STS Turbo

[oztracktuning]

I am considering getting an STS system for my car with intercooler and will tune it myself i want my car to be 0.6s faster at the track and gain about 5 mph.

I like the novelty of something different and the sound of a turbo at the rear of the car acting as the muffler!

Im interested in knowing just how much i will gain or lose by retaining or removing my current cam. Its a 216 220 114LSA comp cam and i also have 1.8 rockers. I cant find the full specs anywhere to get the overlap sorted.
My car also has 10.7:1 comp and ported heads. Its quite timing tolerant - it has 27 deg at peak torque and 29 up top now and is handling this well.

275rwkw locked on a Mainline Dynolog dyno which is like a Mustang in the US. 11.414 at 1625kg (with driver) and 118.6 MPH - the car will with the turbo be intended to be run at least 50kg heavier though.

If i pulled this cam out i would get a LS6 hi lift stock cam. Then maybe add some extra economy.

[johnv]

That cam should be fine,
The rear mount turbo setup could be a bit laggy so you whant a cam with good bottom end to get you moveing.
Are you looking at a US GTO kit or building your own from scratch.

I'm building up a single turbo for mine at the moment currently have TR 224 / 112 lsa cam and 11:1 comp (higgens heads)

Gonna have to put the std heads back on to lower comp and picked up a ZO6 cam very cheap so will give it a try.

Will be rebuilding another engine i have a little further down the track with low comp Ross pistons and forged rods , and the Higgens heads, will end up 9.5:1
then lean on the boost a little

[oztracktuning]

There is now an Australian distributor for STS based in Sydney.
My car may be the first auto test mule in Australia also running EFILive OS5 and the aim is to do all year 11.0s with the minimum boost required.

[ringram]

Dont you mean 10.9x mate?

[oztracktuning]

I race in Super Street - so breaking 11.0 would be a disaster - they would send me home early. I would have to choose carefully when to do a 10.9 as it could DQ me from the next meet as well.

[redhardsupra]

STS kit is quite awesome actually. The moment i heard 'rear mount turbo' i was screaming junk, but then I got to tune one, and i completely changed my opinion on it. It was a A4 camaro with 3.23 gears, and it supposed to be a very nice street car, so we needed a nice powerband. We built it with stage 1 heads, LS6 valves, and LT's, and ATI intercoolers. The car could hit positive boost before 2600, and hit full 5psi about 2700rpm, so I wouldn't call it laggy at all. the fun part of this car that the power would come on so easily, and just go on and on, never really dropping off (not that you'd feel it at least).
tuning with 1barMAP quickly turned out to be futile, as we'd ran out of MAF table by 4800. Another important thing is injectors--svo 42s are just not enough for it, we hit almost 100% duty cycle by around 5300rpm.
The biggest problem with this setup was overheating, as it took 3 fans to keep it from pegging the temp gauge.

[jsttry]

A rear mount turbo seems just plain weird. A couple of problems:

Exhaust looses its heat by the time it gets to the back, so the turbo won't spin as fast. (more heat = faster spool up)

Then there is the issue of getting the intake air back to the engine....seems a long way to travel.

If it comes on at 2500-2700rpm though it sounds well engineered.

It would also have to be mounted high enough not to be damaged.


Why not look at one of the local Australian kits?

[oztracktuning]

These have a special choice of turbo to suit the situation.
They are much cheaper than a usual front mount turbo - using the normalextractors and recirculating through the cats repeatedly so they are good on pollution.
They sound awesome because the turbo is at the back of the car and the main muffler.

I may go a front mount if i can get one at a good price. But I dont need much boost - only 5-6psi to get the capability i want.

Im still waiting on a special price with the STS.

[joecar]

I read someplace that the rear mount turbo has a longer life due to the temps. being much lower.

[kbracing96]

I have a STS, only its on a 4.8 truck. I'm also intercooled and have Meth injection. I'm running 7/10 psi boost. I really like it. As for lag, its really a non issue. Its like most any turbo car, when it's cold, it's petty laggy, but once you get manifolds and all the piping hot, they are very responsive. Also, wrapping the exhaust from the manifolds back to the turbo with header wrap, really helps retain the heat and makes it even more responsive. Let me know if you have any questions about it.