Engine Undertray

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LaurentD
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Engine Undertray

Post by LaurentD »

I remember reading somewhere about an undertray cover under the engine bay or something along those lines, but can't find it anymore. I believe that piece would be missing on my XR. There is some bracket piece under the front crossmember that seems like it would retain some kind of rubber flap, but the flap seems to be sectionned off. Is that what the undertray cover is about?

Image

Also, there is a rubber flap, underneath the radiator that I guess acts to re-direct air flow to the rad. Is this how it is supposed to be, or does it need to be tucked above the bumper cover?
Image

I know these may be small details, but I like to get details right. Thanks ahead for the help!
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Esteban
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Re: Engine Undertray

Post by Esteban »

There is a guard for the power steering rack that you are referring to. This is where the rubber flap should be mounted to, not the bottom of the radiator itself. With the flap in the correct location, it will aid in cooling.
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Re: Engine Undertray

Post by thebronze »

Esteban wrote:There is a guard for the power steering rack that you are referring to. This is where the rubber flap should be mounted to, not the bottom of the radiator itself. With the flap in the correct location, it will aid in cooling.

WRONG... there are TWO "rubber flaps"... one on the bottom of the rad (like the pic shows) and another near the steering rack ( should be a few inches deep)
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Esteban
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Re: Engine Undertray

Post by Esteban »

Thanks for the correction. I never saw a flap on my 89 rad, nor where it would have been.
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John Brennan
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Re: Engine Undertray

Post by John Brennan »

Yeah, Russ at Rapido sold/sells a replacement for the flap at the rad/front bumper junction, which allegedly was a factory fitment; however I have never seen one, even on my first, brand-new XR. Obviously something could be easily fabbed and mounted there.

The other one is an air dam which creates a low-pressure area behind the front crossmember to pull air farther back and help cool the engine/turbo/exhaust/transmission. Missing on a lot of cars, it actually provides a significant and necessary remedy to lack of same. Neither is an undertray properly speaking, which I believe might be a good thing and help with cooling and protecting the engine bay.
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Esteban
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Re: Engine Undertray

Post by Esteban »

Does any one know the dimensions of the flap? Does Home Depot sell a similar type material?
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Re: Engine Undertray

Post by John Brennan »

Width of rad X ~2". Stuff like this is... wherever you find it. I made one for my car out of a truck mud flap, fastened to the lower edge of the rad with ZipTies.
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Esteban
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Re: Engine Undertray

Post by Esteban »

John, I meant the 2nd flap. Not the one on the rad.
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John Brennan
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Re: Engine Undertray

Post by John Brennan »

That needs to be fairly stout, or it'll just bend in the airstream. The truck mud flap mentioned should do. It will allow most road debris strikes to bend it back w/o shearing it off, yet hold its shape in the airstream. Measure the width of the metal piece that holds it in for width, and make it about 3" tall.
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Mike McCreight
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Re: Engine Undertray

Post by Mike McCreight »

That industrial baseboard stuff works well there.
http://www.homedepot.com/p/ROPPE-Black- ... 333?N=aq7r
Spare yourself the headache of removing those rivets. I made a sheet metal sandwich, with the moulding as the filling, the piece of metal towards the back of the car was 2", front 1", just to keep it more or less upright at low speeds. Put it on with 3/4" self tapping screws.
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Re: Engine Undertray

Post by Oldmaddog »

Mike McCreight wrote:That industrial baseboard stuff works well there.
http://www.homedepot.com/p/ROPPE-Black- ... 333?N=aq7r
Spare yourself the headache of removing those rivets. I made a sheet metal sandwich, with the moulding as the filling, the piece of metal towards the back of the car was 2", front 1", just to keep it more or less upright at low speeds. Put it on with 3/4" self tapping screws.
So does plastic lawn edging.
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Re: Engine Undertray

Post by hEaT »

If I can remember, I still have a good OEM lip for the crossmember and can snap some pics and measurements.
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Re: Engine Undertray

Post by In XS 7 »

hEaT wrote:If I can remember, I still have a good OEM lip for the crossmember and can snap some pics and measurements.
That will be great Joe,Thanks in advance, and thanks to the other guys for such a nice tips and great solutions. :cheers
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86XR4Ti5SPD
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Re: Engine Undertray

Post by 86XR4Ti5SPD »

I replaced mine with some industrial belting that I bought at my nearby Tractor Supply. My old 'flap' was still in place, but had split along the mounting edge, so I was able to pull it off intact and trace the outline on the new belting material. (I mention it should you need the dimensions.) This material appears to work perfectly for the application. Can take a pix and post it up as well, if that would help.
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Re: Engine Undertray

Post by In XS 7 »

Sure it will help a lot, thank you very much Ed.
Miguel.
89 XR4Ti Monique; Waking up a real "Night/Mare-Coor".
T5, NPR IC, PIMP ECU, Walbro 255, Dual piston BOV, Manual BC, 3" exhaust, One piece Aluminum drive-shaft, mc2 LSD, Boport 1.5 cam, Ported and polish head, big valves, 80# injectors, Bob's log, (soon HY35).
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