Last year before our hot summer (now) I had my original Hella intercooler pump replaced with a Bosch one. It has made a big difference but o can still get some heat sink when it's 30'C. However the XJR recovers within a few hundred yards, a vast improvement on before
I have wondered for a year or so if a second intercooler pump on the other side of the circuit would make much difference. I suspect the wiring could be an issue, as the pump must draw a few amps. It may also make bugger-all difference.
It could be an interesting experiment...

 

It helps, on the later V8's anyhow, drops the intake helps several degrees, but so far only tested with two stock pumps, not with bigger aftermarket ones.

 

Do you have any supercharger upgrades, or is your heat soak experience happening with the stock pulleys etc?

 

Standard XJR6 apart from ECU reprogrammed by Andy with more-advanced ignition curve and I think leaner mixture
The heat soak is not bad at all, and it recovers quickly now with the new pump. But the car sure has more power on a 20'C day than a 30 day. And. It loves a damp winter's day!

 

Al, can you elucidate; what are your symptoms of heatsoak? Loss of power after thrashing your car uphill or a series of short straights? Or something else?
You say it recovers after a few hundred yards; does this mean if you get reduced power after driving hard and then cruise at part throttle for a bit you feel full power next time you open it out, presumably because the intercooler has had time to dissipate some heat (into the coolant)? I would guess that Jaguar would have designed the car, with an eye to econonomics, to have lots of power to, say, accelerate quickly in an overtaking manoeuvre, and then cruise along at part throttle, but not to be constantly on and off the gas as you might be on a race track.
Other forum posters have talked about fitting a bigger intercooler circuit radiator. Do you think the standard one is adequate but the pump is too small? The increased flow from the Bosch pump has improved performance for you but there must come a point where increased flow just moves hot water out of the rad before it is cooled enough?

 

Recently I did a little research after replacing the intercooler pump with usual Bosch 02.
RADS correctly enquired as to your definition of heat soak. I am in Australia & we have recently experienced well over 30c for the past couple of months.
In normal circumstances the intercooler working correctly will be cooler than the engine to feel & touch, something I realised on my own xjr after a gentle (normal ?) drive with temps over 30c. I also noticed the water hose inlet to the intercooler was relatively warmer than the outlet to the pump. One article in my research mentioned that in practise, the temperature of the water exiting the intercooler will not be extremely high if the water volume circulating through the system is adequate.
You are aware I presume that under normal (high vacuum) driving the s/c feeds through the bypass valve which takes the excess compressed air back to the s/c intake, this effectively take the s/c off-load & thus less heat to be dealt with by the intercooler.
However if one has just completed some seriously fast or heavily loaded driving & shuts down the engine, the heat that has been generated will just sit there heating up the intercooler more - "heat soak". This should be dealt with upon restart after a brief time.
The following website is very informative & worth a look -
AVT | PWR Chargecooler Systems | Water to Air Intercooler

John Herbert

John Herbert