Rear Mounted Turbo?

Dennis,
A friend has a C-5 Corvette with the twin rear turbos. Don't know whose kit. It is incredibly awesome!
Dan

I'm no turbo guy, but I thought the reason to have the turbo as close as possible to the exhaust manifold was to reduce turbo lag?

In a front engine car with a rear mounted turbo, in order to build up exhaust pressure to spin the turbo and then pressurize the intake air back over such a long run surely has to lead to some huge turbo lag? Lots of plumbing, but admittedly runs would be far shorter in a Pantera application.

Here's the link to the rear mounted turbo system we run on my sons corvette. Great setup..
http://www.ststurbo.com/turbo_systems1

Here's a bad b&w picture of a system AK Miller sold for the Pantera way back in 1973.

Looking at the rear mounted STS turbo system, you could probably plumb it into the area above the ZF if not in place of the mufflers. The company says no turbo lag in a front engine car so I would think that the Pantera would not suffer from it either. This system would make access to the engine and turbo system a lot easier.

No matter where you put it in a Pantera you will be close to the engine. There was a Horsepower TV episode in which they mounted a set of these on a C-5. They were very happy with the results. They say that the distance from the engine reduces induced heat from the exhaust and the long intake run would cool the air more albeit not as well as a intercooler. Neither of these benefits would be seen in a Pantera as the distance from the motor is just not great enough. You would likely notice a larger pressure drop from this system but it could still be tuned for plenty of fun. Your spool up time would be slightly slower regardless of claims they make. They likely just install a smaller turbo to reduce spool up times. Having to get all that air moving would also slightly reduce your throttle response. I still agree with the shorter/closer = better theory. The remote system will work just not as well IMHO.

Blaine

I agree shorter is better, because you want the exaust gases to be as hot as possible to spin the turbine up quickly. The down side of course is the hotter the turbine side gets, the hotter the intake gets from conductive heat. I would think the absolute best place to mount turbos would be right beside the block just as close to the exaust valves as you could get it, tucked underneath the engine. That way you would only need a short lead for your oil lines too. You could draw the intake air through K&Ns from the bottom. That would be the coolest air you could get to. Then on the outlet you run it up alonside the engine to an intercooler that sits above the engine and to a plenum that sits just under the intercooler. From the plenum you could have short IR throttle bodies. this way you keep your plumbing to a minimum and that in turn keeps the weight down.
This was what I was thinking anyway. The downside is all that bling that you payed bick bucks for is mostly hidden from view.

You would also have to run a air/water intercooler as you would get no airflow up there for an air/air but it would be the most efficient way to run the plumbing. I plan to change the location of my turbos to the side just as soon as I get a shop/lift/tig welder and some time.

Blaine

To get the boost response in these systems, they use small turbos. They avoid the restriction problems because of the long exhaust between the engine and turbo acts like a damper. It seems to work, but not sure how long term engine wear will be. I would be interested to see how much back pressure these systems have. Although this seems to be the trend now days. Most new turbo systems use a hybrid t3-t4 turbo. I am sure these will work for low boost systems, but in higher boost systems, this might make the car too sensative to throttle and hard to drive. When you run higher boost, it is often good to have some lag. Especially in a car whose rear likes to pass the front.

quote:

Originally posted by PanteraTurbo:
You would also have to run a air/water intercooler as you would get no airflow up there for an air/air but it would be the most efficient way to run the plumbing. I plan to change the location of my turbos to the side just as soon as I get a shop/lift/tig welder and some time.
Blaine when you do that please post every single detail here on the forum. Because if I ever do decide to go turbo, that is exactly the way I want to do it. I figure ten to fifteen pounds of boost will be plenty for a mostly stock CJ build.

Blaine

You bet! It will probably be 3 years from now though.

Blaine

quote:

Originally posted by PanteraTurbo:
You bet! It will probably be 3 years from now though.

Blaine

That's ok. I am on the 15 year plan myself.