GaragedLS2

So I finally decided and pulled the trigger. I purchased a comp oil-less, billet 7679 turbo to do a rear mount setup. I really like the idea and simplicity of this build. I talked to my fab shop today and picked up some shorty headers, a precision 46mm wastegate, Treadstone intercooler as well as the 3" vband flanges that I have amoungst some other misc. things.

I have a question for guys who have done this setup. Where are you pulling water from for the cooling on the turbo? I've read that the water pump is more than strong enough to get water there and back but not sure where its being tapped?

Also, any hiccups that youve run into while doing a rear mount build that you'd care to share with me? I've read up on a few of these builds and it seems relatively straight forward but its nice to have a heads up going into things. The car should be going in the shop in 3 weeks for th em to start all the fab work on the exhaust and charge pipes. I'm hoping to have the car back and tuned on meth in a little over a month.

shizon'00

Cut the heater hose on the passenger side and tap in there.

This isn't a must, but more of a nice to have, but I would suggest redoing the slip fit of the midpipe with vbands. Anything you can do to make leak free fittings (and easy removal) the better on both sides.

GaragedLS2

Thanks for the tips. I plan to VBand pretty much anywhere and everywhere I can. Its a small price to pay for not having to use gaskets and worry about leaks. Plus the ease of install/removal.

On the water line what size fittings are best to run. I dont want to run too big and overwhelm the cooling system nor too small to not get proper cooling. I was planning on doing 1/4" with -6 or -4 lines, does this sound ok? Also, where are you returning the water to after the turbo?

neverstop

i've heard pretty had reviews with using headers due to heat loss, I think most of the fast rear mount guys on here are using Ls7 style exhaust manifolds.

I'm hoping to do this too at some point next year so please keep us updated and curious how this turns out.

GaragedLS2

Ive read and heard the same. I'll be sticking with the stock ls2 manifolds mated to 2.5" stainless piping. I'm also going to wrap the hell out of the hot side to retain heat. I was originally going to go with headers and 3" pipe but my tuner also told me that was a big no-no with this setup. I think its not only an issue with heat loss but also exhaust velocity. Being that I'm running a 76mm, I dont want lag to be an issue. Hopefully sticking with the smaller piping I can get quick spool but still make decent power.

I did opt to go with 3" aluminum on the cold side due to heat dissipation from aluminum vs. steel and i didnt think 2.5" was necessary.

neverstop

curious how you decided on the 7679 turbo size?

GaragedLS2

It was my desire to make more power down the road but keep it small enough to make the power I'd be comfortable at right now. I felt it was the balance between those two.

shizon'00

When you cut the heater hose, you'll put your fitting in and run it back to the turbo and then run your return to the other side of the hose that you cut.

I ran -10 line, but have twins back there.

Ls240sx

The reason that people are claiming that headers hinder the performance and spool of remote mount turbos is because the runner size of the headers. Most people go with the largest runner size because they think it will increase the performance of the engine. While this may hold true for some applications, a remote mount system is different. You need to keep the runner diameter small to keep the velocity up in the exhaust. If you wanted to run headers, I would find the smallest runner size available, which I believe is the OBX headers.

GaragedLS2

Exactly why I bought OBX headers but then ended up returning them. Why spend the extra money when its not going to be a performance advantage? Not to mention the stock manifolds hold up pretty well so you dont have to worry about cracking. I could see forking out a couple bills to get LS7 manifolds but headers seem to be pointless. I'll start with the LS2 manifolds I have and if it seems I can make a bit more on the LS7's I will try them. I doubt its going to make a difference though.

under_psi

Do you have stock heads or aftermarket? non-ls7 manifolds won't clear 6 bolt heads. Ask me how I know 😑.

I had to go to LS7 manifolds after I already even had the v-bands welded on my stock LS3 manifolds. Passenger side was fine but driver side hit more than what we could grind off.

I have my LS3 manifolds with Vibrant 2.5" V-Band already welded on. Will be coated soon as well if your interested in them. I'll be putting them up for sale.

GaragedLS2

I'm actually seeing how far I can push this stock LS2 before it gives so I'm on stock heads/block for now. PM what you are trying to get for them shipped to 92584. If the price is right I might pick them up just so I have a spare manifold and dont have to worry about getting flanges for mine. Thats good info to know for the future though, sorry you had to be the guinea pig lol.

neverstop

that's good info on the ls7 exhaust manifolds.

what hp rating does the 7679 turbo have?

GaragedLS2

Its rated at a little over 1000hp. I thinks its 1100 but dont quote me on that.

SinisterC6

Great turbo, excellent product and support

5.0 mustang man

Another option for manifolds on a c6z is c5z manifolds. They will clear 6 bolt heads and for me they gave more room for the cold charge pipe to fit through. That is probably the most difficult part of these builds is fitting the charge pipe past motor unless you want to hoosier it and run under cradle lol. The rear mount is cool, ive got a pro mod 88 on mine so it lags a bit more then what you are doing but it actually works good for keeping traction during shifts at the 1k rwhp level. Rear mount works great, dont let any of the haters try to tell you differently!

GaragedLS2

Yeah, I like everything I've read in regards to them. I'm getting fed up with all of the ridiculous quotes on fab charges thus far though. I'm essentially asking for an exhaust to be built with a couple out of the ordinary bends. Fab shops seem to think they can charge a premium for the work for some reason. Its always nice to know someone who does this type of work. Hopefully I can get someone to do the work who knows what theyre doing and isnt trying to get me to put my house up for collateral.

I'd like to get this thing going soon. If anybody reading knows of an honest exhaust fabrication shop in the LA, Riverside or San Diego areas, dont hesitate to shoot me a PM.

neverstop

if you find a good/fair/honest fab shop please let us know, I think when I head in this discussion I may just buy a welder and do a lot of the work myself if I can't find a good welding shop locally.

C6 Curtis

Any pictures

GaragedLS2

I could literally go buy a band saw and welder and still come out cheaper than what these guys are trying to charge me. Problem is I dont have the skillset to weld stainless or aluminum so I cant go that route. I know there are options out there, its just going to take me longer than I wanted to take to get this done. I'm meeting up with someone who does custom header work on Monday, hopefully that ends well.

As far as pictures go, theres not much to show. I have a bunch of parts laying around. Seeing as I havent got the project started due to this whole issue im talking about.