Mazda Rotary Club

Cars by Model Type => 3rd generation RX-7's => Topic started by: C J R on April 30, 2008, 12:30:00 PM

Title: Engine Undertray - is it required ?
Post by: C J R on April 30, 2008, 12:30:00 PM
Hi,
I have been reading one or two threads which talk about trays under the engine compartment. I assume these are factory fitted plastic formed covers which stop road dirt entering the engine bay from underneath the car.
 
The car I have purchased does not have such a tray/cover. Is this good or bad ?
 
I thought it may be good as it will allow passing air to swirl around and keep things like the sump temps lower etc. But thats an uninformed assumption.
 
Can anyone offer advice ?
 
Thanks
Chris
Title: Engine Undertray - is it required ?
Post by: G@NDY on April 30, 2008, 12:34:07 PM
Hi Chris, they are very good matey. You should get one, they cool the engine alot.
Title: Engine Undertray - is it required ?
Post by: C J R on April 30, 2008, 12:37:03 PM
If its that good, do I just buy a second hand one from another FD ?
 
Thanks
Chris
Title: Engine Undertray - is it required ?
Post by: G@NDY on April 30, 2008, 12:39:00 PM
Yep, second hand one. will keep an eye out for one on electronic bay ;)
Title: Engine Undertray - is it required ?
Post by: Martiny on April 30, 2008, 01:10:22 PM
Agree with Gandy, it aids with cooling a lot.
Title: Engine Undertray - is it required ?
Post by: SiH on April 30, 2008, 01:21:09 PM
Indeed, It also seems to help keep the car more stable at speed. Refitted mine the other day and it seems a lot more stable, front feels more planted, although mine\'s an MS one, not an OEM one.
Title: Engine Undertray - is it required ?
Post by: antnicuk on April 30, 2008, 01:48:24 PM
the under tray ducts air through the rad, if not the air goes under it.
Title: Engine Undertray - is it required ?
Post by: C J R on April 30, 2008, 10:35:29 PM
Will a standard under tray fit if I have an aftermarket front bumper/spoiler ?
 
Thanks
Chris
Title: Engine Undertray - is it required ?
Post by: Hayward North on April 30, 2008, 10:41:05 PM
Quote from: C J R;495456Will a standard under tray fit if I have an aftermarket front bumper/spoiler ?
 
Thanks
Chris

Yep but it will prolly not meet the front of the bumper so letting air flow under the rad a little.
You could always make a 3mm aluminium undertray that covers everything from the front bumper to the rear of the gearbox like i have :D seems to be sucked to the ground now :D
Title: Engine Undertray - is it required ?
Post by: C J R on April 30, 2008, 10:52:41 PM
That sounds interesting. Would you have a template or a sketch to show where and how you mounted it.
 
Thanks
Chris
Title: Engine Undertray - is it required ?
Post by: Fendamonky on April 30, 2008, 11:12:25 PM
Quote from: C J R;495468Would you have a template or a sketch to show where and how you mounted it.

I second that notion! And yes, fitting the undertray will help your radiator tremendously.

Steve, do you have any pictures of yours installed?
Title: Engine Undertray - is it required ?
Post by: Domwhite on April 30, 2008, 11:18:14 PM
Quote from: Fendamonky;495475I second that notion! And yes, fitting the undertray will help your radiator tremendously.

Steve, do you have any pictures of yours installed?

Thirded, maybe we can get a bunch knocked up
Title: Engine Undertray - is it required ?
Post by: Hayward North on April 30, 2008, 11:49:15 PM
Will be taking pictures at the weekend so you can have a look.
As for template, the best way is to male one out of cardboard 1st then transfer it onto a 8x4 sheet of ally like i did as most bumpers are different.
It relatively easy if not time consuming, i used air tools to cut it out and smooth the edges .
Mine follows the whole front line of the bumper from wheel to wheel and covers the entire underneeth to the gearbox only leaving room for suspension travel and wheel lock.
It also looks the bogs danglys :D
Title: Engine Undertray - is it required ?
Post by: AtomicRex on April 30, 2008, 11:50:28 PM
Weve got a spare undertray if you want one
Title: Engine Undertray - is it required ?
Post by: Hayward North on April 30, 2008, 11:51:39 PM
oh and i cut an access pannel out about 3" diam to access the oil drain as i change oil about every 2 months.
Title: Engine Undertray - is it required ?
Post by: C J R on May 01, 2008, 12:02:08 AM
Atomic Rex, how much for your tray ? - so I can decide whether to start to cut up the aluminium sheet I have to make a tray.
 
And did you ever sort out a replacement for your quick shifter ? You were going to advise whether your old one would be available to buy.
 
Thanks
Chris
Title: Engine Undertray - is it required ?
Post by: RemarkLima on May 01, 2008, 05:47:06 PM
Quote from: steve garbutt;495488oh and i cut an access pannel out about 3" diam to access the oil drain as i change oil about every 2 months.

That sounds very cool! Not too sure on the FD but does the sump aid in cooling the oil as well?

The reason I ask is that on my old Lotus the undertrays had a couple of naca ducts into it, one pointing to the bottom of the sump and the other to the exhaust manifold. But with both oil coolers up front I don\'t know if it\'s just over kill?
Title: Engine Undertray - is it required ?
Post by: Hayward North on May 01, 2008, 07:48:18 PM
Well i was thinking about pressing some vents in to it where the sump was but i have a oil temp gauge on the sump plug itself and have driven the car 3 times since and the temps have droped a little if anything.
Title: Engine Undertray - is it required ?
Post by: murray on May 01, 2008, 09:17:19 PM
Quote from: C J R;495468That sounds interesting. Would you have a template or a sketch to show where and how you mounted it.
 
Thanks
Chris

 
Just found this pic hope that helps cheers matt
 
(http://i260.photobucket.com/albums/ii4/M4TT_2008/Shine-FD-front-tray-200.jpg)
Title: Engine Undertray - is it required ?
Post by: Hayward North on May 01, 2008, 09:56:45 PM
Quote from: murray;495792Just found this pic hope that helps cheers matt
 
(http://i260.photobucket.com/albums/ii4/M4TT_2008/Shine-FD-front-tray-200.jpg)

That looks like mine but streach it back to past the sump and there ya have it.
Title: Engine Undertray - is it required ?
Post by: C J R on May 01, 2008, 10:39:12 PM
Thanks Murray & Steve.
Tin snips at the ready !! (http://www.mazdarotaryclub.com/forums/images/icons/icon10.gif)
Chris
Title: Engine Undertray - is it required ?
Post by: Hayward North on May 05, 2008, 11:47:19 PM
As promised a pic of my undertray, there are a few vents to cut but almost dun :D
Title: Engine Undertray - is it required ?
Post by: Hayward North on May 05, 2008, 11:52:52 PM
made out of 3mm ally sheet :D

Oh look 1000th post :D
Title: Engine Undertray - is it required ?
Post by: gsb876 on May 06, 2008, 01:29:41 AM
Looks a good job there matey :Thumbs-up
Title: Engine Undertray - is it required ?
Post by: Bobbit on May 06, 2008, 12:27:16 PM
what are the rough sizes you used for the ally undertray? Sorry for hijack but this seems a really good idea, especially as the little sods near where i live leave half bricks in the road so i cannot spot them in traffic and they get stuck under my car. This would add a bit more protection. Thanks
Title: Engine Undertray - is it required ?
Post by: probedb on May 06, 2008, 05:32:26 PM
I have a shineautoprojects one in carbon...I had it fitted inside the front bumper just in case something got between the two and ripped it off.