Determining Mod Levels - Hunting Stock - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

DasBaldDog · 11-08-2018, 06:33 PM

Okay,

So the other day I noticed that my coolant never got above 163*F....

So I figured the previous owner installed a 160* Thermostat, not that much of a concern but I started to wonder what else could have been done that I can't see with my eye.

So some thoughts occurred that I figured y'all might be able to help with.

1. Is there any way to tell if the car has been tuned? I mean, is there any way to see if it has the stock tune on it?

2. The car has a very minor lope/lumpy idle, I had always figured that this was simply a characteristic of the Z/28, but now wonder if in addition to possible tune/thermostat, could there be a small cam in it? Is there a way to tell a cam short of removing the valve covers and measuring lift? (I can do this, just would prefer not to if it can be avoided).

3. Say we determine its a stock tune, stock cam, is there any reason to leave the 160*F thermostat in it? As I understand it the car is well-cooled and the low thermostat will only make it run rich without a tune, yes?

4. There are no other mods that I can see, no headers, no catch-can, etc.

MX621 · 11-08-2018, 07:43 PM

Post a vid of how it idles. Prolly able to tell if it’s got a cam. Considering it has the stock ex manifolds unlikely it has a cam. Sounds like the car came From a dealer, not able speak to previous owner?

1970judge · 11-08-2018, 10:57 PM

LS7's are pretty agressive, the lumpiness you're hearing is likely..just the stock cam. Its one of the more aggressive cams we have ever put out in a factory car. Same as the LS9 cam. There is a reason why people installs LS7/9 cams in their mild LSx builds.

The car will also run pretty cool in the right conditions. On a crisp day in Michigan I could get mine easily to run at 170 or so. Benefits of a well cooled vehicle, and no blower to soak it for you. Even in TX right now, its 'fall' (which is Michigan summer) I can easily maintain 180 cruising around.

Yes, despite what some aftermarket companies think, there is a way to see if the car has been flashed.

silversleeper · 11-08-2018, 11:52 PM

Quote:

Originally Posted by DasBaldDog

Okay,

So the other day I noticed that my coolant never got above 163*F....

So I figured the previous owner installed a 160* Thermostat, not that much of a concern but I started to wonder what else could have been done that I can't see with my eye.

So some thoughts occurred that I figured y'all might be able to help with.

1. Is there any way to tell if the car has been tuned? I mean, is there any way to see if it has the stock tune on it? The only that that comes to my mind is read the tune and compare it to a stock tune e.g. with HPtuners software and OBD reader.

2. The car has a very minor lope/lumpy idle, I had always figured that this was simply a characteristic of the Z/28, but now wonder if in addition to possible tune/thermostat, could there be a small cam in it? Is there a way to tell a cam short of removing the valve covers and measuring lift? (I can do this, just would prefer not to if it can be avoided). Pull a few plugs and do a cold cranking compression test. I think any cam larger than what's in there is likely to show lost compression. The bigger the cam the lower the cranking compression unless they made the compression ratio higher which I think would be a less common mod. The other method which is also indirect and uncertain is take it to a dyno and compare to people's stock hp.

3. Say we determine its a stock tune, stock cam, is there any reason to leave the 160*F thermostat in it? As I understand it the car is well-cooled and the low thermostat will only make it run rich without a tune, yes?
I don't think the computer will make it run too rich but I am not inclined to do a 160* for street or street strip. My understanding is there isn't the hp gains like back in the day on the modern engines doing that.

4. There are no other mods that I can see, no headers, no catch-can, etc.

...and I wish I had the LS9 cam as said above.

LeftCoast32 · 11-09-2018, 09:51 AM

The Z28 comes with a 160 degree Tstat from the factory.

DasBaldDog · 11-09-2018, 11:00 AM

Quote:

Originally Posted by LeftCoast32

The Z28 comes with a 160 degree Tstat from the factory.

Really?

I had not heard nor seen this.

I found the Part number 12661950 but no searching tells me the temp.

Update: Everything I'm finding in terms of replacement parts (Stant's website, etc) says 187*.

Update 2: Yeah, I'd love to see where you found that it came with a 160 because everything I find that cross-references the part says either 187 or 190. That being said I can't find an actual temp for the OEM part, just keeps saying "OE Temp"

DasBaldDog · 11-09-2018, 11:25 AM

Okay...

So I found a picture here
https://www.camaro5.com/forums/showt...=440890&page=2

Where someone ordered the part (same number as I find online from GM) for the Thermostat and it says 70*C on the part, which is 158*f.....

Hmmmm..... seems odd.

HorsePowerAddicts · 11-09-2018, 12:03 PM

160 from the factory. GM: 12661950

Original media/ tech review on the Z/28 confirmed this. May still be a link in the stickies.

DasBaldDog · 11-09-2018, 12:09 PM

Quote:

Originally Posted by HorsePowerAddicts

160 from the factory. GM: 12661950

Original media/ tech review on the Z/28 confirmed this. May still be a link in the stickies.

Interesting, thank you for the confirmaation.

Nick S · 11-09-2018, 12:31 PM

An easy way to check if it has been tuned or not is to find someone with HP Tuners that can just read your tune and compare it to a stock tune. They can easily see all the differences with one button click and HPTuners will create a log showing all the differences. Then you can easily see what areas of the tune have or have not been changed.

11-08-2018, 06:33 PM	#1
DasBaldDog Drives: 2017 Focus RS Join Date: Nov 2017 Location: Loganville, GA Posts: 177	Determining Mod Levels - Hunting Stock Okay, So the other day I noticed that my coolant never got above 163F.... So I figured the previous owner installed a 160 Thermostat, not that much of a concern but I started to wonder what else could have been done that I can't see with my eye. So some thoughts occurred that I figured y'all might be able to help with. 1. Is there any way to tell if the car has been tuned? I mean, is there any way to see if it has the stock tune on it? 2. The car has a very minor lope/lumpy idle, I had always figured that this was simply a characteristic of the Z/28, but now wonder if in addition to possible tune/thermostat, could there be a small cam in it? Is there a way to tell a cam short of removing the valve covers and measuring lift? (I can do this, just would prefer not to if it can be avoided). 3. Say we determine its a stock tune, stock cam, is there any reason to leave the 160*F thermostat in it? As I understand it the car is well-cooled and the low thermostat will only make it run rich without a tune, yes? 4. There are no other mods that I can see, no headers, no catch-can, etc.

11-09-2018, 12:31 PM	#10
Nick S Drives: 2013 Camaro 1LE Join Date: Jul 2012 Location: Verona, WI Posts: 1,924	An easy way to check if it has been tuned or not is to find someone with HP Tuners that can just read your tune and compare it to a stock tune. They can easily see all the differences with one button click and HPTuners will create a log showing all the differences. Then you can easily see what areas of the tune have or have not been changed. __________________

11-08-2018, 07:43 PM	#2
MX621 Drives: 2014 z28 Join Date: Oct 2018 Location: DE Posts: 171	Post a vid of how it idles. Prolly able to tell if it’s got a cam. Considering it has the stock ex manifolds unlikely it has a cam. Sounds like the car came From a dealer, not able speak to previous owner?

11-08-2018, 10:57 PM	#3
1970judge Drives: 2015 Z/28, 2007 HHR Join Date: Jan 2014 Location: Republic of Texas Posts: 1,148	LS7's are pretty agressive, the lumpiness you're hearing is likely..just the stock cam. Its one of the more aggressive cams we have ever put out in a factory car. Same as the LS9 cam. There is a reason why people installs LS7/9 cams in their mild LSx builds. The car will also run pretty cool in the right conditions. On a crisp day in Michigan I could get mine easily to run at 170 or so. Benefits of a well cooled vehicle, and no blower to soak it for you. Even in TX right now, its 'fall' (which is Michigan summer) I can easily maintain 180 cruising around. Yes, despite what some aftermarket companies think, there is a way to see if the car has been flashed.

11-09-2018, 09:51 AM	#5
LeftCoast32 Drives: 2015 Z28 Join Date: Jul 2011 Location: Vista, CA Posts: 127	The Z28 comes with a 160 degree Tstat from the factory.

11-09-2018, 11:25 AM	#7
DasBaldDog Drives: 2017 Focus RS Join Date: Nov 2017 Location: Loganville, GA Posts: 177	Okay... So I found a picture here https://www.camaro5.com/forums/showt...=440890&page=2 Where someone ordered the part (same number as I find online from GM) for the Thermostat and it says 70C on the part, which is 158f..... Hmmmm..... seems odd.

11-09-2018, 12:03 PM	#8
HorsePowerAddicts Drives: LSx Powered Join Date: Oct 2009 Location: 19804 Posts: 448	160 from the factory. GM: 12661950 Original media/ tech review on the Z/28 confirmed this. May still be a link in the stickies.