Hello. I'm new to this jaguar world. I just purchased a 1997 XJR and I'm very pleased with it. I recently changed the spark plugs, fuel filter, oil, and transmission oil, and flushed out the brake system. I think I'm ready for minor bolt-on(s). Anyone know a good pulley to buy for the supercharger without needing a tune?

And If I do need a tune, what's brand/hand tuner do people like to use these days?

 

In the USA a "1997" XJR would be the 6 cylinder car. Just wanna clarify that you don't have the V8 XJR....which would be "1998" model year in the USA.

Years ago there was an outfit selling a pulley for the XJR/6 but I'm nearly positive that they discontinued it...presumably due to lack of demand. To be honest, the couple people I knew that had one ended up returning to the stock pulley as the increased supercharger RPM heated the air charge beyond the intercooler's ability to cool it.

There might be some used ones floating around. An outfit in the UK had a a couple on Ebay a year or two ago.

Aftermarket support and high-performance goodies are virtually non-existant for the XJR/6.

Look for postings from "XJRengineer". He's the only one I know of that messes around with XJR/6 tuning/ECUs/programming.

You won't find any hand-held tuners/programmers for this car.

Others will chime in.

Cheers
DD

 

Its best to take your mods in small steps, I speak from personal experience.
First, remove the air box and replace with a cone filter, the stock air box restricts the supercharger and your sc will cut out because of air starvation. Along with this be sure to add the Andy bracket, these two mods alone will TRANSFORM YOUR XJR6. very cheap mods with lots of return in hp.

Second, should you feel the need to go faster have magnum powers rebuild your sc with there new sc plate with bigger vent ports. This will give you 2-3 lbs more boost and increase air flow by 10%. I had mine ported as well but looking back on it I would have not done the port and only the sc plate. Now your car is BEAST.

After I did the above I had the throttle body ported, this was only good for all out racing but bad for street driving, went back to stock TB. I also had my exhaust turned into a true dual exhaust system, problem is I lost a lot of back pressure which causes boost. now my car is just fast and not a beast. This I should have not done, really thinking of going back to stock exhaust to get the boost back.

Now I have a brand new lower sc pulley, these things are expensive, that I am thinking about putting on my car to get the boost i lost. havent decided what I want to do because of the bad press I have heard about the pulleys.

Say you did all the above mentioned mods, minus the exhaust, you car should be screaming!!!. But if you need more, like me, next step is to change the diff. As for tuning, the only person is Andy that can program your ecu, this is needed should you increase air flow by OVER 10%.

 

+1 on the timing bracket and diff ratio change.

The bracket and a change to 3.58 gears made a decent improvement in my XJR

Cheers
DD

 

How did you determine this? I ask because I came across these two dyno run by the same person. This one An Image from the Jag-lovers Photo Album is two runs, one completely stock, the other with the airbox top and filter removed. Removing the filter drops torque below 2600 rpm, and at high revs the power gain is under 7-8 hp. For most normal driving this would reduce performance.

Compare this to the dyno run with Andy's bracket, the advantage of the bracket is very clear:An Image from the Jag-lovers Photo Album Below 2000 rpm the torque gain is massive. At higher revs the hp increase due to the bracket is much more than removing the air filter, so clearly the air filter can't be a restriction. If it was, then the bracket wouldn't be able to increase power.

 

my personal experience is that the sc would cut out at about 50 or 60 when hitting it hard with the stock air box. without the stock air box the sc would continue to pull hard as it is supplied with sufficient air/oxygen.

 

I have had my 1997xjr6 ECU remapped and chipped by Andy the chipping was done in stead of the bracket. the reason for remapping was I fitted a 5 speed Getrag manual plus redone my exhaust doing away with the cats and replace the standard filter with a K/N pod placing it on a longer tube behind the headlights with cold air being forced up from under neath. I had done all these mods before remapping and the car would stall and some times go into limp mode obviously to much for the ECU to handle . The remapping was done 2 months ago and then I got a Dyno run done.The results are rear wheel h/p 298.1 at 114 mph at 5500 rpm
The rear wheel Torque is 348.2 lbft at 67mph at 3260 rpm
The boost is 10.86 at 66mph at3197 rpm. fuel economy also improved after remapping; My next stage is to do the same as Doug and change the diff from 3.27 to 3.58 I am told by the guys at the dyno shop the difference will in creace the torque by up to 17%. There are not very many XJR6 here in New Zealand so parts and after market mods are hard to source. Its an awesome driver
Cheers Ray

 

What's a good cone intake setup? Just a random K&N cone or actual upgraded system?

 

k&n only has the replacement filter & AEM doesn't make intake for this car. Any suggestions?

 

a regular cone filter will bolt right on.

 

Hi I used a K&N 57 series fuel injection performance kit purchased from Total Perfomance here in New Zealand. There must be a speed shop or performance shop in California that sell these. The tubing between the filter and AFM is an important factor to make it work at its best. Using smooth tubing gives a better air flo than the crinkly type of tubing it does not distort or disturb the air flow but forces in at a better rate. Also cold air is H/P hope this helps

Cheers Ray

 

I have found a lower pulley upgrade for the sc on eBay UK. Don't know anything about the quality or the seller, except that a feedback of 99.9% seems convincing. The price is £235 + shipping.

Jaguar XJR 4.0 XJR-6 XJ6 1995-1997 Supercharger Pulley Upgrade | eBay

 

I have this pulley brand new still in the box. Cant decide whether to go back to stock exhaust configuration in order to get my boost back or place pulley and see what happens. what do you think? any opinions?

 

If you have the time, I would say try out the pulley and see what happens. Seems to be a relatively easy fit, that can be undone without too much hassle. If it doesn't work out, then at least you'd know.

 

Try the pulley
I would be curious as well as its the only thing I never did on my XJR6

I also have a better intercooler pump

I was always wanting a pulley but was waiting for Andy to make one he has the design

I trust his products 100% but he said demand wasn't large enough to warrant cost so never went there

If he ever does make one I am first on the list still got my XJR6 its under a cover in the garage got it up for sale but if it does not sell I am keeping it sooner or later they will become collectors items

 

I agree, can't hurt to try. Not all that big of a job to swap the pulleys out.

I've never been there, done that .....but FWIW the reports I heard (and this was years ago) was that the extra boost helped for a few seconds but then power dropped off quite a bit, to a level lower than stock configuration. The air charge simply got too hot. So, maybe you'd get a good improvement thru (let's say) the top off 1st gear but then sorta fall flat by the time you hit 2nd.

Usually people like to report overwhelming success from their go-fast modifications. When I heard from a couple of guys who admitted outright that they went back to the stock pulley, I took notice.

Hearing this, and remembering so many similar reports from my Thunderbird SC days, I divorced the intercooler circuit, added an intercooler fan, and installed upgraded intercooler pump to my XJR and had plans for much more....but never have gotten 'round to finishing the project much less actually buying a pulley.

Those "Charge Chiller" kits sound interesting as well but I've never researched them in depth. I *think* some of the guys here with XJR/8s have used 'em so a archive search might reveal some info.

Cheers
DD

 

I do have an uprated intercooler pump, the sc is ported, the sc plate has a larger vent port to allow for easier air flow and it is winter. This with a true cold air intake system and I hope all will be well, if not the maybe a sc fan. I will swap out the pulley this weekend and let you know iat temps before and after pulley swap.

 

UHM, you are aware that boost is created by RESTRICTION. If you remove restriction you lower boost but have increased airflow into and out of the engine. BOOST is a result of restriction, what you want is VOLUME of air which is what you did by removing exhaust restriction. This meens more fresh air in and less boost as there is less burnt gas standing in the way of fresh air coming in. If you spin a SC at 100,000rpm there is not BOOST, not till you bolt it to something that creates a restriction to flow. remember more air/fuel in=hp. more boost also heats up the air which thins it out and reduced HP too. This is why going higher boost doesnt= proprtional hp increase. More heat and more hp to turn the SC are both detractors...

 

Went this morning for a run in order to get before and after air intake readings. On my first pull my car stumbled, what the hexx, another bad coil! lt looks like every few months im swapping out a coil, seems as each and every coil no matter what supplier just is a disappointment. Most likely pulley swap will have to wait till next week.

 

That's a frustration know where you are coming from

I think my XJR6 is probably in the best state of tune in 5 years and that's because its on the trickle charger in the garage LOL