GMPP LT5 Crate

[jrmitch19]

Hoping someone may have run into the same issue I'm having. We have an LT5 crate engine in a 69 Camaro. Per the GMPP instructions Fan 1 comes on at 207 and Fan 2 comes on at 227. I've verified that this works correctly. This is just to hot for this car. It has katech 160 tstat, ported heads, cam, pulleys, ect. I've tried changing every setting in the systems / fans section. No matter what I change the fans still start at 207. In the fan section it seems there is a lot more adjustability with the tables that are for PWM control. I swapped the stock relay set up for pwm fan controllers. I edited my fan setting to match combos that have worked for me in the past.

The PWM set up also doesn't respond to changes at all. I've changed duty cycle. I've changed the temp that I'm commanding different duty cycles. No matter what I do the fans start at a very low duty cycle at about 200 degrees and reach a max of 49.8% duty cycle at 207 degrees. This is while being set at 98% duty cycle starting at 190 degrees.

Any help here would be much appreciated.

Thanks,

Jason
Chastain_LT5_as_found.hpt
Chastain_order 958_LT5_Heads_Cam_Maggie 2650_15 psi_Pump Gas_Base 5_fans2pwme.hpt

[JANNETTYRACING]

I have had similar issues with GMPP computers.

I think it might be either hard codes or HPtuners have not defined the tables we need.

In my situation either the fans would not turn on or they would not turn off dependin on combination of output state and fan percentage table.

In the fan percentage table I could not put anything other than Zero in the first column.

I am sorry I don't have a solution for you in this case.