Gear ratios for drag cars

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64merc
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Gear ratios for drag cars

Post by 64merc »

I have a 64 comet with a 514 in it right now but I'm going to a 545 this winter, I'm already in the process actually. Everyone is telling me to go with a power glide because it'll soften the hit and be quicker. If the only advantage to using a power glide is to help on the initial hit, why not just use a 2.73 gear keep my c4. Going to a high rear gear and using first and second at the track would be about the same as the 'glide as far as gear ratios go, I'm sure it's been tried before. I may be out in left field, what do you guys think?

popscomet
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Re: Gear ratios for drag cars

Post by popscomet »

THIS is where I'd enlist the advice of ROY !! HE has seen this set up before,I'm sure..and I'd take his advice and tuck it under my arm and run with it...thats JMO :D pop
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64merc
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Re: Gear ratios for drag cars

Post by 64merc »

Thanks pop, I'll sure do it. I just have a lot of money tied up in the c4 and would just hate having to spend more on a new trans.

pro64
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Re: Gear ratios for drag cars

Post by pro64 »

hey steve if your going with the power glide your going to have set ur cam to ur torque converter and also the flow on the cylinder heads. its always been my understanding that the powerglide setup worked better in an allout screaming type uv application. personally id rather run the number with the c4.... talk to lem about ur application tire size gears hp and torque all a factor

64merc
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Re: Gear ratios for drag cars

Post by 64merc »

Yea I'd rather use my c4 and keep drand x parts off my car, but I guess I'm just wondering if its feisable to try. I'm sure if it worked well a lot of folks would be doing it though. Probably just another one of my ideas that won't work lol. I hope to have all the head specs back soon so I can hash out all the details with lem.

popscomet
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Re: Gear ratios for drag cars

Post by popscomet »

MAN just the thought of a brand X part on that comet,makes me dizzy and I'm afraid I'll fart stumble and fall,,,later pop :lol:
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Boss/Cyclone
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Re: Gear ratios for drag cars

Post by Boss/Cyclone »

Both the C4 and powerslide have a 1 to 1 high gear so I will not change the rear end gear you need in my opinion. I always tried to pick a gear that had me at just under the engines red line in 4th gear as I crossed the finish line. I am sure others have another theory but that has worked for me.
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64merc
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Re: Gear ratios for drag cars

Post by 64merc »

Grab a cold drink and relax pop, it ain't gonna happen lol! This is more of a bench racing session, but I don't know why it wouldn't work.

CALIFORNIA CALIENTE
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Re: Gear ratios for drag cars

Post by CALIFORNIA CALIENTE »

64merc;I would say stay with the C-4 you already have! A powerglide is OK if you build your engine combination,and set the car up to handle just two gears! Depending on what RPMs the new combo will make the best HP and Torque,you may need to change rear gears in order to keep the engine in its sweet spot! I would make some test hits just the way you have it setup now,see how it works!Pop can relax as I don't think there are any GM parts left in a race glide!!Of course I would go to a 5 speed Lenco or 5 speed Liberty stick,but that is just me!!! JMO , ROY.
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popscomet
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Re: Gear ratios for drag cars

Post by popscomet »

64merc wrote:Grab a cold drink and relax pop, it ain't gonna happen lol! This is more of a bench racing session, but I don't know why it wouldn't work.
YOU DA MAN,,,,(ain't forgot the 240 6 deal)later ole POP
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64merc
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Re: Gear ratios for drag cars

Post by 64merc »

Boss/Cyclone wrote:Both the C4 and powerslide have a 1 to 1 high gear so I will not change the rear end gear you need in my opinion. I always tried to pick a gear that had me at just under the engines red line in 4th gear as I crossed the finish line. I am sure others have another theory but that has worked for me.

power glide

low gear
1.8 x 4.11 = 7.398

high gear
1.0 x 4.11 = 4.11

c4
low gear
2.46 x 3.00 = 7.38
second gear
1.46 x 3.00 = 4.38

Only using 1st and 2nd at the track with the c4 would be real close to the 'glide ratios.

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Boss/Cyclone
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Re: Gear ratios for drag cars

Post by Boss/Cyclone »

64merc wrote:
Boss/Cyclone wrote:Both the C4 and powerslide have a 1 to 1 high gear so I will not change the rear end gear you need in my opinion. I always tried to pick a gear that had me at just under the engines red line in 4th gear as I crossed the finish line. I am sure others have another theory but that has worked for me.

power glide

low gear
1.8 x 4.11 = 7.398

high gear
1.0 x 4.11 = 4.11

c4
low gear
2.46 x 3.00 = 7.38
second gear
1.46 x 3.00 = 4.38

Only using 1st and 2nd at the track with the c4 would be real close to the 'glide ratios.

I have never heard of anyone running just first two gears on a C4 while drag racing. Don't think that would work but I've never drag raced a slush box. I think Roy ran an auto for a season, he should know.
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64merc
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Re: Gear ratios for drag cars

Post by 64merc »

popscomet wrote:
64merc wrote:Grab a cold drink and relax pop, it ain't gonna happen lol! This is more of a bench racing session, but I don't know why it wouldn't work.
YOU DA MAN,,,,(ain't forgot the 240 6 deal)later ole POP
Yea pops when ever your ready for the 240 we'll go get it.

Rarerat
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Re: Gear ratios for drag cars

Post by Rarerat »

I ran a Super Pro 63 Nova back in the 80's with a glide in it and the car slowed down from the 4 speed but parts lived much longer. :mrgreen: IMHO with a 1.76 first gear you will need a 5500 rpm converter & brake to make them work or it will be a slug out of the hole. The benefit to the glide is it is light, doesn't take much HP to turn it and of course with only 1 shift it's hard to really make a mistake. California Caliente is right, by the time you build a good glide there will be nothing left that is stock Chevrolet.


https://www.youtube.com/watch?v=ZsbpTmak-EM
Last edited by Rarerat on Thu Nov 21, 2013 6:38 pm, edited 1 time in total.

pro64
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Re: Gear ratios for drag cars

Post by pro64 »

kind uv makes sense to use just two the track is only 1000 ft. my guess with that 545 ur going to be motoring pass the competition anyway. you get that thing pumping some serious cfm s your going to need a chute . get the gears to match the tires for your hp and torque and look out. 8)

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