Rpms drop too quickly/car bucking a lot

[CallMeWonder]

So I bought an '03 cobra with a tvs on it tuned on 93 octane. It ran perfect and the rpm decay rate was perfect, it felt stock.

We have 92 octane here so I had it retuned just to be safe and the rpms were dropping ridiculously fast. I couldnt even rev match upshifts and I was shifting as fast as I humanly could. Also when cruising, if you let off the throttle the car bucks a lot. I know you get some bucking even under stock parameters but its pretty rough in this. Even in 6th gear at 70 80mph.

So I took it back and he slowed the decay rate by 15% and the rpms still drop way quicker than stock and its getting annoying that Im going to have to call, make an appointment for 2 weeks out drive back and still be unsure that it'll be solved.

I was wondering does anyone familiar with tuning know what the 'correct' or stock parameter for the dashpot decay is so he can just punch that in there? Or does it even work like that? Can he look at my old tune that I bought the car with and use that parameter? That one worked just like stock.

Appreciate any help someone can provide

 

[Don 95Vert]

You cannot just change the decay rate without also changing the prepostion (if it is >0) and clips...

Don LaSota

 

[Mach828]

He won't be able to view the old tune you bought it with due to the file format.

Most tuners won't even mess with it because a lot of it is personal preference. Mine drops to idle immediately and I love it. There are more parameters to adjust than just the decay.

 

[CallMeWonder]

You cannot just change the decay rate without also changing the prepostion (if it is >0) and clips...

Don LaSota

He won't be able to view the old tune you bought it with due to the file format.

Most tuners won't even mess with it because a lot of it is personal preference. Mine drops to idle immediately and I love it. There are more parameters to adjust than just the decay.

Thanks for the replies fellas. So the plan from here is to just tell him to adjust the decay some more? I assume he is adjusting the parameters you need to change along with decay without telling me 'cause he'd rather save the time having to explain.

Will update and see what happens

 

[Mach828]

It took me a long time to set all the dashpot and IAC settings to how I wanted. If nothing else maybe have him reload the stock values.

 

[decipha]

here you go

http://info.efidynotuning.com/dashpot.htm

it sounds like you need to do a base idle reset, what is your iscdc when at a warm stable idle?

http://info.efidynotuning.com/idleair101.htm

disregard the spout, you could temporarily lock timing in the tune if you want to get it perfect but its not necesarry, chances are your throttle set screw is too far closed and the engine can't breathe