Judging by all the turbo vs super debates floating around the net, I think I might already know the answer to this question.

However, is it possible to have BOTH a supercharger AND a turbo or twin-turbo on the same engine and the same time?

If not, why would that be?

Thanks for the help!

sikander

 

Someone here will be able to give you a more technical answer, but I believe you can only apply so much boost that a motor can handle.

 

If you run a 8lb supercharger into a 8lb turbo you have 8lb's so it would not help. There are siquential turbos (twin turbos) mostly for imports though. They use two different size turbos to help with turbo lag. The smaller turbo can spin up earlier and the larger at higher RPM's. For V8's there are mostly twin Turbo's of the same size, it is more effeciant to run one per 4 cylinders.
I hope this helped

 

yes you can turbocharge and supercharge the same engine, mostly occurs with roots type supercharger for low end hp and torque and once you get goin the turbo takes over with its good top end power!!

here a few links that show it is possible: http://www2.msstate.edu/~sgn1/MR2/mkimod.htm
http://www.automotiveforums.com/vbulletin/t50283.html

 

Large semi trucks used to use both years ago - but I believe they are all using turbos now.

 

Awesome! Would you use single turbo or twin turbo? And does it ruin the engine's life?

 

Depends on what you want out of your vehicle. Two small turbos will spool up fast but not have much on the top end. A large single turbo will take time to build up boost, and be slow off the line, but a rocket on the high end.

 

IMO, to much complexity for very little gain in an automotive application. Its hard to beat a well designed turbo set-up.

Probably for the cost of throwing together a turbo/super-charged combo, you could apply more conventional methods to out perform this set-up.

heck, you would probably smoke the turbo/sc set-up using a a turbo/nitrous rig with the nitrous plumbed in soley as an aid to the turbo (reducing spool up and reducing charge temps)

 

A turbo setup is so efficient that adding a SC on top of it is really a waste of money. A good sized single turbo can put out more power than almost any engine can handle.

Superchargers are great because they are simple and easy to install, but turbos are the shizznit.

 

Or you can keep the engine n/a and get more power out of it by other means.

 

Or you can get a lysholm type twin screw supercharger, i.e. kenne bell and whipplecharger. Instant low end torque (like a roots blower) and massive high end power ( like turboes and centrifugals).

so....twin screws rock.

 

Definately the Twin Screw SC, quite efficient from what I've been reading,
more than enough HP at low and high RPM. and the price seems competetive as well.

 

Actually, a turbo well matched to the engine's airflow and power requirements will produce more low-end torque than a twin screw supercharger.

The only downsides to a turbo vs. a SC is cost and complexity, and the cost differences are disappearing for Mustangs. Turbos make better low-end torque AND better high-end power.

 

Actually, a turbo well matched to the engine's airflow and power requirements will produce more low-end torque than a twin screw supercharger.

The only downsides to a turbo vs. a SC is cost and complexity, and the cost differences are disappearing for Mustangs. Turbos make better low-end torque AND better high-end power.
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prove that one to me, slick..... how do you figure a turbo can produce more low end torque when it hasn't even spooled up yet?
I agree that a turbo can create more boost than an SC but it's all up top, and it can only do so much good considering you're heads can only move so many cfm. I think turbos are retarded on a V-8 that red lines at 6500 rpms.... there's no sense in it at all.
Most people don't have the money to spin a V-8 up to 10-12K, much less 8000 rpms. You'd have to get the engine spinnin' that fast to make the turbo worth it, and by then, you're floating your valves anyways. Turbos are for 4 poppers and sixers.... they don't make much sense on a production V-8.

 

A turbo WELL matched to the engines size will make low end. The maximum amount of boost a turbo can supply to the engine is regulated by the wastegate, which is set to bleed off any xtra pressure over what it is set at. Say you have a mild turbo setup with about 8 psi of boost. On a turbo that's not oversized it will spool up quickly. While the turbo can put out more boost at higher RPMs the boost curve will stay flat at 8 psi because of the wastegate. If your running 8 psi on a roots blower you will probably make slightly less just due to parasitic losses needed to run the blower. However, when the boost goes up, the roots blower will put more low end than the turbo.

 

That's the deal with a screw type SC.... they don't have to spool up and are running 100% right off idle. There is a super flat boost curve and as for the parasitic loss, run a slightly smaller pully so that you're at the boost level you want to be at. As for a roots blower, that's a different story.... they are barely even 50% efficient at best. They aren't a good blower at all. I'd run a centrifugal blower like your Novi, and for that matter, a turbo before I put a roots blower on anything.

 

Sorry, when I said roots I meant positive displacement blowers in general. Twin screw is the way to go

 

oops... and I didn't mean to accuse you of running a Novi... that was MrMorden.....
Anyways..... I'm still gonna get screwed..... run a screw type blower, that is.... and I'll put it on the line with anyone turbocharged at the same boost, and see who gets to the end of the quater mile quicker....
But, as for now, I'm only bench racing... I'll have to wait until this fall to put my money where my mouth is. .... I'm seriously considering waiting for the Mach 1 (or whatever SE) comes out.... I'd like to go with a 5.4 if there is one... I'm waitin' for the '06, and if there's gonna be an SE, I'm thinkin' it's worth the extra pennies.

 

prove that one to me, slick..... how do you figure a turbo can produce more low end torque when it hasn't even spooled up yet?
I agree that a turbo can create more boost than an SC but it's all up top, and it can only do so much good considering you're heads can only move so many cfm. I think turbos are retarded on a V-8 that red lines at 6500 rpms.... there's no sense in it at all.
Most people don't have the money to spin a V-8 up to 10-12K, much less 8000 rpms. You'd have to get the engine spinnin' that fast to make the turbo worth it, and by then, you're floating your valves anyways. Turbos are for 4 poppers and sixers.... they don't make much sense on a production V-8. [/b][/quote]
Depends on your definition of low end, Slick.

A Turbo will generally be making full boost by 2000rpm. Since it's is not eating 30-60 horsepower in turning the compressor off a belt like a supercharger does, it is making much more torque at 2000rpm than any supercharger.

I'll grant you that the twin screw will be making full boost off idle, but how much useful work gets done there? None. And even if you have all that boost at idle, you'll be traction-limited in what you can put to the pavement.

A typical twin screw blower might put out 400rwtq below 3000rpm at 8psi...a turbo setup at the same boost level can easily put out 450-500rwtq below 3000rpm.

It's just physics -- you can't get around the blower having to turn that pulley. Slick.

 

Awesome! Would you use single turbo or twin turbo? And does it ruin the engine's life? [/b][/quote]
I am no pro here but my understanding is that sequential charging is ridiculously difficult and usually not worth the effort. Bi and Quad turbos are more effective.