Alright guys, after nearly 7 years of helping other honda-tech fabbers now I need some help. A guy came to me who was referred to me by a close friend to do a turbo kit for his turbo diesel pulling truck. Its a GMC Sierra V-8 that he's using a pulling truck. Turbo he's going to use is a gt45 with gt47 wheels....no wastegate, thank god.

Now, he's already built his own turbo manifold(as pictured) but wants the turbo manifold redone(obviously) but he wants the turbo in the same place. With that being said, im going to fixture his existing manifold and start there.

He's already dead set on having me make log manifolds for both sides and joining both tubes into a divided t4 flange. The headflanges and t4 flange are being machined as we speak. The tubing im using with consist of the usual 1.5" sch10 tubing as the tubing coming out of the head transitioning into 2.25" sch 10 tubing as the log material per customer request. He previously used the 2.25" sch 10 tubing on his other logs with great success so he doesnt want to venture far from that.

I have never had to make anything like this and need input from ppl who have done, and done it WELL! If any of you have seen my work in the past you know what kind of work I do. He wants to be able to pop the hood and brag about the quality to the diesel world. As you can see he made a log for both sides then going 90 degrees up the one side of the turbo flange. On the drivers side, made a log, came around the front of the engine, vband, up to the turbo flange. I will be taking the same approach but a little unsure on the best way (for flow) to make the logs. I've only done tubular stuff here so I want some advice. THANKS HONDA-TECH

Pictures

The engine


Drivers side


Passenger side


Mock up turbo BW unit


His homemade log




As you can see here on the left where the vband is located connected the tube coming across from the drivers side log

 

do something similar to the ls1 rx7 that was posted on here not too long ago. it had two log manifolds. let me see if i can find a pic

 

here is what i was referring to:



although i still think something like this would be better for power (phil from spoolin made it)
there doesn't look to be much room from the way his original log manifold is set up.
how much room in the engine bay?

 

He needs too run a smaller turbo. When im towing i never go pass 5k rpms, and that turbo is going too take alot of rpms too get it too build enough boost where it would be worth running. thats just my tought

 

Ok maybe i wasnt clear enough....this is a COMPETITION ONLY pulling truck designed to make over 100+psi of boost...this guy isnt even going to run a wastegate lol. Ive seen that ls1 setup before but like I said he's DEAD SET on the log manifolds. I guess a couple of the top dogs who run gmc trucks when tubular and eventually went back, dont ask but thats what he wants and thats what im building. Im just trying to figure out the best way to transition the primaries out of the cylinder head into the log....?

 

you have to be more clear maybe post pics of what he does I thought it was a tow truck lol

 

He is probably doing tractor pull style racing and that is why he wants the big wheel compressor.

 

http://i200.photobucket.com/albums/a.../NXRailEng.jpg

Maybe you can convince him for some new intake manifolds as well.
http://i200.photobucket.com/albums/a...0/P1040899.jpg

 

"He is probably doing tractor pull style racing and that is why he wants the big wheel compressor."

Yes that is correct

 

the first pic i posted seems to be exactly what you're looking for then, correct? looks simple enough, 1.5" sch10 90's into a bigger sch10 pipe (2.25 maybe?)

 

truck pulls are huge around here and in the tri-state area (KY, IN, OH,) in general. i know you are just doing what the customer asks but, you should do whats best for the build and most efficient, IMO. also, honestly by competition truck pulling standards, the turbo mentioned is on the small side. there are guys locally running bigger turbos than that on their daily driven trucks, lol.

the picture in the first reply looks like a good option as long as there is room for a radiator, IC, or whatever.

 

ok ok no reason too get grumpy about it.....

 

I agree that the manifold on the first pic that went into the rx7 looks ideal. Nice transition from the small pipes coming of the head into the "merge collector". Obviously the turbo wouldn't go where that one is in this application, but you simply continue running the crossover pipe to wherever you need it.

 

I saw that pic of the rx7 manifold before but i cant go "down" with my 1.5" tubes into the log I have to go up, but same idea. Turbo will be mounted up by the passenger side up by the cylinder head where it was previously mounted. That way he can run same stack setup coming up out of the hood

 

search "drag race diesal engine" on google (images) those engines have tubular manifolds on them, definitly not log ****

 

Who cares? If the customer wants log manifolds, he should get log manifolds.