It's pointless on the street, but like me, I'm going to de-tune for the street (about 350) and I want 600+ for the track. And with some big *** slicks, traction bars, and a good suspension setup, you can put the 500+ to use very easily.
09-21-2004, 11:51 AM
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Re: how big of a difference will 3" piping make instead of 2.5" (m R g S r)
I can feel a difference b/w a full 3" exhaust system and a 3" sytem w/ a 2.5" muffler.. maybe its just me, but the full 3" just seems to flow better and breathe bettter and the other's.. when i took off the axle back part of my exhaust, the engine seemed to flow even better and the turbo spool was noticably quicker..
just my 2 cents..
btw, this is on a sc61, built gsr 84mm..
just my 2 cents..
btw, this is on a sc61, built gsr 84mm..
09-21-2004, 01:16 PM
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Re: how big of a difference will 3" piping make instead of 2.5" (PIFFSTAR)
i make 290whp at 9psi on my gsr motor. i love it but the lag is a little problem. if im spooling up at right above 4000rpm on t3/to4e on 2.5 inch downpipe and exhaust. how much would the spool time increase with a 3 inch dp and e cutout?
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