You should expect 320-330bhp from the crank and 1/4mile at 13.8-13.9.

 

Hello,

I just purchased a 06 XKR victory edition coupe and have some performance issues too. Here are my observations.

If you are going to get the maximum performance you must hit it from a dead stop. If you launch in first gear it will be significantly quicker. In my car if I let it reach operating temperature it is a dog compared to having a go with a coolant temperature around 140 - 160 degrees. I believe this is due to , no heat soak and a richer mixture in open loop.

I have noticed that the transmission doesn't kick down like I think it should. (perhaps I have a faulty switch) does anyone else have this issue?

with the torque app you will see an immediate temperature rise after flogging it a bit.

I haven't checked the coolant temperature on my XKR but I changed the thermostat on my XJR and it runs at 190 and generally it seems quicker than the XKR, except in open loop.

I think the earlier advise is good:

clean the MAF

check fuel trims

check supercharger coolant / pump

I haven't checked whether the torque app can monitor intake air temp. it will be interesting to see what kind of difference there is between open loop and closed loop.

I think methanol injection would be great, but the Eaton blowers are not meant to be run wet.

Cool intake air temps are worth HP which is why Member Avos's twin screw kit
boosts the HP so much. The twin screw doesn't heat the air like a roots blower does.

 

It's been a little while but from memory it does.

 

Thanks to all who responded above. I've been totally preoccupied the past two weeks, but I'll report back as soon as I've had a chance to apply all your good advice. I very much appreciate this community!

 

Those are numbers that would match up perfectly with an xk8, not the XKR. You sure it's the supercharged model? Post pics of your engine!

 

Trust me, it's an XKR. My original question arose in relation to whether the supercharger is actually... well... supercharging.

The belt & pulley look good, the intercooler pump comes on with the ignition in position II, and there are no lights, messages or OBD codes.

 

Apologies for OT, but is a ~20% HP loss in the powertrain typical for auto transmissions (or transmissions generally)?

Thanks,
Mike

 

OK. I've taken almost all of your advice:
1) grantorino62: Checked throttle cable - it opens fully
2) WhiteXKR: Had both fuel pump relays replaced & verified functionality
3) Matthew: I have NOT yet changed the coolant, but I will look for "ketchup" when I do in February.
4) jamdmyres: I set-up Torque meticulously and used 4,100lbs for weight. Made sure Sport Mode on, Cruise switch off, HVAC off, Step-down switch engaged.
5) JohnKen: Validated againsr SpeedView app - same times.

Subsequent results are remarkably consistent, and I don't want to stomp on it anymore until I've done something to hopefully improve them. As hm1 pointed out, these are very close to expected values without the supercharger, so I am left to conclude that it is somehow failing to function.

Should I expect an indy to be able to diagnose & fix the SC? Honestly, I don't really care how fast it goes; It will just bug me if something isn't working properly.

Thanks all!

 

Roger_B Looking at your picture that engine bay and those hoses look so clean and shiney, almost oily.
Are you sure the SC belt is not slipping? With that much oil/shine around it wouldn't squeak/squeal if it was!

 

Have the fuel pumps themselves been checked or just the relays? The fuel pumps fail much more often than the relays.

 

An indy replaced the relays and I only presumed that he had to check that the fuel pumps were working. How would I verify this myself? (I read elsewhere that removing the primary FP relay would force the secondary to take its place; thus, if the car would start, the secondary must be working... does that have merit?)

 

Yes, that is correct and it is the easiest way to check fuel pump 2. Note that it will take 5 or 6 start attempts before fuel pump 2 kicks in, assuming it is good.

 

The torque app should be able to monitor vac / boost. After reading this thread I adjusted my throttle cable....60 hp in 5 minutes ....woo hoo...and it really pulls a lot harder on the top end.....The bad is I now need positrac!

 

You can probably set it up to data log it so you don't have to look at the phone while driving. The graph will likely plot pressure against rpm. Which can identify a worn supercharger. If that doesn't reveal anything I would consider looking at exhaust pressure.
You could have a failing component. Back pressure will kill power in a big way. I believe I read a post here which said that the supercharger pumps often fail internally (the pump part)

 

I have inlet temp. and manifold pressure set in torque pro. Air temp works fine but pressure reads a steady 21.5psi no matter what engine is doing, even shut down.

 

I haven't investigated all of the sensors on the jag yet, but since it is supercharged it does need something to tell the computer that it is making boost so it can alter the fuel delivery accordingly. It sounds like you might have a bad MAP (Manifold Absolute Pressure sensor) Is far as I can remember the Jag is supposed to produce between 13 and 14 psi max. So 21.5 probably means that you have a bad or disconnected sensor

 

It is my understanding that the MAP sensor is more to do with the EGR system and was not fitted to ROW cars. This is supported by my reading of both the model updates and ECM wiring diagrams.
I imagine the system knows boost is being made by using the information from the MAFS.

 

Indeed the ROW 2000 cars don't have the MAP sensor, eventhough they have EGR, contrary the the NA market, where they did have the MAP sensor. I have attached a MAP sensor on mine (the cabling is there), but the reading via an odbii reader is a couple of values off, probably as its not calibrated in the ROW ECU as that one is not using it , but it was still usable for me to do some tests.

On the XKRs there is no pressure sensor, the MAP only measures the pressure or better said vacuum between the TB and Supercharger.

 

Hello,

I believe I read somewhere that you disabled your EGR? If this is correct, how
did you do that ?

Thanks

 

I get no reading at all for MAP (says it's for Ford only) or for Boost. Should I be looking for something else.