my tuner did it said that b/c of the large cam overlap it would never run right in closed loop. Julio @ Cartek did my tuning. I would do a search on it in the computer section on these forums, you;ll find a ton of info. I think basically open loop just looks at the long term data instead of closed loop monitoring the short term data. For example on a car with a tight LSA such as 108 the o2 sensors are constantly seeing gulps of un-burnt air and also un-burnt fuel and when running in closed loop it is constantly trying to adjust for this and keeps trying to add more fuel (when it sees the unburnt air) when the car is actually already getting enough. In open loop it isn't trying to Constantly compensate for this and looks at the long term averages.

 

It is possible in the programming to check a box that says "open loop only".

This will strictly make it use the open loop AFR tables and the volumetric efficiency tables for fueling. It would still use the same spark tables.

 

thanks. so its that easy huh? but again, i don't want to lose my tune that speed inc did, or otherwise make it useless.

 

The open loop tune is very intensive and actually has to be more accurate than a closed loop tune.

I actually misspoke in my previous post, for some reason I had Speed density mode in my head. The speed density mode is a simple "check" in a box. To force the car into open loop full time you have to play with the closed loop triggers, basicly maxing them out so the car never reaches that and enter closed loop, still somewhat simple, but not just a box check.

 

thing is, jim from speed inc is very good tuner. they don't think i needed a open loop tune. i don't know. it never did any of this until a month ago.

 

Wow, so far I think you're the closest setup to my car I have seen. Only thing diffrent is my heads have been ported some, not sure the lift on your cam, my exhaust valve is a tad bigger, and I have a few different brand of stuff but all about the same. I'm not sure your minor mod boltons though. Like I have a U/D Pulley, K&N CAI, Granatelli MAF, MadZ28 tune, tb airfoil, 1.5 RRs, LTCC ignition, E-Waterpump and all that stuff. Just courious to what you have as far as that goes? So I'm thinkin a should be around the 370rwhp mark.

 

The 1.5 rockers and the lift of the cam is a big difference.

Bret