Supercharger Systems -4GEN Liberty/Legacy

[Spec BSC]

Spec BSC

Is your rpm max 6700, or is that the point of highest pressure?

Hi Tim, highest pressure achieved was 7.5psi at 7000rpm. Unfortunately the engine then expired but all my testing has only recorded similar readings.

OK, thats interesting. I would have expected more than .5psi rise in the last 300 or so rpm. Is your boost pressure more or less linear or does it flatten towards the high rpm?

Heres the read out from the rolling road pressure increases at a steady rate with no noticeable peaks or troughs.



The pressure plot is the rather flat looking line across the lower part of the graph. If you look back at page 26 of this thread there is the same picture I put up but you can see much more of the plot.

[Tradewind]

Spec BSC

Yes that looks good to me, no slip, steady consistent pressure increase, it is good power for the boost.

I am aware that some retuning of a car (Australian) yesterday resulted in raised boost pressure and power gains by changing cam timing (can be worth 1psi gain) in the tune. It is likely you can benefit also. The car features the basic spec supercharger with the cast impeller as was fitted during the time the kit was developed, no upgrades at all.

With the 58mm pulley the manifold pressure should be 9psi and the charger pressure should be 10psi, measurement of either is fine as a reference as the drop across the cooler is .5 to 1psi.

You would need to check with Matt/Kido about these timing changes and how it affects boost pressure and finally engine performance/smoothness.

As I knew, the 58mm pulley can deliver this pressure and it has, however the tuning is critical that this result is found.

Fit the 58mm pulley and have vehicle retuned with cam timing corrected - the higher pressures and power will occur. If you are changing pistons make sure to keep the compression at standard ratio so engine efficiency remains high at this boost pressure.

Something to keep in mind, altitude increase lowers boost pressure, all the testing by Raptor is performed at around 18m above sea level. Around 600m above sea level you will begin to notice boost pressure has fallen a fraction. Therefore if you live at a higher altitude than near sea level the boost pressure can be a touch less than expected at sea level.

[Spec BSC]

Spec BSC

Yes that looks good to me, no slip, steady consistent pressure increase, it is good power for the boost.

I am aware that some retuning of a car (Australian) yesterday resulted in raised boost pressure and power gains by changing cam timing (can be worth 1psi gain) in the tune. It is likely you can benefit also. The car features the basic spec supercharger with the cast impeller as was fitted during the time the kit was developed, no upgrades at all.

With the 58mm pulley the manifold pressure should be 9psi and the charger pressure should be 10psi, measurement of either is fine as a reference as the drop across the cooler is .5 to 1psi.

You would need to check with Matt/Kido about these timing changes and how it affects boost pressure and finally engine performance/smoothness.

As I knew, the 58mm pulley can deliver this pressure and it has, however the tuning is critical that this result is found.

Fit the 58mm pulley and have vehicle retuned with cam timing corrected - the higher pressures and power will occur. If you are changing pistons make sure to keep the compression at standard ratio so engine efficiency remains high at this boost pressure.

Something to keep in mind, altitude increase lowers boost pressure, all the testing by Raptor is performed at around 18m above sea level. Around 600m above sea level you will begin to notice boost pressure has fallen a fraction. Therefore if you live at a higher altitude than near sea level the boost pressure can be a touch less than expected at sea level.

Tim are the sc's tested for output when there made, do we know that mine is within spec? Don't think were going to find 2psi with cam timing but will wait for Matt s reply.

[Tradewind]

If a charger is in doubt I can test bench it where it is run to a exact rpm point at which it must make 5.00psi, if it falls below or exceeds this specific test value then an inspection/change would be made.

The charger is certain to operate as it should, in this application (EZ30) though the application is at the mid range of the superchargers capacity. The same charger is used on engines up to 5.0 liter in the 8-9psi range, plenty of mass flow capacity. As the application is mid range of the chargers capacity pressure (measured at the compressor outlet) is governed solely by charger rpm and tip clearance, given the impeller is always the same diameter. With exducer tip clearance, the closer the better, the range is .014" to .022" for the supercharger unit you have, you can check that by inserting a feeler gauge into the charger outlet and sliding between impeller vane tip and compressor cover, an LED torch is needed so you can see well. Checking and confirming that measurement will give you certainty the charger is adjusted correctly.

If the supercharger you have has a brass bung fitted near the supercharger outlet you can fit 1/8" hose outlet and then a gauge to measure the charger pressure directly. I randomly fit these brass bungs, check if yours has one.

What is the name of the city/town where your tuning shop is? I would like to check the altitude of that place so that we can approximate pressure loss to altitude for that location as well.

I can very easily swap another impeller assembly and compressor cover into your unit for you to try if you want, will give you peace of mind that you don't have something odd.

[Spec BSC]

Thanks for your reply Tim, when I get the car back in a few weeks I will measure the clearance as you suggest. I'm sure if will be fine just need to eliminate all the variables. The rolling road is in Farnborough, Hampshire, UK so you can check height above sea level.

[Aleks]

loud supercharger? or?

[Tradewind]

loud supercharger? or?

Aleks ??

There are liquid cooled and air cooled supercharger versions - The aircooled units can be heard a lot more than the liquid cooled models. That help?

[shav]

Not loud at all. I can vouch for that. Just a subtle whine to let those who notice such things that the car aint stock.

[3rspecb]

loud supercharger? or?

Click on the pic for a short video of it at idle. I'm running an air cooled Raptor S/C with billet impeller and 58mm pulley on my H6.

It used to be a lot louder with the cast impeller.

[Tradewind]

Let me be clear on noise

The watercooled chargers are always going to be the quietest after the initial run in. The transmission casing is entirely sealed and has a partial water jacket

The air cooled chargers can be a subdued whistle or some can be much louder, it all depends on the individual unit.

It does seem that running them in on the blower test bench here can result in a much quieter air cooled unit as we load them up really hard to bed in the transmission.

[3rspecb]

It does seem that running them in on the blower test bench here can result in a much quieter air cooled unit as we load them up really hard to bed in the transmission.

Tim did this to mine when i last upgraded the S/C

[Anson]

Mines still going strong
Have disconnected PCV valve hose from pod filter as engine was spitting oil into the pod filter/super charger.
Since directing hose in catch can, no oil has bypassed. Am thinking the charger was creating a vacuum.
Tim - Going to be replacing clutch in near future. During clutch change, Possible to sent you charger for new belt/checkup?

[shav]

Thats a cool video Anson. Car goes hard and sounds nice.

[Tradewind]

Anson

Yes of course it's OK to send it, email me a week before hand so I can schedule it in

[Tradewind]

There is word that Matt has a new tuning scheme for the Supercharged H6s - the results are promising and may result in the kits being rated at higher power outputs - if the increased airflow into the engine is anything to go by