BigJls1

Ok my first post, here goes.

I just bought two turbos. finally making steps tward a twin rear mount. my question is ? these are garrett t04b
.50 compressor a/r and .84 exhaust a/r. I got the turbos cheap and now am thinking that one of these is about the right size? If i did run the pair I think boost will be late, how about a 50 shot of nitrous to get out of the hole

My car bone stock 98 t/a

BigJls1

looks like the sts kit uses a .81 exhuast housing. But what compressor size?

BigJls1

nobody here running a twin rear mount setup
if so whats your specs?

SUPER DAVES Z

iTrader: (6)

That's a question for the corvette guys bro, their sts kits are twins. I know of at least 1 guy on this board that made 700rwhp with single t-70 turbo, so I think for simplicty, most (if not all) f-body guys are using single turbo rear mount kits.

Good luck with your build.

anarchy99

iTrader: (7)

Shoot a pm to jammer. He built a homemade rear kit and then sold it. He'd probably be able to tell you if your setup would work or not.

BigJls1

thanks I know a single would be more simple, but............. How cool is it when you say " ya I got twins ". Anyway thanks for the help.

fenix999

iTrader: (17)

sometimes cool isnt neccessary/faster/or worth the money lol...just think about it, basically all your costs will double by doing the twin setup...2 wastegates...two sets of pipes up and down, 2 TURBOS not to mention, 2 sets of oil lines running all over the car. Just stick to a nice single setup and get it dialed in right, its a **** load less weight and you can get alot more done in less time and basically same results in the end, trust me ive already done it and im only 21.

SUPER DAVES Z

iTrader: (6)

Very good advice!!!

99Z28LS1

iTrader: (4)

everybody always want to say that
i wish i could tooo

GR33N GoblinM6

iTrader: (14)

dont forget.. double the weight.. and thats alot when you think that an STS kit is 105lbs... now you just added 210lbs to the car...

Superman09

iTrader: (65)

I say do what you want, clearly you asked a question about turbo size and this got off track to everyone telling you to go single turbo... stay on course guys. And no you won't DOUBLE your weight, but of course you will add more. For example my front mount twin kit.... NOT double the piping, my hot side is probably shorter piping due to 2 small pipes vs a giant cross over... i still only have 2 manifolds, not 4 also just 1 intercooler, same as the single guys. I'd say i probably have the same amount of piping or close as a single guy, i have an extra turbo and waste gate. I wouldn't say more weight is really an issue... HOWEVER, twin rear mount, you may have a lot more with twins having to run pipes the length of the car, all depends on design i guess. Of course, i'll be the one to say be creative and do the rear mount twins. Sometimes, going in a straight line as fast as you can is not every single persons goal, be creative, something different is always cool rather than just another STS guy (which is still sweet, don't get me wrong, but it will be a 1 of 1, no one else will have your setup) All really depends on your goals for the car i guess. want to go fast in a straight line, sure a single would be the best route, like to show the car as well, street car... get creative and have some fun with what YOU want the car to be.

As for the turbo sizes.. don't look too bad, compressor side seems a bit small but the exhaust side seems on par with what most guys are running, decent size there. If you already have the turbos and got a good deal on em, try em out and see how you like them.. little laggy, maybe get some smaller turbine sides, etc. May have to fiddle a little bit but it seems they will head you in the right path!

Have fun, good luck with the build and remember, do what you want with the car to reach the goals you want for the car

BigJls1

Superman09,

This is the technical advise i was looking for. what size are yours.
If i use the stock pipe to the axle and then y pie to the two turbos; then y pipe back the two compressor to one pie back to the front, I think it will equalize the pressures in the turbos. Thus
allowing me to run one big 38 or 44mm wastegate before the y into the turbines.

Superman09

iTrader: (65)

yea, i run 2 Tial 38mm wastegates. My turbos are matched for my 346 only for quick spool on the street performance. When i get a motor built and if i up the cubes at all, i'll have to for sure switch out the exhaust side, may do it when looking for more power anyway as they are smaller suited just for the 346. they are T3's with .60 on compressor side and .48 on exhaust side. Keep posted to my thread for info on what it puts down power wise and how it performs on the street! Hope this helps!

anarchy99

iTrader: (7)

like I said before bro, jammer has already done it and could probably offer the best advice since he fabbed his up all from scratch also.heres the link of him selling his kit, in the for sale section but I'm sure he posted stuff about it in the forced induction section, I'm just too lazy to look for it.
https://ls1tech.com/forums/showthrea...win+rear+mount
Here's more...
https://ls1tech.com/forums/forced-induction/249883-customized-sts-twins.html

BigJls1

ok so i cant type pie = pipe (sorry)

superman I am super curious when your car will boost
(rpm)

I Still would like to know ( all the guys runnin "sts" here)
what there intake side is ?

personaly i think my exhaust side is too big. I will be cutting the muffler off this weekend. I'm probally going to go ahead and mount the twins but have a feeling they are to big.found a couple of t4's (real garretts) about the size of supermans on ebay not to pricey. I have noticed alot of folks really empasizing the turbo body or make: ie t3 or t4 and trim pitchs rather than the A/R. To me the a/r seems way more critcal than the turbo make?

Jake@EPP

We made 700rwhp with a 67mm from STS, this was with a 382, heads, our FI cam.

BigJls1

help me out here

67 mm is what? is that your compressor outlet size?
how bout your turbine size? I need to know if the two i current ly have are to big for twins or to small for a single? there is a lot of room to run twins and i am a welder/ fabricator (i work in a aircraft fabrication shop, lots of big fancy fabricaton equipment)
my ? here is sizes ??

Jake@EPP

On stock ci, you might have a bit of lag in the first few gears, i would wrap the exhaust, obviously delete the cats if possible.

Is it a stick or automatic?

If this is a budget build, i would sell the twins, pickup a used 67mm and make your own pipe setup in the back.

BigJls1

auto

I am not aposed to a single (for now, I will have twins someday)
I have a little budget I think I can build this setup properly WIThOUT turbo(s) cost: for 800 to 1000 Wastegate and oil pump are almost 600 tHats not really bothering me.
ITs size I would really like to Know were 67mm relates to A/r.
I feel like an Idoit not knowing how to referance mm to A/R what is the MM measuring? Please help

Jake@EPP

Not a dumb question at all, here is a link i found that explains turbo sizing and AR ratios pretty good,

http://www.turbobygarrett.com/turbob...o_tech102.html