No problem, I think we have the same chart, like most other charts in HPtuners the values aren't activated as soon as you hit a temp on the cell. It has a smoothing effect. Log it yourself and watch. There are areas where the timing gets pulled 5*. If it activated like and "on off switch" that would take away from the feel of smoothness when we drive the vehicles we love so much. Anyway, here is the stock chart:

 

yup doug, we have pretty much the same chart. there are only a few cells that are different (+-0.5*) mostly in the 0.32g/cyl. thanks for posting your chart.

 

I was loading my shotgun.....actually I knew it was a joke and dont own a shotgun.

Congrats on the tuner input.

 

Interesting, can't seem to agree on what temp it actually opens and closes, can't seem to agree on fan operation, can't agree on timing parameters, can't agree on how it actually affects timing, and the best one is what direction is the water flowing. But we know it's better than what GM puts in the car.

 

i guess you can't read...that is no surprise here.

 

Kinda seems normal to me......... When have we ever agreed on anything. This is the Corvette Forum....... there are those of us who would have a long drawn out discussion over what day of the week today is

 

Sorry this is maybe this is a little our of subject. I read many threads about the 160 stats and dyno, and the more I read the more I get confused. Here is my understanding:
Most people states that 160 stats help the car to run cooler, and add more TRQ and HP, and that is why drag racer run on a cold engin.
On another thread, people states that the third or fourth dyno runs give the best numbers, because the car reaches operating temp.

I see contradiction. How the can car runs better when it is cold, and truns better numbers on the dyno when it is hot?

Can any wiz help me understand this?
Thanks

 

Yes I can. The car will also dyno better at a little cooler temp.

 

With respect to what you said, you didn't realy answer my question. You add an additional statement, which added more to my confustion.

You added that the car will run better when it is cold, and when it is hot...how is that possible? and what happen in between when the engin is just warm?

 

Maybe I can help explain it. The engine operates best when it's in its "sweet spot", which is when it has reached operating temp of 180 degrees or so, but when no timing is being pulled for any reason. The things that will pull timing are: intake temp over 86 degrees, coolant temp over 216, or excessive TQ (torque management). There are some times when the coolant temp is under 216, but the engine compartment is warm enough to "heat soak" the MAF, and the Intake Air Temperature (IAT) sensor that is inside. This can happen more easily on the dyno, as the car is not moving. However, on the dyno the hood is open, which you obviously can't do on the street or at the track.

The lower temp thermo helps keep the coolant temps under control, in the "sweet spot". When the coolant temp is under control, there is also a lower risk of heat soak, and so the IAT will also be in the sweet spot.

On the dyno, so long as you stay in the "sweet spot", it is not unusual for the first pull to be slightly down on power. If you watch the tailpipe, you will see some black smoke --- this is carbon deposits being blown out. The carbon can sometimes cause a little preignition, which can cause timing to be pulled. The second and third pulls should be about the same. As the oil warms up, internal friction can be slightly lower, so the power might increase very slightly.

In a perfect world, every dyno pull would be exactly the same with regard to coolant temps, oil temps, and IAT. In the real world, every dyno pull heats up the engine, and sometimes you don't have enough time to let the engine cool down all the way.

Good practice is to use logging software to record the temps during your dyno or track pulls, so that you can make sense of the results. If the temps are the same, air density is the same, and no timing is being pulled for any reason, your results should be fairly consistent.

 

Thank you Hitman for the explaination.
As you explained it above, for optimum performance, engin should run in its sweet spot, hence not too cold and not too hot. Can you farther explain why drag racer run on a cold engin?

 

They don't, or at least they shouldn't. Some might make a pass after letting the car sit for 3+ hours on a cold day but I wouldn't do that without driving it around for a bit first, not only is racing it when that cold (say 170 degrees or cooler) harder on the motor (rings, valve springs, basically everything in there) but the transmission and rear need some heat in them as well.
By the same token racing the car at 225+ degree coolant temps might not be too hard on the internal parts (though it can be hard on some of them) it will also result in slower track times all else (traction, driving skill, air/wind conditions etc.) being equal versus running in that 'sweet spot' as mentioned above.

 

Ok, I will bite.

By cooler I am talking about 180 as opposed to 210.

It will dyno better at 180 and run the qtr mile faster at 180 then it will at 210.

Why? Well I don't know, just know that is what happens. To be honest I really don't care. I would guess if someone is telling you different they probably are just making up some stuff. Lots of guys on here offer their opinion without ever really trying something.

 

Well....In my opinion....These LSx engines like to be between 190 and 200 deg. This is where I think they are the safest...and where they make the best power... SAFELY.

Surely there will be times when the guage dips below 190 and occasionally it might get up over 200....but, the majority of the time I want it 190-200.

Bear in mind, I always use a 160 stat and with my fan settings...The cars always run great with no problems.

Southern USA get slightly more fan....Alaska guys...slightly less.

Also, remember.....my choice of stat has to do with "MY" tuning style and the octane used/climate. All factors are considered when I set up a tune....

Let's lay all this crap aside.... USE A 160 stat in your LSx vehicle and you will be GLAD YOU DID.

I don't care what you read online...or about your thermo-dynamics-physicist masters degree, or what the stat does in a pot of boiling water.......IF YOU PUT A 160 STAT IN YOUR LSx ENGINE, YOU WILL HAVE MADE THE BEST CHOICE AVAILABLE.(assuming you have a stock cooling system)

I've tuned nearly 1,000 LSx cars and trucks all over the country and more recently in other countries...I will not tune a car that does not have a 160 stat. Not ever have I had 1 complaint about the temp or the way the vehicle runs with regard to the stat/temp.

Forget all the science, theories, and textbooks....USE A 160 STAT.

OOPS! I think I just gave away another "tuner secret"... Oh Well....

Simple is smart.
Chuck CoW

 

That's good to hear since the stock stat with adjusted fans will stay in that temperature range. See the below graphs


Highway speeds and idling.



And under extreme conditions

 

Be sure to keep all the facts on the table.....

In most LS1/6 calibrations...the FANS TURN OFF after 35 mph...The programmed fan settings are only used BELOW 35 mph....after 35 mph the vehicle relys on the airflow through the radiator and the fans are off. If the A/C is on things are different.

Additionally, one should realize that the stat is important because it has an effect on the "core" temp around the cyls and is not necessarily representative of the temp that appears on the guage.

I have proven that cars that "appear" to be running at a specific temperature by the guage (without a stat) will on occasion have greater amounts of knock retard than those running at the "same" temp when a 160 stat is installed. I've seen this over and over.

Regardless of the science behind it........ 160 stats JUST WORK!

Chuck CoW

 

The graphs I posted are of an LS2.

Also note that over half of each graph was under 35 mph where the fans are controlling the temp.

I can understand the core temp at the beginning of a run since the starting temp is lower with a 160 stat however after just a few minutes of 190+ degrees the entire system should be the same temperature regardless of stat setting.

The only thing that bothers me about the 160 stat is the huge swings in temperature. I would think one around 175 would be perfect.

 

WCC sells a 170...

 

I haven't seen this. My temp is almost always around 180 at cruise, only gets near 190 in heavy traffic. Even in heavy rush hour traffic jams, temp never gets above 195.

 

Finally, someone with a clue on this subject