View Full Version : Squeazing the M90, when does it pop?

03-02-2007, 04:06 PM
I'm not exactly new, nor am I technically an SC owner. I've got a 12sec XR7, but it's N/A. However, I've been up to my eyeballs in MN12s for 8 years now, and know this is the place I need to go for this information. Some may know me, some may not, it's been 8 months since my last post, but I digress...

My dilema; the 1996 Jaguar XJR. It's my new daily, it's already got 322bhp, and it is a pig. It's fed by a slightly proprietary snub-nosed M90 (http://cgi.ebay.co.uk/Eaton-M90-Supercharger-Up-to-350bhp-Aston-Martin-DB7_W0QQitemZ120093130136QQihZ002QQcategoryZ72205Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem?hash=item1200 93130136) (The DB7 and the XJR share an engine). I'm thinking of coaxing it up to the 400hp mark of its contemporaries, but I've run into some problems:
-The OE pulley diameter is between 2.5~2.75" across the ribs (tuff to get my calipers on it). From all I've read, I cant buy smaller pulleys.
-Crank pulley UD kits are $800 (400 BP plush shipping across the Atlantic)
-Spinning it faster may be too much for it. It's blowing 322hp worth of air now, at what point does the M90 become a glorified heat pump?

So, what I'm looking for is:
-Pulleys smaller then mine
-Info/guides on porting
-anything else within the blower that will help it blow.

On a side note, keep your eyes on Junk yards for 1995-1997 Jaguar XJRs. They have tiny pulies and blower tops that will likely fit SCs. They've got liquid/air intercoolers, too, but I'm not sure how you'd make that work.

Thanks in advance!

03-02-2007, 08:02 PM
You might wanna place a call to Victor at spinning wheels because I beleive he deals a little with the jag blowers so he might have some products or info for you.And he's a great guy to deal with and his wife is also.