Hey Guys,

I started my turbo build today and wanted to share a few pictures. This is the first of many updates I'll be doing, so make sure to check back if you're interested in this type of project.

After some planning, I've decided to do a single rear mounted turbo - mainly because I haven't seen one on a 5th Gen and I'm attempting something a little different. I built a similar kit for a cammed LS2 GTO and it ran a 10.1 at sealevel, so I'm hoping for decent results at this altitude (6000ft).

I'll be using a Turbonetics BB T76 .81 A/R using 2.5 pipe intermediary pipe. If I did my math correctly, the 42psi of back pressure the LS3 creates and the 2to1 merge into a 2.5", I should see full boost around 3100rpm - which I can totally live with.

Since I didn't want to completely fabricate new intermediary pipes, I searched around for a stock H-Pipe setup. My new best friend Larry (2010 SS RS) graciously donated his stocker to me so I could do this build. Thanks again Larry!


So this is what I started out with. Just a plain Jane exhaust system off of a 2010 SS.



The first step is to brace the two pipes together. There's A LOT of cutting involved and the most important thing to do is keep the pipes perfectly separated so that everything will line up with the manifolds once it's ready to be installed.

I just used to some extra 1/4" flat stock I had laying around. Nothing fancy.





Next came the cutting. I made the cut approximately 9" from the first 90* bend and continued down through the intermediary plate (H-Pipe). The trick is to remove enough pipe so that the merge will connect where the old H-Pipe was. We'll get to the actual fabrication of the merge further down the thread.



After the initial cut was made, I had to remove the stock H-Pipe section. It was faster to make a new section and notch it for a merge than using the existing H-Pipe hole. So the first step was to remove the old section.



Remember the other side of the exhaust that I removed? Well I reused some of the straight pipe to make my new section (I'm big into recycling scrap).

 

Before I cut into my main exhaust, I made sure to mark the pipe with a Sharpie so I can make sure everything lines up before I weld it.



Then I made the "real" cut.



Before I started to tack weld the pieces in place, I made sure to level the tubing faces to ensure that the pipes sat flush.



Then I started to tack



Before making the final welds, I made sure the piping was lined up and level.

 

Next came creating the merge pipe. I had some extra 2.5" exhaust bends from my old Corvette, so I cleaned them up and began cutting.



I forgot to take a picture of the hole cutting process, but basically I used a 2 1/8" bi-metal hole saw and then a die-grinder to enlarge the hole. The picture below shows the merge pipe "mouth" tack welded in.



After measuring the distance between the two pipes, I used some extra scrap from the other side of the exhaust and joined the two pipes together.



After doing the final welds, I cut off the bracing and the hardest part of the build was done.




Next week I'll be posting the positioning of the T4 flange, removing the resonator and cutting/fitting the Wastgate pipe.

Stay tuned!

Vince

 

That merge is terrible.... there are soo many other ways to do that and not create turbulence.

 

Care to divulge?

 

I am going to be completely frank but i have to say that everything about that setup is terrible. i would say bolt back up your stock exhaust and go back to the drawing board but it seems that isnt possible. just curious why you would go with the rear mount over the front mount? it looks like you have good welding skills and your attention to detail is above par. you should try at building a set of headers and merge pipe. putting a rear mount on a 5th gen is like putting Yoshimura on my Ducati. just doesnt work.

 

just buy a flowmaster merge pipe in the size you need and weld that in. they are one of the best merges you can buy

 

Well, the good part is that this was an extra exhaust that another board member gave me. My stocker is still on the car. I did that purposefully so that if it didn't work out I can always go back to formula.

This was more of a R&D than anything else. I was also considering doing a log style and running the passenger manifold around the rear of the engine and to the back of the drivers side. Just not a lot of room up front for a single that's why I would prefer a rear mount.

I'm just not clear why it wouldn't work. Plenty of 10 sec 4th Gens running around with remote mounts.

 

Stuff like this, is why it won't work.

 

What? Two 90* and one 45* bends will cause it not to work? Explain your reasoning? Most front mounts I've seen on here have spaghetti piping with equal or more bends.

Are implying that it will cause too much backpressure?

 

How well do you think that will flow?

 

I have no idea....this type of setup hasn't been tried before.

 

rear mounts work but they are a handful and ALMOST ALWAYS get scrapped for a front mount.

 

I was excited when I seen the title, then I seen its a rear mount.

 

theirs nothing wrong with doing a Rear mount. But as stated.. that Merge will cause a great big pile of exhaust turbulence. That, in turn will not be good for proper exhaust flow. Get yourself a magnaflow high scavaging Y pipe like i used on my Y pipe build. or a Flowmaster merge to a 3.5" back.

 

Well....you never know. I have 2 weeks off and lots of J and U bends lying around. If I can find time, I might start designing a front mount. Just for *****.

 

way to crap all over the guy's thread...you wouldn't have any of the stuff we have now if it wasn't for hot rodding like this...
I want to see this when its done

 

Man you guys are dream killers.LOL

First off good luck with the build the naysayers alway say it will never work. I agree that the merge needs to be improved. I dont fully understand the layout concept. Right now it looks more like a mid mount kit. It you are closing down because its a single turbo build I would do it as far back and as close to the turbo as you could.

You are also cutting your ability to flow exhaust in half buy what looks like two 2.5" pipe in to a single 2.5". I would get a better merge to feed a bigger pipe. Or you can merge it right into you turbo flange. So you have a natural venturi, this will help you turbo spool sooner.

I hope you keep trying because I like to see how other people think.

Good luck

 

more power to you... lots of people dont like rearmounts, but they work... good luck.

 

If your going to run manifolds, either run 2 - 2" pipes, 1 - 2.75" or a single 3" to the back. If you run a single pipe, pick up a cheap collector from mandrel bends.com, cone engineering or any of the other web sites. What you have will work, just dont expect good results.