basic motor Mods are - Ported, milled Heads, ported intake/TB, full boltons, GM847 cam.

Im going with Kooks LT's, catless Y, then I want to go single dumped but should I go 3" or 4"?

 

3" is fine for what your doing

 

ok awesome, going with a 3" borla XR1

 

You'll be fine but I just love the sound of a 4" mufflex dumped at the back bumper.

 

I had a 3" system with a Moroso dumped after the axle, sounded pretty mean. But it was with BBk shorties.

 

A 3" single is rated to about 370 hp. 3 1/2 or 4" would be better as would a 2 1/2" duel. You should be in the 420 rwhp range.

 

ok thanks. So far its been about a split 50-50 on 3" is good to 4" would be good. Thinking maybe do the 3" with dual cutouts on the Y. IDK tho

 

Do the 3 inch with a cut-out.

 

do dual cutouts on the Y or just 1 right at the merge?

 

How does a Single 3" compare to dual 2 1/2" systems when it comes to sound and power?

Joe

 

you will get more power with the dual 2.5" but not sure about sound.

 

By whom? That's a bunch of crap.

 

I'm running a single 3 with cutout before axle. Results in sig.

 

[Quote: Originally Posted by lt1-xjs A 3" single is rated to about 370 hp.]
I was skeptical about that too. What's your opinion as to a realistic hp level for a 3"? The reason I'm asking is that I'm currently pushing about 275 rwhp (335-340 flywheel) with my pickup flowing through a single 3" and wondering how much I'm giving up.

 

I ran this for about a year and a half. With the hotcam and stock heads it was great! Then I swapped out the hotcam for a cc503 and some locally ported heads, I've since added a tailpipe section using a parts list posted here on tech. It became too loud as I daily drive the car and also take it for non-stop 1200 mile trips a few times a year.

You can have a single 4" made for a decent price. Cheaper than buying a system. Well mine would have been if I did it from the start, I'm on exhaust setup #5 at this point.

 

I believe RamAirTA is running a single setup and is in the 10's. Don't remember what power he has. I want to say in the mid 400rwhp range? Although I'm not sure if that's w/ a cutout or not... I'm running a 3" with SLP catback into the low 11's w/ the cutout open (at the traditional/before axle area). Car dynoed 430rwhp through full exhaust. IMO a single 3" exhaust system, as long as it's coupled with a quality muffler is not going to be a hindrance.

 

My '05 HD (6.0 LQ4) had a big exhaust from the factory. 3" duals into a single 4" (or was it 3.5"? I have forgotten) outlet muffler. It made 284 on a mustang dyno with just a tune.

 

Would a Borla XR-1 be a good muffler to run? 3" in/out. I think 3" with a cutout should be perfect for me.

 

You may want to do some research on that particular muffler on the boards. See if anyone has any feedback. I don't think you'll have a problem going with a popular name brand like Borla.

 

That's the point when it starts to become a restriction.

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…