needtransam

iTrader: (2)

Ok so I had read a few threads about how rear mount turbos were crap and other saying they were pretty good for the money, so obviously I found out about the sts kits and how good they sound and the turbo lag they associate with. But after searching more I found some really successful people running rear mounts and making huge power with almost no lag.


So my question is, how can i come up with a list of things I will need for this project? cost associated with it and how long can I expect?

My main objective in why I wanted to go with a rear mount turbo is the simplicity of install and keeping my engine bay looking stock and also that I would keep my stock internals, since I was debating between this and a heads and cam swap, but this seems easier in the sense that I would loose MPG (I suppose) and that in any time I want to go back stock I could just uninstall the kit



Post your opinions and comments will be deeply appreciated

US_Army_Z28

iTrader: (3)

Well the guy that owns hawks third generation here in sc has a 99 ss that he did a single sts rear mount turbo on, he did NOT lose fuel mileage, it did in fact go up to around 28-29mpg highway and all while making 650hp/648tq at the rear wheels, he does have other mods to the motor so your results will vary from these but i plan to go with the same rear mount setup on my car, sounds great, makes plenty of power and can still be daily driven a little more than front mount bc from what ive seen the rear mount seems to stay cooler than front mounts do

Isaacs

iTrader: (1)

I foresee another debate thread lol I think if you plan it out properly, a rear mount kit has it's benefits. When/If I do it, my main concern is going to be the oil supply. As long as you have the right size turbo and piping you should be fine. A rear mount kit won't be as efficient as a traditional setup, but especially in my CTS-V there just isn't enough room unless you want to spend a lot of money and cut the car up.

BadgeZ28

iTrader: (28)

I can give a couple suggestions and drawbacks. Go with a turbo that does not require a oil supply and return. Try to tuck up the turbo and piping into the area behind the rear bumper. Your exhaust is not optimal for a rear mount. The stock STS routing of the air charge pipe from the rear forward can be a problem if the car is lowered. Put a water resistant sock on the air inlet filter. This is important if you drive in the rain.

SPRAYED 01

iTrader: (22)

Comp oil less turbo. If I could do it over id so a rear mount.Messing with a front mount and dp, and cooling setups is a huge pain. Keep it simpl

Isaacs

iTrader: (1)

From what I've gathered: keep the stock manifolds, lose the cats, y pipe to single exhaust back to turbo, heat wrap the exhaust, use a properly sized turbo(preferably oilless), route charge piping (aluminum) back up beside the exhaust and figure out the best spot to put the intake filter (build a shield etc)

BOBS99SS

iTrader: (2)

If i do a turbo it will be a butt mount, but as someone said comp oiless turbo is well worth the extra money, use stock headers,lose the cats, wrap what you can,zombie had a very good thread about rearmounts, the sts kits used are pretty cheap but alot of what i have seen look like crap,so just make sure ya can get something you can use, just dont think your going to save money by going with a rearmount, yes you could but always plan to go over your budget with fi, unless you can find a kit with everything included which you can but i have seen those in the 3grand range

ibex37

iTrader: (6)

im not allowed to link to web sites that do not sponsor this web site. but do a search for walker exhaust 88028 y pipes, they are mandrel bent 2.5" pipes that bolt to 2000-2002 exhaust manifolds. Also check out walker exhaust/dynomax (same company) intermediate pipe 55282 this pipe is NOT mandrel bent its "crinkle" bent which i guess is better then crush bent but not as good as mandrel bent. The intermediate pipe bolts directly to the y pipe and exits just over the rear axel to mate up to the STS pipe. I threw away most of my stock exhaust and wanted to start fresh with new exhaust to prevent any rust and other debris blowing through the exhaust and destroying the turbo fins. i plan on exhaust wrapping the entire set up to keep heat in the exhaust back to the turbo which i understand helps quite a bit with spool. I can post pics if any one would like to see close ups of the exhaust.

edit to say a little more about the y pipe. It does not crush down like the stock exhaust does, it also has the funky F-body style exhaust flanges already welded to the pipes so you can just bolt it to stock manifolds with zero modification. It also has bungs welded on for O2 sensors.

HRHohio

All of the above. I love my setup (didn't go with STS, had it custom done)
(Note: Wrap the charge pipe from back to front as much as you can too. Some places get very close to the exhaust pipe on mine which just heats up the charge pipe... mild steel on my setup).

I love keeping my AC... especially out here in the desert and the fact that the engine bay looks mostly stock and unmolested.

I don't have an oilless though, went with an On3 76mm Ball Bearing. Originally got the .96 housing, but spool was a bit too slow. Bought a .81 housing for it and it's much better. Hindsight, I would have done the .81 on a 70mm for my power goals and to get it to spool up a little faster (600 rwhp on stock bottom). Of course when I go forged, I can crank up the boost and be good to go.

Good luck.

Note: I'm running stock manifolds, stock catalytic converters, but had the flattened part (drivers side) of the y-pipe redone with round.

JoshuaGrooms83

iTrader: (2)

working on mine too, custom rear mout centered around an ON3 T76 .81 turbo as well. im going to custom route my cold side on the passenger side.

needtransam

iTrader: (2)

Ok a lot of good info but some questions better to buy a used one and sell the turbo and get an oiless one? Or just make the kit by myself out of scratch????

HRHohio

If you have the skills, or access to a muffler shop, to do the cold pipe, I would say DIY all the way.

Highly recommend the intercooler and some methanol/water injection system too, regardless. Play it safe. Hate to do all that work and blow it because you got greedy and pushed 1-2 psi too much (BOOM!)

WheelsUp84z

iTrader: (14)

make from scratch would be my suggestion. There isnt that much fabrication needed to do a rear mount setup, maybe just a little creativity. You can tailor the kit to your likings and you'll know it will fit without issues.

needtransam

iTrader: (2)

see that's what I want to do I have a muffler shop that is pretty reliable and he could do the welds and cuts, my only problems is I don't know what kind of piping, what sizes ect ect ect, If I had some detail Or pictures I could build it myself and buy an oil less turbo (not sure how expensive they are) and build it to my liking

HRHohio

Generally the cold side pipe would be the same size as the turbo compressor outlet. For example, my On3 76mm has a 2.5 inch compressor outlet, so I went with that from rear to front into an Ebay intercooler (also with 2.5 inch inlet and outlet). From there you have to step the piping up to match up with your throttle body opening. Don't forget the MAF, if you continue to run one. I think most people (rear mount) run 2.5 inch pipe from the turbo to the IC. I would recommend going with mild steel (i.e. Muffler shop) instead of trying to run the aluminum piping. Mild steel is more durable for those times when you accidentally bottom hitting an abnormally high speed bump or unseen dip in the road.

As far as the Oil less turbos go, I think they run $1500+ range. Keep in mind, you still need to run a line to them to cool them, but instead of running oil, you run coolant. Also, the bearing cartridge will require replacing after 20-30,000 miles.

I went with On3 because I am cheap and they have been having very good reviews. Spent the extra cash on uprading my cam (LS9) and putting in the methanol/water injection system. So far, very happy with the On3 Turbo.

needtransam

iTrader: (2)

how much did you pay for your turbo? im trying to see would 1500 shipped for an sts turbo kit be worth it with upgrades oil pump and front mount intercooler?

SSFAST

I love my custom rear set up. I have a built 370 with a precision 76mm ball bearing turbo. I still have ac and power steering and at 18.9 lbs of boost it dynoed at 808 at the rearwheel on a mustang dyno. It is so nice to drive anywhere and change to drag tires to drive to track. I would say go for it.

needtransam

iTrader: (2)

How much did you guys payed the ones that dyi your own kit

great421

iTrader: (1)

NTA Remember -

Above 5 PSI, Meth is your friend.

It kept my stock compression LT1/4 from blowing up for about 40K miles at 11 PSI.

slick99

iTrader: (1)

I just bought a ct43 7879 oil-less for my rear mount build, it was right at 1900 to my door. I wouldn't suggest it if your on a budget though, but it does simplify the system and install substantially.