XJR6: Electric water pump upgrade

[Kember]

I've had a good look around this sub-forum and can't seem to find an answer.

I'm planning various upgrades to the stock motor including the Powerhouse oversized crank pulley and a bored out TB and anticipate that I will need to do something about the heat rejection from the engine.

I understand that it is a good idea to upgrade the electric pump in the intercooler circuit and was wondering which pump is considered the best recommendation. I see from various American sites that Bosch pumps seem favoured but was wondering if there was any JEC expertise/experience.

Thanks

Peter

[J44EAG]

Hello Peter.

See my V8 tuning mods post before you do much. This guide will answer many of your questions in quick time. The guide may be found on the Engine Section of the X350 Forum on this site. It comprises of some 66,000 words and images and will probably take an hour to read. The post will give you a good idea of what you can achieve with either 6 or 8 cylinder supercharged or naturally aspirated models.

Lawson Smith at Powerhouse is probably the best commercial guy to consult as regards parts and services. An ex-gas turbine man by profession. He has been hugely helpful to me getting some grunt from my X350R. Indeed his guidance was used to open up my supercharger and get some air going into the engine.

Yes, the Bosch unit is the pump to have. Best prices and service from AVT in Essex. (Advanced Vehicle Tuning) You will find the pump listed in an ebay advert for about £35. Its certainly rather more powerful than a standard unit and its benefits are good, especially in hot summer weather. The pump helps disperse heat when at the traffic lights and stops the power sags caused by excess heat build up when stationary. A bit more general grunt in normal driving is also noticeable even for a standard car.

Pulley upgrades are well worth doing. You will notice an immediate improvement in low down grunt. That would work well with the AVT pump without anything else being done.

Most Jags have huge internal airflow blockages within the inlet and exhaust tracts. Many can be removed with a die grinder, cutting bit and various garnet rolls to smooth out obstructions and casting restrictions. Accept that the tuning process is gradual with gains coming as you sort out one issue followed buy another...and another and another. It all comes together in the end.

A reflash and also sports cats will be beneficial. As you open up the inlet tracts, supercharger and inter-cooler components, you will then also find that you need to address the exhaust flow which is badly constricted because of the standard 600 cell cats. Talk to the national Longlife Exhausts chain to see what they can do for you. Prices are good and work standard exceptional.

A bored out throttle body is really last on the list. Boring a throttle on its own will achieve little initially. The above sequence done first will achieve far more than initially a bored throttle on its own.

Mike K

[Kember]

Hello Peter.

See my V8 tuning mods post before you do much. This guide will answer many of your questions in quick time. The guide may be found on the Engine Section of the X350 Forum on this site. It comprises of some 66,000 words and images and will probably take an hour to read. The post will give you a good idea of what you can achieve with either 6 or 8 cylinder supercharged or naturally aspirated models.

[Edited down to be kind to readers!]
Mike K

Mike,

Thank you so much for taking the time to write such a comprehensive reply and for your advice.

I'll set to on reading your guide.

Best wishes

Peter

[Kember]

Mike,

Thank you. Very illuminating and well worth half an evening by the fireside. The thread is very readable and I'm very grateful for the time you took to share this information. Now, to implement some of it!

Best

Peter

[ChrisDixon]

Received wisdom is you can only tune an AJ16S to around 400BHP, which is the standard output for the 4.2V8. Whether or not this is correct it would be interesting to know the max power anyone has got from both.