ZeroBanger

Tell me this isn't funny. My first big trip in my 8, I went to reno. On my way back there is a 40 mile descent. Going up and down the hills that will last up to 5 or 6 miles each. anyway, I have done with many, many times with my FD and my old 99 Miata. With My FD during the summer I have to turn my heater on to keep the damn thing from overheating.
My Rx-8 has no such problem. No folks, no overheating issues.

With my Rx8 I have to turn the damn heat OFF during deceleration cause the gauge needle drops all the way to the left after doing down a hill. when I start to climb a hill again, my 8 warms back up and goes back to the middle.

Anyway, I thought this was funny as hell. Turn on the heat in the summer if you have an FD and turn off the heat during the winter if you have an FE!! Go Mazda!!! Oh yea, these are extreme conditions climing and droping elevation for miles at a time like I said.

Oh yea and my miata? the needle never moved, but either did the car.

paw140

If your needle in your 8 is moving around, something is wrong with your thermostat. Unless the 8 is set up in some strange way, your temp shouldn't drop like that. I mean, just idling in your driveway, it should maintain a certain operating temp.

ZeroBanger

in my driveway or driving around (I put about 450 miles per week) no problems at all.

It was just in the mountains when descending for 5 or 6 miles the engine got too cold. after I got into sacramento it went back to normal.

I dont know, I just think its funny. if it ever happens around here I would be worried.

Scrapiron7

I have never had to turn my heat on in the summer.. and never had any cooling issues at all with my FD.

ZeroBanger

well I should explain, I turn my heat on in my FD when the water temps hit 105 on the power FC, I guess thats a bit extreme. Climbing high elevation in 100 degree weather could cause the water temps to hit 110+. but in fairness I never had my guage on my FD move other than the times when my hoses/ast/fans/etc broke.

gen3rx7

If the needle goes all the way to the left, I agree, something is wrong. Car makers have a "normal operating range" for coolant temperatures. The 8 is a water cooled engine, so there shouldn't be a rapid temperature drop coming down the hill. A small aircooled airplane engine is very quick to change temperatures on a rapid descent, especially after a full power climb, to the point where you can cause thermal shock to the cylinders. This isn't the case with cars though. The mass of metal in the engine and roughly 2 gallons of coolant would not allow such a large delta T on a gradual descent like yours. The engine is still producing heat while driving downhill also. It would be interesting to see if other owners have the same issues.....

Str8Down

Wanna race?

ZeroBanger

I'll ask the dealer, but it wasn't exactly rapid. It may have been 20 minutes of coasting down the hill for the gauge to move all the way to the left. and it wasn't completley, it was maybe 3 ticks from the end.

It doesn't sound normal, but its a mazda rotary so it probably is.

ZeroBanger

Sure i'll race your infinity G35 coupe. I'll bring my Rx7 you bring your title, deal?

Str8Down

I don't have a G35 anymore. I'll bring my RX7 you bring your "easy to keep cool" RX8

|aFk| LiMiTz

wait so are you selling your car or what zero?

Scrapiron7

Says so in his signature.

ZeroBanger

nah, I'm keeping my FD today Check back tomorrow, I keep changing my mind. LOL

Androidmj

i don't think there is anything wrong with that...if your traveling down a hill for 6 miles or so, you never touch the throttle, you only ride the brake...so it seems to me it would be like idling your car with 60 mile an hour winds blowing through your radiator...wouldn't that cool the coolant down a bit?

Splinemodel

I read somewhere that the cooling system of the Rx-8 is based on a motor controlled system. i.e. no belts o anything. Is this true?

Because I like the idea. Belt efficiency is often lower than motor efficiency. Plus, you get a much more rev-independent control of the radiator pump.

InsaneGideon

Let us know what it does after you add a couple of turbos...

FWIW, I've never had any heat issues with my FD as well... and I still have the stock AST!

|aFk| LiMiTz: Who's the cutie in your sig? Wow!

cruiser

I never have cooling issues either on the street.
Take it to the track and in hot weather your eyes better be on that temp gauge

grinn253

This also happened to me in my FD with stock cooling system. It was winter around here (Seattle) and I had my heat on high and fast speed setting. When going down a 1 mile hill, just coasting in neutral, the temp gauge slowly began to move to the cold side.

Str8Down

That shouldn't happen. Doesn't matter if you are idling and lots of cool air going through the radiator. The temp is taken from the engine side of the thermostat. If it starts getting cool, the thermostat should close, and the engine at idle should produce more than enough heat to keep the temp up to normal. Sure the water in teh radiator is super cool, but that isn't being used or metered.

RonKMiller

...and this spring will be 11 years in my custody. I've driven in 110F temperatures in Tucson, up and down Vail Pass, CO in 80F temps at 11,000 feet at well over 100 mph. Never a problem.

(Well, except for the stock radiator which leaked...)

tbonerx7

RX-8 also doesn't have a turbo. How long does it take to warm up the 8 and your 7?

Andrew

iTrader: (1)

I think this says more about the difference between the FD's water temp gauge and the 8's.

Black Magic

iTrader: (2)

your comparing a N/A rotary engine to a turboed rotary engine. Yes i know, good call sherlock, point being the turboed rotary will run hotter no matter what chassis. Bolt a turbo kit to that sega genesis renesis and see what happens.
Why did you dump your 7 for a Rx8??

Im not hating on rx8's but when i first saw one on the road cruising on the highway.(silver) As i saw it pull on the highway i thought, god damn that is the ugliest bodykit ive seen for a hyundai tiberon. So i paid no attention to it as i passed, then i saw the HID's. So then im thinking, those POS's dont come with HID's so i slowed down and was like,, Oh F---! thats a rx8. IMO i dont like their styling, but thats just me. Everyone has an opinion just like everyone has an *******.

Edit: what do you have now a 7 and an 8?

ZeroBanger

Actually, while the renesis will run more hot with a turbo, I would highly doubt it will have any cooling issues. For 1 the radiator is very big, 2 the opening under the car is simply sick, and lastly its sealed very well. My money says there will bo need to upgrade the cooling system when a turbo gets installed. The rx-8 in general is far better engineered than the FD.

I didn't, I have both cars.

I happen to very much like how they look. they have an animated look, a ton of character and are probably the coolest looking car on the road.

Yes I have a 7 and an 8.

DCrosby

Remind us again which one has a turbo ??