Thermostat

[Azorian]

I have a '91 Z34 and am wondering what kind of thermostat would fit my car. I'm planning on replacing the stock 195* therm. with a 180* one, but I just don't know what kind would fit.

[dykz34]

I believe it is 44mm in diameter... just take out your old one and bring it to the parts store and find a 180* one that will fit.

[Lyle's GTP]

Does anybody know what preformance gains, (if any) there are with adding a lower temp T-stat? Any HP claims?

Lyle

[JasonZ34]

Does anybody know what preformance gains, (if any) there are with adding a lower temp T-stat? Any HP claims?

Lyle

I would say there are none.

[Anonymous]

If its 44mm then one from a newer gp with the 3800 may fit. I changed mine and it had 44mm stamped on it. Got it at napa and it was a 180*.

[Anonymous]

You won't notice anything performance, just keeps your motor a little cooler.

[Gemmer]

Theres a page floating around here where they measured the gains on a 3800...it was like a couple more horses and a couple degrees of spark. Im guessing that it was on the supercharged version though

[Anonymous]

Yeah a lower temp thermostat helps reduce the knock, at least on the 3800.

[RednBlack]

Don't know about 91s, but I have read on the Internet, (which is always right), that the computer compensates for temperature differentials on the 94. It supposedly changes fuel and spark to compensate for a cool running condition. So, since the Internet is always right, I see the only gain is keeping the engine cooler. NOW, by design, is that a good thing? This post is merely a question.

[Lyle's GTP]

I guess another good question is, did GM use a high temp stat with the engine or heater in mind? If cooler running were a benefit to the engine, a better heater core would be required for us canadian types. OK now lets all do a cost-benefit analysis and see which it is.......yeah whatever.

Lyle

[pocket-rocket]

I think hotter engines reduce emissions, and the heater would work better too.

[montessgtp]

I believe its the other way around...a hotter engine produces more emissions or atleast i know it will increase NOx gases....only wait it wil increase emissions is if your cat doesnt get hot enough. But the other hotter your combustion chamber get the more your NOx will increase. Trust im goin thorugh inspection on friday for the 5th time...NOx gas... failed

[Gemmer]

Ive always heard the opposite...hotter engine = less emissions...even NOx, I think because you gain NOx with spark advance

Of course I have no idea

[grandprixgtp_91]

if a bunch of people are failing emmisions, just check this out on your cars, it was what happened to mine, my cat completely disinegrated internally( you could look right through it, the honeycomb dissapeared) and also if you have a 5 speed, check your rear A.I.R injection hose that runs to the rear manifolds, mine was all dry rotted and it wasnt even hooked up anymore.

Jake

[pocket-rocket]

My A.I.R. is getting taken off of the 92. Worthless peice of garbage that make too much noise and has no use in this area. About the only good thing about Indiana, no emissions.