Or sometimes i've seen the CTS located IN the thermostat housing, along with the EFE TVS on older carbed motors. I moved it to the manifold location after I pulled the canister purge TVS outta there. ------------------ DR Stevens 1984 Trans Am 305HO L69 sucks gas, hauls *** 1991 Firebird 305 LO3 for days when I need a/c

I just got done changing my Tstat today and here's my take on this(from 160 to 180).
Before:
1.Car was running rich I could really smell it coming out my exhaust
2.Decrease in gas milage
3.While running at 50mph and up I would feel something like my trans was downshifting but my rpms didn't change. Very annoying! My though was my TC.

After:
1.Car isn't running rich (doesn't smell)
2.My gas milage went up just a little
3.My TC problem isn't noticeable anymore

I think was a good idea for me to change to a 180 tstat and I'm very glad I did!

------------------
'87 Trans Am:
(Engine)
305 TPI
180 Degree Thermostat
JET Fan Switch
TB Bypass
Accel 300+ 8.8 Racing Wires
Accel Super Coil
Bosch Platinium Plugs
Custom Ram Air with K&N
Removed Emissions Equipment & Cat.
(Stereo)
Full Kenwood Excelon System

Just thought I would offer up my .02 cents here. I bought my 92 with the 160 stat in it and it always smells rich and since I set the fans to run at all times, the temp never gets much above 110. I am seriously considering moving to a higher temp stat, simply because I feel that my car would run better if given the chance to "warm up" properly. But, this is also what works for me in my car. Every one's car has different characteristics and mods, so I think that a different operating temperature would be in order for each individual's car.

Chris

A 160 thermostat can increase power however an internal combustion engine is a heat engine and requires a certain amount of heat to perform efficiently. As the temperature increase then the efficency increase but power goes down. As temp decreases the opposite happens. A normal I.C. engine is only around 35-40% efficent at best. If you want cool air coming into the engine then buy or design a cold air induction system. I would not change the thermostat in my car just to get a few more horsepower. Take a Nascar engine. They run around 220 degrees and even get up to as high as 240. They make around 750 horsepower and eventhoug they run around 8000 rpm they are stil efficient. Some of the design aspects can still be applied to 300hp street engines.

I have a 160* stat in my TBI car, plus a manual fanswitch, put it in about 8 months ago I think. The car definitely idles smoother, and the temps don't climb in traffic like they used to. In fact, the car has never run better. Possible increase in power as well. I have a new rad, and with the 160 my car never goes above 160 degrees, unless it's warming up, in which case it spikes a bit before the cheapo thermostat opens. However, the car seems to be using a little oil, ie. a quarter quart in 1000 miles, which it never did before. Wondering if that's because of the cold motor/looser tolerances issue.

Just ran across an article the other day, connecting low temps to engine wear, and after searching these threads, I've found that many are of the opinion that TOO COLD EQUALS MORE ENGINE WEAR, just like "too hot." So I'm going to switch to a 180* to be on the safe side, and see if that affects performance. If anything, I expect performance to improve, since it's a TBI car, hence "wet mixture" and the car always ran great at 200 degrees, even higher, just didn't idle as nice when waiting at the drive through and the temp was hitting 220, waiting for the stock fanswitch to come on. (In which case I hit the AC.)

P.S. Met a drag racer with a 650hp Camaro, carbed, and he said he wouldn't race unless he is at 220* So I guess race cars and street cars have different requirements, also carbed, TBI, vs. TPI cars.

Yes. You can also do what I did and block the heat riser on your intake from the exhaust. It runs noticeably stonger from just that! Takes a little longer to warm up though.

Nascar guys don't tape up the front to run hotter, they do it for more downforce. Ever watch a race where they put too much tape on and the engine is running too hot, so they have to pit and take some tape off? Anyways, I'de go with the coolest stat possible that will still allow you to have heat.

Ok, put in the 180 degree stat tonight, and damn, the car runs the best yet. Had gone right from the OE 195 to the 160, never did try the 180. I tell ya, the motor actually seems to have more power, and has a more "well oiled" feel.

Also, the weather is getting a bit cooler here in San Diego, so that might have something to do with it, but even so, the motor runs so much smoother I think 160 was just too cold, period. Only ran it that way for about six months or so, and the car ran fine, so no harm done. Now it has the deeper rumble it had with the stock thermo, without the high temps. With the 160, the motor felt tight, like it never totally warmed up.

Now the needle stays at 180, and I've got the fanswitch to keep it there when stopped. I would even say I have more power now.

I know this is a delayed post but, i have to vouch for colder temps. My car is an animal when it hits 160. I burned out through 1st gear by flooring it from a stop. I have a CAI and it doesn't make that much of a difference on a hot day. I also have a gale banks free flow exhaust. They make the engine expel and breathe better but not cooler. Even in 20 degree days in the winter my car still gets over 200 almost over 220 till the fan kicks on. It's not good. The car runs like crap when it's hot. It runs sluggish and throttle response is poorer than when its first started and when its IN THE LOW 100S. I guess it depends on the mileage of your engine. My original tpi has 12 900 miles on it. It's a healthy girl.

I read the "test" regarding engine wear and cooler temps. The test was conducted by GM. Maybe to justify their high temp operating engines to meet emission requirements. A true scientific test would need to be conducted by an independent outfit. At this point I am not taking sides on the issue. I want to know the truth. I will take sides with the truth.

Another issue that leaves me scratching my head is the reverse coolant flow the LT1 engines have. It is to keep the heads cooler for more advanced timing and in turn, better performance. Why does cooler mean better performance in this case? Food for thought.

I have a 160 in my LG4, and it runs great with no mileage side affects. It is a carbed engine of course. I tried one in my tbi, and it seemed to use more fuel, so I switched back to 180.

Old school days and my auto mech teacher told us a cooler engine will last longer than a hot one. HMMMM? I know old myths are busted all the time, but i need emperical evidence.

I guess each engine is different. Depending on the mileage, exhaust, intake, etc. For my specific set up and mileage. The ecm adjusts the a/f ratio and timing based on the conditions of ambient temperature and internal temperature. I notice a different surge in power from 130-175, and lower throttler response once the temp hits 200-220. My idling is also rough after running on hot days like 90* +

Seriously? These guys are resurrecting a 10 year old post to talk about that? I think it's been discussed before. If the automotive and industrial engine industries findings aren't clear enough for people, then you might as well just stick to "opinions", and not even bother discussing it.

This subject should be approached as a hard science. There are no opinions with 1+1. The findings are clear, I just don't have faith in GM being objective.

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http://forum.grumpysperformance.com/...p=13660#p13660