ppsi

With an auto do I launch-w-the OD turned off and then turn it on at some point down the track? I understand this locks the converter? Sorry for the newbie drag question. Also I would appreciate launch RPM. I have no guages so a boost recommendation is appreciated but won't help me at this point.

bulabula

Not that I have an auto truck, but I'd keep the OD turned off, bring up the revs as high as the brakes will hold at the lights, and drop the hammer/release the brakes just as soon as you see the last yellow light illuminate. Then sometime down the track push the OD button in.

Why not go out on Test & Tune Night and experiment, then report back your lessons learned?

Don't forget to turn off the AC and roll up the windows. And since weight kills speed, its a good time to do a spring cleaning in the back and remove any heavy things that have accumulated back there. Its also good to wait to fill up AFTER the racing ends.

Then after all that, and if your first run turns out lousier than you expected, you can say to everyone within earshot "yeah, but I still had all that heavy junk in the back, a full tank of fuel, and boy oh boy does that AC work great going down the track at max cool!!"

JKE

launch RPM maybe difficult to establish on the auto. It will only stall so high before loosing the rear tires at the light.

Get it as high as you can and....depending on the how these autos act, get off the brakes at the last yellow. as soon as you feel the truck move THEN hammer down.....this method will depend on your traction of course. If the truck will not spin the tires, hammer down at the same time you are releasing the brakes to get a better 60' time.
sorry, do not know about the OD thing.


Practice, practice, practice....JKE

ppsi

I suppose Fri PM will be valuable for testing. I have never raced but had always heard to leave on the last yellow but this would seem to me the recipe for a red light?

bulabula

You need to get out there and try it. I think the timing of the lights matches up well with the typical reflex response time. You'll know when you screw up and red light.

John_P

Howard:

You definitely need to to get a full set of gauges including,
fuel pressure, pyrometer and boost!

We will be down there on Saturday at the event in Rockingham
and will try to help you. My suggestion would be to get up to
the lights, leave your transmission in "drive" with your overdrive
"off". Hold the brake and begin slightly accelerating (with a boost
gauge try to get up to 10-12lbs) and hold that until you see the
last yellow light come on and then release the brake and FLOOR
IT!! Let the transmission shift up through the gears and once
it shifts into third unlock the overdrive to let it shift into OD.
Another "variation" to this is to just leave the transmission
in drive with the overdrive "on". You will have to try each
method to see what work best.

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John_P

ppsi

10-4 John-I will try both. I am headed to the 2nd generation area to get some info on the Holley pump set up.

GeorgiaCracker

If you are trying to get the best 1/4 mile time, use some of the advice provided here - powerbrake, anticipate the light...etc.

I would consider launching in 4 wheel drive to avoid the time losses related to wheel spinning. When you get the hookup, then switch to 2 wheel drive for the rest of the run.

If you are playing on the street, you can beat faster cars by launching in 4 wheel. A Cobra will lose a lot of time burning out while you are on down the track. In the 1/8th mile, you can beat a Corvette if you are running about 450 RWHP and you get a good light and a hookup.

bulabula

Good advice, but his sig says 2WD. I think I'd spend the cash on gauges before modifying it to 4x4. Even then I'd wait on buying the gauges only to drag race a stock truck.

On a serious note, would the system shift out of 4x4 easily when under power like that? I'm wondering if it wouldn't be just as good to keep it there for the run if you had to lift to shift out?

GeorgiaCracker

With electronic shift-on-the-fly, I just cut it back to 2 WD as soon as I am past the point when the wheels would break loose. I do not let off the gas to make the shift. I dont think it is a problem to do the whole run in 4 WD if you choose.

But, I am really just going by what works. It may not be good for the system.

ppsi

Cracker - what times are you getting? Any other mods or dyno runs. I am looking for some encouraging news.
I cannot locate a transfer case and front diff in just the few days I have left.

JKE

"I think I'd spend the cash on gauges before modifying it to 4x4."

Gordonville

1. Disconnect trailer
2. Put cover on coffee mug and tighten cup holder
3. Warn neighbor kids to get out of the street

John_P

I have run both my trucks in 4WD the full length of the quarter
mile and have also started in 4WD and then shifted into 2WD
once the tranny shifts into 3rd gear. With my trucks, the E.T.'s
are higher when I leave it in 4WD the full length of the strip so
I now shift out of 4WD to get a lower E.T. Other members
experiences may vary.

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John_P