Hello everybody,

I thought it could be interesting to someone to read about my experience with supercharging the XK8. There are 2 pdf files attached for the convenience. I've done this modification this summer and feel very happy about the result. My XK8 now comprises spectacular classy look and plenty of power. I'll be happy to answer any questions.

p.s. Please forgive me if my english will look far from ideal

Cheers,
Alexander

 

WOW! Great work, beautiful car, best color. Thanks for the great write up.

 

Alexander - great write-up, I do have some questions
1) Do you still have the higher compression ratio of the normally aspirated engine?
2) Are you using only the single fuel pump from the XK8 of did you fit a 2nd fuel pump?
3) Are you using the stock ECM from the XK8?


It appears that you are creating the potential for catastrophic damage to the engine from high compression and lean fueling conditions

 

Hello,

1) Yes, my compression is stock at the moment, but I have not yet experienced any trouble with it. I am going to lower it anyway for more safe operation.

2) I have experimented with higher flow pump. It worked great in terms of fuel delivery even at the highest load, but it also cased excessive fuel pressure at idle. This could be potentially solved by fitting the aftermarket fuel pressure regulator. Another side effect of this pump was excessive heat in the fuel tank, it became difficult to touch the tank after 2 hours of driving. So now I have put my stock single fuel pump back and awaiting to get the Boost-a-pump. With the stock fuel pump my there is no lean condition up to 4500 revs, I avoid revving the engine higher until I fit the Boost a pump.

3) yes, the ECU is the stock one. I am thinking on adding the piggyback unit that would retard the timing based on the charge air temperature sensor measurements signal for safety, but otherwise the stock ECU seems to work with no problem.

Cheers,
Alexander

 

In case if someone is interested, the car is running great. No engine/transmission damage of any kind so far. But as it usually happens, I want more power. My 10.75 compression ratio engine is a limit for raising the boost. So here is the key:





This is a clean 2002 4.0 S/C engine. Many pics of engine swap process are soon to come.

 

Hi!
Thanks to charing.
Nice to see others convert the XK8 to supercharged. Nice to know:
I use forged piston from Wiseco, two fuelpumps, aftermarked fuel regulator, Unichip Q piggyback. ++
(Custom transmission valve housing, Quaife differential++)
Intresting to follow yours project.
Keep going.

 

Hi Magne

Extremely interesting to discover more about your project. Have you measured your power output? How is the transmission holding? Have you done any tranny modifications beyond the valve body(friction discs, A drum, torque converter)?

 

Very nice. Fun to read.

 

Hi!
I dont want to mutch attention, but the power is measured to 457 HP, 598 Nm at the wheels. I use Eaton M112, ported and new coated, 13 psi boost.
Big water and oil cooler.The engine is "blue printed", cylinder heads, intake, exhaust, custom down pipes, race catalytic, sports exhaust, K/N air filter.
Fuel injectors from Subaru Impreza turbo++.
i have been driving for two years and everyting is fine with the engine.
But the differential was not good, so i put in a Quaife LSD with custom oil cooler and pump, (the system lubricate the pinion bearing). The gearbox is the next project. I use Castrol transmax Z oil and mounted a big oil cooler. The valve body uppgrade just rise the oil pressure, so it shift faster/harder. I shift gear manually for now and a hope it hold this summer.
Thanks

 

Great result, you've made an amazing work on your car.

 

Well this is how you get attention ;-)

Can you share the dyno slip? Are you sure this wasn't an estimated engine hp figure?


Can you show some pictures of this setup? I have thought about a mod like this as well to provide more longevity to the diff, its on a long list of things to do some time...

 

Interesting stuff!

What's the static compression with the Wiseco pistons?

 

Hi!
Sorry to acquire your tread Alexander...
Compression ratio is 9;5:1.
The Dyno numbers is at the wheels.
Possible the dyno is a "nice" one. Is just numbers.
I have several basic things to mention for higher outputs:
-10000 km "run" in time, after newly built.
-high octane petrol (99).
-good air flow, intake, heads and exhaust manifols ( blueprinting).
-oil breather tank.
-block EGR system, if you have.
-heat insulation to exhaust manifold and down pipes, catalytic underneath the car, not in the engine room.
-low exhaust back pressure,(sports exhaust and race cat).
-cold air filter loocation.
-ceramic coated low friction piston.
-high flow water/air cooling pump.
-high capasity fuel system.
-good adjustment tool for ignition and fuel curve. The power increase much with the right ignition curve.( I have Unichip Q).
But my advise is to buy a supercharged modell and go from there.
The differential cooling system is function good, but i had problem with noice from the oil pump. It is in the trunk, the cooler is in the front of differential. Outlet from low rear of the differential goes to the filter in the trunk and to the pump, from the pump to termostat (right front side of differential), to cooler and a oil T-spray nozzle above the pinion shaft, lubricates both the pinion bearings.An-6 hose and fittings. Use a timer relay 0-10 min to start the pump.
Thanks

 

That must have been a very nice dyno, would have loved to see the printout as this type of rwhp power isn’t really Eaton territory for our cars ;-). But as engine hp would fit where I would have expected it with the mods you have.

Thanks for the feedback on the diff oil pump!

 

Another brilliant thread!

On question, how he the charge oil temp sensors been wired into your loom and ecu?

 

The old naturally aspirated engine is finally out of the car. I should have removed it together with the tranny because at last moment I decided to do some work on the transmission to make it be able to handle more power and torque. I wish I had more than one day a week to do wrenching, the progress is so slow...

 

Thank you for the kind words,


Perhaps you mean the charge Air (not Oil) temp sensor? If so, it is currently unplugged in my setup. As I have read in some Jaguar technical manual, on the Supercharged engines the charge air temp sensor is used instead of the air temp sensor located near the MAF sensor. But I am not sure that you can just connect the charge temp sensor instead of intake air sensor as their output voltage function may be different. I haven't yet had time to investigate this.

 

The new engine is prepared to be finally put into the car:




-new power steering pump
-new tranny cooling pipes
-fresh camshaft cover gaskets (although the factory gaskets on this motor were like new despite being 13 years old and could probably be reused)
-new engine mounts
-supercharger rebuilt with all new bearings, seals and coupler


Also, because my car is the AJ26 one, and the new engine is from the 2002 AJ27 car, to make everything work I used the following components from my old engine:
-drivers side intake camshaft timing ring. This thing is tightly pressed into the camshaft, it's necessary to carefully knock it out. To completely remove the timing ring (and fit the new one) you'll need to partially undo the camshaft caps to allow the camshaft to be moved up a bit. Thanks to Adam699 for the tips on this!
-AJ26 camshaft position sensor. The one on the AJ27 engine has another plug that doesn't fit the AJ26 wiring
-AJ26 crankshaft position sensor. The sensor on the AJ27 engine has no pigtail and doesn't plug into the AJ26 wiring
-AJ26 crankshaft flywheel (the part that is bolted between the crankshaft and tranny torque converter)
-AJ26 ignition coils

 

Jaguar puts a heat proof foam pillow in the valley to protect the valley hoses from melting and bursting from the heat of the eaton. You should try that out too. I found mine, cleaned and painted it.

 

I am very impressed. Leave it to a Russian! Great job!


Mark