Anyone have any first hand experiences with pulley, Arden ECU or Arden suspension upgrades?

I've read some folks having problems with car stalling and MAF sensor problems with pulley upgrades. Who makes a good pulley? I know that you can get one eurotoys or jaguar xp but neither say who makes them.

I also noticed that nobody really makes a larger sway bar for the X350.

 

I admire anybody thinking of doing performance tuning to this luxury car. The money it will take to get measurably more usable power and handling from this particular car will support a small country for some time to come. Trying to get this car to handle any better with its air suspension, CATS and acclerometerhandling control system will take an engineering groupa long time(as it did initially). I would be pleasantlysurprised if any serious aftermarket products show up that will do anything usefulother than make the car tweaky and less dependable. Of course, I am looking at this from the position that the car is expensive and hard to replace easily. For someone who can experiment freely without concern, it could be quite an interesting exercise. It's all a matter of perspective.

 

@Oldmots,

If you do want to have better track lap times, then loose weight, improve power and improve handling, probably costly. Better to get another car if that is what you like.

But for normal street driving? Why would you need everything done at the same time?

IMHO even with my XKR Conv (does not have any handling, even in stock trim) it is fantastic to have the additional power (much more then 500 bhp), more than just great fun to drive (street only, and occaisoanly the German Autobahn). We have heavy cars, that can use some extra power.

@wendelz
How much extra power would you be looking for? Just a pulley or just a ECU tune will not give that much extra hp imo, but it could be just noticable. Best to look for improved exhuast, maybe also intake improvements as starters.

There are electronic boxes on the market for air suspsension cars that lower the car a bit, which will improve handling a bit.

Andre.

 

Already have k&n cold air intake and mina exhaust system and both are great. I've done all the research and the pulley, Arden ECU and Arden Electronic Suspension kits (specifically Arden) seem like the next best bang for the buck (and safest) for next steps. Stage 3 would be port polishing which I probably won't do.

Basically, I'm looking to build an all in one daily driver that's basically the best sleeper on the road. (and I don't have a 3rd car garage for the Exige 240 weekend car) I've gone from a C43 to an S8, now XJR. C43 AMG and Audi S8 were not really tunable without importing REALLY expensive parts from Brabus or ABT respectively (intake was all that you could do and I trashed the first MAF sensor on the S8 because excess oil from the K&N box filter). The reason I really love the XJR is because it's incredibly customizable thanks to great parts support and relatively simple engineering...and all you need is your right foot to wake up in the morning instead of waiting in line at starbucks.

So the questions are:
1. Who makes a good pulley and if you've put one on, have you had any of the problems I mentioned in the first post?
2. Any experiences to share with Arden performance upgrades mentioned above?

 

Have you already dyno'd your car? Might be worth it as then you will at least know your baseline, and if any future change does actually work and for how much.

I think Ardens claim for 35 bhp might be on the high side for an (safe) ECU tune (and the price also, I think it was €3800). The better option would be if you are interested in speeding up the Eaton, to first do that, then make a specific tune for your car/setup (if you plan to stick to that setup). The latter tune will be cheaper than the additional box from arden.

Here is a pulley, though imho these are somewhat overpriced, any good machine shop should be able to make one for less than $100.
http://www.minagallery.com/jagxp/XJ_350_Performance.htm
If your car is in good shape, no issues with the MAF are to be expected with a pulley change. Issues with the MAF sensor are to be expected if you go for a custom intake where the MAF sensor fits in, these things are very sensitive.


My 2 cents.
Andre.

 

OK. Now we're getting somewhere. My car pulls an average of 400 at the wheels (of 4 tries). I can get the Arden suspension kit for about $2600 which will wire into the sport button. What I also would like to do is somehow also wire the ECU so there's a modified mapping that kicks in simultaneously when I push sport. APR makes an ECU like this work modulates on the windshield wiper wand for VW. Yeah, the Arden unit is pretty damn expensive, but I haven't seen any others out there that I would consider reputable. A lot of money for 35 bhp. So basically I'm trying to mimic the //M button in the M5 with a Jag...at least that's the desired end goal.

The pulley is nice since I can modulate the power with RPMs. Thanks for the feedback Andre. Now I'd like to know if anyone's tried both?