Hey guys, I'm new the forum and to Jags. I currently have an 03 CL600, among other cars, and am looking for a change. I love the timeless look of the 98-03 XJ's, just as I loved the looks of the 00-06 CL's.

My goal is mid 10's in the 1/4; and I'm fairly certain the most effective way to reach this goal is with an LSx engine and a 4L65E (or 4L80E if it will fit) transmission. I'm not sure which way to go with the rear end yet; but hopefully I can get that figured out in time.

I have a lot of questions before I start this; mostly related to how to retain the majority of the factory Jag functions like power windows, locks, seats, A/C, etc...

To start with, how many of the above mentioned functions tie into the ECM? I ask this, because I was going to do this swap on a CL500; but in the brainstorming process with my CL600 found it impossible to control the windows in order to open/close the door properly.

 

I've actually had all my questions answered and will be proceeding with this swap!

 

On a similar topic, I would LOVE to put a Porsche V8 or Jaguar V8 into an old American car. The 32 Valve Porasche V8 has HUGE valves and can really breath (unlike my current Mopar wedge engine that is starved for air at anything about 6000 rpm) and with the right mods would knock the stuffing out of a Mopar Hemi, and be lighter also. The Jag V8 into a caddilac- to replace the problematic and head gasket munching Northstar could be fun also.
It's just one of those things I'd probably never do though.

 

This will break your heart, don't bother.......to transplant an engine that never saw Browns Lane is a job that will require massive amounts of time and effort. The ECU is mainlined to the BCM and TCM. I've seen a post on here about a possible swap, but the guy never posted back that it actually works with the rest of the car's systems. Better to strap twin turbo's to the Merc....

 

If you have done a LS Swap you'll know that all of the incidentals will cost at least $1500 over and above the cost of the engine/transmission.

FWIW, I'm doing a simple no adapters swap on a Jeep right now and expect that in the end the whole deal will cost about $4000 total of which $1500 was the engine/trans.

 

The Mercedes already has twin turbos...

The ECU/TCU are going to be replaced with the LSx ECU/TCU. I have a source for an "interface" that will allow the LSx ECU/TCU to communicate with the Jag's BCM in order to retain the factory functions of A/C, power windows, heat, etc. This project is not an effort to mullet-ize a Jag; it's a project to have a supportable car in 30 years that can also take semi-regular drag strip abuse. I have nothing against the AJ series of engines - but in my application they do not have the potential of the LSx series of engines.

I already have a car with the 722.6xx transmission in it and am aware, first hand, of it's limitations. I have no desire for that transmission in my next project vehicle.

If such an "interface" existed for the CL Merc, I would happily perform this swap in the W215 - however it does not...so I must move on. Besides, I don't want to deal with ABC in 30 years.

Yes, I have done several LS swaps on various vehicles (including 2 boats). I will say that a lot of the cost is dependent on your ability to source parts at a low price. With the current price of X308's; it's still not an expensive project. I would love to do this on a 75-77 XJC; but they are quite a bit more difficult to find.

 

Are you going to supercharge/turbo the LS engine? Nitrous?

If keeping the XJR at full weight (4000lb), you'll probably need about 700-800 hp to run mid 10's. Less if stripping it out for lower weight.

That sort of power should be doable out of the 4.0. Nowadays, 200hp per liter is hardly pushing it, although probably hasn't been tried on the Jags. There's a few that claim 600+ hp, although I haven't seen any 1/4 mile numbers from them.
Maybe you could try modding the XJR engine and if it blows up, then do the LS swap?

There's also a couple companies that can strengthen the transmission to handle the power.

Of course the LS swap would probably be easiest way to go about it, just because there's so much aftermarket support and it has more cubic inches.

I have thought about doing an LS swap with forced induction for a stripped out XJR drag car. It's just such a backasswards engine though, albeit with a lot of potential.

 

Looking at a 434 ERL Superdeck 1 engine, single turbo + nitrous (don't think there's anywhere to put 2 turbos); 4L80E; and some way to shove a solid 9" axle under it (I doubt the stock IRS can handle 1000 hp, but maybe I'm wrong).

It's tough to try to justify keeping the Jag engine, parts to accomplish what I want will cost far more than the LS-type engine. And, as I've said before...I don't have much use for the 722.6 transmission in this application. It's a fine transmission for what it was designed for - but it can't reliably back up the power I'm looking at. My CL is currently at ~700 hp/1000 trq at the flywheel. The engine can handle more...but the transmission and rear end are at their limits (for 1/4 mile use) unless mega dollars are involved. As for Jag guys looking for a strong 722.6; because of their use in the Mopar SRT8 vehicles, higher strength rebuilds AND higher stall torque converters are available for these transmissions at very reasonable prices...

The LS might be a backassward engine, with only 16 valves and 1 cam...but it sure is hard to argue that it makes serious power in a dimensionally small package with the durability of an anvil. I guess I'm not sure what could be improved upon (at least aftermarket wise)...

I currently do not own a 434 SD1; but I do have a 347 @ 440 hp and a 383 @ 560 hp; so one of the two would be used a stepping stone to the "big" engine.


If the N/A 4.0 intake fits the XJR, it would be interested to see how the engine would respond to a turbo. I'm sure it's been done if it's possible...

 

Someone here claimed to have done twin turbos on the XJR with 640 hp about a year ago but has since disappeared. There was no pictures or dyno graphs.

Not sure if the NA intake fits (probably does), but if going the turbo route, might as well get a proper one made to handle the power.

 

In doing a little more reading, it appears as if no one offers dyno tuning for the R series of cars?

 

Eurotek Designs offers ecu tuning. You send them your ecu and they tune it and send it back. Don't know if they do custom tuning for your specific vehicle.

A couple UK companies as well; like Paramount Performance. Probably same deal as Eurotek.

Although Avos on here is running a twin screw with 600+hp and hasn't done any ecu tuning.

 

By the way, what does your CL run in 1/4 mile?

 

12.29 stock with a 4500' DA; Have not been back to a track since all the work was done. I got transferred and there is no drag strip near where I am...