Saw Hennessey running turbos WITH the supercharger system on one of his Ford GT's. I have seen articles with rally cars in the 80's running them in tandem to make big hp out of small displacement motors. Think there would be enough gain to attempt this.

 

Disregard this post. This combo wouldn't work with a Vortech supercharger only the screw types.

 

there was a good article in muscle mustangs and fast fords on this about 2 years ago. John Urist was adding a good size turbo (I think an 88) to the stock 03 cobra and making well over 1000 rwhp with a stock setup, with the only change being the turbo setup. You might be able to check his website for more info. His company is hellion.

But yeah, nobody does it with centrifugals because they don't compliment each other as well.

 

In April 2009 "Hot Rod" there is an article titled Hellraiser.

"The secret is compond boost and Water/methanol injection. The Hellraiser kit uses two 61mm Turbonetics turbos that blow into the stock Cobra supercharger. The turbos send 13 psi of boost through an air to-air intercooler and then to the blower, which componds the bost to 24.4 psi and pushes it through the stock intercooler and into the engine. To allow that kind of boost and power safely on pump gas requires a Snow Performance water/methanol injection system, which Hellion set up with six nozzels firing into the induction tube just before the blower, and they are fed by three pumps and an 8-gallon fuel cell monted in the trunk. Without the methanol injection, the system can still make nearly 1,000 hp, but the engine is on the ragged edge of destruction."

"The best thing about the arrangement is it makes that power with a bone stock engine. The factory '03/'04 Cobra DOHC engine has been proven many times ober to be robust enough to handle 1,000 hp,so it doesen't need better pistons, rods, or anything. If you want 1,000 hp, the only requirement is 75lb/hr injectors, which are optional in the kit."

"$7,495 + fuel system+ clutch + water-injection + tubular K-member to clear the turbo plumbing."

 

Yep, I should have thought about this a few minutes more before posting this. This as you guys have shown, only works well with screws type superchargers that build boost very early and then later in the revs the turbo comes in. Just bored with with my setup and thinking modify or sell.

 

Actually this should work with a vortech type setup as well.

There are two types of "twin" or "dual" types of setups

1.) The supercharger kicks in at low RPM to create boost to help spin a HUGE turbo that takes over in the upper RPM and bypasses the supercharger competely.

2.) Boost is compounded being compressed by the turbo's first, Intercooled, then compressed by a supercharger, and intercooled again.

According to the quote above we are looking at type #2 here. All this method does is cause the air going into the super charger to have more density, however, the increase in pressure is proportionally the same before and after the super charger.

All they are really doing is finding an easy way to increase the boost and using the more efficient turbo to do it instead of trying to pulley down the super charger.

This method should work with the vortech type supercharger as well.

Now if you were looking at type #1 then you should be using a roots type blower. If you are using a Centrifigal blower then you don't get boost until the upper rpm's and you need that boost to help spin the large turbo. So you wouldn't get the turbo to kick for a long time. Where as with a roots blower the boost comes on as soon as you go to WOT and it helps spin the turbo right away. Once the turbo spins up you then bypass the supercharger to let it free spin and use as little energy as possible.

 

A company in Oz did a GTO with a magy and a vortec blower on there. theyran the air form the vortec straight into the magy. made over 600bhp at the rear.

also its was dont on the lancia Delt S4 group B rally car. then ran a setup as follows:

Air Filter
Turbo
Intercooler
PD SC
Intercooler
Intake Manifold

Half in between the intercooler after the turbo and the SC there was a bypass vavle. at a set RPM the valve would open. this would enable the SC to boost the engine low down and then the turbo to take over once sufficent RPMs are reached.

today you could do a similar system but use a presure switch between the turbo and the SC. once this starts to read possitive presure then it open the valve. should aloow you to run a MASSIVE turbo and still get REALLY good spool!

obviously the biggest probelm is packaging. it would be very easy to run a traditional compund setup (turbo into SC as discribed above) but this has some pretty big downfalls.

for onecoompounding cars isn't new. the MINI guys have been doing it for years! and te ford guys are also having a very good go at it! the problems are HEAT!!!!! if you cant run a decent sized intercooler between the turbo and SC then your temps are going to sky rocket! also the mini guys have had SC fail due to the exspanssion due to high temps. also you will find that in compound setups you need to run more boost to equal the same power as the turbo only guys. however you will be making alot more BHP in the mid range than a turbo only guy!

Cheers

Chris.