400 RWHP range... anyone go from 3" to 4" single exh and measure gains???
#1
400 RWHP range... anyone go from 3" to 4" single exh and measure gains???
Just curious who has done it and if there was big improvements. The big heat spots on mine are right where the header collector goes from 3" to 2.5" y pipe. Everything else looks good so I wonder how much I would gain from going to a dual 3" y and a single 4" intermediate/muff combo
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I have a dual 3" into 4" ORY and had it reduced to the stock catback. I recently installed a piece of 4" pipe and a Borla oval muffler and dumped before the axle. I didn't dyno it but it picked up .07 sec and over 1 mph in the quarter, and that was in worse weather than my previous best.
#4
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The 3" mufflex/QTP Y-pipe (which includes a 4" flowmaster Y merge collector) combined with any free flowing catback works well. I had this setup (using an SLP 2OTL catback), and it performed really well- holding up to the TD's that were previously on the car.
Going 4" all the way is for max'ed out 346ci Heads/Cam or larger cube setups.
Going 4" all the way is for max'ed out 346ci Heads/Cam or larger cube setups.
#5
Cool thanks. So you guys figure just running a 3" y into a 4" collector then down to a 3" catback would be noticeable and worth the effort? Its very easy to see where the heat spots are on mine as the entire exhaust is stainless. The discoloration is most noticeable right at the 2.5" drop to the y I have now.
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I didn't dyno it but it picked up .07 sec and over 1 mph in the quarter
A 4" system is is an overkill in most cases. If you outgrow the single 3" I'd go true duals before I'd go single 4".
Re'
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Originally Posted by RE AND CHERYL
I don't call that a difference at all. Weather accounts for that easily. As the 4" dumped pipe will cost you a lot of low end tourque I'm guessing your 60' was better than before (less wheel spin) and gave you the 1mph.
A 4" system is is an overkill in most cases. If you outgrow the single 3" I'd go true duals before I'd go single 4".
Re'
A 4" system is is an overkill in most cases. If you outgrow the single 3" I'd go true duals before I'd go single 4".
Re'
The car never spun on any good run I ever made and its and automatic with a torque converter so i dont care how much power I make below 3400 rpm. Plus the 60' was only about .03 better.
I don't see a single 4" being much more overkill than 2.5" or 3" duals dumped before the axle. Plus with duals, you dont have as many torque arm options ans I lost about 20 lbs compared to a full catback and probably about 10 from duals.
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thats 7 hp at theleast.....
Originally Posted by RE AND CHERYL
I don't call that a difference at all. Weather accounts for that easily. As the 4" dumped pipe will cost you a lot of low end tourque I'm guessing your 60' was better than before (less wheel spin) and gave you the 1mph.
A 4" system is is an overkill in most cases. If you outgrow the single 3" I'd go true duals before I'd go single 4".
Re'
A 4" system is is an overkill in most cases. If you outgrow the single 3" I'd go true duals before I'd go single 4".
Re'
RGAL1 has been here 2 years you have been here 3 mo
ill take his word on it.....
to the op anytime you go bigger on exhaust your gonna gain power....who cares about low end tourqe thats what stalls are for...I sy do it....
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This is from the sticky
A 2.75” (stock) single system is good for a 310hp engine with zero loss…
A 3” Single system is good for a 370hp engine with zero loss…
A 3.5” Single system is good for a 503hp engine with zero loss…
A 4” Single system is good for a 657hp engine with zero loss…
A 2.25” dual system is good for a 457hp engine with zero loss…
A 2.5” dual system is good for a 513hp engine with zero loss…
A 3” dual system is good for a 812hp engine with zero loss…
A 2.75” (stock) single system is good for a 310hp engine with zero loss…
A 3” Single system is good for a 370hp engine with zero loss…
A 3.5” Single system is good for a 503hp engine with zero loss…
A 4” Single system is good for a 657hp engine with zero loss…
A 2.25” dual system is good for a 457hp engine with zero loss…
A 2.5” dual system is good for a 513hp engine with zero loss…
A 3” dual system is good for a 812hp engine with zero loss…
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Originally Posted by MikeG
Regal1, I'm sure you get this alot, but why do you have an LS1 intake on an 02 car?
#13
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I'm about to do the swap on my car and I will have before and after #'s to share but iyt may be 2 weeks before I gewt around to doing it.
Sawp details:
Current setup:
Grotyohan(sp) 1-3/4 headers into Grotyohan Y, twin 3 into 3" bullet
New setup : Cut Y pipe and weld on Flowmaster Y TWIN 3" IN AND 4" OUT PN Y0300400(I THINK) THEN A 4" BULLET. I have all the parts but I just havent had the time to do it and things dont look so good for the next few weeks either as work is killing me. When I do get it done I will post some #'s.
Sawp details:
Current setup:
Grotyohan(sp) 1-3/4 headers into Grotyohan Y, twin 3 into 3" bullet
New setup : Cut Y pipe and weld on Flowmaster Y TWIN 3" IN AND 4" OUT PN Y0300400(I THINK) THEN A 4" BULLET. I have all the parts but I just havent had the time to do it and things dont look so good for the next few weeks either as work is killing me. When I do get it done I will post some #'s.