is there any reason to leave this in, or any benefit to taking it out (i.e. airflow)? i'm talking about the flat black peice that is left underneith aftermarket intakes. I haven't see anyone remove this after installing an intake and i was considering getting Esmeril's battery relocation bracket if removing both of these peices, bottom of intake box and battery tray, will allow more airflow through the radiator and out through the vented hood. and yes, i am thinking turbo in the future or atleast planning to be available for it. if both of these peices are removed wouldn't it creat a larger straight path for the air to flow out of the radiator? just thinking outloud. this isn't a "i'm 17 and daddy just bought my car and i heard it gives xx HP" kind of a thing. just thinking outloud thats all. Input?

 

When I had the AEM I kept the under tray installed at first, but then I thought it looked ugly so I removed it.
People claim that it helps reduce heat, but I'm not sure by how much.
Here is the only pic I could find with the under tray removed in my car:


I currently have the RB intake installed without the under tray, but a pic of that would be worthless since you wouldn't be able to see it.

 

I tried both ways, with and without it.

but it seems that the temp will go down faster WITH the tray in there.

Keyword ---- *seems*

 

^sort of a butt dyno type of feel! haha

 

thats funny, i thought that it *SEEMS* as if the airflow would increase substantially with it removed. the bottom of the battery box and the bottom of the airbox force the air to go ???

 

I'd say that having that panel in there directs the airflow toward the radiator keeping that cooler. Removing that would would then let the air flow into the rest of the engine bay more freely, causing less direct air to flow to the radiator causing it to maintain higher temperatures and have a longer cool down.

If its in the way now, remove it. If not, leave it until it is in your way and you do decide to go for that turbo--that panel would be the least of your worries by then.

^My uneducated input.

 

The intake's under try is behind and above the radiator.
I think you are referring to the tray under the car.

 

So it is. Guess I didn't look as closely at your picture as I thought. Scratch my earlier comment then! Maybe its there to keep random debris from falling down there? I know mine sure is dirty.

 

I think BHR was looking at a product to either fill that void or make it more attractive. They were talking about pics like a month ago, but I haven't seen any yet. (Hint Nudge Wink BHR guys who read this)

 

I think thats what it is for.

ITs more like the tray will direct the air to blow directly at the engine itself --- then to the rear of the engine. then pushes down on the transmission.

just a thought.

 

I couldn't find any other info on this subject, so I'm bringing back an old thread.

After a pretty furious lap and the Nurburgring yesterday, I noticed that I had smoke coming in through my vents and out of my hood. Coolant temps were "normal" (stock gauge) and it seemed to be running fine, the bay was just really hot. After talking about it with some of the guys I was with some of them suggested removing the stock intake box and undertray and relocating the battery so I could free up the radiator fans. It seems like a good, logical idea. BUT one thing I've learned with the RX8 and Renesis is normal mods aren't always the best idea.

To me, the intake tray seems to be only a place to hold the intake box in place. I think it will help to open up the bay some, and I'm going to try it as soon as I can, but it's been a while since this thread came out, so I was wondering if anyone has any more info on this subject?

 

I think you might want to find out where your smoke came from first.

Don't rely on stock's gauge for "normal" coolant temp readings. Get a real gauge.

Mine is almost always under 89 Celsius and about the same for oil temp.

 

Well smoke might be too strong of a word, its was more of a light smoky steam. We looked all over for a while and couldnt find anything leaking or low, so I'm thinking something just got really hot in the bay. The car smelled like clutch and brakes really bad, but that's to be expected. Can the clutch smoke like that?

Gauges are probably the next big mod I want to do, seeing as I'm going to the track more and more. Its just hard to bite that $470 bullet for the setup I want.

 

I am very interested in this subject, i was looking at an aem intake so i can remove that tray. I am on 29 palms and 120 f is not uncommon, and yes it messes with the 8. I was sure freeing up airflow into and out of the engine bay would bring down operating temps.

Some hard data would be great, i am running about 215 f on the freeway here doing 70 mph, 4k rpm. Seems like 100 degrees over ambeint is a little much for normal driving.

 

215 F on the OBDII engine coolant temperature? Seems quite high, though desert-folk may contradict me on this. I doubt that intake tray removal will have a big effect at highway speed. The most bang-for the buck is to pull the front bumper and use foam water pipe insulation to plug all the gaps around the the radiator and oil coolers where air can slip by without going through the fins. Make sure the lower tray is intact and well fitting. Tape up all but one of the drain holes in it. Also open up the vents on the fender liners to get more air flow through the oil coolers. The stock or Racing Beat intake has the advantage that hot air from the engine compartment is not fed to the engine - most aftermarket intakes eliminate the cold air intake, which seems a step in the wrong direction. Many many detailed threads on cooling around here, but start with the simple cheap stuff first.

 

I did some test a couple of months ago while playing with different intakes systems trying to get my intake temps down (little did I know my heat soak issues were engine related).

Without the tray, intakes temp were 10-20F higher while running the AEM. I also tried a short ram setup using the AEM and a large Diesel air filter and it worked great until temps went up and then intake temps shot through the roof. Once the temps get up there, they are very hard to get back down without just shutting the car off and letting it sit.

Mazda did a great job on the factory intake, it really cannot be improved on for a daily driven car.

 

Good info ... That level of IAT increase will drop the air density by 3-4% or 7-8 hp in a non-turbo application. Stock or RB is best. I'm using the RB air duct as well which sucks air a little cooler than with the VFAD, but blocks some cooling air. Ok for me in Michigan, but probably not for desert areas.