x308 xj8/r differences

[zepe]

Couple of questions on the x308. Besides the engine what was done to the xj8 to make it an R? Also does anyone know if the pedal box from the x300 fit the x308?

Thank you

[Markymark69]

Suspension, brakes, black trim and sports seats.

Cant think of anything else off the top of my head.

Oh yea, exhaust trims.

Edited by Markymark69 on Sunday 17th October 22:41

[zepe]

Thanks Marky, I guess I should ask specifics. I have a performance project in mind and was wondering if an xjr was a better base than xj8 to start the project. Xj8 are considerably cheaper so if I can upgrade the 8 with "R" parts I would save a substantial amount of money. The car I am looking at is a non running 1998 xj8 with 135K on the clock so all bushes suspension parts would be renewed along with a new limited slip diff. Basically turning the jag into an e39 m5 with jag looks. the only x308 I have ever driven is the R, and the steering was very light so I wonder if the 8 has an even worst steering feel.

steering rack different? interchangeable?

Brembo brakes direct fit on xj8?

The car must have manual gearbox, that is why I ask if I can use an x300 manual pedal box/master cylinder.

[a8hex]

The difficulty is not the pedal box it is the engine management unit. It wants the gearbox too. Or are you trying to squeeze the BMW mechanicals into the Jag?

I would have thought it was easier to find a non running XJR as a donor than an XJ8 then find all the "R" goodies.

[TheD]

Markymark69 said:

Suspension, brakes, black trim and sports seats.

Cant think of anything else off the top of my head.

Oh yea, exhaust trims.

Edited by Markymark69 on Sunday 17th October 22:41

And a big feck off Supercharger

[zepe]

"The difficulty is not the pedal box it is the engine management unit. It wants the gearbox too. Or are you trying to squeeze the BMW mechanicals into the Jag?

I would have thought it was easier to find a non running XJR as a donor than an XJ8 then find all the "R" goodies."

Yep been doing some research and I am better off with an "r" as rack, brakes front and rear sway are all different. The car I was looking at is local, the right color (black of course) and I can buy it for $1500 us, the cheapest non running "r" I can find is about $4000 us, I can buy the parts cheaper than that but the fitting will make it a wash. As for the drive train that will be solved with a supercharged gm ls series engine backed up by t56 manual gearbox. A US based Jag conversion business just finished a kit for installing any ls based engine in the x308, it runs the gm engine module and interfaces with the can system so everything from gauges to cruise still works. I have seen the car (pictures) and the install is very clean with no cutting or welding required and it uses 100% stock gm parts. So the pedal box remains my only unaccounted for factor. I converted my automatic xjs into a 5 speed by importing a pedal box from a manual car, I am thinking an x300 pedal box would work but would like confirmation from an expert.

Edited by zepe on Monday 18th October 09:33

[zepe]

here is a link to some photos of the development car.

http://www.ls1tech.com/forums/conversions-hybrids/...

This should be the ultimate sleeper, proper jag with no external mods and close to 600 hp.

[varsas]

I had an XJR and have briefly driven an XJ8. Steering in both was the same, and yes I agree it's a little on the light side.

XJR's will have the CATS adaptive suspension, which was a rare option on other cars.

ETA: The 18inch wheels are XJR specific, others had 16's or 17's as option.

Edited by varsas on Monday 18th October 20:40

[a8hex]

zepe said:

here is a link to some photos of the development car.

http://www.ls1tech.com/forums/conversions-hybrids/...

This should be the ultimate sleeper, proper jag with no external mods and close to 600 hp.

You might like to check out some of NormanD's postings if you are aiming towards the 600BHP mark.

[zepe]

a8hex said:

You might like to check out some of NormanD's postings if you are aiming towards the 600BHP mark.

Hi a8hex, NormanD's car is a true exotic and it would be nearly impossible to duplicate on this side of the pond, not to mentioned no one would touch the car or know how to work on it. There is virtually no support for older Jag's and the price of parts and maintenance are astronomical. You must remember I am saving the car from the crusher, so I don't want to throw to much cash at it. The LS engines have huge aftermarket support, cheap parts and any independent shop will work on it at very reasonable rates. My favorite sedan to drive is the e39 m5, but my favorite car to look at is the x308. If this works out i'll have a fun sleeper if not it won;'t break the bank.

P.S. I do plan on using normand's rear diff

[a8hex]

I always though of Norman's car as being a new Jag. It's newer than both of mine :-)
My main interest is in the first set of XKs, I know for them there is a huge industry supporting them in the US.

Good luck. There is a long history of lumping (Less Upkeep More Power) Jaguars in the US.

[GavinPearson]

zepe said:

P.S. I do plan on using normand's rear diff

You don't need it.

You are actually far better off using the X300 differential (15HU), A frame etc because you get an 8.5" crown wheel (and more importantly matching pinion) and then using an X300 or XJS Powrlok diff. The parts swap is extremely straightforward.

[groomi]

GavinPearson said:

zepe said:

P.S. I do plan on using normand's rear diff

You don't need it.

You are actually far better off using the X300 differential (15HU), A frame etc because you get an 8.5" crown wheel (and more importantly matching pinion) and then using an X300 or XJS Powrlok diff. The parts swap is extremely straightforward.

Would a standard diff handle the power though? In my experience they seem to need rebuilds every three years or so in normal use.

[zepe]

GavinPearson said:

zepe said:

P.S. I do plan on using normand's rear diff

You don't need it.

You are actually far better off using the X300 differential (15HU), A frame etc because you get an 8.5" crown wheel (and more importantly matching pinion) and then using an X300 or XJS Powrlok diff. The parts swap is extremely straightforward.

Well this is why I came here, thanks for the info. I understand the x300 diff. was the same for the 6 and the 12, I have to look into it. Keep it comung guys.

[zepe]

a8hex said:

I always though of Norman's car as being a new Jag. It's newer than both of mine :-)
My main interest is in the first set of XKs, I know for them there is a huge industry supporting them in the US.

Good luck. There is a long history of lumping (Less Upkeep More Power) Jaguars in the US.

Original xk and e-types have huge support here, but anything newer has none. You can't get a main dealer to work on anything older than an x350 and it is rare to find an indy to touch an x308 (my xjs mechanic won't touch them), there are a few that will swap a bad motor but none will Mod the car.

[GavinPearson]

groomi said:

GavinPearson said:

zepe said:

P.S. I do plan on using normand's rear diff

You don't need it.

You are actually far better off using the X300 differential (15HU), A frame etc because you get an 8.5" crown wheel (and more importantly matching pinion) and then using an X300 or XJS Powrlok diff. The parts swap is extremely straightforward.

Would a standard diff handle the power though? In my experience they seem to need rebuilds every three years or so in normal use.

The standard diff is a good road diff. You can uprate them just by changing the clutch pack fitting order to maximise the number of friction surfaces working against each other. Obviously the more you use it the more it wears. This is why Engineers like viscous lsds - they provide very consistent service for the life of the vehicle. But the OP wants to do the job on the cheap so let's help him.

Next step up is an XJS unit which has ramps and has more locking capability.

The 15HU is a very strong unit, copes very easily with a highly tuned s/c V8.

In terms of what to look for at the junkyard the diff has a coloured square on the backplate, the one with a cross on the square indicates that it is pow-r-lok and the ratio should be on a tab attached to the backplate - e.g 43/12 PL would be a 3.58:1 with LSD.

[zepe]

Thanks Gavin,
I was able to easily find a complete rear end off a xjr6 with a 3.27 gears, so when the time comes I will be able to see how the budget is going. So my main concern now is the pedal box, I am convinced that the x300 box should work with minimal fabrication ( the conversion kit will supply everything else).

Edited by zepe on Wednesday 20th October 04:22

[ARAF]

I'm confused Zepe, your profile country says UK, but you talk as if you're in the US.

If you are, and you're looking for engine parts, doesn't the Jag engine also get used in the Ford Thunderbird and Lincoln LS? If so, I'm sure you must have tuning shops for them.

[zepe]

ARAF said:

I'm confused Zepe, your profile country says UK, but you talk as if you're in the US.

If you are, and you're looking for engine parts, doesn't the Jag engine also get used in the Ford Thunderbird and Lincoln LS? If so, I'm sure you must have tuning shops for them.

Ooops it must default to UK or I didn't notice, I fixed it now. Actually the lincoln engine is similar but has enough differences that development would have to be done. The reason for using the ls engine is that all development has been done (including electronics) and I can basically buy a kit and install the engine. The lincoln engine has no support, the biggest issue with the car is the electronics interface and that is pretty much sorted with the kit. I would love to use the new ford coyote engine but then I would have to develop the car myself and I have neither the skill nor inclination to engineer the conversion. BTW the LS support eclipses the ford, especially the electronics side. Just about any local speed shop can reprogram any parameter of the ecu or build a custom harness for little money. BTW to give you an idea of how cheap power can be had from the LS motor, $4900US buys you 585 hp with a iron block and escalade heads, for about $5k you can buy a used all ally blocked escalade engine complete with every accessory and a cam change away from 500 hp.

P.s. I know it probably sounds awful to put an escalade engine in a jag but remember the escalade has the same engine as the regular corvette with the heads off the mighty z06 ls7 so it's a proper engine.

Edited by zepe on Wednesday 20th October 20:46

[zepe]

ARAF said:

I'm confused Zepe, your profile country says UK, but you talk as if you're in the US.

If you are, and you're looking for engine parts, doesn't the Jag engine also get used in the Ford Thunderbird and Lincoln LS? If so, I'm sure you must have tuning shops for them.

Ooops it must default to UK or I didn't notice, I fixed it now. Actually the lincoln engine is similar but has enough differences that development would have to be done. The reason for using the ls engine is that all development has been done (including electronics) and I can basically buy a kit and install the engine. The lincoln engine has no support, the biggest issue with the car is the electronics interface and that is pretty much sorted with the kit. I would love to use the new ford coyote engine but then I would have to develop the car myself and I have neither the skill nor inclination to engineer the conversion. BTW the LS support eclipses the ford, especially the electronics side. Just about any local speed shop can reprogram any parameter of the ecu or build a custom harness for little money. BTW to give you an idea of how cheap power can be had from the LS motor, $4900US buys you 585 hp with a iron block and escalade heads, for about $5k you can buy a used all ally blocked escalade engine complete with every accessory and a cam change away from 500 hp.

P.s. I know it probably sounds awful to put an escalade engine in a jag but remember the escalade has the same engine as the regular corvette with the heads off the mighty z06 ls7 so it's a proper engine. The reason to use the escalade engine is that breakers charge a "corvette" premium so a complete vette engine is closer to $9k for late model.

Edited by zepe on Wednesday 20th October 20:47