Rear Mounted Radiator

[p1234 22 2 Cars]

With a bit too much thinking time on my hands today I was throwing around the idea of fitting the rad in the back.

 

This is in my rallycross car before someone pictures me driving down the road with the radiator splashing about on the back seat.

 

Im thinking of lengthening the life span of the rad by moving it. plus was wondering would shifting some weight to the rear make any handling difference or would any gain be lost with the fact the system will have to hold more coolant.

 

Would the standard water pump be up to the job was another problem I came across.

 

 

Anyone tried this or should I stop thinking!

[brumster 135 1 Cars]

The nearest I've got to this is when I had kit cars 'back in the day'... GTMs... they have the radiator still in the front but the engine had been moved to the back. The pump had no problem pushing the distance, if that's what you're worried about.

 

I'd be guessing your main challenge is getting airflor through it, but plenty of other rallycrossers must be doing this so just copy them also see if they up the side of the rad to cater for loss of air flow.

 

The other thing to watch is something that frequented the K-series when it was moved into the GTM.

 

You've got the distance between your thermostat and the radiator now much longer, which means there's more cool water in there to hit the engine when the stat opens. Now the Pug is not a K-Series in any way, so I wouldn't worry too much about this in terms of the notorious K-series problems and head gaskets, but it might be worth putting a low-switching stat in there or even drilling a tiny bypass hole in the stat (which is what I did in my K-powered kit). If it's a race car, this isn't too much of an issue as you've got plenty of time to warm the car up before giving it the beans.

[p1234 22 2 Cars]

I was thinking of a duct/vent in the fly window feeding down to as you say a larger rad with 2 fans as I could ditch the 205 rad for something bigger also making more room for my throttle bodies up front. Id imagine some sort of vent will have to go in the tail gate to aid unwanted airflow.

 

Wouldn't think the stat would be a problem as its well warmed up before any serious work.

 

Ill have a root around to see what sort of parts are out there that might help.

[rallyeash 155]

look at the Renault 5 gt turbo radiator. its a good size and ive got one in the front of my 205

[Turbo7379 3]

Back when I was stock car racing a 205gti I had the radiator mounted where the back of the rear seats normally is. I used a citroen bx rad (I think) which was wider than a 205 & I fitted the twin fans of a turbo diesel on a manual switch.

The pipework was done in 28mm copper pipe with rad hose at the ends. I kept a check on the water temp by feeling the copper pipes which ran inside the cabin. When the pipes got warm I knew the stat was open & turned on the fans. More than once I forgot to turn on the fans & the car didn't overheat. Then again, the rad was getting plenty of airflow due to there being no windows in the car!

The system held a lot of coolant & it took ages to fill to avoid airlocks.