Hey all!

Just wondering if removing the rain tray will give me some additional cooling that might be noticable on the temp gauge. Anyone done this or have any data to support it?

Also, the side grills in my car have some sort of plastic covering over the holes underneath (no air passes thru). Not sure if this was standard on the late model cars or not.

Thanks!

Yes, removing the rain tray "should" result in additional cooling. It will likely not be enough to see on a temp gauge.

I've never heard of the side-grill covers, but that doesn't mean they weren't an odd option.

--DD

Yes a little bit.
I don't have any numbers for you, but I had always heard 5 degrees difference or there abouts.

brant

yup, i got about 5 degrees. it was noticable on my gauge.

I am trying to decide on whether to ditch my rain tray or not for this weekend. What if it rains?

I agree with Dave. When I put mine back on I saw no detectable change in my gauge readings. You will however notice a huge drop in temps of you remove the engine lid all together.

QUOTE (jkeyzer @ Apr 19 2005, 03:09 PM)

I am trying to decide on whether to ditch my rain tray or not for this weekend. What if it rains?

then you'll have a water-cooled engine, right?!

QUOTE (Brett W @ Apr 19 2005, 01:11 PM)

I agree with Dave. When I put mine back on I saw no detectable change in my gauge readings. You will however notice a huge drop in temps of you remove the engine lid all together.

a neighbor with an original /6 had his engine lid rigged so that he could pull on the lever and have it pop open only to about an inch to an inch and a half...claimed he'd get a 15° reduction in engine temp on a hot day....

Jason, bring it over sometime. Once the engine temp has stabilized (you driving it over to my house) we can measure the temp where the air exits the heads for a minute or so with my digital thermometer, then open the engine lid and see if it goes down any. If it does not go down, or very little, then probably no point in removing the rain tray. My thermometer has a remote pickup and reacts almost instantly to temp. changes.

QUOTE (jkeyzer @ Apr 19 2005, 01:09 PM)

I am trying to decide on whether to ditch my rain tray or not for this weekend. What if it rains?

I think Sklines ten day forcast for rain has a few people worried, (including me). One thing to keep in mind is ten day forecasts aren't worth the paper they are printed on. I removed my rain tray but if it looks like rain on thursday or friday morning I will re-install it or take it to the WCC with me and intall it when needed.
My car runs a bit cooler without the tray but the calibration on my cage is hard to tell 5 degrees but I would bet that is pretty close estimate.
Cheers, Elliot

I removed mine this past week. ...it added at least 5 hp to my car

The testing of the 914 DTM is almost finished. I only await my new 16 channel data logger to log the results of some various changes so they can be documented.

I plan on testing with and without the rain tray to see the differences and even modifying a rain try to also see the effects.

BTW- Those infrared temp gauges are worthless for this type of test work. By the time you stop the car, get out and aim the gun the temps can drop as much as 100 degrees.

Thanks for the posts! It won't rain here for another 3 months so maybe I'll try it out, can't hurt. Now only if my air cleaner was chrome!

My car seems to run a bit warm here on the 80+ degree days (at least according to the gauge). A couple of times, I've seen it inch up towards 5/6ths up the gauge on longer drives. That scares me.
It is a 75 with the smog crap on it so I'm sure that doesn't help. I'm thinking about going the oil cooler route. Maybe something like Demick's as I do not want to cut my tub. (maybe mount one in the front valance w/no chopping?)

Guy.. thanks for the offer. I'm curious as to what my actual temps are. I'll take you up on that.

DD.. During the last meet I went to, I think one other person had seen those side grill 'covers'. If you pop the grill off, you can't see down into the engine. There is a molded thin layer of plastic (almost membranish) covering the hole. I figured that they may have done that on the late models to help keep water off the battery.

An infrared temp gun is a great way to find out what your oil temps are (I think Jake is talking about head temps which can change very quickly). Oil temps change pretty slowly. Shoot the sump plate with an infrared gun and get an accurate reading for what your oil temps are. Find out what 5/6's up the gauge really is.

I'll bring my infrared thermometer to WCC if anyone wants to check their temps.
Only takes a second.

Demick

QUOTE

It is a 75 with the smog crap

FWIW, getting rid of all the smog crap isn't nearly as difficult on a 914 as it is other later model cars. Lose the pump, plug the holes, eliminate the CAT. Might even pick up another 5HP! Especially if you don't need a heater and get some decent headers. I don't know the smog rules in AZ, but my 75 is exempt here in WA.

Randy.. thanks for the post. AZ is not bad, but if you live in one of the 2 big metro areas (Phoenix or Tucson), you are subject to smogging. They actually do a physical inspection to ensure you are running with a CAT and air pump. SUCKS....

However, there is a bill on the govenor's desk to exempt 15+ year old collectable type cars.. If that happens, I'm definitely losing smog hardware..!

Ouch. Guess we're lucky here. Hope they pass that bill!

The reduction in temps from removing the rain tray are hard to measure because they happen slowly. When you first remove the rain tray you may notice little difference.. but in a few years once those extra holes open up, you'll get extra cooling air form the passenger compartment and wheelwells.

The reason that I recommend not using the intfrared temp guy is because the surface temp of the case or the sump plate is not the same as the oil temp.

Aluminum conducts heat fast and the case can soak up heat made all throughout the engine. Measuring the surface temp is never as accurate as measuring from a probe on the head or submerged in the oil.

While any data beats no data I'd still shy from infrared temp guns as a tuning or comparative tool.

Buy gauges- With numbers and live by them.

If your car is running hot then figure out why it's running hot. Leaves blocking the oil cooler? Flaps operating correctly?? If you car is not overheating then leave the rain tray alone. I can drive all day in 100 degree heat and my temperature gauge never goes above the 3/4 mark.