Brandon's Z

I have been driving my Z a lot in hot weather recently. I normal drive it in cooler weather. My car has a stock engine with B&B exhaust, headers and someone's chip (not sure who chip). When it is above 85 degrees, the car feels like it has 30% less power. Should I relocate the air intake sensor or have a Mark H chip? I hate that it performs so much worse when it hot. Thoughts

ZR1Bob

I relocated the air intake sensor on both of my Z's to lower down on the air filter holder. Marc H normally relocates them to the grille opening as I recall. That might be what is affecting your power on hot days, although there are many folks more knowledgeable than I on such things. Is your engine temp getting high? A clogged radiator is a common issue on C4 bottom feeders. On my '93 the radiator was about 40% clogged with sand and leaves. Had it removed and hosed out and temps returned to normal. Lastly, I know Marc's chips turn on the radiator fans at a much lower temperature than stock, I believe about 205 degrees.. Don't know if your current chip does that but it definitely helps to have them go on at the lower temps. --Bob

Bryanh24

Not sure if there is much you can do here.. all engines are faster in cold weather. But I don't blame you for asking, when it is winter and it gets to the 50's and 60's in North Florida my car feels completely different. Aaron Scott did say the LT5's loveeee cold weather, but I don't think there is a way to do any sort of modification to make the car think it is cold outside 24/7 IMO. Just enjoy the power it provides in the warm weather and be patient for cooler weather.

The Dingo

According to Marc Haibecks website, relocating the sensor could absolutely make a difference if you have a stock ecu calibration.

http://zr1specialist.com/HAT%20Web/p...r%20sensor.htm

pushrod-v8

Bypass the coolant going through the throttle body, plenum and relocate the i.a.t. sensor. I put mine inside my cold air intake.

Dominic Sorresso

The MAT sensor does affect timing when above a certain manifold air temp, but that occurs when you are above 70kPa, ie more aggressive throttle opening. Its also designed to modify the VE table values to consider intake air temps as part of the final fueling calculation. In this manner, the ECM modifies VE calc in order to maintain a consistent air/fuel ratio in varying operating conditions.The relocation of the MAT sensor however actually has a “global” effect on fueling. The calibration uses Manifold Air Temp to modify the fueling dictated in the VE tables. The MAT table modifies fueling by changing the ratio of manifold air temp vs coolant temp the ECM should utilize to determine final fuel calculation. So if you move the MAT sensor effectively making it an Intake Air Temp (IAT), the ECM will register MAT that is typically seen during colder weather operation. The VE tables are calibrated for air intake temps that are higher than what the IAT will ever report to the ECM, ie 20-40C instead of 70-90C. The MAT table values should be modified to reflect the “new” operating conditions the ECM will be registering w the MAT now operating as an IAT.