Turbo upgrade alternative, Supercharger

[slickd1]

Had a thought, what if we just got one of those belt driven, snail shaped superchargers and used it to help our little turbos do less work for more boost?

Exactly the same as the magna guys do, except we have turbos, so its kind of like a compound turbo setup for us.

Pros/cons?

Some reason it wont work?

If we run a bar across with a bearing on each side we could have it sitting on the intake side and there would be bugger all pipework that would need changing.

 

[Kaldek]

Manifold work required, plus intake pipes to intercooler. Can't see much change from five grand or more. How much are the supercharger units?

 

[Kaldek]

Oh wait you're saying in addition to the turbochargers. That sounds like a lot of engineering design. More cost!

 

[slickd1]

I mean this style, no manifold work required, a centrifugal supercharger to help our turbos where they struggle.

 

[slickd1]

https://www.google.com.au/search?q=...AhUDx7wKHe9cBFAQ_AUICSgB#imgrc=9Iz13ltvtqftmM:

 

[slickd1]

This one... Soz been a while since i forumed on a phone

 

[Jakevr4]

Bullet superchargers reckons not much change out of 10 for a c38 Rotrex, and and that's if they can get it to fit.
I think it was a scare quote because they weren't interested in working on a galant, I got this attitude from every place I have been to with this stupid car.

 

[6A13TT TYPE S]

I could go on a big speil about compound charging and the 50 different ways you can go about it with a centifugal charger but I can't be bothered sitting here for hours writing it all and you probably cant be assed reading it.
so ill just say this. for the money you would spend making it work with stock turbos for a reasonable power gain over stock with stock like response, you could make more power with a small to mid sized single turbo or upgrade the twins.
Superchargers by nature are far less efficient then turbochargers, and although centrifugal supercharges are more efficient than rootes or screw blowers they have a more or less linear boost curve
http://dsportmag.com/word/wp-conten...Boost101-PosDisplacementSuperchargerCurve.jpg
you could make it work but there would be a hell of a lot of time and money going into it to make it right. and why bother when other options are proven to be better, for example..

At work we have done 4 compound setups opposite to what you are proposing. (3 4AGZE's adding turbos and one 4G63T adding the supercharger)
Small positive displacement supercharger fed by a large turbo.
this way at low revs the boost comes on like a switch with the supercharger. like in the case of the Evo it has a toyota SC14 (from a 1G-GZE) which makes about 8psi as soon as you step on the gas.
then the positive displacement supercharger sucking air through the compressor of the turbo helps bring the turbo onto boost quicker. and once the turbo is on boost the supercharger multiplies that pressure due to its positive displacement nature

remember positive displacement superchargers multiply the pressure fed into them at a rate dictated by a few factors such as
-their displacement per revoloution
-how much air the engine consumes per revoloution
-the crank to supercharger pulley drive ratio
and so on
So with 8psi boost aka "gauge pressure" which is 22.7psi absolute pressure (gauge pressure plus atmospheric pressure) out with atmospheric in (0psi boost + atmospheric pressure = 14.7psi absolute) gives (22.7/14.7) 1.54:1 ratio.
So if you have 15psi gauge boost from the turbo (29.7psi absolute x1.54 = 45.7psi absolute) = 31psi gauge

so doing this means not only does a larger more efficent turbo come on boost earlier. but even before the turbo is on boost your supercharger is already providing boost. and even only working the turbo at a mild 15psi (not working it too hard and pushing it past its best) your still able to get 30psi at the intake manifold out of the back end of the supercharger.

in a VR4 finding the space to mount the supercharger is the issue but with the evo we just made a bracket, hung it under the intake manifold above the front axle, and switched cold side intercooler pipe from the intake manifold to the supercharger and then connected the outlet of the supercharger to the the intake manifold. super simple!

 

[Kaldek]

I think it was a scare quote because they weren't interested in working on a galant, I got this attitude from every place I have been to with this stupid car.

This is why I immediately liked Rick from Intense turbochargers. He admitted that this work is very bespoke and most places aren't interested. It really is hard to find places that are willing to do custom work.

 

[slickd1]

Thanks for the responses guys! Good to have this up here for the next person thinking about it.