I Have all of this on it's way, it came off a wrecked car with 90k. It has everything from the heads up, except the wiring harness and coolant lines. Does anyone know if the XKR models have different internals? If so, can I use my internals, or would they cause issues? I know they have different compression ratios. Does anyone know based off of the pic if there is anything else that I will need to change from aside from possibly the fuel pump/adding a pump? Any advice or information is greatly appreciated.

 

Pistons are different to name one important part.(lower compression)

 

What year is your car ? The 4.0 XKR cars used a different MAF sensor than the 4.0 XK-8.

 

For starters:

Pistons
S/C doesn't have VVT, (and your ECM expects them to be there)
Intake Air Temp sensor
etc., etc.

There are many differences. It may be a journey best not started.

 

Getting past the high compression pistons and the VVT is not going to be easy no matter what one’s experience level

 

Well.... The journey has already begun.
As far as ECM, I'm going to have it tuned to compensate for the upgrades. Possibly change ECM altogether.
I'm mainly trying to find out what parts I still have to purchase/change. I understand the size of the job, I just want to do it correctly.
The parts that are coming: heads, valve covers, plugs, ignition coils, intake, supercharger, fuel rail, injectors, throttle body, amongst some other parts. I can add more pics if needed.

 

I would keep your heads with the VVT, you will need an XKR crank pulley to drive the blower and I would keep the boost way down like in the 5# range because of the compression issues mentioned above. I would be wise to get a boost-A-pump on the fuel pump (not sure that is an option on the 05) for some additional fuel. The factory computer should be able to compensate for the rest. You will also need to fabricate a pump and heat exchanger system for the intercooler, again not plug-n-play easy but not complex.

That is going to be a bigger project than it seems on the surface but the fun ones always are! Nothing you are doing to your car that cannot be undone if it doesn't work out (assuming you don't throw a rod or melt a piston!!)

 

Honestly, my end goal, I'd like to get close to 500 HP. That's why I'm ok with changing so much.

 

that is a big number on a stock high compression engine. You honestly may need to go to XKR pistons, at that point you are either rebuilding your block or swapping it out. If you swap it out you get the better pistons and oil jets (not sure the XK8 had them). It might we worth a discussion with a head gasket maker to see if you can have an MLS gasket made that is a little thicker to help lower compression. I am in the middle of building an engine and I will tell you first hand, to do it right is NOT cheap or easy. Forged Aston Martin crank ($ first born son), forged rods and oversized forged pistons ($5000), block work ($2000), head work (no idea, not there yet), gaskets, bearings and misc parts ($1500-2000).

Either way, document your progress for the forum, there some brilliant folks in our ranks. These cars are finally at the age and price where people are not afraid to push the limits.

 

suspension and brakes will need to be upgraded too.

 

Exactly!! I love my car. I just want it to be able to scare the newer cars, not necessarily beat them. I'd like to think with a good tune, different pulley size and XKR internals I can get close to my target HP goal.

 

It needs all four struts already. 😅😅 Brakes will come last probably.

 

Will the differential handle 500 horses?

Jack

 

I'm not entirely sure of the limits of the diff. Unfortunately there isn't much in the way of information on mods in these cars. I've seen the 07 XKR model running 500+, but I'm unaware of the differences in those 4.2 and diff vs the 06 and older XKR. I say XKR because after all intended upgrades mine will essentially be an XKR.

 

and if there was a cost effective aftermarket solution for installing a sbc in the last version model xk100s. that would be my choice (+kennebell). 500 hp + semi cost efficient reliability.
good luck
WJ

 

With the hgiher compression pistons I wander if it's possible to run meth injection to prevent knock?

 

I have a 1987 Porsche 928 running a 2 liter autorotor that's not quite able to pump 500 hp. That's running 8psi into a 9.4:1 CR on premium fuel into the OEM 5 liter engine.
i think you're going to run into more trouble than you anticipate with the NA Jaguar's 11:1 stock CR if you plan to run pump gas.

 

I’m curious, why didn’t you just look for an XKR in reasonable shape?

 

It would be cheaper and easier to just buy an XKR. But I get it.

Supercharged with VVT should be good for power delivery.

 

Mainly because my car has a red title, it's resale is nothing. For me realistically, it's cheaper to swap it than to try and sell mine or trade it to a XKR. So for all of my upgrades I'll be out 2500 to 3500 at the most. Even with selling my car and putting 3500 with it, I won't come close to getting a XKR with as low mileage and in as good a shape as what my car is in. Not to mention I'll have to drive 200 miles in one direction just to look at the closest XKR in this specific model. I looked extensively before buying my car, for an XKR in my price range. I have all the tools necessary for the job at my place of work to swap everything and the help of some experienced mechanics. So after all things considered. This was the best course of action, at least in my mind.