Bee-Raddd

Hey Everybody!

Whos flat bottomed their evo for motorsport or autocross?

Specifically wanting to know what you did around the diff areas and wether the diffs require some form of cooling or not?

We do 10 lap sustained races in my car so will be 15 - 20 min of constant full throttle. Just not sure if the diffs will overheat if we flat bottom the entire floor area from splitter to diffuser?

Also pics if youve done it would be a massive bonus!

honda-guy

iTrader: (55)

most of the flat bottom evos ive seen are built for time attack, so they only do a couple laps at a time. i saw a pic on Instagram of a rear diff cover that has cooling fins and higher capacity, also ports for oil cooler. i was going to get it if i wasn't selling the evo.

LetsGetThisDone

iTrader: (1)

10 laps is only 15-20 minutes? I probably wouldn't worry about it. 20 minutes sustained isn't that long. Maybe put a NACA duct to send air up to the diff, and a vent behind it.

Meathooker

iTrader: (2)

i spent too much time stressing over this and finally decided against a flat floor for now. If we do planning on an oil to water heat exchanger for the trans, tcase, and rear diff with a separate radiator.

iirc pegasus auto had a cool little 2 or 3 circuit radiator that looked it would work sweet

Bee-Raddd

maybe its worth putting a temp gauge sensor into the drain plug and measure the temps? wonder what temps are acceptable.

At this stage we r just gona leave the tunnel open which will allow plenty of cooling down there and also let exhaust heat escape.

jedibow

iTrader: (1)

Been running mine for years with 20-30 minute sessions without any issues, with that being said the air behind my front wheels enters above the belly pan and then runs the length of the car so that is most likely aiding in cooling the rear diff.

George

Bee-Raddd

Hey George do you have any pics of your underbody by any chance?

jedibow

iTrader: (1)

I just re did some of it over the weekend so I can try and snap a few. You can PM me your email if I can't post them here also sir