View Full Version : running exhaust between motor and tranny into log style

04-19-2012, 01:47 AM
Hey guys,
Looks like some people are running the drivers side exhaust between the trans and motor. Then into a log that is the passenger exhaust manifold. Then one pipe to the turbo. Anyone have any info on whether that would be as good as running both to the turbo flange? Would that hinder the exhaust on the passenger side with the force of the drivers side exhaust? Kind of like a crank case evac. I suppose with regular manifolds, its the same principle but its the whole drivers side exhaust. There is a guy with a 70 chevelle that di it and it cleans up the engine bay really nice.

04-19-2012, 08:49 AM
My first kit I built was that way. I ran into back pressure issues with a 5.3 and a TC78 .96 a/r, the car peaked power at 5400 550rwhp on 13-14lbs. Same set up but with both pipes merging at the turbo flange made power to over 6k making 690ish rwhp on 17-18lbs.

It does work, and will make decent power, just not as effeicent.

04-19-2012, 09:28 AM
damn thats quit a bit of diffrence.. ive been looking into possibly doing something else if you picked that much

04-19-2012, 09:41 AM
Hey again Maxx! I should just start pm'ing you. lol :nod: That is great info! Thats what I was worried about. what size did you use for the log?

04-19-2012, 08:00 PM
and there's the chevelle i was referring too lol it looks really nice on your car and made me think about doing it to but was worried. That of course goes into the manifolds vs headers argument. Would you have enough room to run the pipes parallel then to the flange? on a side note. you both have done multiple ls swaps. im really worried about the wiring. Ive only done carbed stuff before. Is it that bad? My motor and tranny should be a complete pull out to make it easier.

04-20-2012, 10:42 AM
Depending on the car you may beable to run both to a merge then to the flange or merge at the flange. I had a 2.5" (2.25 would also work) running from the manifold to the back of a 3" log I made.

This was my log manifold kit, I am on turbo kit #3 in my car, probably the 15th I've done in the last few years.

Wiring isn't too bad, just take your time and double check your pins once your done. Also if you feel overwhelmed walk away from it and come back, your just trying to go from A-B, may have to change how long the wire is, may have to shorten a few.

04-20-2012, 02:56 PM
wirng go to alot of helpful info..

04-24-2012, 12:25 AM
thanks for the link. Alot of good info on there. Ive just never done an ls motor. Or fuel injected for that matter. Intimidating. Thats alot of turbo kits max. Are you guys mandrel bending your tubing? Does the tube running under from the drivers side take away much ground clearance?Did you guys wrap them as well? I know its no different to run the pipes up front. Just trying to see what would be easier. I figure running the pipes up front would have alot of heat to the inlet tubes but I might be over thinking it. lol

04-24-2012, 11:36 AM
I buy mandrel bent builder kits in what ever material I need and go from there.

I did lose about an 1" or more and my car sits pretty low so I hit that pipe every now and then. I did wrap the whole thing as I was trying to prevent heating the trans more than needed.

My firebird's 2nd kit had forward facing manifolds feeding a T6 flange for my GT88 set up (in sig). The one I just finished is a forward facing manifold kit feeding T70s.

04-25-2012, 05:45 PM
I have build MANY turbo kits for trucks like this.

I have one customer who has made over 1100 rwhp with a PT88 and over 1000 with a GT76/94. I've made 800rwhp with this kit on my truck with a BW S480/83. Works pretty well. :)

04-30-2012, 11:48 PM
Thats great info as well.Do you have any dyno comparisons against the two into the flange? What rpm and boost numbers are you getting with it?