Everything about the supercharger from size, pulley, pulley pullers, pictures, this is awesome. Thanks to Peter Scott from Planetsoarer.com

http://planetsoarer.com/boost/boost.htm

tried to post info here but the graphs didn't appear

 

Excellent resource material. THANK YOU for posting it.
It does suggest our Eatons are about maxed out in output.
If it take 25 horsepower to make 5 psi boost, It has to be upwards of 75-100 to make 12 psi. Worse, it it make 95 degrees temp to make 5 psi, it has to go of the chart for 12 psi. A hundred horsepower to turn and 200+ degree temp increase pre-intercooler? Not good numbers for sure.
It HIGHLY suggests water/alcohol injection would do wonders.

 

Great info......Now I know why it was so damn hard to get the stock pulley off

 

Sorry for the lame question, but what supercharger is used for the 1996 xjr? I am doing a swap (full drivetrain) I would love to get a diff pulley and step it up a notch..

 

The six cylinders XJRs use the M90 supercharger.

Somebody....Mina, I think....used to offer a pulley upgrade for the XJR/6 but lack of demand resulted in them pulling the product. Ask around...you might be able to find a used one. I know of only a couple people that had them and they took 'em off after not too long.

Cheers
DD

 

man, I can't believe how puny our stock crank pulley is. The stock mustang one is 7" if I recall.

 

Thanks for the info. Wnenn

 

about planetsoarer ideas,

increased valve overlap, reduces MPG, and runs rougher engines and increases emissions.

IMHO ,stock cams can be brought to extremly hi levels of power, and are easier to tune, meet emissions, good fuel milage.

he did not say any thing about NEGATIVE OVERLAP cam timing,?

 

On the AJ27 the bottom pulley size was kept relatively tame. The AJ27 step up ratio as stock was 2.08:1 and the AJ33 went up to 2.1:1. The 5th gen M112 has a maximum speed limit of 14000 rpm - and we're way under that. The speed was kept relatively tame in the interests of belt change life/intervals. In R and D pulley ratios up to 2.2:1 were tried with good results. Indeed the concept car XK 180 used a 2.2:1 ratio. Above this there is little gain as the intake restriction/losses become too great which makes the supercharger run at unfavourable pressure ratios.
If the intake losses/restriction could be tackled- there could be benefit to upping the ratio further.

 

i read that Eaton has released an M118 supercharger?

 

Theres now an m140, and a M122 however the new TVS series from Eaton are a generation ahead. Very efficient- peak efficiencies in the 70% region mean that the twin screw compressor or lysholm compressor no longer has the decisive advantage they used to.

 

I would even go further than that, imho it is a no brainer, when running conservative boost levels, the TVS is probably as good or better than the twin-screw if you compare equally sized units.

However at higher boost levels (think from 15 or so) the scale will tip again in favor of the twin-screw, especially when you also increase the internal compression on the twin-screws like on the Kenne Bell ones, then they will become better and deliver more power. As this is not a common boost level on production cars, I would say that the TVS has a clear advantage in that area, bet it is even cheaper to produce for OEMs in large quantities.

 

they do have the m122 blower now but they don't have anything that is a direct replacement for our 112. I've seen the m118 mentioned on the internet, but I think it was a typo; eaton doesn't have any info on that on their website.

I asked Magnussen if they made or knew of anyone doing modified rotors for the m112. They said that eaton offered a slightly different set that offered a very small amount of top end, high boost efficientcy. They also said that they can't even get those anymore. I believe that magnacharger had a graph of the two rotors on their website at one time.

In my opinion, the problem with our setups is the intake track as Count mentioned above. Re-geared and ported Eatons make quite a bit more power on the mustangs. Everyone knows that positive displacement blowers are sensitive to intake track restrictions. I doubt any of us even has 400 rwhp on our cars with a regeared or ported eaton with the hp limiting factor being the intake track and lack of tuning....

I may be wrong, but I know I'm not seeing any additional top end performance from spinning the blower any quicker. At least my trap speeds don't indicate any additional power (although I've only run the 1/8 mile).

 

anyone using turbochargers on the newer Jag V8s?

seems as tho they can make serious power on USA v8s, and on European(german) cars!

and forget the rice rocketts there outa control, a 4cyl. makin a 1000hp, seems like a handgrenade with the pin pulled

 

AVOS, I'm confused, please educate me.

I thought a TVS WAS a Twin Screw. What is the difference?
You fitted the 2.6 liter Kenne Belle Twin-Screw to your car and his. In the Modern Sporting Icon book it says your buddy Norman Durban's car was putting out 650hp but he detuned it to 550hp. Is that for real? Is he really getting that much power out of his 4.2 with your Supercharger kit? What is a safe limit on a 4.0 engine? I know head gasket sealing is a limiting factor.


ADDED...later
OKAY THINK I know now...a TVS is another name for ROOTS type? If so I know the difference.

 

In simple terms, the old style M122 roots is pushing air similar to the old Mississippi steamboats paddles, and the TVS is functioning more like the modern screws used on boats. The difference between the TVS and Twin-screw is that the latter compresses air in the casing itself, and that becomes more efficient at higher pressures.

I can’t speak for the performance figures Normand is giving, this was from the handmade version I have made utilizing the stock throttle body, and he has some other mods on his car then I have on mine. Also we do not have engine dynos, so any number mention is just an estimate.


The KIT I have is different and more powerful as most of the intake inefficiencies are resolved, and that leads to less power consumption of the supercharger, more boost, so end result more power to the wheels (especially top end).

For my KIT (and the one Normand has) the power is not limited by the twin-screw (contrary to the M112 roots blowers), you can select the power level for yourself by simply changing the upper pulley, and this how you determine the power output.

Just in upper pulley I can still go much smaller to achieve 25% more speed on the twin-screw than where I am today, but I may flirt already with some boundaries, so each next step will have to be done with care. Also you get then into boost levels that would require higher octane fuel to be safe against detonation. Once I have installed my new 3.5” MAF (another restriction in the system) I will try to go further, but this is not something I will advise others to do.

For now in street setup (so normal fuel) I am somewhere between 480-500 rwhp (on a single drum type of dyno), and assuming a 17% drive train loss this would translate to about 578-602 bhp.

Some in the states even dare to go to 22% drive train loss, but I just don’t believe that as that would mean even 615-641 bhp.

This is the main reason I only look at rwhp figures to get some idea, as engine hp will remain just another estimate.

 

Wow that is huge! More than enough for some serious fun. Using your 17% drive train loss, a 370hp 4.0 would have about 307hp RWHP.

Would you please answer a question about DIN rating. Today in the US the standard is SAE Net (I think) with all the ancillaries in operation i.e. water pump, power steering pump, alternator (probably not with the AC compressor engaged). As I think I understand, Jaguar's DIN rating is without the above in play. So would the SAE Net rating (at the flywheel) be about 300hp or a bit more maybe? As I remember, back before 1971 the industry used a gross rating, so for example, the 1965 Fuelie Corvette rated at 375hp would be NET rated today at maybe 80% or 300hp.

 

Am not sure about the exact differences between SAE Net one and the DIN now used in the EU for correcting the power. Both are with the ancillaries you mention, but it was more a difference in temp/pressure in the correction factors between the 2.
Here is an example of how the SAE is calculated from dyno figures.
Equations: Dyno Correction Factor and Relative Horsepower

 

what is the difference in eaton superchrger numbers like M112 vs an Eaton R2300??

 

I'm sorry for getting this thread off topic a little bit. I've read that Jaguar rated the 4.0SC AJ27 at 370hp DIN; which I was lead to believe was a rating without ancillaries. As opposed to SAE Net which today is with ancillaries.

I sent a PM to Count IBlis asking about this..he replied he knows the dyno testing done by Jaguar was with "idler pulleys" (in lieu of the actual parasitic drag caused by the alternator and power steering pump). He believes SAE is about 98% of DIN. But is this the "Net" figure. So I'm not sure if my basic question has been answered. That being:
What would the Jaguar engines be rated at by US, SAE Net standards which are the HP figures stated in the automotive magazines.