r0gu3 kindly pointed out to me that I was missing the deflector that directs air through the radiator (the plastic piece that stretches from the front mouth to right below the radiator). So ya, that probably explains why my car tried to overheat on the trip from Houston to San Antonio. Anyways, I guess I'm lucky I havent had any problems with it yet. So where can I find a replacement?

 

Oh - and I plan on getting a greddy front mount before spring break. Should I even invest in a good replacement or just fab up one out of sheet metal to serve as a temporary solution? Remember, I havent overheated....yet.

 

Your car should not run hot to the point that it's gonna overheat just cuz you don't have an undertray. I've ran my car for quite a bit w/o the undertray (it keeps on breaking lol) and my temps are fine. Sound like you have a prob w/ your cooling system...

Also, if you think you have issues w/ cooling now, good luck when you get your front mount. Those things are notorious for causing heat soak, since the IC sits in front of the radiator. That's why in the real world, FMICs are for dragging, but something like auto-xing that generates a lot of sustained heat, you go w/ a SMIC. Just my $0.02

 

Try Mazdaformance.com

 

Cant you remount the radiator to stand verticly in the engine bay when you go front mount? Wouldnt that solve a lot of cooling issues?

 

I could be wrong (so someone correct me if I am), but I believe that's actually what causes the prob...when the radiator is vertical, and the FMIC is vertical too, sitting directly in front of the IC.

Check out Chuck's V-mount setup @ RotaryExtreme. Now THAT'S the best of both worlds IMO...hell of a setup!

 

mounting the radiator vertically would give you less frontal area, just like this diagonal line [/] is longer than this vertical line [|]. It also keeps the center of gravity lower than if you were to set it vertically. To me, the main problem in our cooling systems seems to be low boilover temp due to either air bubbles, lack of pressure, something like that. The lack of airflow to the radiator at low speeds is also a concern, due to the small front air dam. Look at the newer '99 spec Rx-7's, they seem to be using a similar radiator mounting, with mostly airflow improvements to the radiator, airbox, and IC. I'd like to know what pressure their cooling system runs at, and if there are any differences in the water pump , thermostat, and coolant passages.

-scott-

 

Dont all vmounts require the removal of the a/c?

 

No. The HKS one does not.. neither does the Knightsports.

 

you can keep the ac with the RE extreme v-mount kit too..I just opt to take it off because I never use it anyway.

 

I would think that mounting the radiator vertical would give you MORE frontal area versus mounting it in a 45 degree angle such as your "/" depicts?

Vertical = more frontal area
Horizontal = less frontal area

Also if i mount my radiator like so / it does not make it any longer. Just less frontal area.

 

The undertray is what forces the air to pass through the radiator. The air will follow the path of least resistance and without the undertray the air would be more inclined to pass under the radiator than through it. Fans only help so much.

Your car will tolerate much higher outdoor temperatures and harder driving if you install the undertray. I would never drive this car without one.

 

Yeah I was missing mine when I bought my FD as well. Haven't run it since I drove it home, so I haven't dealt with it yet - planned on making something out of sheet metal.

 

look for them used here on the forums. also try pm'ing flyin fritz to see if he has a used one.

as for the running hot/overheating, the absense of the undertray as it is called will not make you overheat alone. i suggest you take your car to a good rotary specialist in your area and have them give it a once over before you go spending a small fortune on an intercooler. you just might be in need of an engine if you are running hot.

do a search and check the newbie links.

 

I'm w/ you 100%, but as Alberto said, your car STILL shouldn't overheat just cuz you lost your undertray...there have got to be larger issues at hand...

 

One thing to note is that original poster was driving from Houston to San Antonio.

Just because *you* don't have problems w/ overheating in Northern Virginia doesn't mean it won't happen in locations significantly more southward.

Like Texas.

-b

 

Hmm...you make a good point. I guess if the air temps in that region are significantly warmer, to the point that w/o the undertray, that little change in cooling efficiency is enough to make the diff, then you're right. Good point.

 

My car has never had heat issues. It tried to overheat driving from Houston to San Antonio while cruising at 80mph with the a/c on. turned the a/c off and it got it back to normal temps. The heat above the highway surface was horrible. I'm guessing long trip + really damn hot + A/C is what it took.

Also, I had the fans on the whole trip and I have a koyo radiator.

 

Just out of curiosity...when you say that you had the fans on the whole time...I'm guessing you have a manual switch to turn the fans on and off?

 

Put an undertray on and see if it cools better. The undertray is an important element in the cooling system. I know of several instances where folks have run w/o and had cooling issues that went away when the undertray was put back on.

 

With AC set on level 3 fans always come on (and if you remove AC relay you get fans on whenever you like without activating actual AC).

 

My only concern w/ that was, will the fans still turn on automatically in the event the temps go up? Cuz I know some ppl (depending on their setup) run electric fans w/ a switch that they turn on and off...and if you forget to turn it on, pop goes the motor...

I personally don't see a prob. w/ leaving the fans running all the time...