60ft Consistency

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BracketNova
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60ft Consistency

#1 Post by BracketNova » Sun Oct 24, 2010 12:38 am

Having some issues getting my car to 60 consistently. I know this is a vast question, but I would appreciate some direction. Maybe it's my car? Maybe it's me? I can never get my 60s to be close lane to lane. That's my biggest problem, but the 60ft time does vary within the lane more than I like.

Car has Calvert Split Monos and Caltracs set in bottom hole preload to just touching with driver in car. I have super awesome summit racing 3way shocks that I have no idea what setting they are on, and the same up front set to 90/10. Car uses a 28 X 10.5 MT slick. Trans brake, leave at 5K. 4.88 gears I was running air at 13, this weekend I went down to 11.5. My 60s seemed lower and the air was about 400ft worse then my last time out, but I did play with the carb a bit before heading to the track (turned idle screws out, leaned the jets out a bit).

The thing that gets me is that the rear of my car is stiff when I push down...granted this is a leaf spring car, I really haven't ever tried to pull up on the back end of it. If I remember right I set the shocks to 50/50 :scratch:


Like I say, I'm not looking for the answer...but maybe guidlines for what people check/typical setup. My current thought is maybe the tires are unloading right after the hit? The front pops up real quick then falls right back down.


Run | #1 | #2 | #3 | +/-
Lane | R | L | L | --
60 FT | 1.5558 | 1.5701 | 1.5654 | .0143
60/330 split | 3.0752 | 3.0786 | 3.0731 | .0055
330/660 split | 2.6224 | 2.6248 | 2.6247 | .0024
et | 7.2534 | 7.2735 | 7.2632 | .0201
mph | 93.23 | 93.26 | 93.26 | .03
air alt. | 2250 | 2319 | 2247 | 72
egt | 1318 | 1305 | 1309 | 9



and lastly....
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
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'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

mytmouz
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Re: 60ft Consistency

#2 Post by mytmouz » Sun Oct 24, 2010 9:33 am

What size/compound/manufacturer of rear tires?
Trucks are for haulin...

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spib
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Re: 60ft Consistency

#3 Post by spib » Sun Oct 24, 2010 11:24 am

I heard you should always check your air pressure right before run, do same burnout all the time
and if 60ft goes away and times are all over place slicks are worn out
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Re: 60ft Consistency

#4 Post by BracketNova » Sun Oct 24, 2010 2:48 pm

mytmouz wrote:What size/compound/manufacturer of rear tires?
Car uses a 28 X 10.5 MT slick.
compound is M5, 12" rim

spib wrote:I heard you should always check your air pressure right before run, ...
Yes this is true. I always add a shot of air to each before I head to the lanes just to be sure I can get the pressure back to exactly where I want it just before I pull up. You need to check right before due to the sun. Let's say the sun is on the right side of your car in the pit and the left side in the lanes. This will cause the pressure to drop in the right one as it cools and raise in the left as it warms up.

spib wrote:... do same burnout all the time
and if 60ft goes away and times are all over place slicks are worn out
I try as much as much as possible to do the same burnout. Yesterday I was having a problem in the left lane. The car was moving sideways during the burnout so my burnout wasn't quite as long. But, this (different 60s) is a problem I've been chasing for a few years. I used to have old 12" slicks on the car so I chocked it up to them being worn out. I got them used. Now my 10.5 MTs have maybe 150 passes on them, and I'm still fighting this problem.

Another gent, on another board, said not to worry about it. Said there clocks for the 60 was probably out of sync. This seems logical to me. But, other racers at my track do not complain about this. They also don't seem to have the problem I have either. I would also think if this was the case my ETs would be closer?


I'm assuming there is room for improvement in my 60s?
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
http://www.findmoneyraces.com


'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

bert
Posts: 41
Joined: Sun Feb 22, 2009 2:10 pm
Location: Sacramento CA

Re: 60ft Consistency

#5 Post by bert » Sun Oct 24, 2010 4:19 pm

150 passes on that size tire is done even if they have tread left it doesn't matter the side walls are shot out for sure. Put new shoes on her and see a real improvement. If your car goes side ways in the burnout check and make sure you got enough wheel speed, if you got a 3 step bump it up another 200 rpm on the burnout and that should work.
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BracketNova
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Re: 60ft Consistency

#6 Post by BracketNova » Sun Oct 24, 2010 5:45 pm

bert wrote:150 passes on that size tire is done...
I gotta replace my slicks every year! :shock: Now that you mention it, the sidewalls on the MTs were alot flimsier than the Goodyears I took off it.

Maybe I should go wth the stiff sidewall version next time. Car is 3200Lbs w/ me in it.
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
http://www.findmoneyraces.com


'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

bert
Posts: 41
Joined: Sun Feb 22, 2009 2:10 pm
Location: Sacramento CA

Re: 60ft Consistency

#7 Post by bert » Sun Oct 24, 2010 8:14 pm

For instance this is my situation, my car and me race weight is 3200 lbs, I run hoosier 30x9 slick with the D5 compound, I leave off the trans break at 4800, power glide 1.76 first gear, 4.57 rear gear, I like to change my shoes at about 50 passes. Otherwise the 60 ft starts to vary more than a hundreth either way more than I like. My car runs 10.0x and an occasional 9.9x. And leaves pretty hard. I think the harder your stuff leaves on a small tire like we are using the. the lower the pass count you will see before th side walls give up. I don't know a lot about big tire deals but I've taken off a lot of smaller tire slicks with plenty of tread. But the side walls are just done. - hope this helps try some new shoes on her and you will see a good result.
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BracketNova
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Re: 60ft Consistency

#8 Post by BracketNova » Sun Oct 24, 2010 8:37 pm

Sounds like our cars are a lot alike, except yours is faster :?

Do you run a stiff sidewall?
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
http://www.findmoneyraces.com


'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

bert
Posts: 41
Joined: Sun Feb 22, 2009 2:10 pm
Location: Sacramento CA

Re: 60ft Consistency

#9 Post by bert » Sun Oct 24, 2010 8:58 pm

I have not tried the stiff wall tires, I have heard that they are good on heavy cars. I would give the tire manufacturers a call and see where the weight break is that those work best fir if you are thinking of trying those on your car...
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BracketNova
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Re: 60ft Consistency

#10 Post by BracketNova » Mon Oct 25, 2010 12:03 am

I think I read it was 3000 lbs. for the MTs.
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
http://www.findmoneyraces.com


'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

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