BrianS

I'm having Ron Davis make me a secondary front mount heat exchanger which I'll get in a few weeks. Meanwhile I decided to split the intercooler coolant circuit, add a reservoir, and wire the pump to turn on when in accessory mode. I kept my stock pump for now until the heat exchanger arrives, but will swap in a CM30 during that install.

No IAT logging done before and after splitting the circuit since I was going to do it anyway for the new HE. I plan to log temps with this setup and then after I install the HE.

Pics of course....

Here are the components for splitting the circuit. Reservoir, mounting bracket, hose clamps, 3/4" hose splice, and 3/4"-5/8" hose splice. I made the extension bracket and tapped it for mounting.


Cut the Oetiker ring style clamps off existing line and remove stock tee. Reconnect hose using 3/4" splice and install new clamps. Install the reducing splice into the intercooler circuit.


Run a 5/8" inch heater hose to the reservoir.


Tighten the mounting bolt on the reservoir. I put a thin rubber washer under the fender washer to help protect the surface and painted the stainless washer black to blend in better. Add coolant, run the pump, and take for a drive to test.



Here's the wire I grabbed for switched power to act as the trigger on the relay I installed for always on pump operations. It was a pain in the butt to find but that wire goes to a relay stuffed in the corner of the fuse box. There might be other options but this worked well for me.

JAYCL600

Nice DIY, how much is the custom HE?

BrianS

All parts inlcuding HE, CM30 pump, relay, wiring, plumbing, hoses, fittings, and reservoir came to less than $750. The HE itself was $495. It willl have mounting tabs and -12AN fittings welded on as well. If the installations goes nice and smooth I'll be glad provide contact info since they'll have the plans already stored in their CAD department. Easy to replicate.

ChicagoX

That would be awesome.

Thanks !

areuv

Thanks for the informative post, I for one always enjoy your DIY posts, keep them coming

JAYCL600

we have a bunch of local meets as well as track events, email me sometime jason@gemsbyjwade.com

BrianS

Will do. Thanks.

Jrocket

Brian,

Great job as always.BMW offers a differnt resivour that has a better brackett on it for mounting,not sure if you saw that one or not?

BrianS

I haven't seen that one in person, but I liked this one because the outlet came out of the bottom at an angle which was essential in clearing the idler pulley. This reservoir and bracket was OE for a Saab 9-5. If the BMW one will fit then that's a fine choice too. The one thing I did want to make sure of was that the reservoir be thermoplastic since radiant heat is so high under the hood. Aluminum got too hot to touch.

Jrocket

BMW 2007 power steering res. About $23.00 Looks the same but has a better bracket.

TopGun32

very nice!

it's time to get our E55's into the real world prices. Paying $2k+ for an secondary IC and pump is way too much.

Code3smith (c32 member) and I are working on a HE replacement.. bigger HE with a better core design. (more capacity and better coolant distribution)

I should have my unit installed this friday and I will also take readings for ITA before and after.

I do have the CM30 pump already.. so we will see if we see a drop to make the product feasibible.

stevebez

What type of H/E have you gone for ... like Evosport or like Finny's ?

BrianS

Mine will be more like Evo's but larger and will be plumbed in series to the stock HE.

BrianS

I couldn't see the pics but sounds good to me. Multiple ways to skin this cat. The Saab reservoir was about $65. I'm not sure how they compare in size if that even matters since it's only a reservoir. Guess you could fill it full of shaved ice prior to a run....like an ethylene glycol snowcone.

Jrocket

Same size but doesnt have the little ears sticking off the side and its cheaper.

Ron Davis does some nice work.Ive had them build me a few radiators in the past.

stevebez

I am still not 100% convinced a split circuit is the way to go ..... you might have cooler temps initially but your total water volume is a fraction of what it was with a linked circuit, bleeding the system is also more difficult.

The other queestion which I am not sure how it translets is the system pressure... the Motor circuit will clearly be under pretty high pressure and not sure how this affects the linked I/C circuit but perhaps it slows the flow down and mbe thats why the bosch pump suffers...

The split circuit may have less pressure (does it?) and puts less strain on the motor ... but what cools better? (assuming the coolant temp is the same)

A higher pressure system or a lower pressure system? Or is there no difference?

Am I being a complete tool imagining that a higher pressure system will have a greater capacity to carry heat ???

Also is water in a pressurised system a better conductor of heat at all?

I also think if you are using a Evosport located H/E then you are OK splitting the circuit as engine cooling is not starved. Using a H/E like Finny splitting the circuit reduces the effective cooling to the motor so I would be less inclined to split the circuit in this application.

If you not finished the project yet it may be worthwhile to install a valve that allows the circuit to be run split or linked. At the very least you will be able to bleed the system in open mode and run the car in closed mode. Just my 2c.

vrus

Great work Brian!!

Add a rear mounted reservoir and you've got a total solution!

BrianS

I agree. Getting the reservoir out of the engine bay would be best.

TexasSteele

So other than that "t" fitting, the pump, intercooler and heat exchanger are isolated from the radiator and waterpump?

Seems like it would need to have a spot to re-enter into the main cooling system.

Intercooler(under sc)->Pump->Heat Exchanger->Intercooler(under sc)? Thats it?

I guess I'd just expect to need another line...or if we do a remote/trunk mount cell run a send and return line...ideally feeding directly into the intercooler and then using the heat exchanger as an aftercooler on it's way back to the trunk. Thoughts? Am I way off?

Jakpro1

It's a trip isn't it? Just the T Fitting and she is separated.

Trunk res has been one of my favorite mods just because the car stuggles so badly with heat.

Not to mention I watched Chiromikey pack it with ice and blow off an 11.3 while most of us with similiar mods were near 12's.

Amazing too, tub was just PACKED full of ice and he runs the super pass, comes back and she is pretty warm and all gone.

Like a little German Volcano the 5.5.

Blacksport350

As the 2 systems are completely self contained, the T is only used as a fill point for the HE cooling system. Also, as the HE cooling system does not actively circulate with the engine cooling system, it is not self bleeding.

This is one reason that separating the systems does not make much of a difference. You have to increase capacity and put the new reservoir in circulation for the increased capacity.

FWIW, The C32, SLK32, and SL55 all have a return or bleed line from the supercharger cooling circuit to the coolant reservoir so they are not only self bleeding but there is a significant amount of mixing between the engine and HE cooling circuits.

This makes me wonder if MB didn't realize that the E55 was prone to heat soak issues during testing and eliminate the return line.

Bramage

I know this is an old thread, and the DIY is great. But What If:


The BMW P/S resevoir has 2 connectors. What if the 5/8" was connected as shown feeding the Heat Exchanger circuit on the "IN" side, and a smaller 3/8" hose was connected to a T on the "Out" circuit?

This would allow the small res to be part of the circuit, but with reduced flow. Running the CM 30 through the resevoir would certainly be too much, but by only connecting the return with a 3/8", you would at least reap the benifits of having the extra 20oz circulating. The overall flow would not be impaceted, as most water bypasses the T + the recirculated water would ensure actual flow through H/E would be identical.

Any benift to this?

I was talking to a well known tuner, and he said: "Split the system with the BMW part, and when you can, add the truck res." He stated that even with the system split using the method described within this thread is better than leaving stock (with new HE installation)

mikey33

I am not sure I follow 100% because I do not know this stuff to well, but recently when I did my set-up the one connector is used and the other is sealed off. This was with the split cooling and added heat exchanger. Hope that helps.

sgtstanko

These are no longer $23.00 but rather $127.00 and the bracket is $45.00


.

NikleinR6

I believe he was quoting eBay prices and you can still pick them up for cheap.