Hey Everyone ,
Im fairly new to the forums and purchased my XKR last April. Currently looking for doing some mods like the , chip, pulley, and intake. Any recommendations and how much realistic gains.

 

Check out board sponsor ETG- I have heard good things about them

 

The most gain can be achieved with a remap and pulley upgrade from a reputable tuning shop such as ETG. However, it is pricey. I'm looking into it myself. The only hurdle is the $2,000 price plus $200+ for tuning equipment shipping. Maybe if we get 5-10 serious takers, Jags, at ETG, will lower the price. I'll was going to meet with Jag's last week in LA but I was pressed for time and I'm not convinced the 1-time remap is worth the price. If we can get 5-10 serious takers I approach Jag's for a group rate.

I'd like to see 4 selectable maps:
1. Valet map with reduced milage/speed.
2. Manufacture map
3. Performance map
4. Economy map

I'd also need assurance that if for some reason, by the dealer, or other such as manufacturer software update requirement, my $2,000+ remap investment is over written, I have a solid warranty from the vendor.

Stay away from chips and intake upgrades. Chips are just added junk and an upgraded intake is a waste of money (not necessary).

 

Checked out paramount performance as I've heard the name referenced elsewhere. Don't know anything about the quality of their work but their estimates of performance increase are listed as follows:

• chip tuning - 25 bhp
• upper pulley - 28 bhp
• air intake filters - 8 bhp

For a total gain of 61 bhp... Now I will not vouch for anything that has not been benched in front of my eyes, but that will put the cat at 477 bhp and "that makes a difference!"

 

Start from the beginning and read all of this:

https://www.jaguarforums.com/forum/x...upgrade-64594/

It should put you on the right track.

 

Either Spires or Arden claim they can get it up to 600 hp. Unfortunately there aren't any suspension upgrades for the XKR that I'm aware of. They put a lot of work into the XKRS suspension and a lot of reviews talk about it being too powerful for the chassis and it only has 550hp. Good luck and keep the shiny side up!

 

Thats not quite true - I found swapping my stock XKR springs for XKRS springs made a very noticeable difference in handling (for the better).

 

I have a feeling the stiffer springs may unfortunately serve to reduce rear tire grip under throttle, contributing to oversteer.

Bruce

 

So its win, win

 

I have found the opposite to be the case. The rear of the car sticks better in aggressive cornering than before (though it does not udersteer). I assume that maybe the rear suspension is geometrically sensitive to body roll angle, and performs better the closer to level it is. But I have nothing to back this assumption with.

 

option 1
I spoke to a Company called EuroCharged Located in Houston Texas. They do a Pulley and ECU upgrade for 1200 installed and recommended not to do a intake and get a good filter like BMC. Gain of about 95 horses

option 2
Spoke with my local Jaguar/Aston/Bentley/Lambo, mechanic and he has a deal with Arden . Pulley , ECU, and air filter for the same price of 1200 installed. $699 for the ECU and 260 for the pulley plus labor ..This would be a all Arden setup..

Let me know what you guys think.. I do know the Arden prices are very high but he said he gets special pricing from them..

 

A pulley and tune giving 95 hp extra horses? Did they accidentally doubled the number?

As far as I know Arden doesn't have an ECU tune, they do have a piggybag ECU for 2.900 Euros for 33hp more. Better check with Arden to verify.

 

Whichever route you decide to pursue, it will not be cheap. From my research on the forum, my money would be on a kit from Avos. The numbers you get with the twin screw s/c are real and serious. Yes, its more $$, but it will get you results. If you are not ready to spend the dough, best to leave the car alone. Otherwise, you may buy quite a bit of disappointment. Contact Avos to get the particulars.

 

As discussed earlier in this thread, ETG Tuning Group (CA., USA) has an effective package that includes 1.5 pulley and an ECU tune that likely helps for 50+ chp. This plus a Mina intake may make the power you'll be satisfied with. Otherwise an Avos 200+ TS kit will put you easily in the 600+ chp club...Cadillac V, Corvette, MB V8 Kompressor, Porsche slaying power. An Avos TS will go on my future 07 XKR.

 

Suspension tuning is tricky stuff. For the XKRS GT they stiffened the front springs by 68% and the rear by 28% over the regular XKRS. The XKRS was increased by 28/32% over the XKR. The XKRS has much more tenacious stick but when it breaks loose you have to be quick to catch it. Maybe they realized increasing the rear spring rates more than the front actually exacerbated the oversteer and reversed that ratio on the GT. Maybe I don't know what the F I'm talking about!

Let the pros do it. I had the negative camber increased to try to get it to handle more neutral but it didn't seem to help. I guess I'm going to have to learn to take the proper line while cornering so I don't have to worry about it. Gently squeeeeze the throttle on exit!

 

You are correct in that a relatively stiffer front spring rate will reduce oversteer...all other factors being constant. It's also true that going too stiff all around will cause loss of grip on some surfaces more than others. And overly stiff sway bars, and the ratio of front vs rear bar stiffness, can make things hairy. And then there's the factor that's impossible to analyze...damper valving for compression and rebound.

Yep, when all else fails there's just one thing left to work on! The throttle is uber-sensitive I find, particularly after coming from turbo'd track cars, and you really are rewarded as you become smoother with it.

Bruce

 

I searched but cant find a number to AVOS or Arden, I know Eisenhaus was the last dealer for Arden anyone else a USA dealer for them.

 

See post #12 above for AVOS and Google Arden Performance

 

The biggest I have with mine is hooking up. I'd like to play with suspension, wheels, sound but more power won't help - at least not the 5.0. Traction is a big issue and I feel like I have to feather and lean into the throttle or they will light up in 2nd and 3rd much less 1st.

From your pic it looks like you may have 4.2. I suspect it still has traction issues but you may have a better chance at appreciating more power.

 

Congrats on figuring it out the solution. The XKR probably has more low rpm torque than any other car that most of us have owned. Where you have to really put the spurs to it to get most powerbands to chirp the rears, the XKR spins easily due to the supercharger creating so much torque where you never had it before. Mega low rpm torque + low gear + low vehicle speed = wheel spin. Cool tires + road surface temps = greater wheel spin. When you get the tires warmed up on a road course you notice as big improvement in grip. When your rears lose grip it's because the driver applied too much gas for the conditions or gear.