Supercharging an XK8
Discussion
I'm going to be putting a 4.2 XK8 engine into my Ultima. I have all the supercharger components to do the blower conversion.
Any hints and tips for putting it all together would be welcome.
Also, has anyone on here dry-sumped their X350 engine? I know Aston have done it to some of the X350's that went their way, but cannot find any technical references.
Cheers
Scotty
Any hints and tips for putting it all together would be welcome.
Also, has anyone on here dry-sumped their X350 engine? I know Aston have done it to some of the X350's that went their way, but cannot find any technical references.
Cheers
Scotty
Edited by Scotty-Boy on Thursday 1st May 22:26
The engine in a XK8 has some differances to the one in a XKR
Lower compression ratio
ECUs for a start
As you would not be using the Jaguar gearbox the engine ECUs will not work as they need to 'Talk' to the Gearbox ECUs
All things can be got round, but if you need to ask what is needed I din't think you will be up to the job
Sorry, but you did ask.
Lower compression ratio
ECUs for a start
As you would not be using the Jaguar gearbox the engine ECUs will not work as they need to 'Talk' to the Gearbox ECUs
All things can be got round, but if you need to ask what is needed I din't think you will be up to the job
Sorry, but you did ask.
Cheers for the vote of confidence Norman... I said I didn't know much about Supercharger's - not engines, and I asked about Supercharger set up - not engine set up, but thanks nonetheless for teaching me how to suck eggs on the ECU and compression front!
Edited by Scotty-Boy on Wednesday 30th April 21:57
I'm no expert, but i think there's a lot more difference between the engines then just the supercharger, i believe as well as the lower compression ratio, the supercharged engine has the oil cooled pistons, but it's a great engine, if i were you i'd contact avos about his screw supercharger conversion
pk
pk
Hi Scotty,
I assume you will use your own ECU as I doubt you will get it to work with the Jaguar ECU like NormanD also said. There is so much the ECU is communicating with, you would need a lot more Jaguar internals (well almost the car) to make it work.
The NA version has indeed a higher compression, which is of course not the end of the World, but you may need to lower the boost pressure compared to the standard SC engine. Another thing is that the NA has variable valve timing, which is computer controlled, so you would need a new camshaft/gear from the SC engine. I am not sure if the fuel injectors are different, though that would not surprise me, so you also probably need the fuel rail/injectors from the SC engine.
All in all it is just an engine, that needs to be controlled by a good ECU, and you do have the full set of supercharger components as far as I can see. You also need a good fuel pump and a valve to control the fuel pressure in relation to the boost pressure. The Jaguar ECU (4.2 SC) is controlling this electronically via the pump, though you could also do it the old way with a valve and return line. As you say you know about engines, then this is probably not new to you.
A twin-screw could give you indeed much more power, especially since you have a higher CR, as the twin-screw will delivery air at a lower temperature and needs less power to drive, so a win win situation. On my car I have moved from the stock 310 rwhp to 455 rwhp, so that gives some idea ;-).
Good luck,
Andre.
I assume you will use your own ECU as I doubt you will get it to work with the Jaguar ECU like NormanD also said. There is so much the ECU is communicating with, you would need a lot more Jaguar internals (well almost the car) to make it work.
The NA version has indeed a higher compression, which is of course not the end of the World, but you may need to lower the boost pressure compared to the standard SC engine. Another thing is that the NA has variable valve timing, which is computer controlled, so you would need a new camshaft/gear from the SC engine. I am not sure if the fuel injectors are different, though that would not surprise me, so you also probably need the fuel rail/injectors from the SC engine.
All in all it is just an engine, that needs to be controlled by a good ECU, and you do have the full set of supercharger components as far as I can see. You also need a good fuel pump and a valve to control the fuel pressure in relation to the boost pressure. The Jaguar ECU (4.2 SC) is controlling this electronically via the pump, though you could also do it the old way with a valve and return line. As you say you know about engines, then this is probably not new to you.
A twin-screw could give you indeed much more power, especially since you have a higher CR, as the twin-screw will delivery air at a lower temperature and needs less power to drive, so a win win situation. On my car I have moved from the stock 310 rwhp to 455 rwhp, so that gives some idea ;-).
Good luck,
Andre.
Thanks guys.
Will be stripping the engine back to it's core function... turning the wheels! Obviously no AC, PS, etc, etc.
I'll probably be running a Emerald ECU as I've always been very impressed with them in the past - generally speaking they offer great functionality and certainly have enough to control this engine and the ancillaries I'll be using.
I was planning on using 'return' fuel rails.
The only other thing that I was considering was a water / methanol injection system.
I was hoping for 450+ BHP.
Andre - I've not been inside the engine yet, anymore info regarding the VVS?
Will be stripping the engine back to it's core function... turning the wheels! Obviously no AC, PS, etc, etc.
I'll probably be running a Emerald ECU as I've always been very impressed with them in the past - generally speaking they offer great functionality and certainly have enough to control this engine and the ancillaries I'll be using.
I was planning on using 'return' fuel rails.
The only other thing that I was considering was a water / methanol injection system.
I was hoping for 450+ BHP.
Andre - I've not been inside the engine yet, anymore info regarding the VVS?
Edited by Scotty-Boy on Tuesday 13th May 14:23
450 BHP on the engine (I assume not wheels?) might be tough to get to, as even stock cars with the lower compression have a hard time to get there.
You need to be careful increasing the boost, especially if the ECU you are using is not able to detect detonations and respond accordingly. The Jaguar ECU is pretty advanced in that it can detect a knock per cylinder and adjusts the ignition only for that one. So you need to be in the safe zone. Also Jaguar keeps the A/F mixture pretty rich (around 11), for cooling down and avoiding detonations.
The Eaton supercharger gets pretty hot when used, again increasing the chance on detonation. The Jaguar ECU is reading the temperature after the supercharger to compensate (retard ignition and enrichening the fuel).
There are companies that clean injectors, and they can also let you know the flow, so you can get some idea of what the max is for the injectors you have.
You need the intake camshaft from the SC engine, as the one from the NA is different (I think it can change about 45 degrees or something), and also the sprocket, that should be it, as I think the exhaust is exactly the same between the 2.
Good luck,
Andre.
You need to be careful increasing the boost, especially if the ECU you are using is not able to detect detonations and respond accordingly. The Jaguar ECU is pretty advanced in that it can detect a knock per cylinder and adjusts the ignition only for that one. So you need to be in the safe zone. Also Jaguar keeps the A/F mixture pretty rich (around 11), for cooling down and avoiding detonations.
The Eaton supercharger gets pretty hot when used, again increasing the chance on detonation. The Jaguar ECU is reading the temperature after the supercharger to compensate (retard ignition and enrichening the fuel).
There are companies that clean injectors, and they can also let you know the flow, so you can get some idea of what the max is for the injectors you have.
You need the intake camshaft from the SC engine, as the one from the NA is different (I think it can change about 45 degrees or something), and also the sprocket, that should be it, as I think the exhaust is exactly the same between the 2.
Good luck,
Andre.
Cheers Andre.
Not many after-market ECU's out there that do DBW. Top end MoTeC's only as I understand (I could be wrong... I frequently am!).
It would seem that the simplest (and most cost-effective) thing to do is find a mechanical TB of the same size.
Not many after-market ECU's out there that do DBW. Top end MoTeC's only as I understand (I could be wrong... I frequently am!).
It would seem that the simplest (and most cost-effective) thing to do is find a mechanical TB of the same size.
Edited by Scotty-Boy on Friday 2nd May 13:51
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