Tuesday, February 03, 2009 - 06:43 pm, by: Gary Swift(Garyswift87)
Has anyone ever seen or heard of someone installing a centrifugal supercharger on a JZZ31, or any soarer? despite only getting around 8psi of boost this seems pretty good, from what I've seen. Little or no lag! cheaper installation (I assume).
Tuesday, February 03, 2009 - 07:15 pm, by: David Vaughan(Davidv)
Why little or no lag? Centrifugal superchargers tend to show their effort at the top end. That is, there will be no lag between 4000 and 6000 RPM and no grunt below it.
Wednesday, February 04, 2009 - 04:35 pm, by: Mike Beck(Gold_40gt)
I attempted to S/C a JZZ31 with a M90, but after a time planning it, the costs for gain did not weigh up and during that period I got a UZZ31 which took over my interest.
A TT is a better deal, cheaper in the long run and saves all the hassles. If you want a FI six, just turbocharging it would be more logical than a S/C setup, all the parts are out there for it and its commonly done - but still cheaper to just sell your 3.0l and get a TT.
If you are determined on supercharging, your best to have a V8 to start with.
Sad, but that's how it is - not much you can do with a JZZ31 unless your set on keeping it and spending plenty on getting it up to speed.
Andrew Stewart TryHard Queensland Manual GT-T VVT-i Single Turbo
Wednesday, February 04, 2009 - 11:14 pm, by: Andrew Stewart(Daboom)
i have seen a fair few videos on youtube with people centrifugal supercharging IS300's and they seem to go pretty good. it depends on what you want. low end torque or high end pull. as said above a centrifugal supercharger is good for high revs (Dyno Queen) cars or drag cars. streeting is ok, but if you still want to supercharge, go a positive displacement charger, something off a 1G-GZE. they are a fairly decent size, otherwise i know blitz make a few that you may be able to adapt. if you do it, would be interested to see the results + it is something different
Thursday, February 05, 2009 - 08:59 pm, by: Steven Anderson(Cusscuss)
Centrifugal superchargers are very biased toward top end power, their boost production in relation to RPM is almost exponential.
Meaning that if you have a centrifugal supercharger making say 8psi at 7000rpm, you will only have 4psi at ~5000rpm
My suggestion would be a 2jzge-t, there are plenty of kits around that are suited for the n/a 2j's. There is a huge market because of all the supras/sc300s in the US.
Thursday, February 05, 2009 - 11:34 pm, by: Damian Ware(Frozenpod)
The JZZ31's are the quickest soarers off the mark from factory from what I have experienced. They are really responsive down low but have a poor mid range and a complete dead top end.
A centrifugal blower would suit the natural power curve of the motor, cams, ECU tune ect as it will add a lot where the factory system is lacking.
A centrifugal would be perfect for the track (with the ease of intercooler installation and added reliability of a lower intake charge) and good on the street if you set them up correctly. No point having a blower set up to produce 10psi at 8000rpm. Set it up to have for example 10psi at 6000rpm and you will have about 5psi at 3000rpm.
An intercooled 5psi at 3000rpm will surely provide very good gains and it is right in the very useable street driven range.
If you want something different and want to keep the car and not use turbos I say go for it.
Friday, February 06, 2009 - 08:02 am, by: Matthew Sharpe(Madmatt)
Funny, I'd say my JZZ31 is the opposite, pretty dull off the line and really wakes up around 4000 rpm, right thru to 6200. Its an arse as when it changes from 1st to 2nd, 2nd is so tall it drops out of the power band. 2nd to 3rd is OK though.
Friday, February 06, 2009 - 12:16 pm, by: Steven Anderson(Cusscuss)
Damian Ware wrote on Thursday, February 05, 2009 - 11:34 pm:
Set it up to have for example 10psi at 6000rpm and you will have about 5psi at 3000rpm.
No, you wont, thats the problem. What you described is a linear curve, it isnt linear, it's near exponential. You would see 5psi at about 4500rpm. Its the major downfall of centrifugal superchargers. They have other benfits, but as far as producing boost across a wide range goes, they are terrible.
Friday, February 06, 2009 - 01:06 pm, by: Damian Ware(Frozenpod)
Actually practicle boost seen in real world dyno charts for centrifugal blowers is near a perfect linear curve.
If you size them correctly you can achieve just over 1psi of positive boost at 2000rpm.
As for the graph you posted it is incorrect it is typically marketing BS.
Positive displacement chargers do not have a linear curve as it describes but a flat curve with near full boost typically at 1700rpm even better that the aerocharger.
With a centrifugal blower, you will achieve 1/2 of the maximum boost pressure at approximately 3/4 of the max impeller rpm because the boost is a product of the square of the impeller speed.
Friday, February 06, 2009 - 08:13 pm, by: Damian Ware(Frozenpod)
Close enough but the dyno chart starts at 100km/hr.
It isn't a good graph and I cant understand why dyno operators CBF connected up RPM. Either way it is not as bad as the graph you posted.
The graph you have posted is complete marketing BS look at the positive displacement blower curve it is not even remotely close to what they really are. In fact roots and twin screw blowers have a better boost curve than they aerocharger they are advertising.
Friday, February 06, 2009 - 09:26 pm, by: Steven Anderson(Cusscuss)
I completely agree re the aerocharger, i have no idea what it is or any interest in it but it had an exponential curve on it. The graph you posted is better, perfectly accurate and real world.
Centrifugal supercharges work like this. 1/2 Max RPM - 1/4 max boost ~3/4 Max RPM - 1/2 max boost (its actually just over 7/10ths) Max RPM - Full boost.
or if you want to look at the dyno sheet, there is a range of 0-200km/h 100km/h - Start of the graph - 2.5 psi - 1/4 max boost 142km/h (just over 7/10ths) - 5 psi - 1/2 max boost 200km/h - 10psi - max boost
Its maths, its exactly an exponential function, I dont think it can get any clearer.
Saturday, February 07, 2009 - 12:12 am, by: Daniel Clarke(Dieseltrain)
Centrifigal blown Soarers still have posted the most HP and quicker times to date though And running much less boost than any Twin screw or Roots style setup so far.
Saturday, February 07, 2009 - 12:55 pm, by: Damian Ware(Frozenpod)
I don't want to get into this argument again but centrigulas have proven themselves on the track and strip.
I think you will be supprised how well they will really go in real world conditions.
The US guy with a centrifugal is having traction issues off the line and has very good 60ft times.
From personal experience I have been in a LS1 that was running 9psi at red line (6000-6500rpm I cant remember exactly but pretty certain it was more than half boost at half rpm) and had 6psi at 3000rpm.
It have huge amounts of torque and with very sticky 275 wide p zeros it had massive traction issues.
Sure it is a 5.7lt but it was very impressive throughout the rev range compared to a stock LSI.
Anyway back on topic, up to you Gary what do you think its your car.
Saturday, February 07, 2009 - 03:06 pm, by: Daniel Clarke(Dieseltrain)
Yep Damian, i have a mate with an Alfa GTA 147 thats supercharged. Only makes 6psi and made 220fwkw. Car stock ran 14.7, blown it ran 13.3 . Not bad for a bolt on 6psi kit
Saturday, February 07, 2009 - 06:18 pm, by: Steven Anderson(Cusscuss)
On a track you might see similar results as they are always in their peak, but I dont know how you can argue about how something works with an example right in front of you?
My point was to explain how they would so their limitations are known, a twin screw or properly sized turbo will have a better low-mid range than a centrifugal blower, that is fact, there is no debate in it.
A centrifugal blower has 3 main advantages. 1) efficiency - output temps are quite low, especially compared to a roots type blower. 2) Cost - much easier and cheaper to install than a pd or turbo. 3) 'Bolt on' because they only make top end power, on a stock engine they will put less stress on it.
Saturday, February 07, 2009 - 10:55 pm, by: Paul Drane(Paulwd)
Steven Anderson wrote on Thursday, February 05, 2009 - 11:09 pm:
Noone has done a proper twin screw setup yet.
Been driven for over 12 months, at 9lbs of boost with stock injectors and factory ECU. 311HP at the wheels.
Now has a Wolf stand alone, bigger injectors and about 15lbs of boost, now that some issues have been sorted it just waiting to back for its final tune.
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