Anyone look into STS Turbo?

Not much in this forum for aftermarket stuff. My Cousin just put a STS turbo on his Dodge Hemi. Has dropped 2.5 seconds off of the stock truck 1/4 mile times (Probably 3 seconds after some more tuning). Now this is possible in the Subaru due to the design of the turbo. Its rear mounted. It replaces your muffler so it can be placed anywhere under the car. He is also using Methanol injection instead of the inefficient intercooler.

Something I may think of in a few years (dont want to void warranty just yet). Just something to think about.

http://i.b5z.net/i/u/1473169/i//TBSS_Turbo_View.JPG

http://www.ststurbo.com/universal_system

I guess the more piping, the more surface area to get rid of heat between the turbo and TB. But the more piping, the larger volume of air fills it. I am not sure how that would affect throttle response.

I saw a twin turbo kit for a vette on some show. Of course they installed the kit in 30 minutes but when they were done the car was NUTS and sounded amazing. Not sure if it was STS or not, but the turbos were in the back.

If you calculate the actual volume of the pipes and compare it to the CFM of the motor you will fid that the motor will fill the pipes in milliseconds. Throttle response is aother matter, sort of like an FMIC vs TMIC

If there is no other reasonable way to get a turbo into a car, the rear mounts stuff makes a lot of sense.

I know someone who is doing that on their V8 BMW E36 swap , not me though.

wow that is insane. wonder what kind of power you can get out of a system like that, and what kind of lag would it have.

wait for it....5 mins later...off we go

I saw the previous numbers that someone posted up. The CFM used assumed WOT at 6000 rpm. At that condition, lag is not an issue.

My car at WOT at 3000 rpm and 17 psi boost flows 140 g/s of air. That's approximately 4.1 cubic feet per second. If the piping is 1 cubic feet that would result in 244 milliseconds of lag.

Throttle response would be a lot worse. Cruising, the engine is flowing around 30 to 40 g/s of air. The average flow going from cruise to WOT would would be about (140+40)/2 = 90 g/s of air. That's approximately 2.64 cubic feet per second. If the piping is 1 cubic feet that would be an additional 370 milliseconds of throttle response.

I think that's enough to be noticeable.

I saw the previous numbers that someone posted up. The CFM used assumed WOT at 6000 rpm. At that condition, lag is not an issue.

 

My car at WOT at 3000 rpm and 17 psi boost flows 140 g/s of air. That's approximately 4.1 cubic feet per second. If the piping is 1 cubic feet that would result in 244 milliseconds of lag.

 

Throttle response would be a lot worse. Cruising, the engine is flowing around 30 to 40 g/s of air. The average flow going from cruise to WOT would would be about (140+40)/2 = 90 g/s of air. That's approximately 2.64 cubic feet per second. If the piping is 1 cubic feet that would be an additional 370 milliseconds of throttle response.

 

I think that's enough to be noticeable.

Re-run the calculations on a 5.7 liter engine and 2" piping

The problem is that turbos work (spin) by the temperature differential from the hot side to the exiting exhaust and to a much lesser extent from the air pressure. Since 99% of the turbine energy is coming from the heat differential, moving the turbo further away from the engine (source of heat) would cause substantially more lag than having it by the engine.

Plus, do you really want a hot (granted, they say it's not "as" hot as by the engine.. . but not as hot as 1600 degrees is still hot) turbo coming into contact with cool rain water when it rains?

The point is not if a close couple turbo 10" from the engine is better than a rear mount. If you cant fit one under the hood without extensive mods than the negatives of 300-milliseconds of lag is pointless. if your concerned about lag than just learn to drive a turbo, you keep your RPM's up and shift accordingly. If its launch lag that your concerned with, I have heard that people will use NOS to inject on launch to give you the punch before the turbo kicks in.

Also you have to remember that when you put a turbo on a NA car you are dealing with a engine that already has a higher compression ratio. For example a NA car will have the 180HP that is stock with the car before the turbo. So when you put your foot into it you have that 180HP before the boost kicks in. With a engine designed for a turbo you have allot less compression ratio and thus you have allot less base HP when the turbo is not spooled up. Ever drive a car that has had the turbo blow up? No power right?