twin turbos

There were very few twin turbo Panteras ever built; most during the late '70s- early '80s, due to smog laws etc. Almost none are still running, and none to my knowlege used Indy-car-style exhausts due maybe to the enormous heat-generating area of such pipes (even without the turbos, you need big heat shields). Stock Hall 180's probably wouldn't work, either- the collectors are way too far from the intakes, giving enormous turbo-lag in the equally long inlet pipes, plus the requirement for double-thick pipe flanges, stainless steel tubing, and the proximity of 20+-gallons of gas to the left-side exhausts. IMHO this is pure race-car stuff; if you pursue this, I suggest you not use a 351C block or heads, as they probably won't take the heat or horsepower for very long. OLd saying- 'experience with blowers comes with the number of engines you've blown... up! You might contact Dave Doddek (pantera@pobox.com) who built an injected 2-turbo Pantera in the Chicago area thats still running, albeit on its 4th or 5th 351C block. No 180s on it though.

Thanks for the reply jack. I have a 4 bolt block with a 383 stroker kit installed, forged crank,h-beam rods, forged pistons. My heads are the new aluminum alloy ones from australia.
The gas tank is no longer in the stock location,I built one to go in place of the tire and battery. The turbo lag is something I will need to look into.
I'am only looking for about 5 to 7 lbs of boost which wo give me about 150 hp I think.

I have pics of Fred Terry's 615hp twin supercharged Pantera I can send you.His engine is extremely close to yours.Do you have any pictures of your gas tank?
As for 180 deg headers,I have had them on my car for several years with no heat issues at all.I had thhem HPC coated and added two small stainless steel heat shields to the car and a shield on the deck lid.

There's a kid named Blaine Carmena that has done what you're asking but with a custom setup. I believe there's a PI article in-the-making regarding his off-the-edge Pantera.

I don't have his email handy but he normally transits this bulletin board.

It's great seeing young folks like Blaine and others enter the Pantera community bringing with them fresh ideas to an aging Pantera community.

We're seeing it too with the current crop of young NASA engineers and their recent success. They're infusing new blood into what used to be a stale and beaurocratic organization.

Nothing stops progress!

God BLESS George Bush!

Steve O.

I believe Bart has a nice turbo set up by Lance, as shown by PI photos. Not sure on the 180 headers though.
http://www.pantera.net/mont2002a45.jpg

Using any kind of tube headers has a negative affect on turbo performance, an exhaust manifold that has short runners from the exhaust ports to a common tube is best. The heat generated contributes to the force of the exhaust gas which is important for optimal turbo speed. The gases are still expanding after it leaves the exhaust port and pressurizes the exhaust manifold. Elaborate headers allow cooling of the gases and the larger volume (long tubes) to expand and have less pressure.
The advantage of using 2 turbos is that the size of the rotors will be smaller for the same boost as a single turbo, hence the mass will be less (maybe a squared function) minimizing the lag often associated with turbo applications. Controls allow sizing the turbo to reach the desired pressure at lower RPM�s and maintain constant pressure when the engine is at maximum RPM. Waste gates with intake pressure feedback is an example of such a device.
A properly converted engine, with o-rings in the head, oiling considerations and coil per plug ignition can double engine HP, unfortunately turbo sizing, plumping and controls are not well understood by many. Your limit of 5 to 7 lbs. of boost is conservative, it�s not worth applying two turbos for a 150 HP gain, a better route is traditional engine modifications.

As posted in another string:
I have a full Turbo kit for a Pantera for sale. It was originally Darryl Ratchner's (I think that's his name) from Albuquerque and I purchased it from him and have never used it. The kit has literally everything and more to bolt up to a Cleveland powered Pantera. Full induction system, full exhaust system, Arias Pistons and rods, Garrett Turbo worked by Turbonetics and more. He truly had the system working very good from what I was told and saw.

Also, I have nearly all new never used parts for the complete long block with machine work done to the closed chamber 4V heads. Machined for 7/16 studs, 3 angle valve job with Milidon SS valves and guide plates, guides, hardened exhaust seats. 4 bolt main block at standard bore size, ready to be bored to needed rebuild size. Machined Crank ready to install. and much more.

I am inventorying it all and getting digital pictures ready for mailing to those interested.

It must all go, for I need to fund my motorcycle roadracing addiction.

If interested anyone is interested and wants to contact me before I officially post it, here is my email.

nathan.weber@lmco.com

Thanks,
Nate Weber

I can understand that 150 hp is conservative, that is why I don't need a coil per cylinder and o-ringing of cylinders.
The engine has about 500 flywheel hp now, more without boost or nitrous would make it hard to drive,
The idea of twin turbo is for looks and some 650hp is enough for me on a street car.
The cost is not important, the looks of the car is.
I understand there are cheaper ways to get 150 hp,but that is not what I am asking.

Wes, O-ring�ing the head is due to the maximum pressure at RPM, at low pressure you don�t need it. The compression that turbo engines is about 8.0 to 9.0 and allow the turbos to do the rest. If you are making 500 HP now you probably are at 10.x so either lower the compression ratio, and pressurize to 650 HP or the route you originally considered keeping the turbo pressure to a minimum. Be careful to add PSI to an already high compression engine, I think 7 psi maximum, this arrangement should minimize turbo lag.
As far as looks and cost, you can still use the 180 headers with modified collectors, but the long runners on the intake side may effect driveability.

Steve, I am flattered. I must say it is great to be a part of such a amazing community. As for my car I had every intention of using 180 deg exhausts to my turbos but it did not work out that way. My system has headers that come up and over the rear inner fenders but are only 90 deg. The car is being built for open road racing so I have no concerns with lag and such. If you were to fabricate a 180 deg turbo system I would highly recommend using tangential style turbine housings to make it worthwhile and ball bearing turbos to minimize friction. The only way to help offset the cooling effects that Jon mentioned would be to use the thinnest wall stainless you can find and have secondary supports to hold the turbos weight. Thinner wall tubing will actually give up less heat than a thicker wall and stainless has the best high heat characteristics. You could also have them ceramic coated. If I am not mistaken there was an article about a twin turbo 180 deg system in one of the most recent PI issues. I say go for it. With a goal of 150 hp gain it is obvious that you are not going for all out HP therefore performace is not as much of an issue. A 180 deg twin turbo system has to be one of the most amazing looking systems out there. Take Care and good luck with your project.

Blaine Carmena
#6214

[This message has been edited by PanteraTurbo (edited 02-05-2004).]

The 150 hp gain from 5-7 psi may be optimistic, depending on what else you do to your engine. Rule of Thumb is, 14psi boost will effectively double the horsepower one gets from a given engine. So if the engine is properly built for supercharging, it may only put out 200 horses without the blower, so theoretically a 7psi boost on that motor will give another 100 horses.With a supercharger, I find it helps to consider that part of the engine's compression ratio resides in the blower boost. Many supercharged engines run 8:1 or even 6:1 mechanical compression, getting the rest from their little wind machines. Conversly, running 10:1 c.r with blower for instance is usually a recipe for a 'grenade engine,' unless extraordinary ($) mechanical things are done to the engine, such as aftermarket rods, forged pistons with the ring pack positioned low for a thicker piston crown, short-overlap cam, special head gaskets etc.

quote:

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Originally posted by PanteraTurbo:
Steve, I am flattered. I must say it is great to be a part of such a amazing community. As for my car I had every intention of using 180 deg exhausts to my turbos but it did not work out that way. My system has headers that come up and over the rear inner fenders but are only 90 deg. The car is being built for open road racing so I have no concerns with lag and such. If you were to fabricate a 180 deg turbo system I would highly recommend using tangential style turbine housings to make it worthwhile and ball bearing turbos to minimize friction. The only way to help offset the cooling effects that Jon mentioned would be to use the thinnest wall stainless you can find and have secondary supports to hold the turbos weight. Thinner wall tubing will actually give up less heat than a thicker wall and stainless has the best high heat characteristics. You could also have them ceramic coated. If I am not mistaken there was an article about a twin turbo 180 deg system in one of the most recent PI issues. I say go for it. With a goal of 150 hp gain it is obvious that you are not going for all out HP therefore performace is not as much of an issue. A 180 deg twin turbo system has to be one of the most amazing looking systems out there. Take Care and good luck with your project.

Blaine Carmena
#6214

[This message has been edited by PanteraTurbo (edited 02-05-2004).]

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I plan on going ahead with two t3/t4 turbos, so I will let everyone know how things work out.
My cr is 9.85, which I have been told by several venders will be ok.
When I put the engine on the dyno I won't be able to have the turbo system on because it will interfear with the dyno itself.
Thank you for all the good information.