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The stock thermostat in the 3.8 V6 is either 180° or 195° depending on model year. The Hypertech 160° thermostat (also known as the Hypertech PowerStat) is a very cheap modification that you can install yourself in less than fifteen minutes. Its benefits are lower engine operating temperatures, which results in more horsepower and better E.T.'s at the track. Considering the price/benefit ratio, this is one part no 3.8 owner should be without. Hypertech claims that it reduces engine detonation as well, which is probably true to a minor extent. It would seem to be a wise choice for someone running forced induction or nitrous.
You can order the thermostat from Thunder Racing for $10.99, the Hypertech part number is 1009 for the 3.8 (or part number 1006 for $12.99 for the 3.4). Installation is simple: unbolt the casing over the thermostat, use a sharp scraper to scrape the old partially disintegrated gasket out, and install the new one.
The operating temperatures with the new thermostat range from 160°-165°, although your engine will still heat up to about 210° when you're sitting in traffic. On one of my stock trips to Rockingham Dragway I noticed quite a difference in times with varying engine temperatures. During Friday night test 'n tune I hotlapped the engine, running at about 210°, and got timeslips ranging from 16 flat to 16.5--quite a disappointment, considering that was my first trip to the track when my car was almost bone stock. The following day, during the bracket races, the engine had plenty of time to cool off and I ran consistent 15.5's with a best of 15.47 @ 89.36 mph on a 163° engine. Many people there even went so far as to buy large bags of ice which they laid on the engine block to keep it cool. No doubt, for the 3.8 V6, a colder engine produces more power (to a certain extent). Iron blocks just don't react well to heat.
In the spring of 1999 I decided to test the effect of engine temperature on horsepower on one of my trips to Woodbridge Dynotech, still when I was close to stock. On three runs, the first produced 172.4 hp and 205.0 ft-lbs. The second showed 173.8 hp and 206.6 ft-lbs. On the third run we turned off the giant fan they had sitting in the shop and allowed the engine to idle for a few minutes until the water temperature needle hit it's maximum of 210°. Sure enough, power dropped dramatically, resulting in 165.3 hp and 195.1 ft-lbs. The engine lost 8.5 hp and 11.5 ft-lbs when it was running hot! Higher engine temperatures are more detrimental to cars with less horsepower to begin with. My car was running around 170 hp, so a loss of 8.5 hp was quite profound, resulting in noticeable E.T. differences. However, for a hotrod with 700 hp, losing 10 or even 20 hp due to a hot engine does very little to affect the performance of the car. This is why at the track a lot of guys with super-powerful engines don't bother with ice or keeping the hood open in the staging lanes, while many owners of weaker-engine cars do. Makes sense.
There have been rumors that the 160° thermostat causes the coolant system to go into continuous loop mode, and people have offered all sorts of technical explanations for how this will destroy your engine and ruin your performance. They can say what they want, but fact is that the lower temperature does cause the engine to produce more power, it does improve your times at the track, and there are thousands of people across the country with low-temperature thermostats in their 3.8's and 3.4's and I yet to hear a complaint. A buddy of mine named Jonathan had problems with one on his third generation 92 Firebird 3.1, but that's because his initial thermostat was set for 210° and that engine runs a lot hotter than the 3.8 does. For him, jumping to the 160° was drop of 50°--quite a bit more than the 20° drop experienced by the 3.8. I have never had a problem in 75,000 miles on highways, crowded city streets, and tracks alike.
If you want bang-for-the-buck, this is a great part that can't be beat. Because it potentially reduces engine detonation, it should be considered absolutely critical for anyone running a supercharger, a turbocharger, or nitrous.
3 Pros:
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3 Cons:
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[ March 06, 2004, 01:08 PM: Message edited by: Stefan ]
You can order the thermostat from Thunder Racing for $10.99, the Hypertech part number is 1009 for the 3.8 (or part number 1006 for $12.99 for the 3.4). Installation is simple: unbolt the casing over the thermostat, use a sharp scraper to scrape the old partially disintegrated gasket out, and install the new one.
The operating temperatures with the new thermostat range from 160°-165°, although your engine will still heat up to about 210° when you're sitting in traffic. On one of my stock trips to Rockingham Dragway I noticed quite a difference in times with varying engine temperatures. During Friday night test 'n tune I hotlapped the engine, running at about 210°, and got timeslips ranging from 16 flat to 16.5--quite a disappointment, considering that was my first trip to the track when my car was almost bone stock. The following day, during the bracket races, the engine had plenty of time to cool off and I ran consistent 15.5's with a best of 15.47 @ 89.36 mph on a 163° engine. Many people there even went so far as to buy large bags of ice which they laid on the engine block to keep it cool. No doubt, for the 3.8 V6, a colder engine produces more power (to a certain extent). Iron blocks just don't react well to heat.
In the spring of 1999 I decided to test the effect of engine temperature on horsepower on one of my trips to Woodbridge Dynotech, still when I was close to stock. On three runs, the first produced 172.4 hp and 205.0 ft-lbs. The second showed 173.8 hp and 206.6 ft-lbs. On the third run we turned off the giant fan they had sitting in the shop and allowed the engine to idle for a few minutes until the water temperature needle hit it's maximum of 210°. Sure enough, power dropped dramatically, resulting in 165.3 hp and 195.1 ft-lbs. The engine lost 8.5 hp and 11.5 ft-lbs when it was running hot! Higher engine temperatures are more detrimental to cars with less horsepower to begin with. My car was running around 170 hp, so a loss of 8.5 hp was quite profound, resulting in noticeable E.T. differences. However, for a hotrod with 700 hp, losing 10 or even 20 hp due to a hot engine does very little to affect the performance of the car. This is why at the track a lot of guys with super-powerful engines don't bother with ice or keeping the hood open in the staging lanes, while many owners of weaker-engine cars do. Makes sense.
There have been rumors that the 160° thermostat causes the coolant system to go into continuous loop mode, and people have offered all sorts of technical explanations for how this will destroy your engine and ruin your performance. They can say what they want, but fact is that the lower temperature does cause the engine to produce more power, it does improve your times at the track, and there are thousands of people across the country with low-temperature thermostats in their 3.8's and 3.4's and I yet to hear a complaint. A buddy of mine named Jonathan had problems with one on his third generation 92 Firebird 3.1, but that's because his initial thermostat was set for 210° and that engine runs a lot hotter than the 3.8 does. For him, jumping to the 160° was drop of 50°--quite a bit more than the 20° drop experienced by the 3.8. I have never had a problem in 75,000 miles on highways, crowded city streets, and tracks alike.
If you want bang-for-the-buck, this is a great part that can't be beat. Because it potentially reduces engine detonation, it should be considered absolutely critical for anyone running a supercharger, a turbocharger, or nitrous.
3 Pros:
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- Increases horsepower</font>
- Reduces detonation</font>
- Very cheap and easy to install</font>
3 Cons:
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- Possible computer errors</font>
- Decreases fuel economy (engine runs slightly rich when cooler--but this is why it produces more power)</font>
- Can decrease heater effectiveness in cold weather</font>
[ March 06, 2004, 01:08 PM: Message edited by: Stefan ]
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