Hello all. Happy Weekend.

I am having a pulley made for my V8 Supercharged engine, the reason i am not buying one off the shelf is that I am need to incorperate a drive for a dry sump. I have a few questions that I would like opinions on please.

The normal upgrade is 16%, is this simply a 16% increase in size ? If so, because I am having a pulley made from scratch, is there anything stopping me having a bigger pulley which will negate changing the size of the top pulley.
20% ? 25%. Do i need to investigate max blower speed and go from there ?

Anyone know current blower speed vs max usable blower speed ?

My engineer has taken off the front charger drive, he is wondering where the best place to mount the new pulley to. I have sent him the damper that I saw in various pictures but i cant find them now.

The guys i am using are old school father and son. They are building a crazy supercharged drag bike, so I really trust their workmanship.

Does the supercharge cush drive act as a damper for the charger ?

Can we fix the new pulley to the inner or outer pat of the pulley ?

Ideally should my dry sump drive be damped ?

Would be great to get some feedback , especially guys like Avos if he is still around these parts ?

Thanks all

 

Running in stock configuration the m112 is on the edge of its max efficiency, don't think going much bigger is going to accomplish anything other then heat soaking it and going through bearings quicker. I'm running the larger lower pulley and smaller upper pulley with re-mapped ECU. You can't just throw pulleys on it and expect the fueling to know what to do with it. Anymore boost then what mines running would be over kill. My P.O also had the (correct me if I'm wrong atb) ARP stud kit installed with uprated head gaskets and I put an increased flow aircharge coolant pump on to increase flow/cooling. Probably something else you want to consider if you are dramatically increasing boost. Remember the right hand has to know what the left hand is doing and has to be ready for it.

 

Thanks for the reply.

The engine is more of the discussion so I posted in a V8 thread, it will be in a XJS, running standalone ECU, no Cats, separate charge cooling circuit, the charger will be will ducted with bonnet scoops. Modified cold air intake system. Manual gearbox.

Its a project, i have a standard running engine to go in, but i also have another engine i have stripped, de-coked, will port and polish heads, and supercharger side of things. Renew with 4.2 gaskets.

I have read many threads, and these engines seem quite happy to take more power and I fully understand the limitations of the Eaton. At the moment a TS is out of my budget as I need to get the car actually up and running.

I have read about the many mods, but I have to have a drive made for the dry sump pump so thought I might as well enlarge the pulley. The Car will weigh considerably less than an XKR/XJR so i will be gaining that way as well.

 

Anything will weigh less then the XJR! Mine is at 5005lbs according to the door sticker and I know my XJS is well below that. If I could drop my current XJR drivetrain in my XJS it would be far more formidable then it already is in its 5005lbs form. Yours sounds like an interesting project and refreshing to see someone actually put a Jaguar V8 drivetrain in one instead of the LS or worse yet LT engine.

 

Bulkhead mods



Bulkhead mods



Sitting on modified mounts



Bespoke rear axle

 

5005 lbs is the gross weight with passenger, luggage etc. The car itself weighs about 4000 lbs.

 

Last time I checked a car doesn't accelerate and drive based on its "curb"weight, so yes when it's me and a passenger and a full tank of gas it's at its gross wt. or close to it.

 

Not unless you weigh 500 lbs each. The door sticker shows how much weight a car CAN carry, nowhere close to what it weighs. No one compares cars using the GVWR sticker. In that case check the sticker on your XJS. It's only couple hundred pounds less than the XJR.

 

"Sigh"

 

JTsmks does have the overdrive crank pulley and the smallest supercharger pulley on his car. When the PO of his car wanted me to do the work, we had the ECU sent out like he stated. After we got the car running and delivered to the owner, it was 500 miles later that the car came back to us because he stated that the head gasket(s) we're blown. Basically when he was under full boost, there was white smoke coming out of the exhaust. He said it stops blowing smoke out the exhaust when not on full boost. The problem was that the engine from the factory already had the 4.2 style metal head gaskets. The factory head bolts were stretching due to the heads wanting to lift off the engine block from the overdriven supercharger. At this time the car only had maybe 33K miles on it so you can't blame it for high miles. Anyways, if you're gonna overdrive the snot out of the supercharger, you MUST replace the factory head bolts with ARP fasteners. I'd also like to see a Killer Chiller along with a seperate cooling system on that car because that overdriven Heaton charger is pushing some serious heat in there now, but he doesn't agree with me.

 

It's not that I disagree with you, I'm just not "in the throttle" like the PO. I'll put it on the car, you just have to provide it! 😁

 

You can "sigh" all you want. Your assertion was ill founded.

Curb weight is the correct bench racing method of comparing
relative performance based on weight to horsepower ratio.

Ignore the passengers + baggage because in any comparison,
they would add the same amount to any particular curb weight.
Unless of course in one car you have your 98 pound friend, and
in the other car you have your other 260 pound friend.

On the other hand, the difference between curb weight and gross vehicle
weight of a MG Midget and a Buick Roadmaster wagon makes a comparison
based on GVW completely inaccurate.

You could also compare based on the GVW of a MG Midget and any
18 wheeler of choice. A completely useless comparison with zero
validity.

 

The "sigh" was because I originally posted something "not so nice" and the forum (at least on my iPhone) won't let you delete posts. I'm not a fan of those who simply add to a conversation when they can point out faults and then chose to "keep it going" right or wrong I moved on, it was adding nothing to the original posters question. Similar to what your doing now by commenting on my "sigh"

 

Thanks

 

I'd go ahead and post it in the XJS section as there are a couple of conversions going on currently over there. Some of those guys are pretty sharp and may be able to provide some insight. I can tell you I ran mine for a while with just the lower pulley mod then went to the lower/upper. Not a tremendous difference with both but I can say the stock intake pipe was really restricting things on the high end with both pulleys, switching to the Mina intake pipe helped dramatically but required some mods for hood clearance. Your situation is very different as you'll be running the 8 in an XJS without stock ECU and most likely a non stock intake/filter setup. Wish I could be of more help to you.

 

please correct me if I'm wrong . but i have done the 6% top pulley mod to my 4.2 .
and the write up from powerhouse had me believe the 6% is how much faster the blower will spin , not the size difference at all . i also checked before 13.8psi and after 14.6psi boost and that was also a boost increase of pretty much bang on 6% . so id be more inclined to say the percentage relates to the psi increase or blower rpm increase rather than the before and after outer diameter/measurement of the pulley .