Ryanbgb22

I'm thinking about doing a low boost, budget rear mount build this winter.

Some background:
200,000 mile stock ls1
stock 4l60e
stock 10 bolt

Turbo/Engine
-on3 76mm journal bearing turbo
-ebay 38 or 40mm wastegate with .25 bar spring (~4psi)
-ebay blow off valve
-ebay intercooler
-aftermarket valve springs
-aftermarket push rods
-new timing chain and sprockets
-stock fuel supply for now including injectors
-obviously some sort of oil return pump

Piping
-2 3/4" stainless piping from the stock 'y' to the turbo
-2.5" cold side piping


This will be my first major fabrication project, and it seems simpler to go this route than front mount (less tight clearances). I do understand I am on borrowed time with the engine / transmission / rear at this point, but I'm not too concerned about that. I have an lm7 long block in my possession that I intend doing a bigger build with in the future.

Basically, I will be using this project as a learning experience and to get my feet wet in the world of boost.

I'm looking for any recommendations with my setup, other builds to look at, etc.

3800SII

Maybe 2.5 exhaust from the Y to the turbo, or it will be more laggy.

RooRnZ28

iTrader: (14)

Your stock 4L60E will need to be upgraded. There is no borrowed time with that, it won't last more that a week.

xxrillixx

iTrader: (118)

I love my rearmount. And i dont have any of the issues my friends with front mounts do. Car still spools super fast. You'll love it.

Only Con I can think of is all the extra piping is more weight. But i like having the pretty much stock looking engine bay, no heat issues, and I have to have AC.


Im not sure which is going to go first, but id put my money on the trans. lol Be ready to start breaking stuff!

Ryanbgb22

I'm surprised there is so little hope in the trans. I wasn't expecting it to last long, but I thought I could get a season of lightly spirited driving out of it. I guess I'll start looking for a built 4l60e or 4l80e, or mabye go the TH route. I'm going to start with the stock trans either way, I guess I will just come up with a backup plan for when it goes.

I should be fine with stock injectors and stock fuel pump at 4psi correct?

got-a-ls1

iTrader: (12)

4l60 gets a **** rep. guess thats what happens when gm has produced probably a billion of them, you see a lot more failures and people bitching. i put my 4l60e through hell over 25 passes at the track on the 100 shot (and way over 100 passes on motor at the track on et streets)and the trans was fine. ofcourse putting over 500 horsepower at the tires in a 3700 pound race weight with 3.23 gears means it would be on borrowed time. it had 100,000 miles on it anyway, but you know what? trans was still fine when i spun a rod bearing.

oh and i did probably a WOT 4th gear to second gear on the highway ALL the time (daily)which supposedly kills these transmissions. probably have done that way over 1000 times since ive owned the car for 6 years.

run it.. be smart with it, realize its a stock transmission

willizm

iTrader: (10)

I preemptively had my 4l60e built buy FLT(level 6) as I didn't want to get the thing running only to have it go on me. If I could do it again, I might have just ponnied up the money for a built 4l80e with a trans brake. The 4l60e when built seems to handle pretty good, but hell if I know how long it will hold up. If it goes, I'll go with the 4l80e then. Don't want a TH400 as this is a primarily street driven car so I'd like an overdrive considering I hav 3.73's.

89LS1FOXER

iTrader: (47)

Exa oil return pump and run a 1 ps1 cracking check valve in the oil feed line, got mine from granger. Keep the cross over 2.5" as said above, heat wrap as much as you can to keep the heat in and exhaust velocity up!

JRENIGAR

iTrader: (37)

Exactly... My setup has 187k on it and everything is stock; Motor, Trans, and 3.23 geared rearend. It's had the blower on it for 15k miles or so. I also do 4th to 2nd kickdowns almost daily. Like already mentioned, Be smart and realize its a stock high mile setup and go from there. I shift @ 6000rpm, Might be the reason its all still together with that many miles on it. Tme will tell as I fully expect it to make 250k. Im a firm believer in a good safe dyno tune going a long way towards making **** last. Id rather give up 20hp or so in the tune for 50k miles of fun driving than have a rod knocking or slung through the block....

pber13

the only thing that stands out to me is the ebay wastegate (since you didn't specify a brand). not something to go bargain bin on IMO. spend the money on a good unit.

sams02Z28

Gut/remove cats..don't wanna take a chance on havin one blow any type of **** out of it and runnin through your turbo!!

T76s10

iTrader: (6)

I heard emusa's 38mm gate works pretty well. In my opinion, I would try to do front mount. Less piping, no oil return pump, and I read somewhere that more heat keeps velocity up so not only spoiling faster you'll make more hp per boost. Some guy said his customers make about 30hp per boost with frontmount and like 20hp per boost on rear mount but i cant confirm this. On the other hand, you'll need to do more fabricating with a frontmount and you need to wrap all piping up with header wrap to keep the heat in and space is very limited. Although sts systems make great hp and as xxrillixx stated his spools pretty quick. Either way, throwing boost at anything is going to be a hell of a blast and each set up will make good hp numbers.

mconway68w

iTrader: (2)

Dynomax has a direct fit catless y pipe. Mine works great with the stock manifolds. Make sure you wrap it from the y back. I'm making about 9#s of boost with my sts and the stock 4l60 and 10 bolt are still strong. Of course I'm only running 2.73s

JoshuaGrooms83

iTrader: (2)

what numbers are you making cause thats almost my exact setup i have right now, minus the dynomax ypipe

MrMixnMatch

iTrader: (1)

Catch can.

Also it wouldn't hurt to AT LEAST replace the seals in your trans/rear, just in case.

simplysix

iTrader: (1)

Just do a front mount. Less piping, no oil return pump that could fail, turbo is not sitting out in the elements, and there are kits that still let you keep a/c.