: Will a 160 thermostst help a stock engine



Trainman SRT-10
05-12-13, 05:37 PM
I have a simple question. How much will I gain by going to a 160 thermostat on a stock 2012 CTS V coupe, 6-speed manual? I am also thinking about an Airaid CAI. I am located in Bakersfield where it gets really hot in the summer, but I am thinking about going out to Famoso this Friday(May 17th) for a test and tune event. High temps should be about 85 and down in the low 70's or high 60's by 10pm. We will run till midnight. Last time out I had a 12.37 with a best of 117.16 mph on stock tires. 60' on that run was 2.059. What is the best tire pressure on the stock tires?.....I think I may try 22 psi....any help appreciated.

nguyennhatquang
05-12-13, 06:21 PM
if u lower your car engine temp..u will damage CAT soon...

You need your ECM tune..u can buy HP tunner to tune it yourself...mostly is make the fan run sooner at 160F...i have HP tunner and i play with it. It very easy to use.

how much it will faster...i really don't know..because the rest of your car is stock and your car have 556hp like mine...i do not feel any different when i lower the temp of my car... May be it have too big engine...BUT if you delete CAT..like mine..put a header in it..you can feel the power...slightly more when acc....and the car easier to breath..

BUT when you DELETE CAT like mine..you need to DISABLE rear O2 sensor..if not SES light will go on for P040xxx i don't remember exactly..it about Cat efficiency. Because the way the rear 02 work is it compare the value with the front.. the Front is for Fuel control mode. the rear is for Checking CAT.

for the 3.6..i feel the car breather better in city..a little quicker...does it really faster or it just the feeling..i need to clock 0 to 60..for make sure..but for just the feeling..i feel it lithe quicker..(the car have small engine may be that is the reason i feel it)...

you can try it just for the hell of it..because thermostat only worth about $20..and Hptunner is $650 for the rest of the vehicle life. If you buy other car..just buy credit and it cheap, you doesn't need to buy HPtuner kit again.
but remember..before bring the car for warranty..paste the original EEPROM back...so Dealer can't track dow.

Trainman SRT-10
05-12-13, 06:39 PM
Thanks, I'll definitely talk to a tuner before using the lower temp therm, as I have talked to my dealer and they will allow me to do a few basic mods (CAI, tune, exhaust, etc) and still keep my warranty.

Trapspeed
05-12-13, 06:42 PM
Thanks, I'll definitely talk to a tuner before using the lower temp therm, as I have talked to my dealer and they will allow me to do a few basic mods (CAI, tune, exhaust, etc) and still keep my warranty.

Leave the thermostat alone, IMO. Not somewhere I'd tinker with right away...if ever.

nguyennhatquang
05-12-13, 07:00 PM
Thermostat as i was in school before ( i took GM class just for fun.. so i can play with mine)

1st : Help the engine raise back to operating temp as soon as possible
2nd : restrict the coolant flow..basically is it keep the coolant in the engine block a little longer to make heat transfer all to coolant before sent out to the radiator. That the book said. I saw a lot of racing car they just put a restrict ring instead of thermostat or some even don't :suspense:

i have a ague with my instructor about that..i asked him..so what happen if your hand get burn..you want to drop a slightly water in your hand..then let the water absorb all the heat before throw the water away or u want water in your hand as mush as you can...:tisk:
he didn't say anything..and we still ague about it.

About me..personally.. just live and learn..learn then play..play and practice.

personally mine i remove thermostat..didn't see any different... doesn't see engine break down like BOOK said..even i beat the hell out of it.. the 3.6 one. Only i see is the engine take longer to warm up..

trust me..you just do whatever u feel like you want to do..all is experience... i believe lot of Tuner out there..they just live and learn..
i get a lot of scare..like will damage your car bla bla.... but it still work fine....and day to day get more toy with my spirit.

before i own a e65 750li..If i read everything on internet..or listen to people expericen.. i will never have a real time nice experience with this bimmer. It not worst like people try to say and scare us.. specially those mechanical out there. They just scare us..because if ALL OF US IS DIY..they will loose them job.


if you lower your engine temp.. in theory..the car will run in RICH mode.. you can see it by the O2 sensor voltage. ( the first one)

O2 Sensor
Lean Indicator
Vacuum leak
Low Fuel Pump Pressure
Clogged fuel Injector

Hight voltage = Rich
Low voltage = Lean

Rich Indicator
excessive fuel pressure
leaking fuel injector
leaking fuel pressure regulator

so in theory..it dump more fuel in..make the air/fuel richer.. suppose to run faster..

Trainman SRT-10
05-12-13, 07:10 PM
Thanks guys. I will talk with my tuner (Charlie at RPM Motors) before doing anything. I have had a 170 therm in my Ram SRT-10 almost since it was new, no problems at all. My engine runs at 180 and oil temp at 180 most of the time. I have one of the quickest stock engine SRT-10 Rams in the country, just exhaust work and tuning with major weight reduction on race day (11.63@118). I have had the SRT-10 (2004) since new and it has 66,000 miles ( but no cats ) and there are no problems with the engine (probably over 200+ passes down the 1/4 mile). I hadn't thought about the temp affecting the cats, good point.

Chrispy
05-13-13, 09:11 AM
160 thermo is fine if you set the fans to come on lower accordingly. You'll lose less power from heatsoak and get more airflow across the heat exchanger from the fans operating earlier.

Another good tip is to set the tune to run the intercooler pump in the acc position.

After installing the 160 stat you will likely want to change your oil more frequently as you'll have generally lower oil temp in every day driving.

6speeder
05-13-13, 09:51 AM
"if you lower your engine temp.. in theory..the car will run in RICH mode.. you can see it by the O2 sensor voltage. ( the first one)"

Not with a 160 thermostat. The car changes from open loop to closed loop and runs at 14.7 A/F at WAY lower temps than you will see with a 160 thermostat. You won't run richer. What you WILL see with a 160 stat is potentially a little more WOT power as the ECM pulls timing at higher ECT's. So, run a little cooler, get less timing pulled.

Also, running a 160 Vs. a 187 degree thermostat WILL NOT affect the cats.

wait4me
05-13-13, 10:04 AM
Correct that the cats WILL NOT BE damaged from the cooler engine operating temperature. The Spark applied and fuel applied are what effect cat temp..

Cats are more damaged from fuel quality and invalid tuning/misfires.

160 is fine to run in any car that are effected by heat soak. Any decrease in temperature in the "OVEN" will help out.



The reason why race cars put in a restrictor instead of a thermostat is so that the engines run cooler than what they would with a thermostat in place. A thermostat is basically a restrictor as well. The opening is LESS than the diameter of the housing. The only difference is between the two, are that the thermostat will close at a set time, and the restrictor never closes so therefore it acts like a 0 degree thermostat instead.. AS it can not close at any temp...


Fan settings in the computer regulate the percent of fan rpm. So it is easy to target what you want. I say cooler the better.

The temp settings for closed loop fueling are 176, which even though you run a 160 thermostat, you are always in the 170s range - 180s anyways.. However, with the correct tune settings, you can move that down to say 150, and you are all good...

Trainman SRT-10
05-13-13, 12:02 PM
Talked with my tuner and he said that these engines make the most power at 195-202 temps, so I will probably not change the therm for now. Thanks guys for all the input.

6speeder
05-13-13, 04:15 PM
The temp settings for closed loop fueling are 176, which even though you run a 160 thermostat, you are always in the 170s range - 180s anyways.. However, with the correct tune settings, you can move that down to say 150, and you are all good...

I don't know where you got that number, but my 2010 CTS-V goes from open loop to closed loop at an ECT of 102 F.

2013CTSV
05-13-13, 04:19 PM
Talked with my tuner and he said that these engines make the most power at 195-202 temps, so I will probably not change the therm for now. Thanks guys for all the input.

Not so sure I agree with your tuner but to eachs own.

wait4me
05-13-13, 04:36 PM
I don't know where you got that number, but my 2010 CTS-V goes from open loop to closed loop at an ECT of 102 F.

Sorry, I was thinking 2000-2008 controllers, as I was tuning one while typing.

The actual temps for this exact car is
closed loop happens at 102F
however, long term fuel trims are allowed at 95F as per the exact tune.

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Talked with my tuner and he said that these engines make the most power at 195-202 temps, so I will probably not change the therm for now. Thanks guys for all the input.

This is NOT VALID. I have tested tons and tons and tons of these EXACT cars, and they always make more horsepower the colder they are.

nguyennhatquang
05-13-13, 06:29 PM
Not with a 160 thermostat. The car changes from open loop to closed loop and runs at 14.7 A/F at WAY lower temps than you will see with a 160 thermostat. You won't run richer. What you WILL see with a 160 stat is potentially a little more WOT power as the ECM pulls timing at higher ECT's. So, run a little cooler, get less timing pulled.


No, wrong. Close loops is when the Front O2 COLD. With the heating O2 sensor it heat the O2 sensor fast enough to react.

even when you engine temp at 120F..with good heating O2 sensor...u still can see it run in CLose loop via TEch2.


This is NOT VALID. I have tested tons and tons and tons of these EXACT cars, and they always make more horsepower the colder they are.


this i totally agree with you..but for just a thermostat only on the V..may be he won't feel it..like mine..

lower engine temp..mean u can dump more fuel..and more air... (supposedly) ...because the Air or fuel can compress more when it colder... (correct me if i was wrong, we 're learning here)

i think 195 to 202 is the best for Emission is more CORRECT.


PS..the reason i think it will damage the CAT is if you have a tool to check emission.. you will see emission go up...=> more harmful to CAT.


After installing the 160 stat you will likely want to change your oil more frequently as you'll have generally lower oil temp in every day driving.


i don't think it will effect the OIL change interval..because i saw people install OIL cooler in performance car all day...
if they just want to set correct oil temp..why they need to do that... or install a Oil Heater..with thermostat (maybe)

6speeder
05-14-13, 09:29 AM
No, wrong. Close loops is when the Front O2 COLD. With the heating O2 sensor it heat the O2 sensor fast enough to react.

even when you engine temp at 120F..with good heating O2 sensor...u still can see it run in CLose loop via TEch2.



I'm gonna presume English is a second language for you, and if so, you're doing better than I would in another language. :) To the point, you've got your temps wrong, mine goes into closed loop much sooner than it gets to 120F. Once a car warms up enough, (102F ECT for my 2010) including the heated O2 sensors, THEN it goes into closed loop, not when the O2's are cold.

OP: As far as your tuner, he's got it wrong also. Have him look at the timing Vs. ECT tables, It'll show show much timing is pulled when the temps are in the 200+ range. BAD for making HP.

Trainman SRT-10
05-14-13, 11:32 AM
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I'm gonna presume English is a second language for you, and if so, you're doing better than I would in another language. :) To the point, you've got your temps wrong, mine goes into closed loop much sooner than it gets to 120F. Once a car warms up enough, (102F ECT for my 2010) including the heated O2 sensors, THEN it goes into closed loop, not when the O2's are cold.

OP: As far as your tuner, he's got it wrong also. Have him look at the timing Vs. ECT tables, It'll show show much timing is pulled when the temps are in the 200+ range. BAD for making HP.


I may have mis-quoted him, as I am not really mechanically inclined, I will be seeing him on Thursday to get an AIRAID CAI installed and the car tuned. I met him through a friend who has a ZL1 Camaro. This ZL1 made 489rwhp and 499 ftlbs ( 6 speed manual) stock. After Charlie at RPM Motors did heads ,cam, pulleys, headers, intercooler, 160 Therm, and tune the car made 706.5 rwhp and 725.8 ftlbs without Meth and 733.6 rwhp and 732.5 ftlbs with Meth. It idles at 800rpm, very mild street manners, but makes over 700 ftlbs from 3,000-5,000 rpms. All on the stock bottom end. He came highly recommended from several Vette owners, a real master with the LS motors.

nguyennhatquang
05-14-13, 11:51 AM
OP: As far as your tuner, he's got it wrong also. Have him look at the timing Vs. ECT tables, It'll show show much timing is pulled when the temps are in the 200+ range. BAD for making HP.


i play with my own Hp runner. I don't have any people teach me how to do it. Anyway thank you so much for helping.

you talk about the timing pull when the temps are in 200+ range..are you talk about the ignition degree? thank..

6speeder
05-14-13, 02:05 PM
i play with my own Hp runner. I don't have any people teach me how to do it. Anyway thank you so much for helping.

you talk about the timing pull when the temps are in 200+ range..are you talk about the ignition degree? thank..

Yes, ignition timing. At higher coolant or intake air temps the computer backs down the ignition timing from where it thinks is optimal. It does this to prevent detonation. It's better to keep the temps just a little lower to prevent this.

If you have HP tuners pull up your file comparing ignition timing and engine coolant temps, you'll see how the timing is reduced at higher loads and higher temps.

That ZL1 sounds like a fun ride. Noticed he put a 160 in it, you wouldn't do that if you wanted to run it at 190-202.;)

Trainman SRT-10
05-14-13, 03:37 PM
That ZL1 sounds like a fun ride. Noticed he put a 160 in it, you wouldn't do that if you wanted to run it at 190-202.;)[/QUOTE]

That's what I was thinking, thus my original question about a 160 therm. I will get that qualified on Thursday. I was wondering if it was good for a modded engine , then would it be good for my stock engine?

6speeder
05-15-13, 11:25 AM
That ZL1 sounds like a fun ride. Noticed he put a 160 in it, you wouldn't do that if you wanted to run it at 190-202.;)

That's what I was thinking, thus my original question about a 160 therm. I will get that qualified on Thursday. I was wondering if it was good for a modded engine , then would it be good for my stock engine?[/QUOTE]

I run them in all my cars, for the reasons cited.