Mod Bugs

So the coolant temp has been reading 95-100c in daily driving. I have a power fc. Vegas heat is 105-115!

The fd has a mishimoto thermostat (I think 68??), just replaced stock radiator with new koyo nflow and installed the pineapple racing pulley.
it still gets way too hot 90-100c driving normally.
is there a way I can program the fans to kick on earlier than 90-100?

not sure if I bled it correctly.. but I used a Lyle funnel w the front end jacked higher while idling the car w the heater turned high. After hitting operating temp, The car would boil over while bleeding though.
Does it matter if the Lyle filter is on the Ast or the water filler?

Sgtblue

iTrader: (16)

You’re NOT way too hot. And what you’re reporting would be expected with those ambients.
That said, Yes, if you have a PFC there’s a way to lower the fan threshold. Or you can install a S5 FC thermoswitch to do the same, from 108 C. to 95 C. But if you’re using the AC, the fans are already running at a higher speed anyway.
And the aftermarket t-stat doesn’t help.

Other things to consider…
use more distilled water but not less than about 20% coolant. In your climate there’s not much threat of freezing winter and water is much more efficient than the coolant in carrying heat away.

Look thru the nose of the car and use some upholstery foam to plug gaps around the radiator.

Search function

Yes, the coolant mix expands as it heats up…so you’d expect it to overflow if the pressure cap isn’t on.

GoodfellaFD3S

iTrader: (213)

Talk to us about your oil cooler system and brand/weight of oil that you're using

gracer7-rx7

iTrader: (16)

Yep. That's a normal operating range.
v-mount setups really help this

c0rbin9

iTrader: (2)

As the other posters stated, those temps are normal. V-mount is not really necessary unless you're track driving and even then it won't affect coolant temps. Besides, your car is way too original to hack up for a V-mount. Downpipe will help with engine bay heat if you don't already have one.

Montego

iTrader: (1)

Agreed that's not too hot at all.

But if you don't like those engine temps you may want to invest in a vented hood. I say that because the day I had my hood installed was an unusual hot day for my area. It was like 105F (IIRC)... So anyway, I as I drove over to the body shop to get my hood installed, my water temps were somewhere like +103C (IIRC). The body shop installed it in about 30 minutes and on my way home my temps hovered around +98C (IIRC). Given that so little time had lapsed between my two trips I can safely say that my car ran 5C cooler with the vented hood. Now it is also fair to note that I have my fans set to kick in at +85C, so on average days my car always hovers near 85C no matter what hood.

Regarding V-mounts: I had a GReddy unit recently installed and I will never look back (and this is coming from a guy that had a pettit style LARGE SMIC). The car runs cooler in both intake and water temps. Agreed that the v-mount is not a necessity, but the reality is the stock SMIC is a small pile of crap that has a tendency to get heat soaked (and stay heat soaked) after just a few of pulls.

cr-rex

iTrader: (114)

im not one for unnecessary mods but a vmount and a vented hood should be standard on all FDs. in all regards except cost, its superior to the factory configuration. even a front mount with a vertical radiator would be an upgrade. also as goodfella mentioned, your cooling ability isnt all in the radiator. the oil coolers play a role as well. factory twin coolers are great but twin 19s are better. if you have a single factory cooler, look into upgrading whether it be to the factory dual set up or to an aftermarket twin 19 set up.

Mod Bugs

Wow interesting.. Thx guys for the feedback! I thought normal temps (or especially with the cooling mods I added) would be closer to 80s.
yes I suppose a vented hood would help and ducting. As well as a vmount. But yes the car is relatively stock & contemplating a lot about the mods I want to do (single turbo etc). I know most people would say keep it stock because of how rare it is to have a stock original running fd 😬😆 but I feel adding mods and upgrades to really waken up the cars potential is of more importance, than just resale value.

i will put it all back together, and have the under tray installed as well and report back here.

i should find how to turn the stock fans on at a lower temp as well

Montego

iTrader: (1)

bah... The reality is that not all FD's are collectibles, especially if they are above 20K+ miles. So unless your car is actually a very low mileage, meticulously maintained, and you don't plan to drive it much then do whatever you want to it. It's your car plus you can always put back in what you take out.

The truth is 100% stock FD's suck. They are underwhelmingly slow since they are being choked straight out the factory. Luckily all it takes is just a few bolt-ons to really wake these things up. IMO FDs are best with a full exhaust, CAI, V-mount (or at least a medium sized SMIC), with sequential twins at 10-12psi. The car will be pretty darn fast, run cooler, be more reliable, and very easy to return back to stock if you ever wanted to (the V-mount would take some work compared to an upgraded SMIC but not all that hard either).

If you don't have an aftermarket ECU that you can set the fans to, then get an FC thermoswitch as Sgtblue said earlier.

Read this:
FC thermoswitch for FD - RX7Club.com - Mazda RX7 Forum

Sgtblue

iTrader: (16)

Ummm, I just assumed you had an undertray/belly pan already in place. If you didn’t that will make a HUGE difference in cooling efficiency.

GoodfellaFD3S

iTrader: (213)

Depending on many factors like the power levels and use of an FD away from the track, a V-mount is certainly a beneficial addition.

Due to improved direct airflow it absolutely will lead to a reduction in coolant temps, all things being equal.

Sgtblue

iTrader: (16)

This for a little emphasis. Dual oil coolers will also help overall cooling. As will a WI system. Given the OP’s location I’d consider both if he wants to stay (essentially) stock, want a little more margin and those are not already in place.