Can't improve my 60ft..... why?

[scv_guy]

How can you lower the fan turn on without going to the 2 Bar OS in HP tuners?

[acammer]

Originally Posted by scv_guy

How can you lower the fan turn on without going to the 2 Bar OS in HP tuners?

If you want them to still be able to turn off, then fan on at 195*F is your limit with the stock OS, as the table only goes down to 192*F and you'll need that cell to trigger them off.

If you're ok with them running all the time, then that first cell can be a value high enough to go to state one (fans on low) and they'll come on when you start the car.

I am looking into potentially using the A/C pressure <> Desired Fan % table as a predictor of under-hood temps, and trigger than fans from that table. Someone on the HPT Forum mentioned doing this - it may have some merit as even with the a/c off the pressure creeps up as it warms up under the hood, and drops as it cools. Just not sure if the stock table will have the right points to work with where it lands.

[Pro Stock John]

I'll fire up my HPT tonight since I'm loading in a revised trans tune. I'll screen shot my fan settings then.

On at 207, and then off at 195 or something.

You don't want the fans on all the time, I had that a while ago, car didn't like it. It actually ran hotter (I couldn't explain why).

[scv_guy]

Originally Posted by Pro Stock John

I'll fire up my HPT tonight since I'm loading in a revised trans tune. I'll screen shot my fan settings then.

On at 207, and then off at 195 or something.

You don't want the fans on all the time, I had that a while ago, car didn't like it. It actually ran hotter (I couldn't explain why).

That would be great!

[acammer]

Here is the stock tables, then my tables (which run the fans on low all the time, and go to high at 195*F - sub-optimal, will be having my new tuner change, not sure why the old tuner didn't at least provide logic to at least have the fans go back to low), and finally your best option with a 160*F stat and the stock tables. That will turn the low speed on at 195*F, then high at 199*F, then all off at 192*F.

A quick explanation of how these work tables work. The bottom left table, Fan Desired % vs. ECT, set a percentage of fan duty cycle commanded at a given coolant temperature. In a Corvette, a pulse width modulated fan is used, and actually can vary its fan speed with the commanded percentages here. However, in our application on the Camaro we either have off, low, or high. So, the leads us to the next table.

Fan State Transition Desired % vs. Current State basically translates the Fan Desired % into a "State". These will be used to command the fans to off, low, or high. As the ECT goes up and the Fan Desired % increases, the pcm will command a higher state, and as it cools it will swing back into the lower states.

The top left table is the Fan Output Control vs. Current State. The row across the top represents the 7 potential fan states. Fan output 1, in the Camaro application, runs both fans at low speed, Fan output 2 runs both fans at high. What you need to take away here is that state 1 = low on both fans, state 2 = high on both fans.

So, with a stock tune, when the coolant reachs 221*F the PCM will command state 1, and the low speed fans will begin. If the temp continues to rise up to 228*F then the PCM will command state 2, and the fans will go to high. As the engine cools, when it reaches 217*F the PCM will command state 1 and the fans return to low speed. If it continues to cool to 210*F then the PCM will command the fans off.

[scv_guy]

Originally Posted by Pro Stock John

I'll fire up my HPT tonight since I'm loading in a revised trans tune. I'll screen shot my fan settings then.

On at 207, and then off at 195 or something.

You don't want the fans on all the time, I had that a while ago, car didn't like it. It actually ran hotter (I couldn't explain why).

Any chance you can post your fan setting??I'd like to compare to the posted settings

[Cuda7050]

OP I am guessing your running Sacramento Raceway. One thing you need to realize is track prep is critical to launching your car and getting a good 60' time. I have raced all over the country and let me tell you, Sacramento on a typical test and tune night is about as bad as it gets. Typically they just broom and blow the track. I haven't seen them use VHT in a long time. At a good track, your feet will feel like their Velcro'd to the starting line. Maybe you should try Sonoma or Bakersfield (Famoso), their management seem to care much more. Sacramento Raceway is up for sale and its surrounded by development. I think the owners are more interested in cashing out, rather than invest in a good racer experience.

[209camaross]

Originally Posted by Cuda7050

OP I am guessing your running Sacramento Raceway. One thing you need to realize is track prep is critical to launching your car and getting a good 60' time. I have raced all over the country and let me tell you, Sacramento on a typical test and tune night is about as bad as it gets. Typically they just broom and blow the track. I haven't seen them use VHT in a long time. At a good track, your feet will feel like their Velcro'd to the starting line. Maybe you should try Sonoma or Bakersfield (Famoso), their management seem to care much more. Sacramento Raceway is up for sale and its surrounded by development. I think the owners are more interested in cashing out, rather than invest in a good racer experience.

Yea sacramento is where I go... it's weird cause every time I don't do a burn out it's usually my best passes.. when I use the water or do a dry burn out it's usually my slowest passes... I just put some hoosiers slicks hopefully that helps which ever track I go next

[Cuda7050]

If you get a chance, go to Sonoma. The drag strip is run by Georgia Seipel. Her and her family all drag race. Their great people. I was there last weekend and it was 58-84 degrees while Sacramento was around 100. Just the temperature alone could be 2 tenths et.