plastic engine undertray - heating issues?

JSE · Postby **JSE** » Tue Nov 20, 2007 6:00 pm

i took my undertray off...

just want to know how this affects heating/cooling issues? is removal a positive effect or negative.

Fatty · Postby **Fatty** » Tue Nov 20, 2007 6:04 pm

negative.

a lot of the air that is meant to go thru the radiator just goes around / under it if you're undertray is not in place.

Juffa · Postby **Juffa** » Tue Nov 20, 2007 8:25 pm

Fatty wrote:negative.

a lot of the air that is meant to go thru the radiator just goes around / under it if you're undertray is not in place.

Quoted for the truth. I was having major coolant over heating issues last summer. At the time I had a massive intercooler and the undertray was removed. I have since put in a smaller intercooler and put the tray back. So far over the past few 35-37c days no more overheating.

hamish71 · Postby **hamish71** » Tue Nov 20, 2007 8:36 pm

For a definitive answer, read this article. In summary, you dont know what its doing, unless you test it. BUT, it was put there for a reason by the oem.

http://www.autospeed.com/A_2159/cms/article.html

JSE · Postby **JSE** » Tue Nov 20, 2007 9:02 pm

thanks guys for shredding some insight. that article was a good read as well hamish. cheers to all of you...

looks like it will be going back on come the weekend :lol:

4sfed5 · Postby **4sfed5** » Wed Nov 21, 2007 3:31 pm

the tray assists in creating a negative pressure inside the engine bay and behind the radiator...without it the pressure differential accross the rad is less and hence less airflow through it...
im not running my tray, but i dont live in Aus either!

StanTheMan · Postby **StanTheMan** » Wed Nov 21, 2007 7:13 pm

My undertay has been off for years with a Number plate mounted right infront of the air intake. No dramas in normal traffic & spirited driving ever.

However I think it depends on the individual car some cars will struggle without the undertay just like some cars overheat as soon as you start giving them a little stick when the Number plate is mounted in the air intake.

On the racetrack.....thats a little different. I did have heating issues at wakefield once when he undertray wasn't fitted. But it got a good flush & some decent coolant & next time on the track there was no problem.
My Number plate also comes of at the racetrack.

But if you want to be on the safe side......fit the undertray back on.