Anyone have full 3" exhaust all the way back with mufflers?

[gr8lover]

Wondering if anyone has a full 3" exhaust all the way back including mufflers?.... I have a corsa 2.5" and seen most guys have 2.5"..... The only aftermarket big name 3" exhausts I have seen is from Kooks and from Magnaflow... no one else seems to make it...

I think once you go over 500rwhp the exhaust is starting to restrict us big time.... especially when getting above the 700 rwhp mark....

any thoughts? anyone have a full 3"? how is the sound?... clips?.... hows the fit?....

Thanks!!

[Devilish34]

I thought Parish had 3" duals ...

[hayabusa160]

Id imagine with a cam or even a blower people can benefit from a 3 in exhaust

[SRG963]

MGM GT (Sky) has 3" I believe.

[TonyKarter]

I've got 3" back to the flange, then stock axle-backs for now. No Cats. I was wondering the same thing regarding what to do behind the flange. Will subscribe to this one...anyone got an answer?

[wreckwriter]

Mine is 3" to the axle-backs I believe, they are 2.5. They're straight through, no mufflers. its loud of course. Cats are the big restriction, any cats.

[VegasNate]

Wondering if anyone has a full 3" exhaust all the way back including mufflers?.... I have a corsa 2.5" and seen most guys have 2.5"..... The only aftermarket big name 3" exhausts I have seen is from Kooks and from Magnaflow... no one else seems to make it...

I think once you go over 500rwhp the exhaust is starting to restrict us big time.... especially when getting above the 700 rwhp mark....

any thoughts? anyone have a full 3"? how is the sound?... clips?.... hows the fit?....

Thanks!!

I fully agree with what you are saying. I think parish picked up some crazy hp just from doing a 3" setup. It was like 80hp iirc.

[familycaronROIDS!]

I have a 3 inch custom full exhaust catless with an x-pipe all the way to the tail pipes...

[Devilish34]

Mine is 3" to the axle-backs I believe, they are 2.5. They're straight through, no mufflers. its loud of course. Cats are the big restriction, any cats.

my cats are going bye bye soon... I though Kooks were 3" to the X then back to 2.5"?

[jcmGT]

Interesting read on some science behind exhaust sizing based on HP.

Text article (http://www.gmtruckclub.com/forum/showthread.php?20690-Exhaust-Links-and-Articles-H-pipe-X-pipe-Mufflers) starts at post three

or here if you want images and charts (http://www.superchevy.com/technical/engines_drivetrain/exhaust/0505phr_exh/index.html)

[gr8lover]

I have a 3 inch custom full exhaust catless with an x-pipe all the way to the tail pipes...

WHo did your exhaust?..... brand name?

[gr8lover]

Interesting read on some science behind exhaust sizing based on HP.

Text article (http://www.gmtruckclub.com/forum/showthread.php?20690-Exhaust-Links-and-Articles-H-pipe-X-pipe-Mufflers) starts at post three

or here if you want images and charts (http://www.superchevy.com/technical/engines_drivetrain/exhaust/0505phr_exh/index.html)

Interesting.....

[familycaronROIDS!]

WHo did your exhaust?..... brand name?

It's a custom made mandrel bend exhaust done in So Cal. w/ a 3 inch Magnaflow xpipe and 18inch Magnaflow mufflers with 3inch inlets/outlets (straight through)..

[Darkside]

Stainless Works systems are 3", at least last I checked. I picked up HP when I put in a restriction where my cats should be.

[G8-4-Speed]

my cats are going bye bye soon... I though Kooks were 3" to the X then back to 2.5"?

They stay 3" Half-way back after the "X", then step down to 2.5".

[Devilish34]

They stay 3" Half-way back after the "X", then step down to 2.5".

wasn't sure if they made it 3" past the X..... I'm debating to either take my catted pipes to a shop and have them remove cats and weld in straight pipes or just order the catless pipes

[gr8lover]

So kooks goes down to a 2.5".... so I think Magnaflow is the only one that is 3" all the way back... (besides maybe Stainless steel works like mentioned above..) Magnaflow says that the 3" is borderline illegal for the street.... i think they said its over 90 decibals... not sure how that would compare to my current setup.... ?..... wonder how bad it is?..... every cop going to pull me over for it?...... worth it?...... they said you can add another muffler that would quiet it down a bit also.... but not sure how loud... I would hate to worry about police all the time if I drive it around.....

or maybe do 3" and do a really good muffler at 2.5" or so and then change out mufflers when I want to "go fast"...... thoughts?... options?....

[STL_G8GT]

So kooks goes down to a 2.5".... so I think Magnaflow is the only one that is 3" all the way back... (besides maybe Stainless steel works like mentioned above..) Magnaflow says that the 3" is borderline illegal for the street.... i think they said its over 90 decibals... not sure how that would compare to my current setup.... ?..... wonder how bad it is?..... every cop going to pull me over for it?...... worth it?...... they said you can add another muffler that would quiet it down a bit also.... but not sure how loud... I would hate to worry about police all the time if I drive it around.....

or maybe do 3" and do a really good muffler at 2.5" or so and then change out mufflers when I want to "go fast"...... thoughts?... options?....

My opinion is that they can only pull you over if they can catch you. :-)

[wnt2gofst]

wasn't sure if they made it 3" past the X..... I'm debating to either take my catted pipes to a shop and have them remove cats and weld in straight pipes or just order the catless pipes

Why not just have the cats gutted? Cheaper and same effect.

My Kooks was 3" all way back to the axle back. Where stepped down to 2.5 for the mufflers.

[Darkside]

So kooks goes down to a 2.5".... so I think Magnaflow is the only one that is 3" all the way back... (besides maybe Stainless steel works like mentioned above..) Magnaflow says that the 3" is borderline illegal for the street.... i think they said its over 90 decibals... not sure how that would compare to my current setup.... ?..... wonder how bad it is?..... every cop going to pull me over for it?...... worth it?...... they said you can add another muffler that would quiet it down a bit also.... but not sure how loud... I would hate to worry about police all the time if I drive it around.....

or maybe do 3" and do a really good muffler at 2.5" or so and then change out mufflers when I want to "go fast"...... thoughts?... options?....

My exhaust is loud but I've never been pulled over for it.

[-Ray-]

wasn't sure if they made it 3" past the X..... I'm debating to either take my catted pipes to a shop and have them remove cats and weld in straight pipes or just order the catless pipes

Order the catless mid-pipe. I cut my cats off and had to weld in straight pipe.

[BigRed585Lbs]

Not that it matters to anyone,but I've got a 3" system from the cats thru the muffler and out the tailpipe, but it's on the GMC.

Oh, well.

[1stGXPmaggie2.3]

Same hear custom stainless steel mandrel complete 3in. exhaust to tip. Inline magnaflow and magnaflow mufflers.

[gr8lover]

Same hear custom stainless steel mandrel complete 3in. exhaust to tip. Inline magnaflow and magnaflow mufflers.

How does this work out?... fitment good?... sound?.... you just go to a muffler place?.... or special?...

[1stGXPmaggie2.3]

Fitment great. I installed inline muffler to help rid of interior drone. Sound while at idle, part throttle, and cruise is stealthy. Full throttle is jet sounding. Muffler good reputable muffler shop in your area should be able to handle this. Trans is almost done and doing a bigger brake package, when at the shop will try to get some video of exhaust.

[Boostpatrol]

Wondering if anyone has a full 3" exhaust all the way back including mufflers?.... I have a corsa 2.5" and seen most guys have 2.5"..... The only aftermarket big name 3" exhausts I have seen is from Kooks and from Magnaflow... no one else seems to make it...

I think once you go over 500rwhp the exhaust is starting to restrict us big time.... especially when getting above the 700 rwhp mark....

any thoughts? anyone have a full 3"? how is the sound?... clips?.... hows the fit?....

Thanks!!

STAINLESS WORKS makes a badass full 3". We made 537whp on a 2010 camaro with only a cam swap, headers and exhaust, its 3300 bucks in canada.

[wreckwriter]

They stay 3" Half-way back after the "X", then step down to 2.5".

At what point is the step down? I'm thinking of having turn-downs put on the back of my X and just ditching the rest. Exhaust will be off this week for the trans rebuild (finally) so may try to get it done then.

[1ChargedG8]

At what point is the step down? I'm thinking of having turn-downs put on the back of my X and just ditching the rest. Exhaust will be off this week for the trans rebuild (finally) so may try to get it done then.

If you have the kooks exhaust, the step down (2.5") starts after the x-pipes ends, i got rid of that portion and put 3" pipes right after with magnaflow universal straight trough mufflers. Also, i have race bullet mufflers where the cats used to be. My car toooo loud with the catless x-pipes and the pypes violators mufflers.

[wreckwriter]

Thanks Alex. That means putting 3 inch turndowns at the end of the x will work perfectly. Will have to look and see where the hanger is; if its part of the x I'll be ok, if its aft of the x, not so easy.

[Ktlplxm]

I have it 3" all the way. It made NO (less than 4hp) difference on my 2300'd 427. On the TT set-up it did make a difference but not a ton. Keep on mind Parish went from a factory exhaust to a 3" and made other crucial changes as well. On NA cars a 3 inch is completely unneeded.
Well other than noise or if someone is turning the engine over 7000...

Sent from my Droid using Tapatalk

[gr8lover]

I have it 3" all the way. It made NO (less than 4hp) difference on my 2300'd 427. On the TT set-up it did make a difference but not a ton. Keep on mind Parish went from a factory exhaust to a 3" and made other crucial changes as well. On NA cars a 3 inch is completely unneeded.
Well other than noise or if someone is turning the engine over 7000...

Sent from my Droid using Tapatalk

Do you think my setup with the 403 and procharger F1d @19psi would make a difference with a 2.5 in versus a 3"... ?... I think my cam is also alittle off for FI being its a +113... I have read that this LSA tends to allow blow thru more than the +114 and that the exhaust makes more of a difference for +113 than for a +114 or +115.... is this true?...

[Ktlplxm]

FI cams always have a wider split because it does help harness the pressurized air better than a narrow split; the narrow ones do allow more of the intake charger to pass through. My first concern with the boost level you are wanting to run is, is it needed. In other words, how much more power are you making @ 19lbs than you are 16? Or 15? You reach a point where the boost is nolonger doing anything other than increasing aircharge.. the power you make per lb drops drastically and temperature rises just as drastically. Second, is the camshaft you plan on running going to be efficient at that boost level? the same reason applies as above. In an ideal situation, yes the 3" could help you move the exhaust out quicker and help the power. However, if all your additional CFM is getting bottled up in the intake, resulting in "boost" (which lets face it, is a measure of restriction not airflow), then you can put a 5" exhaust on the car and it wont help. A good example was a F1m on a 383 LT1 car i had. the car didnt pick up hardly anything when going from 18lbs to 24lbs; maybe 15hp. We changed the camshaft to a bigger FI cam, left the exact same pulley set-up on the car, the "boost" dropped to 19lbs but we gained 79whp. Afterwards we increased the exhaust from a single, yes SINGLE, 3" Borla catback with Hooker 1 3/4 headers to a 1 7/8 Kooks header, 3.5" collectors, true dual 3" over the axle to a pair of Borla mufflers and gained another 47hp, and dropped the boost to 17lbs. Its all about the efficiency of the total system, not just the size of the exhaust. Now, for the guys wondering what the dual 3's would have done on a lower hp engine, another customer wanted the exact exhaust we built for my personal car on his Procharged 97... he only netted 18hp and was pissed as hell that he spent so much money having it done after we told him it wouldnt help much... If you dont need it, more often than not, its a waste.

[G8-4-Speed]

FI cams always have a wider split because it does help harness the pressurized air better than a narrow split; the narrow ones do allow more of the intake charger to pass through. My first concern with the boost level you are wanting to run is, is it needed. In other words, how much more power are you making @ 19lbs than you are 16? Or 15? You reach a point where the boost is nolonger doing anything other than increasing aircharge.. the power you make per lb drops drastically and temperature rises just as drastically. Second, is the camshaft you plan on running going to be efficient at that boost level?

Good stuff, but would like to add a few things things. Going with your saying, some get carried away with looking at a 20 psi combo and trying to use one part of that combination on theirs thinking it will make more power. Same goes with different motors, other brands, years, ect like different combinations to make power. Doesn't mean it will work on everything. Runner size makes a difference on what will make power on a wide LSA. Large intake runners don't like late intake ICA with long duration #'s. The L92's are a huge runner compare to most factory street engine stuff. It doesn't take much duartion to kill the intake charge on this head which kills torque. The FI intake has a sweet spot under 7000 rpm, don't cam it for anything else. LSA has to match the boost level. 7 psi is nothing for boost and wouldn't change a N/A cam other than maybe make the intake a few degrees shorter in duration. Boost only multipies the power you have. The more power you give away with wider LSA's, the less you will make at the same boost level. Same goes for compression, the more you give up, the harder you have to spin the blower to make the same amount of boost and it cost HP. Compression should be dropped: when you can't go larger on a cam, too much timinig retard to work with pump gas and/or you can't get timing in a motor using a water/meth injection, or it wont hold a head gasket. Guys with street setup's tend to over-think there combination. 7-10 lbs of boost is hardly something to get carried away with special cams and dropping compression. Gr8lover, the only thing with a 113LSA cam running 19 psi is I would install it on a 113-111 ICL. A 115 LSA cam "might" work better but unless your having a tuning issue or are hitting a wall where you aren't getting gains from more boost, then leave it! If you make 400N/A with that cam, then it should be around 800 with 15 lbs of boost. Provided you aren't killing timing and over-fueling for low octane. If you kill power N/A for a better "boost" cam it can make more power at the same boost levels "IF" you can run a better tune-up. BUT if it dropped to 375 N/A with that cam, then 15 psi would only gross you 750HP. As a general rule, for every 14.7 psi of boost = potential for 2x the HP. If you go wider on the LSA, you may want to shorten your intake duration and add a little lift.
For 3" exhaust, the biggest gains are to run 3" to the x pipe (Kooks and ARH are this way). 3" out the back is a wash unless you go to 3.5" to the x-pipe. If you go 3" out the back, then use 3.5" to the x-pipe.

[shane]

http://forum.grrrr8.net/showthread.php?t=27243

[gr8lover]

http://forum.grrrr8.net/showthread.php?t=27243

Yea I saw your thread.... I like alot !!!! I want one after I get the rest of the stuff done on my car... I do truly believe the 2.5" exhaust really restrict things and hold us back after you move above 550rwhp.... so I cant wait to do what you have done!! nice job, by the way!!!

[shane]

Yea i had the stock midsection which was 2.25 but yea my buddys shop who built the exhaust for me and also sponsors the car said if im gonna do it might as well do 3" over 2.5 or 2.75( he does ALOT of procharger installs) but yea 20/21 peak and more power below the curve made it well worth it.

[Old Cop]

I was thinking of doing three inch from Kooks LTs, doing the low profile cut outs in the bends to the xpipe and then back to stock. Opening the cut outs for serious bidness!

I will be running a 1900 Maggie with at least the 1:85 rocker upgrade initially with some type of CAI.

Will this cause any problems that you all can see?