Well, seeing as how this thread is lost in space and
we've all moved on to the timeslip rather than the dyno...

I find 13.8s very impressive. XJR engines peak around
40-50k miles I would guess, and Car and Driver only
managed a 13.9@102 (if memory serves, the trap
speed may be a bit off) And Motor Trend a 13.7@ 103.8,

Those are professional drivers, with 3000mi cars and new
Pirelli rubber. For a daily driven XJR, I am impressed.
Obviously your dyno run was on a poorly calibrated machine,
but your XJR is no slouch. I'm sure I would be in the 14s
range in mine, I don't want to do a diff-slamming, gearbox
harming launch. I don't even care where the torque converter
stall point is. My car has done 40k more than yours anyway.
Too risky.

If you didn't do a proper launch, you could be losing .2-.5
seconds off that quarter mile time. I would say your car
is specially gifted, (or at least it is in the peak performance
of its engine life) and 420hp may not be as far off the mark
as you were expecting. Maybe it has 20hp tucked under
there secretly.

Ian

My newly installed boost gauge is reading only 9 lbs max, so I've ordered a goodyear gatorback belt to check if the stock Jag belt is slipping. The SC does have 53K miles on it so the tolerances could be loosening up a little.

My launches were both without any wheelspin, almost identical with and without traction control. I couldn't ask for better launches, except for my reaction times. The track here was nicely sticky.

I'm going to get another baseline dyno on the same machine that Rob and Marc used so we can compare apples to apples as we do our mods.

Cheers

EDIT: This 9 lb reading is with the STOCK pulleys. I am going to upgrade to add a 4lb lower when I can source one for a reasonable price.

Might you have a gates part # that would fit with a 4 lb lower pulley?

If you give me the size of the pulley (boost doesn't tell that), i can calculate. But the company you bought it from should be able to tell, and which gatorback partno did you order?

I'm jumping ahead of myself again...I don't actually have the pulley yet. I was hoping all 4 lb lower pulleys were close enough to be within the same tensioner adjustment range.

The gatorback part # is 4080515 but that is for the stock pulley.

I have never heard of a 4lb upper pulley. That would require quite a bit of grinding. If you purchase a lower pulley it should come with a belt. If you want a lower pulley I have one ready to go on an exchange basis.

Hi,

Yes, 4 lb lower pulley. I couldn't imaging one could have a 4 lb upper without major slippage of the belt with so little surface area to grab on to.

Can you please tell me the price for yours? You can PM me if you prefer.

I was thinking of having a local machinist make me one if I just give him the outer diameter and a stock pulley. I think I would then just need to buy the crank dampner bolt and belt,...but that would require some time to mess with. I've been loosely quoted $40-50 just for the pulley out of steel, then the other stuff is maybe another 40-50??

I'd be happy to pay a bit more for a complete proven kit, but think the prices Eurotoys and powerhouse are asking are ridiculous.


p.s. just to clarify, my 9 lbs of max boost reading is on a completely stock car with stock pulleys and stock intake box with K&N drop in. The only mods I have actually made so far are to remove the 2 resonators just in front of the rear axle and added a meth kit which is currently running 2 x 175ml/mn = 350 ml/mn total injection of the Snow 51/49 boost juice. I had the meth injection turned off when getting the 9 lb max boost reading.

JgaXkr,

Sent you a P.M. yesterday. If for some reason the PM system is not working, please email me directly at nicefishtanks@gmail.com

Thank you,
Jeff

p.s. I'm not expecting to get it at cost, I would be happy to pay a reasonable markup, just not the $500 that eurotoys is asking, given the actual costs are less than $100.

177 mm diameter

Thanks again AVOS, you are always so helpful

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