Bracket Talk
Reaction time-60’ issue

This topic can be found at:
https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/9367052186

June 17, 2018, 09:27 AM
green1
Reaction time-60’ issue
Any body ever have issue where when 60’ gets better the reaction time gets worse? Also if car spins bad I go red.
I have been fighting this issue with a new car since last year and thought I had it figured out as being tire pressure but wrong.
It is a four link- strut round tube chassis car.
June 17, 2018, 09:56 AM
Sugar Shane
Well....... Your first sentence makes sense, should be a suspension issue somewhere, but then the 2nd sentence doesnt really add up? If the initial hit is tire spin, then yes its going to create a lot longer rollout of the stage beam, so reaction time will be slow and 60 will be faster. When you go red, are you sure its spinning and not maybe hooking, possibly snatching the front end up and out of the beam? I dont know how a car can spin and pick up reaction time? In other words, you have to make the car either roll thru the beam every time or it has to snatch the tire up and out. Like most dragsters are going to roll thru the beam every single time.


"Sugar Shane"
June 17, 2018, 09:59 AM
banjo
How does your car leave the beams? Is it wheels up? Straight out? Up and out?


From what I have experienced, when I make my car react faster, sixty foot will slow, and when I slow it down, the sixtys will pick up.

It all has to do with how long the front tires stay in the beams. For example, If I tighten up the extension on the front shocks, the car will react faster because it will drive straight out. When I loosen them, the front end rising will delay the tires coming out of the beams, thus slowing down reaction time, and giving you more of a running start at the sixty foot.

My car will carry the wheels with the best of them, but I have found, the more I can keep the front wheels on the ground, the more consistent my reactions times tend to be.


Bill Simpkins
74 Nova
SBC 406
3240 pounds
Speierracing heads

60 1.27 (10/16)
1/8 6.03@111 (10/16)
Best 9.87@131 on the rev limitor 1 Feb 2013


nova

quarterpanelview

wheelie

FTI Converter
www.speierracingheads.com

June 17, 2018, 10:02 AM
banjo
If his reaction time is set up with alot of front end travel, it needs that hook to get the delay(front end travel). If it spins, it drives straight out and reacts faster. That is the only way it would make sense to me.

How red are you when this happens?


Bill Simpkins
74 Nova
SBC 406
3240 pounds
Speierracing heads

60 1.27 (10/16)
1/8 6.03@111 (10/16)
Best 9.87@131 on the rev limitor 1 Feb 2013


nova

quarterpanelview

wheelie

FTI Converter
www.speierracingheads.com

June 17, 2018, 12:20 PM
green1
Usually if I am sitting around .010 green and it spins it will pick up between .010-.015 reaction time. My theory right now is at night with cooler track it is working suspension more this slower reaction time.
It just squats and drives out, I don’t know if it even gets any air under the tires. I only got a few videos and not talented enough to post them.
When it spins I can feel the backend sliding around and 60’ fall off a lot.
June 18, 2018, 06:28 PM
Bad Nusz
Lol, in some cases like this, I don't suppose with enough 'pitch rotation' that one is actually tripping the 60' beam with the back tires? Big Grin
June 18, 2018, 08:25 PM
green1
Not with this car. As far as I have been told front tires never leave the ground.
June 18, 2018, 09:22 PM
Strange Magic
quote:
Any body ever have issue where when 60’ gets better the reaction time gets worse? Also if car spins bad I go red.
I have been fighting this issue with a new car since last year and thought I had it figured out as being tire pressure but wrong.
It is a four link- strut round tube chassis car.


Yes, the answer is, to put a wider tire on and wider rim if need be.


strangemagicperformance.com
oldsperformanceproducts.com




WD dealer for just about all your performance needs.
June 19, 2018, 04:11 AM
green1
It has 33-16-15 on 15” rims right now.
June 19, 2018, 01:04 PM
green1
The car is only running high 5.30s to low 5.40s so not a real fast car.
June 19, 2018, 08:18 PM
Strange Magic
How many passes are on those tires?


strangemagicperformance.com
oldsperformanceproducts.com




WD dealer for just about all your performance needs.
June 20, 2018, 04:11 AM
green1
Not exactly sure but this has been an issue since I got the car out last year when everything was new. I was about ready to park it last year when I thought I had it figured out but turns out I was wrong. If I had to guess I would say 75 passes.
June 20, 2018, 08:00 AM
TomR
Going red when it spins makes sense. The suspension doesn't react and the tires don't have time to wad up then move the car forward.


72 Nova "Hooptie"