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Old 03-26-2024, 09:30 AM   #1
Pauley
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Default Re: RPM dip doing onto stop, w/ racepak graphs

Whos carb and what size?
What size carb?
Electric or air stop?
Are shifting on stop or on rpm?

I dont know much but maybe i can help

ep
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Old 03-26-2024, 10:11 AM   #2
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Default Re: RPM dip doing onto stop, w/ racepak graphs

Don’t let Pauley bullshyt you, he’s a bad man running a throttle stop.
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Old 03-26-2024, 01:17 PM   #3
Pauley
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Default Re: RPM dip doing onto stop, w/ racepak graphs

dont let 1290 bullchit you sir. i blind squirrel it most of the time.

by the looks of your graph i would say the you are shifting on rpm. the creep in it leads me to think rpm. most will say to try and get your graph to lay as flat as possible which you can do on time not on rpm so much. the creep has never bothered me that much as long as it repeats. but you definitely don't want the dip. that will make you pull your hair out. that is why i dont have hair. i would like to know also how fast your ride is wide open also.

ep
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Old 03-26-2024, 01:22 PM   #4
Pauley
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Default Re: RPM dip doing onto stop, w/ racepak graphs

gas or alcohol?
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Old 03-26-2024, 02:05 PM   #5
Pauley
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Default Re: RPM dip doing onto stop, w/ racepak graphs

Sorry for the dumb shift ? I see the shift.

ep- told you blind squirrel
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Old 03-26-2024, 04:21 PM   #6
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Default Re: RPM dip doing onto stop, w/ racepak graphs

Timing issue?
Timing of low gear band release and Hi gear clutches apply..
Both applied at the same time could drag RPM down.
Different servo spring or adjust the spring pressure higher.
or
More clearance in the Hi clutch pack can increase time to apply and free up drag when in low gear.
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Old 03-28-2024, 09:41 AM   #7
Phil S/ST
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Default Re: RPM dip doing onto stop, w/ racepak graphs

Not knowing the O2 readings, my guess the carb is a tick fat causing to 60ft to change. Try switching to shifting on time and try a bigger intermediate air bleed on the carb. Other fixes include raising the stop RPM, slowing stop closing speed. A smaller carb may work also. Just some thoughts
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Old 03-28-2024, 09:45 AM   #8
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Default Re: RPM dip doing onto stop, w/ racepak graphs

Quote:
Originally Posted by Pauley View Post
Sorry for the dumb shift ? I see the shift.

ep- told you blind squirrel
You looked good at SGMP until Webb kinda ran over everyone! Myers was too.
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Old 03-28-2024, 10:34 AM   #9
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Default Re: RPM dip doing onto stop, w/ racepak graphs

This setup is pretty similar to mine, although you have more power and are 200 lbs lighter.

Shifting on time would cost a lot of MPH. I wouldn't do that. I'd probably go up a bit on the cruise RPM to 4300 or so.

I go on the stop at .500 to get things moving. You seem to have a similar thought. Moving that timer would be a good thing to try, but I don't know which way might be helpful in this case.

Do you have a crossover hose on your carb bowl vent tubes? Maybe some fuel slosh.

Intermittent issues are always the worst.
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Old 03-28-2024, 02:18 PM   #10
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Default Re: RPM dip doing onto stop, w/ racepak graphs

Quote:
Originally Posted by Phil S/ST View Post
You looked good at SGMP until Webb kinda ran over everyone! Myers was too.
The Webbs are good people and very tough to beat. it seems i have to run Donald or Chris every week. Donald gave me the lap that I was expecting and unfortunately i missed the tree a little. 27 up front will typically not get it done so i knew at the 1000' it was not looking good for me. no choice but to quit and hope. Donald rarely makes a mistake and when i do i pay for it.

i agree with above posts. i feel rpm is too low and shifting on time will clean some things up. would like to know if it is gas or alk

ep
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