Rear mount radiator

[jalopi]

Sup bros, anyone got pics / details on rear mount radiators in our cars? Because either my search keyword choices suck or the info just isn't out there. Will only be doing if I end up doing a turbo on my car. I know I could put the intercooler in front of the radiator, but I know for a fact I'd have even more temp issues than I currently have if I decided to go that route ('murican v8 swap).

I already have 4" box flares in the front, same is in the process for the rear. If I did the radiator in the back I'd probably integrate scoops into the quarters to supply air, then duct to the radiator which would be mounted about where the rear seat backs go. Further ducting would take the air from the radiator to the license plate area (pictured below) which would either vent via swiss cheese holes or vented slits. Not sure what I'd do though I'm guessing slits would look cleaner.



I'm assuming this would work since the sides of the car (well, a scoop on the side of the car) would be significantly higher in air pressure than the license plate area, yes? FWIW, this is pretty much a track car so if I decided to do it the license plate would be removed during track use. Either that or I'd swiss cheese the license plate and be like #fuckdapolice

Proposed quarter flare design would be like this:



I have a sedan just like the pictured e28 so I could make the flare come up even further to the front doors if necessary.

Thoughts on this?

[e30_302]

Should work. May need a bigger exit hole than just the license plate area though. Going to require a lot of fab work, obviously. What are you going to use for pipe for the water?

[jalopi]

Everything I've seen online about rear mount radiators, or just cooling plumbing in general, says that aluminized exhaust pipe works just fine.

I did think that maybe the license plate area was too small, but I'm not sure if any other option is "low pressure" enough. There's under the car (which I'm really not trying to add lift to the rear) and the trunk lid, though I'm not sure if that's a low or medium pressure area vs the license plate area.

[roguetoaster]

Use your C pillars for scoops
Cut the spare tire well.
Add a tray for the radiator, mount either flat or at a small angle.
Send air in under the radiator, hot air removal above the radiator, using rear bumper/valence "swiss cheesing"/removal for exhaust.

/looks pretty in my mind

[e30_302]

Exhaust it through the trunk floor into a diffuser, tell people you have F1 tech in your car.

[jalopi]

LOL, I'm sure that'd rustle some jimmies

Not sure how c-pillar scoops would look... this is the only thing that comes to mind



Not sure if that'd supply enough air or look good.

As far as the trunk floor goes, I'm down for that idea, though I'm not sure if that's as low a pressure area as the license plate area though.

[TheTacoMan]

Local guy has a setup like you mentioned on a scylone.
Id say with some pretty big fans as well as some big intake ducts like the old dtm car could cool well actually. Only issues is making sure all the lines and what not will not leak.

[e30_302]

As far as the trunk floor goes, I'm down for that idea, though I'm not sure if that's as low a pressure area as the license plate area though.

Probably not, but still lower pressure than the air coming in. A nice big electric fan, like from a Taurus, would supply the pressure delta I imagine. Since nothing will be behind the core, air should flow through quite easily assuming the ducting in is nicely sealed up to the radiator.

[jalopi]

like the old dtm car

pictured?



Also, was that the cyclone on /tuned?


As far as the fan goes, yeah, that's one thing I'd be pumped about - actually being able to use a real fan. The push fan I have just isn't cutting it when driven hard.

[TheTacoMan]

It is, farah drove it after the e30 last year.
Im sure with enough airflow it would be very possible.

[jalopi]

OK so I figure I might as well spill the beans about this project... there will be no fan for the rear mount radiator. 100% ram-air design, at least that's the plan anyway. From what I've read fans are really only good for speeds under 30mph - anything over that and they're actually a restriction.

NOW

That's not to say I won't have a fan on a radiator though... I plan on keeping the one up front too. So yes, that's two radiators. Didn't wanna bring it up right from the get-go since I don't have a quadruple layer flame suit laying around... still might need it though.

Anyway, yeah, still gonna have the turbo and everything I originally mentioned, just a radiator up front which does most of the cooling while under 30 (which would be the weakness of the rear mount rad) and then the rear mount to supply extra cooling while over 30/racing. Basically I don't ever, ever wanna deal with overheating again. At the bare minimum I expect this setup to double the amount of time I can spend on track before having to stop to cool down.

New thoughts on this? I realize it's extra weight and more places to leak from but I have tried EVERYTHING to keep this car cool and I've had zero luck. Hoping the auxiliary radiator will finally solve the problem

[SkiFree]

Andy Hately's FD car....

http://www.iemotorsport.com/gallery/v/car-of-month/January+2014+-+Andy+Hateley+-+Formula+D+E30+325i/

He was kind enough to post lots of detailed shots

http://s149.photobucket.com/user/Shmately/library/Project%20E30?sort=3&page=9

[e30_302]

I wonder if the water pump is up to the task of dual radiators and all the piping?

You might want to try other less intense methods of keeping cool. My Speedway motors universal aluminum radiator (26" I believe) has no problems keeping my car cool. Flogging it around VIR in 95* weather and my temp gauge never moved a degree warmer than my thermostat temp.

In my first race with the car last year, I left the fan (Taurus) on accidentally and the temp wouldn't go above 160* on the track. That same race, I had a weeping timing cover and lost about half the coolant- still stayed cool.

Do you run an oil cooler?

[HennaE30]

Exhaust it through the trunk floor into a diffuser, tell people you have F1 tech in your car.

Lol is it sad I was thinking this while reading the original post? As an actual idea... It would solve OP not wanting lift under the car.

[Aleman]

LOL, I'm sure that'd rustle some jimmies

Not sure how c-pillar scoops would look... this is the only thing that comes to mind



Not sure if that'd supply enough air or look good.

As far as the trunk floor goes, I'm down for that idea, though I'm not sure if that's as low a pressure area as the license plate area though.

Holy shit! That's my old MR2! I sold it in 2001. I do sorely miss that car. Here's how it looked when I had it, before the next owner 'flavored' it how he wanted it. I like the wheels he chose, but dat red interior is a no-go.







Just so I don't get accused of threadjacking, here are some more pics of that snorkel he added: