hey guys, just a quick question. i was wondering if its possible to put a supercharger and a turbocharger on my car (or any car for that matter). like what are the advantages and disadvantages, will it wreck the engine.....etc...
:confused:

Yes it's possible. It's been done more than once, and discussed in this forum more than once as well:) Not worth it though, as it will cost you an arm and a leg.

hmm what kind of horsepower do u think i would get. say from my inline 6 thats got 200 horses. with a super and turbo wouldnt that be like rediculous compression?

Originally posted by The CoCoNuT BoY
hey guys, just a quick question. i was wondering if its possible to put a supercharger and a turbocharger on my car (or any car for that matter). like what are the advantages and disadvantages, will it wreck the engine.....etc...
:confused:

ON your car!!?? How about on your engine!! (just kidding)

Seems redundant, how about for ignition you use both a sparkplug and a hot-tube? And you use both a carb and FI? And each wheel has both disk and drum brakes, and you use acetelyne and electric lights, a crank a pull rope and an electric starter - all at once!

Point being - one kind of forced induction is enough for one engine.

I actually love the idea for cars that don't get the low end torque they need. But you wouldn't run them together, it would be sequential.

You would have the supercharger run until your big turbo spooled up ;) This gives you all the low end benefits of the supercharger, and gets rid of the turbo lag of a bigass turbo.

And why do people use one big and one small turbo in some twin turbo setups?

Lets not forget the complex as hell fuel management system you'd need to devise up to run such a setup... for the sake of your sanity. Just stick to one type of Forced Induction.

Well, I guess I should have have warned you, I'm no where near sane. I'm also friends with Cbass, I think that might clear some things up?

hahahaha

Originally posted by Deakins
And why do people use one big and one small turbo in some twin turbo setups?

Not all twin turbo setups are like that. The Skyline GTR uses a parralle settup while the RX7, Supra, and Subaru Legacy GT turbos use sequencial.
The reasoning is the smaller turbo or primary turbo enables low rpm boost to occur while once the rpm's increase the larger turbo then begins to take over. This give you in theroy a much better throttle responce and broader power band. The major draw backs is the primary turbos tend to over boost and die easily.

Originally posted by Deakins
in some twin turbo setups

:finger: :right:

Yes, a single turbo system is so much more mechanically sound then a twin setup, I am still confused as to why so many cars use twin turbo setups. Obviously having a broader powerband is appealing to a market, but at the cost of massive amounts of money when the system breaks?

http://www.autosportracetech.com/RX-7/TurbochargerBig.jpg
That is an rx-7 TT.

Twincharging combines the benefits of both the turbocharger and the supercharger. The best example I can think of is the JDM twincharged MR2 MK1. The supercharger makes good low end boost, and this makes for more exhaust pressure, which helps the larger turbocharger spool even faster.

Twincharging is a pretty good idea, especially on smaller displacement engines making lots of power. Coal's 1.0 Turbo Suzuki G10 engine is a good example of this, as is the 1.5 liter 4AGTZE of the MK1.

I once saw on TV a drag Camaro with Twin Superchargers, Twin Turbochargers, and nitrous in some shape or form, i cant really tell you, this was about two or three years ago.

i didnt know it was even possible to have twin superchargers!!

Originally posted by Deakins
And why do people use one big and one small turbo in some twin turbo setups?

smaller turbo boosts low end torque, large turbo boosts high end horsepower, both turbos paired boost the mid-range

Originally posted by The CoCoNuT BoY
i didnt know it was even possible to have twin superchargers!!

I assume that they were using two centrifugal superchargers, or one centrifugal and one roots type.

Nope, back in the late 50's and early 60's twin Roots blown engines were a solution to the NHRA's "fuel ban". You see, in 1959 or so, nitromethane cars were deemed unsafe because speeds were going beyond the primitive tire, suspension, and safety technology of the day. Thus, rails were forced to run gasoline. Many bizarre contraptions were birthed during this period. Here's one Eddie Hill drove that had two engines grafted onto one crank. http://www.pontiacheaven.org/images/jpgs/pontia27.jpg

In recent years, multiple induction setups have been used to either overcome lag or show off fabrication skills in the classic 80's Pro Street movement. The most famous of these cars is Rick Dobbertin's Pontiac J2000. This car had two turbos and a Roots type supercharger. It's considered the world's wildest Pro Streeter and was Hot Rod Magazine's Car of the Year in 1986. Here is its engine. http://web.rosenet.it/funnycar/assets/images/Dob_engine.JPG And here is the car. http://www.auburnmoon.com/2003.jpg

Spooky, huh?

Going from what Octagon said, would it not be possible to have 2 (roots) SC's, with one on each head of a "V" style engine?

Originally posted by tman2093
Going from what Octagon said, would it not be possible to have 2 (roots) SC's, with one on each head of a "V" style engine?


Yeap, that's exactly what Eddie Hill's car was...Check out the first pic in Octagon's post above. Two V8 engines, grafted onto the same chassis, each spirited by a seperate roots blower.

There was an insanely nice looking black Corvette one time on ebay with twin superchargers. Guy sold it cuz his big ass couldn't fit in it.

Self, Im not sure that we are understanding each other. What I meant was, Picture a V8. Put a roots style SC on the left cylender, and a another on the right cylender bank. Octagon's picture has 2 engines, whereas I am trying to do it in one engine.

Originally posted by tman2093
Self, Im not sure that we are understanding each other. What I meant was, Picture a V8. Put a roots style SC on the left cylender, and a another on the right cylender bank. Octagon's picture has 2 engines, whereas I am trying to do it in one engine.

Oooohh, ok, I'm reading you now. I misunderstood the first time. Um, I don't think you could do that really...The way roots work is that the sit atop the intake usually and feed directly down into it I think. If you have two of them, both wouldn't fit on the intake. But I could be wrong...anyone else know if this would even be possible??

I think you would run into problems routing the air around the valvetrain, but I could be wrong.

like the ol saying goes anything is possible with money......

heres a though...



I would run it similar to a VG30DETT intake setup. Each bank of cylinders has its own plenum, its own throttle body etc...

Have a roots built for 4 cylinders.... run it on that side and have it run into its seperate plenum and runners for that bank of cylinders, likewise for the other side.

That would require some trick belt placement lol.

Originally posted by SR20DETpower
like the ol saying goes anything is possible with money......
heres a thought...
I would run it similar to a VG30DETT intake setup. Each bank of cylinders has its own plenum, its own throttle body etc...

Have a roots built for 4 cylinders.... run it on that side and have it run into its seperate plenum and runners for that bank of cylinders, likewise for the other side.

That would require some trick belt placement lol.

Yea, I figured you could do it that way...man, that's a lot of work though, a completely new upper half of an engine ust about. Not to mention the wild belt routing like you said, hehe.

Its possibel to run twin roots on a single V8

I've seen it in person, theres a guy around here with a KUSTOM setup. Its in a old Ford with a Chevy dropped into it i believe.

Its got Twin 6-71s tilted at about a 60* angle with a Kustom intake that holds both superchargers. Its go four carbuerators, two for each blower. Its also got a huge belt that runs between both Blowers and the crank.

Veryy odd looking, it does run.. it moves under its own power to the local car shows.... i've never seen it run.. but it gets there. In other words I dont know how well it runs, but it does cause I've never seen a trailer hiding anyplace in the near vincinity.

I'll try to get a picture of it next time we have a carshow... Its really sweet lookin cause its all polished out.

Originally posted by Self


Oooohh, ok, I'm reading you now. I misunderstood the first time. Um, I don't think you could do that really...The way roots work is that the sit atop the intake usually and feed directly down into it I think. If you have two of them, both wouldn't fit on the intake. But I could be wrong...anyone else know if this would even be possible??

Well you would have to have 2 separate intake manifolds. Which means you would have to run multiple TB's and you would have a hell of a time getting them synchronized. I'm actually considering doing something similar to my car, a single turbo feeding twin intercoolers, each IC going to one of 2 throttle bodies (one for each "side" of the engine), and a small custom manifold for each side. I have no practical reason to do this, but it would be cool. :D

There was a picture floating around the internet a while back of a Lamborghini Diablo with twin roots SC's. And a little more recently was a Skyline engine with twin turbos and a centrifugal SC.

Edit: nevermind, dude up there beat me to the explanation part. :p

Originally posted by R1-rider
Yes, a single turbo system is so much more mechanically sound then a twin setup, I am still confused as to why so many cars use twin turbo setups. Obviously having a broader powerband is appealing to a market, but at the cost of massive amounts of money when the system breaks?


The most common reason for using twin turbos is space. It's easier to package 2 small turbos in an engine bay than one larger.

Or if you're aiming for extreme power levels, twice the turbos means twice the flow. Look at the Bugatti EB110, it was a quad-turbo from the factory :eek:

Some people do twin turbos for the "ooh aah" factor.

Or there is the concept of turbocharging a turbo - series turbos... The outlet of the 1st turbo is piped directly into the input of the next. A turbo doesn't really care how much boost it makes, it only cares how much it has to compress the air over what it was when it came in. So say you use 2 turbos that will compress air 3:1. Air comes in to the 1st turbo ar regular ambient air pressure (14.7 psi, but we're just gonna round it to 15psi so I can do it all in my head ;) ) so you have 15 psi in, the turbo compresses 3:1, and air comes out at 45 psi, which would be 30 pounds of "boost" over regular air pressure. Then it goes in to the 2nd turbo at 45 psi, 3:1 compression, comes out at 135 psi, subtract that 15 psi of ambient air pressure, and you've got 120 psi of boost, way more than you would get through any conventional turbocharging.

Now what you're gonna do with 120 pounds of boost is beyond me, but there ya go :hehehe:

well, from the article in one of the random magazines ive read over the previous months (turbos of the future, dave coleman, sport compact car june 2003 volume 15 issue 6) that sounds eerily familiar to what you just said. Diesil fuel trucks like boost becuase they use direct injection, so they can put as much fuel pressure as they want, meaning they can use as much boost as they want.

anyway, back to twin charging, i have a picture attached that shows a RB26DETT with a supercharger. the explination (to sum up all the previous messages) is that the supercharger makes boost at low rpm's providing the bottom end torque that the V8 guys like, then at (estimated and approxamite) 4500rpm or until the turbos are making more boost than the supercharger. Then one of two things could happen, either the supercharger stops (either through a clutch fan type mechanism or through a type of BOV) or it keeps working in conjuction with the turbos to increase air flow (not boost pressure). This way you get good bottom end, very powerful mid-range, and the high rev power of the turbos.

The fuel system wouldn't need to be modified too much since it only cares how much air it is getting, not where it came from. the same is true with the ignition.

my idea, wich is very theoretical at the moment, is to put the supercharger directly into the air tract from the turbos, causing the turbos to feed into the supercharger. What this would do is at low rpm, the supercharger would function a little below a normal one because it is literally sucking the air through the turbo, however this would cause the turbo to spool up much quicker since it is not just the exhaust gasses, but also the difference in intake air pressure that is causing the turbine to speed up. This would also act like sequential turbos because the already compressed air from the turbos (at mid and high rpm) would be again compressed causing the effect that i have explaned above.

any feedback?


also, i know that blitz made a twin-supercharger kit for the lexus sc300 (Toyota Soarer) i would post a pic, but i cant find a pic of it, i know it was in a superstreet article (yes i read that ricey magazine, but only because they send me posters every once in a while)

I cant believe you guys are having a conversation about twin turbo engines and you have forgotten the best twin turbo engine of all time- The porsche flat six twin turbo. Some of the crazyiest street legal cars run with this motor.

Just check out some of the european car magazines- Theres always some nut in there with a twin turbo setup running an easy 800 hp and a top end of 220 mph or so.

thats because were not talking about twin turbo engines, we are talking about twincharging, not twin turbocharging, twin charging is when you have both a supercharger and a tubo. its just that some of the engines we are talking about (and subsequently have pictures of) are factory twin turbocharged.

You COULD get a lot more flow through two superchargers than with one high-psi supergharger. However, I would think that centrifugal superghargers would make more sense than roots-style you could also run them through intercoolers and then into each bank of cylinders...

Somewhere I saw a drag car that had a dual overhead cam V-8 and that had been modified to accomodate 4 small centrifugal superchargers (one driven by each of the 4 cams).

If you were hellbent on running roots style, you would have to use two seperate intake manifolds for the two banks of cylinders, unless you made one intake manifold that sourced from two superchargers, put the compressed air into one plennium and then split it again to go to the two banks, but even then you would still need an additional throttle body and some kind of increased carbeurator or fuel injection...

unless you're rich it's probabaly not worth the cool factor...

good luck either way
-MR

thanks guys, i undertstand how it works now! haha woohoo!
twin charging for me then.