I recently put in a MTuned reroute along with the new updated VH060650 36mm Koyo radiator on my 99 NB.

I've noticed that if I hop on the freeway before the car is fully warmed up, like say anywhere below 170*F the car will never go above that while on the freeway.

However, if I let the car get to around 190* before getting on the freeway, the car will sustain 188-195* while on the freeway.

I have a feeling it may be thermostat related, but I am not sure because the car will stay above 180* if the car is fully warmed up.

Any input?

 

How long of a freeway drive are we talking in minutes? Five? Thirty? How cold is the ambient temperature?

Either way, it sounds like your thermostat is sticking open or something like that.

 

Thermostat installed backwards?

 

My commute to work is only about 10 to 15 minutes on the freeway, and it's been in the low 60's ambient. This morning the car stayed at a solid 168-170* while cruising until I hit a slight grade, then the temps increased to fluctuate between 174-177* (Per torque app)

However, when I first installed the reroute I had a 30 minute drive home and temps never exceeded 175* (upper low 60's, possibly high 50's ambient) Getting the car up to temperature has taken noticeably longer as well.

 

Not enough detail about your install, but I know from experience that big radiator plus heater stream returning to radiator rather than to the mixing port will prevent reaching operating temperatures with outside temperature below 75F.

 

It is the MTuned kit so I didn't bypass the heater stream to the mixing port as far as I am aware of.

 

How large is the bypass/bleed hole in your thermostat? And is it clocked correctly at 12 o'clock?

 

It still had the brass jiggler in it when I installed the thermostat. And I made sure it was positioned at the 12 o'clock position.

I did however buy the reroute off a good friend of mine, so I did not physically install the thermostat into the remote housing. He reported long warm up times, but he did not have any auxiliary gauges to measure temps.

 

Wait, you installed it, but you didn't install it?

 

I think he means that he didn't install the thermostat but he could see it in there and positioned it correctly as best he can tell. Am I right?

 

What temp thermostat do you have installed?

 

Chiburbian got it right.

I was told it was purchased from 949 over a year ago. So I am unsure if it is a 180* or a 195* thermostat. I know Emilio currently sells them with a 195*, but I don't know if he's always sold them with the 195*.

 

Your hole is too big.

 

Most thermostats have the temp stamped on them.
I found this helpful when choosing a thermostat temp:
A newbie's adventures in racing: Should you run a thermostat in Spec Miata?

 

Thanks for the tip. I guess I'll just order a new thermostat and gasket and see if that relieves anything

 

Yea FWIW when I had the reroute with a trackspeed radiator, everything worked correctly if it was warm or if the car was idling, but freeway speeds on anything colder than a 60 degree day, I'd never reach operating temp. My radiator had some crazy ducting though.