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Jonathan

Chargecooler efficiency project

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Always been a thought of mine - the chargecooler is a great addition to the car without a doubt, however sat on the engine and looking at the pipes I think it can be improved ?

I've had a little experiment tonight and the heat soak into the system is quite amazing actually (even more so for people with mechanical pumps - via the pump body which nicely saps heat from the engine).

Ambient temp tonight was about 15 degrees - chargecooler got to about 22 degrees after a 2-3 miles, when left OFF the heat soak rose to 35 degrees !

1. Chargecooler Body

Sits only 5mm away from one of the rocker covers (80 degrees) and 1" or so ontop of the inlet manifold (again 80 degrees).

The conduction off the engine is quite a lot as it happens - the underside of the chargecooler was quite warm.

2. Pipes

They all run near and about next to the hot water pipes so they conduct heat from them, some of the pipes are noticably hot at certain spots (and not where you'd think)

The chassis also contains the chargecooler pipes and I believe they run hand in hand with the heater matrix, hot oil and radiator pipes - they MUST get hot in there, the cabin gets hot as it is from the tunnel !

3 Electric pump.

Having run both I am convinced the electric pump is by and large better than the mechanical one - on a heat basis alone the original alloy pump body must have been at a pretty high temperature in comparison to ambience becuase it was connected to the engine.

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My ideas were to make a chargecooler jacket which protects the main sides of the chargecooler from radiated heat.

Also has anyone ever had any ideas to run the chassis pipes UNDERNEATH the chassis itself ? I was going to use a magnetic mounts to hold it on and run 2 bare copper pipes down under the chassis - this will stop the conduction inside the tunnel plus the pipes would act as an additional heat sink at high inlet temps.

Finally I was going to sheath all the cold pipes in copex plastic electrical sheathing to trap insulating air inside - tried this on the hot water turbo>tank tonight and the difference on the surface temp of that hose was 40 degrees less than normal !

I reakon I can get the temps down to almost ambient but question is am I chassing rainbows here becuase will all my (small) efforts be knocked back the moment I use my right foot ?

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Didn't Dermot do something similar maybe he can shine some light on the subject.

I wouldn't run pipes pipes outside the chassis as they are well protected inside the chassis. Maybe insulating the various lines inside the chassis is an option although I realise it will be a big and major job to do. I would start with insulating the chargecooler from the engine as well as insulating the pipe/hoses of the chargecooler system inside the enginebay and see how much effect this has. Depending on the results you can then decide to take things up a step or not.

These are just my

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Insulating them inside is way too much work, they run through solid pipe as well so it's a complete mountain.

At least if they are underneath they can be easily repaired (only copper tube) - the brake lines run under there and are fine, if the chargecooler lines break it's also not a reliability problem - you can still drive the car ok.

I'll work on it bit by bit, quite interested to see where the heat is creeping into the system.

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This is all good stuff mate, I would be very interested in the results, also happy to assist where I can in assessing the temp reduction. Model variants, state of engine, set up and wear on the mech pump will make your improvements not necessarilty directly transfereable to others.

I for one would start on the chargecooler itself, insulating it from the environment, it could also have better fins to disipate the heat, some foil wrap, and wrap the pipes to and from. There is a simple calculation (if I can rememeber it) to work out the heat gain per meter of pipe per degree c. This would indicate whether or not its worth running copper pipes the length of the car, remember your adding more weight.

Also you should check to see if the gains in HP are linear with temp reduction. There may be a point of deminishing returns.

Keep in touch, its interesting stuff.

Dave

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From what I have seen on idle the chargecooler temp rises about 10 degrees above ambient, more when the engine is off so heat soak is definatly an issue.

I think the top losses in the chargecooler are the pipes in the chassis and the fact the main chargecooler body is so close to the engine and has no ventilation. Yes the pipes in the engine bay are affected by the heat in there but I think this only acccounts for a small % of the total.

Pipes under the car will add about 2 kilos at most which is not really going to affect 0-60 times.

Even if it was just the one return pipe you did it would possibly be a huge bonus, I am sure the heat exchanger radiator at the front is able to draw off a lot of heat, by isolating that one return line from the rad back under the car I reakon you could really reduce the temperatures. Infact 1 pipe you could probably zip tie to the brake lines under there.

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I dont't have a charge cooler , but anyway....

Could you insulate the bottom of the charge cooler with an engine blanket? I have one fitted on the land rover to reduce noise. They are heavy duty, fireproof wadding (fibreglass I think) and also a lead sandwhich to reduce the noise in the landrover application. a large blanket would reduce heat in the whole bay. But you would be trading off with the weight of it.

Good luck

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Not so sure tieing the pipe to the brake pipes is a good idea, however it would be very interesting to understand the temp full at either end of the copper tube under the car, this is clean cool air and if the pipe was finned in some way you could achieve a good additional reduction in temp. You are right about the weight issue, its the weight of a couple of gallions of fuel.

Dave

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Ahhhh I see what you've done by putting a brace where the seat bolts come through to hold the tubes - good work thats exactly my idea with a better way of mounting them :)

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Heat soak only happens at idle or post shutdown. Not really an issue unless you're chasing ultimate bhp at standstill, or you want to perform well on a rolling road.

Once you're underway with air circulating everywhere, do you still have the localised hot spots? Are they detrimental enough to warrant extra fiddling?

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Hi,

Don't know if this helps or not but I heard that the new Ford GT uses a small portion of the A/C circuit to chill the intake air. So it made me think...

Wonder if a section of aluminum a/c pipe could be coiled and then re-routed through the intake chamber to cool the air. Sort of a air chiller.

Or, could the a/c be forced on via a kickdown switch on the gas pedal at full throttle to cool the intake air somehow. Obviously it would have to give more power then it draws.

Rich

Edited by Rich

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As mentioned the heat soak only comes into play at idle or with the engine off. Insulating the intercooler will increase the time it takes for the intercooler to gain, say, 10 C over its running temperature but will not prevent it.

Some numbers - Engine power increases roughly with the square root of the absolute temperature. So a 10 C drop in the charge temperature would give about a 1 to 1.5% power increase, i.e. about 3 bhp. You may get a gain with adding fins to the duct between the compressor oulet and the intercooler to reject heat into the engine bay as the compressor outlet temperature can be 150 C, well above the 90 C or so under the engine cover.

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