• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Tuning trans question / Major WOT problem

Frosty

I Write E85 Stickies
I did a bunch of searching and I wasn't able to find answers for this so I thought I would ask. When tuning part throttle shift its pretty self explanatory but whats the relationship between wot shift speed and wot shift rpm? Should they match up? Which one does the pcm actually use or does it use both? What happens when set grossly different? (4000rpm shift at 70mph or 7000rpm shift at 20mph).

The other question I had, which might be related to my first question, is what could be causing my car to cut out whenever playing with wot shift speeds / rpm above stock? It feels almost like fuel / spark cutout but both of my limiters are set to 7k so it isnt that. It only happens right at the top of the gear right before the shift and it gets worse whenever I raise my WOT shift rpm to the point that the car cant even reach the shift point if set high enough! Its not a gradual thing its like it hits a brick wall. This is on a 2001 gt with mild porting on the lim, Hv3, PLOG, Catless Downpipe, Stage 1 tb, and rockers. My stock injectors are reaching 90% duty cycle so im on the verge of buying bigger injectors just so i can maybe shift at a decent rpm other then the crazy stock 5400 rpm shift!

I am getting no kr either (Seems like my pcm ignores the high octane table? Never see it command more then my low octane table at wot?)

Any help would be greatly appreciated! This thing is getting supercharged soon so I need to figure this out!
 
Last edited:


For shifting, it wants to meet both speed and rpm. Some folks set the speed to 0 so that it's always met and then use the rpm to command the shift. Or you can figure out where both happen.

Check your injector disable table, you may be hitting a torque or power limiter that is pulling 3 of the cylinders power through the injector table.
 
For shifting, it wants to meet both speed and rpm. Some folks set the speed to 0 so that it's always met and then use the rpm to command the shift. Or you can figure out where both happen.

Check your injector disable table, you may be hitting a torque or power limiter that is pulling 3 of the cylinders power through the injector table.

Thanks for the tips!

As far as i can see I have all injector disable tables 0ed out. This is a base tune made by overkill so he has it all set up to just go pig rich and pull timing instead. I will try zeroing out the wot shift speed table and just set the rpm and see what happens. Do you know if theres a PID that I can scan that will tell me if the pcm is dropping injectors?
 
Back
Top