combining turbo and superchargers

January 30, 2006 9:57 PM

i know that you can take an engine and put two turbochargers on it, my question is can you take an engine and put a turbocharger and a supercharger on it?

The idea being that while turbos draw from the exhaust and supers draw from belts; could you combine the two to come up with some happy medium.

[disclaimer: this question is primarly acedemic. i'm really just curious if it's even possible]

[double disclaimer: i have a non-collectible 1965 Mustang (the engine and transmission have been upgraded to a 302 with a C6 tranny) that i am thinking about doing horrible things to. Since i can't get collectors plates, i was thinking it might be fun to turn the car into a proving ground for more modern technology, led display dash, GPS, high-end sound system, shoulder harnesses, etc.]

My understanding is that turbos are easier to deal with, but i really like the idea of building "the last of the V8 interceptors, eh?"

posted by quin to travel & transportation (13 answers total)

Half-bakery entry
posted by milkrate at 10:05 PM on January 30, 2006

It would definitely be possible. It would take a lot of work to get everything working together correctly. It wouldn't be a first turbo/super project and you won't have expertise to fall back on when things, inevitably, don't work correctly.

Turbos are more efficient than supercharges as they are using essentially waste energy. But my understanding is superchargers are easier to set up. You don't have the complicated exhaust plumbing.

If you want the last of the V8 Interceptors, go ahead and put a super on. I think superchargers are way cooler. Someday I would like to have a blower sticking out of the hood of my 72 Skylark. It already has a 455 and blower would just be awesome.
posted by 6550 at 10:12 PM on January 30, 2006

Well, you can put more then one turbocharger on an engine (The veyron has 4, I think the ford GT has 2) so I suppose you could put one supercharger and one turbocharger in an engine.

However, I think it would be a bit of an engineering challenge, because the pressure put out by the supercharger would be different then that of the turbo, so if you put them parallel, you would throw the engine out of balance or maybe cause air to run out the other one.

If you put them inline you might end up just reducing the total airflow. I think the reason you don't see this isn't because it can't be done, but just because it's a dumb idea.
posted by delmoi at 10:13 PM on January 30, 2006

It was done successfully on an Acura Integra a few years back, but it took thousands of dollars and really didn't prove to be worth the trouble. Neat trick, even though it wasn't that awesome.

I'd twin turbo the mother and have fun with the import kiddies by showing them what even a little displacement + forced induction can do.
posted by chrisfromthelc at 10:31 PM on January 30, 2006

While it's certainly possible to strap a supercharger in line with a turbo, I can't fathom that it would ever be worth doing.

If you want something slightly ridiculous, I'd throw my vote in for a compound turbo. (or if your wallet is uncomfortably thick, twin compound turbos).
posted by I Love Tacos at 10:40 PM on January 30, 2006

Sure it's possible. In fact, I think there were limited production run cars (check the lancia) in the 80s that were created to provide a "production" platform for Group B rally cars. These days, it sounds like VW has been showing examples at autoshows
posted by Good Brain at 10:44 PM on January 30, 2006

To expand upon what others have replied: yes, and the Lancia Delta S4 (google video) is the ultimate example of such a car. Lancia unofficially claimed that the car could do 0-60 in 2.2 seconds on gravel.

The motivation behind such a system has to do with the way the different induction systems work. Superchargers provide lots of power at low RPMs, while turbochargers provide lots of power at high RPMs. You can put both on the same car, but you need a clutch that will automatically switch between the super and the turbo at the right RPM.

The problem is that if you do it right, you will end up with far more power than your Mustang can handle. If you don't destroy the engine, and manage to build a drivetrain that can transmit the power to the wheels, you will have an insane amount of power in a vehicle that is already a less than excellent cornering machine. This might be useful for drag racing, but then you would want to find out if there are any classes that allow mustangs with both turbos and superchargers.

Some google video of the slower Lancia Delta Integrale:
on a rally course
spinning on pavement
posted by b1tr0t at 11:07 PM on January 30, 2006

A common term for it is twincharging and it's been done many times! In fact, I was just talking to a guy this past weekend who blew up a twincharged Mini Cooper S. :) Anyway, knowing that term should give you plenty of Google fodder.
posted by knave at 11:32 PM on January 30, 2006

Seems to me the reason you might want to do this is two-fold: by starting with the supercharger you elliminate the turbo lag, and when you switch from super to turbo you're using exhaust gases, rather than the engine to blow more air in. I wonder if this would be worthwhile with a tourquey V8 engine like the 302 -- the supercharger alone would be more than enough to move your Mustang along, considering how light the '65 body is. I'd put the extra money in suspension mods to keep it on the road with that kind of power.
posted by SteveInMaine at 7:11 AM on January 31, 2006

The turbo and supercharger both increase horsepower by cramming more fuel/air mixture in your cylinders, effectively increasing compression. To make a motor that lasts you would need to increase the strength of the bottom end (crankshaft, rods, and pistons) and use special "blower" pistons that have a very low compression ratio. Considering that a blower setup is around $2500 and a turbo is about the same and an engine rebuilt with crank, rods and pistons for $3000+.... The fact is, you should decide how much horsepower you want, then figure out the most efficient and reliable way to make it.
I love the idea of updating an old car though. I'd put that money in a new aluminum V8 with electronic fuel injection (cutting weight is one way to increase performance and efficiency). Now you can use that onboard computer to tweak the engine. Then get a new 5 or 6 speed manual trans from a new mustang (w/ overdrive). Get a disc brake conversion (if it doesn't have them already), coil over shocks and a-arms with negative roll.
Check out Art Morrison's GT-55, a '55 chevy that pulled .94 G's on the skid pad.
posted by 445supermag at 7:19 AM on January 31, 2006

This has been done on airplanes for years. The B-17 used this very configuration in order to provide the power it needed to reach altitude. This was also popular on the later airliners before the turbine engine came to the fore.
posted by Elvis at 8:59 AM on January 31, 2006

As others have said twincharging has been done lots, both on cars and airplanes. Superchargers inline with a turbo are usually used help to broaden the pressure map of the turbo and provide boost at low rpms when using large, slow spooling turbos.

IIRC the engine bay on a 65 mustang is fairly tight for a turbo setup, there is lots of exhaust plumbing and not a lot of space side to side. Packaging is much easier for a supercharger (cut hole in hood, done) and of course there isn't anything cooler sounding than a roots blower. On the down side the effecience of a blower um, blows compared to a turbo, and that goes double for the roots style. Plus a blower is always drawing power even at idle, a turbo only draws power when you are on the loud pedal.
posted by Mitheral at 9:19 AM on January 31, 2006

Thanks for the responses everyone. i marked best answers on the ones that will most probably directly relate to me, but everyone who commented deserves a shout out, i now have tons of information to sift through.
posted by quin at 4:46 PM on January 31, 2006