FT-86 low temp THERMOSTAT

[Toma]

Originally Posted by DylanFRS

Getting 250hp out of a small engine is much more expensive than getting 200hp. Making a thermostat that opens 30* costs the exact same amount as any other thermostat. A different amount of wax and a different spring rate is all it is.

Did the factory have the same goal in mind as people that want to boost a internally stock 12.5:1 na engine and double it's output on pump gas?

[Dezoris]

Switch the factory cooling fans from cycling at 212F to 200F or hardwire a switch and call it a day. That or buy a $300-400 radiator, problem solved.

[Toma]

Originally Posted by Dezoris

Switch the factory cooling fans from cycling at 212F to 200F or hardwire a switch and call it a day. That or buy a $300-400 radiator, problem solved.

I want 180. How does a rad help with a 194 thetmostat?

[Dezoris]

Originally Posted by Toma

I want 180. How does a rad help with a 194 thetmostat?

Have you ever said why you need it that low? What is your real application?

[Toma]

Originally Posted by Dezoris

Have you ever said why you need it that low? What is your real application?

Lol. I was clear. I asked for a colder thermostat. I was not looking for opinions on the pros and cons. Lol.

[Dezoris]

Originally Posted by Toma

Lol. I was clear. I asked for a colder thermostat. I was not looking for opinions on the pros and cons. Lol.

There isnt one yet, that I have seen.

I wont argue with you except to say, regardless of what you think is better for this engine the ECU still controls power delivery. And it is finicky about coolant temps that are too high and too low.

So if you believe lower is better, below 175 the ECU will trim power. Since there isnt a lower temp tstat, flipping coolant fans to always on will drop your temps by 10 degrees, and more in clean air. Which would put you at about 180 to 185F NA. Larger radiator in clean air will put you at 180 most of the time with fans.

So there is more than one way to handle it.

[Fast_Freddy]

This one is a little pricey but it should do the job for those who know WTF they are doing.

http://www.ebay.com/itm/SARD-SUBARU-...item4ac0fdc131

[Yamajee]

I think what the OP has meant is that here in Dubai it gets super friggin hot and we're worried about higher engine temperatures in the afternoon would reduce engine horsepower since the air intake would be much hotter than usual (yes I've seen differences between summer and winter pulls). There is a difference that you'd notice but has nothing to do with lowering the coolant's temperature, on the contrary I think the engines would perform much better on the temperature it was designed to run fully efficient at. I think what we should be looking for is somewhat a colder air intake design to help get more colder air into the intake (like snorkels on 4 wheel drive cars).

[FirestormFRS]

Originally Posted by Fast_Freddy

This one is a little pricey but it should do the job for those who know WTF they are doing.

http://www.ebay.com/itm/SARD-SUBARU-...item4ac0fdc131

That's a ridiculous price for a Tstat

[mad_sb]

Originally Posted by ft86-UAE

most of our cars we run the lowest stats available that in summer the temp goes to 120F and more.

that way i am saying we will be making more HP with a cooler thermostat

Modern ecu's have comp tables for fuel, timing, fan turn on and off etc based on coolant temp and the car not reaching normal operating temps. Putting in a colder thermostat will have the car cycling in and out of "warm-up mode" frequently and generally not do anything positive for the car.

Your probably better off to get a tune that will turn the fans on at a lower temp :happy0180:

[mad_sb]

Originally Posted by Yamajee

I think what the OP has meant is that here in Dubai it gets super friggin hot and we're worried about higher engine temperatures in the afternoon would reduce engine horsepower since the air intake would be much hotter than usual (yes I've seen differences between summer and winter pulls). There is a difference that you'd notice but has nothing to do with lowering the coolant's temperature, on the contrary I think the engines would perform much better on the temperature it was designed to run fully efficient at. I think what we should be looking for is somewhat a colder air intake design to help get more colder air into the intake (like snorkels on 4 wheel drive cars).

Intake air temp compensation pulls out ignition timing based on air temp at the maf. A colder thermostat will not change that or the temp of the air coming into the intake once the car is moving forward (because of the location of the factory snorkel).

When you sit at idle (not moving) the intake air temp climbs quickly due to convection from the condenser and radiator and the location of the snorkel inlet. But, once you start moving temps quickly drop to a few degrees above ambient.

at 120*f ambient, the ecu will pull roughly 2 degrees ignition timing. At 160 it will pull 6 degrees. sitting at a stop light in 120 ambient temps the intake temp will probably climb to 160 so it will feel slugish when you leave from a stop.

Nothing you do with the thermostat will change the intake air temps. Turning the fans on sooner might help though. I'll have to do some logging and see what happens to iat (at a stop) when the fans kick on.

[Toma]

Originally Posted by Fast_Freddy

This one is a little pricey but it should do the job for those who know WTF they are doing.

http://www.ebay.com/itm/SARD-SUBARU-...item4ac0fdc131

Ah, nice. That's close to the 2jz ones.

Thanks!

[Yamajee]

Originally Posted by mad_sb

Intake air temp compensation pulls out ignition timing based on air temp at the maf. A colder thermostat will not change that or the temp of the air coming into the intake once the car is moving forward (because of the location of the factory snorkel).

When you sit at idle (not moving) the intake air temp climbs quickly due to convection from the condenser and radiator and the location of the snorkel inlet. But, once you start moving temps quickly drop to a few degrees above ambient.

at 120*f ambient, the ecu will pull roughly 2 degrees ignition timing. At 160 it will pull 6 degrees. sitting at a stop light in 120 ambient temps the intake temp will probably climb to 160 so it will feel slugish when you leave from a stop.

Nothing you do with the thermostat will change the intake air temps. Turning the fans on sooner might help though. I'll have to do some logging and see what happens to iat (at a stop) when the fans kick on.

I think you've got me wrong, I said maybe implement a way to get colder air intake not anything to do with thermostats, but thank you for the clarification.

[mad_sb]

Originally Posted by Yamajee

I think you've got me wrong, I said maybe implement a way to get colder air intake not anything to do with thermostats, but thank you for the clarification.

Your right I only read half your post. I agree that what you guys need to focus on is reducing intake air temps as much as possible rather than worrying about a cooler thermostat.

Do you guys have E85?

I think those that want to run cooler thermostat can do so with some benefit, assuming all of the coolant temp related tables in the rom are adjusted so the new lower temp becomes the "normal" temp. My original point was that just dropping in a cooler t-stat without adjusting the rom is not going to do much other than cause a wider range of operating temps.