Dual Chargers ?
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Roll the clock back to the mid 80's and Franks knowledge of Rally cars and you might find his inspiration :
One of the last of the World Rally Championship Group B monsters, the Lancia Delta S4 was an instant classic since its debut in 1985, where it won the first race it was entered in, the RAC Rally of Great Britain. With over 550 horsepower available via a supercharger to reduce throttle lag and a turbocharger for top end performance, acceleration to 60mph in came in less than 2.5 seconds on gravel, the Delta S4 was destined to be a dominant force in the rally championship. Delta S4 features included carbon fiber bodywork, lightweight tube frame chassis, all wheel drive, and a mid-mounted engine for optimal weight distribution. In 1986, Henri Toivonen took victory at the prestigious Monte Carlo Rally, and suffered a fatal crash in the 1986 Tour de Corse while leading the event. The sad news signaled the end of the Group B era, with the cars being deemed by the WRC governing body as too fast and too powerful for the conditions.
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One of the last of the World Rally Championship Group B monsters, the Lancia Delta S4 was an instant classic since its debut in 1985, where it won the first race it was entered in, the RAC Rally of Great Britain. With over 550 horsepower available via a supercharger to reduce throttle lag and a turbocharger for top end performance, acceleration to 60mph in came in less than 2.5 seconds on gravel, the Delta S4 was destined to be a dominant force in the rally championship. Delta S4 features included carbon fiber bodywork, lightweight tube frame chassis, all wheel drive, and a mid-mounted engine for optimal weight distribution. In 1986, Henri Toivonen took victory at the prestigious Monte Carlo Rally, and suffered a fatal crash in the 1986 Tour de Corse while leading the event. The sad news signaled the end of the Group B era, with the cars being deemed by the WRC governing body as too fast and too powerful for the conditions.
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You get a whole lot of stuff that can go wrong.
But it can be done and has been done many times...
Edit: He's not going to be running it threw the wussy MP62 is he? If so it'll be slower and make less power than the turbo by itself due to restriction and massive amount of heat in the charge air that will be produced... Not to mention the power loss to the little supercharger trying to compress already compressed air. It'll take a large intercoolers with a huge cores to try and pull away that much heat... Should be an interesting build just to see the results if it can be done without all the childish innuendos and name calling.
But it can be done and has been done many times...
Edit: He's not going to be running it threw the wussy MP62 is he? If so it'll be slower and make less power than the turbo by itself due to restriction and massive amount of heat in the charge air that will be produced... Not to mention the power loss to the little supercharger trying to compress already compressed air. It'll take a large intercoolers with a huge cores to try and pull away that much heat... Should be an interesting build just to see the results if it can be done without all the childish innuendos and name calling.
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I don't know Frank, but I'm sure from seeing stuff he does, he knows what he's doing....
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Had 1 shop try to do it here in SoCal on an Evo, but it ended up being a real PITA to deal with
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It can be done, but it's really only suited for really bizarre applications, like the requirement of using a massive turbo on a tiny engine and needing as much off-idle torque as you can get. E.g., rally cars.
These days with the restrictor requirements, there's no point in twin charging, as there's no point in using a huge turbo to begin with. That's why current rally cars run lots of boost at low revs (thanks to anti-lag) and galactic craploads of timing with much less boost in the high revs once the turbo becomes considerably less useful thanks to the restrictor.
On an Elise, the packaging and heat management for such a system would be an absolute nightmare. Much better and easier to just use a VTG turbo.
These days with the restrictor requirements, there's no point in twin charging, as there's no point in using a huge turbo to begin with. That's why current rally cars run lots of boost at low revs (thanks to anti-lag) and galactic craploads of timing with much less boost in the high revs once the turbo becomes considerably less useful thanks to the restrictor.
On an Elise, the packaging and heat management for such a system would be an absolute nightmare. Much better and easier to just use a VTG turbo.
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Yup
AND it will be cheaper and MUCH easier to tune. The actuator controllers have become far better than just a few years ago and there are all sorts of gadgets on the market for running these things now. Im surprised nobody is running one in an Elise yet.
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I think it's a cool experiment and knowing Frank, it'll turn out and run perfectly. Lots of low end torque and high end turbo power. :shift:
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Packaging is simple because the VF, BWR and Katana both position the throttlebody in the stock position. Heat management isn't a nightmare but does require some thinking.
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Yes
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Seems like over-kill? :shrug:
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opcorn:I saw this done with a Mini Cooper S (before the turbo model) on a show car in Orlando - he said it worked well - small turbo ahead of the stock supercharger.
PS: ZTEC - Nice of you to let that car into your lane with the yellow winged beast yesterday under the East-West underpass.... such a gent!!
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Exactly, well said! :evil:
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It'll be interesting to see how it will handle the volume of air from the turbo. It'll also be interesting to see how the super charger psychically holds up to the amount of stress and heat it will be enduring. I'm assuming he will go with a larger exhaust housing on the turbo now as it will spool faster with the supercharger on it. I'm pretty sure it will definitely pick up some bottom end, but I think It will sacrifice power at the top end. Overall cooling the air charge is gong to be a PITA.
Keep us updated on the progress...
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Cooling charged air is easy since the VF will redirect straight into the existing single intercooler, no PITA.
Different turbo housing, yes. Additional stress? - remember the air entering the supercharger is already compressed by the turbo.
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I don't think that intercooler by itself will be able to cut it, but it will help.
Additional stress will come from much hotter air in to the supercharger and much much much hotter exiting and the fact that it will be compressing a much higher volume of air. In theory the super charger will run a lot hotter and have more resistance on internal parts and bearings. You have to remember your trying to pump 400-500 hp worth of air threw it on the top end. That is what he was doing with the turbo set up isn't it?
If he want's more low end I think a Sequential Twin Turbo set up with one small turbo and then a slightly larger one would be the best bet for actual function. Plumbing it all however would be interesting to say the least...
Edit: Just fount the post over there.. I see he will be using a large intercooler so that should take care of heat going in to the engine.... It still should be fun to see how the little MP62 will handle it. But then us guy's over here on LT like me that have built in the neighborhood of 100 engines and transmission and tuned with multiple EMS's, built 20 or so 400-700hp cars don't know what we are talking about.
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I do know from a stress point of view supercharges and turbochargers are "supposed" to be designed to handle quite a bit more pressure than there operational range to deal with the high spikes. For example when the throttle closes and the BOV just starts to open for a very small amount of time the pressure against the compressor blades is much higher than it would typically operate at. In comparison the change relative to pre-compressing air is quite small, I can't say its not significant or that it wouldn't be the straw that break the camels back but i would be very surprised.
Personally I’m more a fan of the dual turbos as well but there is really no reason this concept won't work. The only problem I can foresee would be managing heat and if Franks going to run the same amount of boost I think it will be passed the surge limit of an MP62.
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...that's my thinking, too - dramatically simpler and lighter...
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