Turbo...Up front or in the back?

[jerrys85iroc]

I have two friends arguing over something i actually dont know the answer to...one says that turbos in the front makes more horsepower and the other says if they are in the back of the car they make more power........it doesnt make a diffrence....right?????

[GetMore]

Too many variables.
As the exhaust gasses move through the exhaust system they will cool down, losing volume and energy. This means that they will not spin the turbo as fast. It also means that there will be less heat transferred to the compressed air going into the intake. Plus, you don't have underhood heat adding to it.

Turbos up front have a shorter path to push the air, so response is quicker. However there is more heat in the intake charge, so you need an intercooler, which adds to the intake volume and slows response.

I don't know if one really is more powerful or not. I suspect that they are equal when all factors are used. The same volume of air fed into the engine at the same temperature will make the same power.

[Turbo67camaro]

Too many variables.
As the exhaust gasses move through the exhaust system they will cool down, losing volume and energy. This means that they will not spin the turbo as fast. It also means that there will be less heat transferred to the compressed air going into the intake. Plus, you don't have underhood heat adding to it.

Turbos up front have a shorter path to push the air, so response is quicker. However there is more heat in the intake charge, so you need an intercooler, which adds to the intake volume and slows response.

I don't know if one really is more powerful or not. I suspect that they are equal when all factors are used. The same volume of air fed into the engine at the same temperature will make the same power.

Ditto on all points.

Here's the reasoning why I'm planning to try the rear mounted STS system (assuming it will fit - something I'm working on to confirm)...

It is EASY to make a lot of boost.

It is NOT easy to make a lot of boost without detonation.

When boost increases (higher pressure), the temperature trigger point for detonation is decreased.

Power under boost is mostly limited by how well you control detonation, which is highly dependent on keeping the intake charge temperature down.

It is much easier to control the intake temperature with the turbo in the rear. For my vehicles purpose, those benefits outweigh slightly slowed spool-up time and slight decrease of efficiency of the hot side if the turbo. Added benefits are elimination or reduced intercooler requirements, reduced engine compartment crowding, and I suspect added reliability.

Moving the weight of the turbo(s) to the rear is a bonus, but at the expense of more total weight for a longer boost tube and an external oil pump.

From what I hear, STS has the system designed with very minimal lag, although I have no personal experience to confirm that.

For an all out race car, I suspect the front mount response time improvements would be the deciding factor, leading to a front mount decision, especially if said car had to make many transitions between a non-spooled turbo and a spooled one during a race.

Lots of variables...

Mike

[shmoov69]

Closer to the engine will always make more balls out power, that is why race cars of all different types run them close to the engine. But for a streetcar, wherever is convienient will do just fine with a good well thought out system.

[jerrys85iroc]

So....basically it really doesn't matter because neither of them are building a race car...i figured it didn't make a diffrence...thanks guys I got the answer i needed to give them so they can grow up...lol

[MonzaRacer]

Basicly depends on what you wanna do and where packaging allows.

[MonzaRacer]

I have rode in several STS equipt cars, VERY impressive. One guy was having oiling issues and the turbo locked, took kit off, sent it back and STS sent new setup with better oil boost pump I think. Even with burnt turbo the Z28 with mild 350 would flat run, smoke tires at 55 in 3rd, and hit 100 nearly instantly, but after the repair, the whole car became insanely faster.