Pulling out timing to lower ET

[SUPERSTOCKRACER]

When my cars are running at 32 degrees total timing, my ET is about a .1 worse but my MPH is higher than when I try 34- 35 degrees.
So at what RPM would you start pulling timing to get the mph back? And would you do it only in 3rd gear? I lose close to 2 mph with the higher timing.

Forgot to add, I'm shifting at 7000 rpm's

 

[69 GTX]

I have nothing to base this on but maybe at 1000 ft. That's where I used to hit the leanout valve on the alky bike.

 

[bobtile]

When my cars are running at 32 degrees total timing, my ET is about a .1 worse but my MPH is higher than when I try 34- 35 degrees.
So at what RPM would you start pulling timing to get the mph back? And would you do it only in 3rd gear? I lose close to 2 mph with the higher timing.

Forgot to add, I'm shifting at 7000 rpm's

Pull the timing out at 7001 rpm. You're fast enough!

 

[dvw]

Mine runs the same mph at 32 as it does at 34. 34 helped the ET by about .03. I tried to slow it down to 9.50 index a few years ago. Had it all the way down to 26 degrees and it still was in the low 9.40s
Doug

 

[Budnicks]

Just spit-balling thinking out-loud IMHO
I'd say run it at 35* to start off with &
pull it back progressively, starting at about 330ft mark down 1* what ever et your at there
then another 1* degree at 660ft, another 1* degree at 990ft/1000ft or every 330ft
or maybe every 3 seconds after, to get it back to 32* total in the traps

that's way you'll get the best of both worlds
good 60ft to be able to et well
& big MPH to run the guys down at the big end,
then you'll have your cake & eat it too

 

[Canyon707]

My et at 30 degrees was 11.055 at 117.48 and at 33 degrees it ran [email protected] I was going to kick it up a degree and see what happens.

 

[SUPERSTOCKRACER]

Just spit-balling thinking out-loud IMHO
I'd say run it at 35* to start off with &
pull it back progressively, starting at about 330ft mark down 1* what ever et your at there
then another 1* degree at 660ft, another 1* degree at 990ft/1000ft or every 330ft
or maybe every 3 seconds after, to get it back to 32* total in the traps

that's way you'll get the best of both worlds
good 60ft to be able to et well
& big MPH to run the guys down at the big end,
then you'll have your cake & eat it too

That's fine & dandy but at what RPM do you start it because on my digital 7 ,you need to plot dots at the RPM you want to retard the timing at. My digital 7 doesn't know where the 330, 660, 1000 foot mark is.

 

[bobtile]

:yes:Test-n-tune

 

[SUPERSTOCKRACER]

:yes:Test-n-tune

As long as it doesn't go like this one.

 

[lewtot184]

i think there are too many variables here to give a definitive answer. to pull something out of my butt, i'd say a gradual pull back between 5000 thru 7000. the engine wants the timing (torque) at lower rpm but doesn't want it at max rpm (maybe a cylinder pressure issue?). my thoughts are valve timing is what needs to be played with, but what the heck do i know; i don't race.

 

[Hemirunner]

Start pulling the timing after peak torque rpm. It should be on your dyno graph.

 

[383man]

I agre test & tune as there is no one answer since many combo's wont all work the same. Bill Jenkins was pulling timing from his 427 Pro Stock eng in 1970. I have the article in a mag from 1970 and I believe it was a "Populat Hot Rodding" mag. He used a dual point and ran on the singe set until he hit fourth gear when he brought the second set of points in with more dwell and it also retarded the timing a tad. I am sure he refined it more as electronice came more into play and I am sure many others use it. Most with an average street car or bracket car dont worry about it but it can help you pick up a little et and for a class racer every bit counts. Ron

 

[Budnicks]

a MSD 3 Stage Retard Controller {#8970 or 4 stage #8975} might help, it's also RPM activated thou

not 100% sure that's the right one or the one below either

Dedenbear make electronic N@0 controllers that may serve the same function also
it doesn't have to be just for N20
http://www.dedenbear.com/noc1txt.htm


{your time slip should have 330 660 1000 ft et incrementals, at certain parts of the track}

do you have a Race Pak with read out/computer & sensors on this car ?,
IIRC it would have all the times & rpms at the specific times too

I haven't dealt with any in years now

or maybe something like this
http://www.electrimotion.com/Command Module Timing Control.pdf

I know somebody makes "a time activated ignition or Retard controller" that would work,
I'm having a brain fart

Maybe Jacobs Electronics {I think they are owned by Mr. Gasket now}
they use to have a great controller, rpm or time activated 12 settings or something
{I tried to find the box I use to run, my computer is acting weird, I'll try later}

a MSD Boost controller has a time based setting too IIRC

By RPM I'd just back it out 1* every 1000rpm {or 0.5* every 500rpm} after like 4500rpm maybe

NOS has a timed based controller...

sorry not being of much help

 

[SUPERSTOCKRACER]

a MSD 3 Stage Retard Controller {#8970} might help, it's also RPM activated thou

not 100% sure that's the right one or the one below either

Dedenbear make electronic N@0 controllers that may serve the same function also
it doesn't have to be for N20
http://www.dedenbear.com/noc1txt.htm


{your time slip should have 330 660 1000 ft et incrementals, at certain parts of the track}
do you have a Race Pak with read out/computer & sensors on this car,
IIRC it would have all the times & rpms at the specific times too

I haven't dealt with any in years now

or maybe something like this
http://www.electrimotion.com/Command Module Timing Control.pdf

I know somebody makes "a time activated controller" that would work

Thanks my Digital 7 box can do it, I just trying to figure out what RPM to start it at?
I can do it in any gear too.
You gave me a good idea with the Racepak graph readout. Thanks

 

[Budnicks]

anytime,
sometimes I have to think about it for a while,
my memory {or lack of, long term, sometimers...LOL} &
not racing or not keeping up with it for a while doesn't help much either

good luck

- - - Updated - - -

what 7 series MSD box do you have
is it a 7AL-3, 7AL-2 Plus or Digital 7AL Plus Programmable

just curious

 

[SUPERSTOCKRACER]

what 7 series MSD box do you have
is it a 7AL-3, 7AL-2 Plus or Digital 7AL Plus Programmable

just curious[/QUOTE]


MSD 7530T in the 65 blue dodge and MSD 7530 in the black dodge. I have a backup 7531 and another 7530T new just in case one goes bad.
The 65 Plymouth still retains an original MSD 7AL which might get replaced after I fire up the new hemi.

 

[Budnicks]

MSD 7530T in the 65 blue dodge and MSD 7530 in the black dodge. I have a backup 7531 and another 7530T new just in case one goes bad.
The 65 Plymouth still retains an original MSD 7AL which might get replaced after I fire up the new hemi.

thanks
I don't remember all the differences,
I'd have to do some research

sounds like you've already updated them to a newer style anyway

 

[bobtile]

I have an msd6
Bob

 

[Canyon707]

thought I would throw out some pictures and a video if I can of my updated rpadrunner.

 

[Budnicks]

thought I would throw out some pictures and a video if I can of my updated rpadrunnerView attachment 244543

What no NHRA div. 7 #'s...LOL
RR looks nicer, it's good for getting into the 10's now...

but;
you probably should start your own thread, on that specific topic

this thread was about backing out/retard ignition timing,
to get good launch/60ft's & get good mph

no harm no foul

good luck have fun, either way