questions about low 1st gear
 

My cousin runs a 67 mustang bracket car. He runs cal tracs in the back with a 28x10.5 bias slick. He has a mild 408w that will run 6.60's in the 1/8th mile. He would like the car to wheelstand higher than it does now, he was wondering if he went to a 2.75 1st gear would it help. Also if if made the switch how much 60 ft and ET can he expect to pick up.

Re: questions about low 1st gear
 

I would look at what he's got for front shocks and springs before going the lower first gear route. He may gain a few hundredths with the ratio change, or it may even slow down because of the wider ratio. There are a lot of other variables that can affect how the car leaves/wheelstands including starting line ratio, converter flash, starting line conditions, weather conditions, etc. Keep in mind that high wheel stands will certainly affect reaction times and consistency if he's trying to go rounds as well. My 02.

Re: questions about low 1st gear
 

Good friends's 3100 lb. '68 Mustang bracket car with 51 cubes less, C4 trans, 8" ATI converter, cal tracs and 30 x 10.5 radial slicks runs 6.60's in the heat, 60 foots high 1.30's/low 1.40s and his first gear is the stock 2.46. Launches like this off the footbrake, every pass...

http://i381.photobucket.com/albums/o...LeighETown.jpg

Re: questions about low 1st gear
 

any more details on his combo motor/converter/suspension etc?

Re: questions about low 1st gear
 

Old school, small solid cammed .030 351 Cleveland, maverick 6 cylinder coil springs, Calvert front shocks, Rancho rear shocks.

Launches at 4000, shifts at 7000

Re: questions about low 1st gear
 

what rear gear and how much stall does it have, what are the specs on the cam, is it a roller cam

Re: questions about low 1st gear
 

4.86 gear, converter flashes to 5400, Comp solid lifter cam, 246/256 @ .050, .589/.615.

Best numbers to date are 10.38 @ 127, 1.37 60 foot

Re: questions about low 1st gear
 

my cousin only runs a 4.33 gear shifts at 6500 and his converter is 5100. has roller spring perches in the front and also runs a maverick springs and the calvert shocks his wheel stand is only about 1/3 of that one. but he wants his to look like that one. the two combo seems pretty close to the same, except the gear do you think it would make that much of a difference.

Re: questions about low 1st gear
 

The more you race / the older you get, the less you'll care about wheelstands.
Besides , its all shocks springs and IC.

Re: questions about low 1st gear
 

c4 with 2.46 first gear / ptc 8'' conv flashed 6,600 off footbrake / 4.62 rear gear /289 A code short block with after market heads /intake and cam / 3000lbs on 275 drag radial with slapper bars..

http://i123.photobucket.com/albums/o...3sBKVVh_th.jpg

Re: questions about low 1st gear
 

4.33 vs. 4.86? Yes. BTW, this Mustang has roller spring perches too.

Re: questions about low 1st gear
 

so what can/should he do to try to get the car to wheelstand better?
rear gear/trans gear/converter ?

Re: questions about low 1st gear
 

need to know more about the current combo as it stands. Converter is critical as well and can't be compared by size and stall alone.

Re: questions about low 1st gear
 

408W 10.5:1 compression
AFR 185 heads
hydraulic flat tappet 240/246 541/544 106lsa
Victor jr intake Holley 950HP
1 3/4 headers
C4
8" ATI
4.33 gear
M/T 28x10.5 bias stiff sidewall
3100lb w driver

Re: questions about low 1st gear
 

Based on the info you provided, this engine is making less than 500HP. He probably is shifting a few hundred RPM too high and the converter is a few hundred too loose. More rear gear will help providing he can hook. A move to a 4.71 gear should be worth at least .02 in 60 foot but will have him turning upwards of 500 RPM more at the stripe which isn't a bad thing providing his valve train is up to the task.

Re: questions about low 1st gear
 

gear change to 4.71 will tighten the conv

Re: questions about low 1st gear
 

agreed, that's why it was suggested

Re: questions about low 1st gear
 

Proper shock settings, dynamic adjustable strut rods and min 5 inches front travel before you consider playing with gearing or god forbid some message board know it all's GUESS at your converter needs..............

Re: questions about low 1st gear
 

Everything he ^^^^ suggested, and free moving control arms. With the ball joint not connected to the spindle, raise the ball , then let go. Should drop. You can always slow it back down with the shocks and take travel back out with travel limiters on good starting lines. You should be fighting excessive wheel stands (they will cost you a couple hundredths) , not wheel spin.

Re: questions about low 1st gear
 

That Mustang is a good car, and runs real well. He has changed the rear gear since that pic and calmed it down some but it runs the same, if not faster.

A low gear helps some people and not others. Depends what kind of car engine, ect.
My brother has a Maverick with a .040 Boss 302. Bracket race car. He went from a 2.46 to a 2.91 in his C4. His car picked up around .08 and .04 in the 60'. Carries the front wheels almost to the 60' clock. When he leaves high on the converter. Made a big difference for him. Small engine, no tq what so ever. A lot of the NHRA class cars run a lower first gear. You will have to test and find out for your self to get your answer.
YMMV. Good luck

Re: questions about low 1st gear
 

Todd, just to clarify for the op, Leigh did not change the rear gear to calm the launch/kill the wheelie, he changed the rear gear ratio to reduce his trap RPM which increase by 200 when he made the switch to radial slicks 4 years ago, a gear ratio he had been running for nearly 30 years.

Re: questions about low 1st gear
 

Ed, I didn't / wasn't going to state the reason for the gear change. Just was relaying the results.

Re: questions about low 1st gear
 

couple of questions for todd & 1320racer about the mustang

- when he went to the 4.86 i take it he had a 5.13 in there before just curious how much difference that made in how the car left.

- you say he runs a 30x10.5 radial slick taht he went to 4 years ago, was curious what tire he ran before and how much ET did he pick up when he made the switch

- if my cousin keeps his 4.33 but goes to a 2.75 1st gear that would be the same as a 2.46 1st and a 4.86 rear. would that make a big difference, how would that affect the converter.

Re: questions about low 1st gear
 

The rear gear was changed early this season, so he hasn't run in the good fall air yet. At this point the wheelies are slightly less.

As to the tire, previously he ran 29 x 11 bias slicks. The radial slicks were worth less than a tenth, ~ .07.

Re: questions about low 1st gear
 

The 4.33 and 2.75 would give you a slr of 11.91...The 4.86 and 2.46 slr is 11.96

Re: questions about low 1st gear
 

1320racer you said your friends Mustang ran 6.60's in the 1/8th was just curious with those 4.86 and 30 radials what kind of RPM is it turning at the stripe in the 1/8th

Re: questions about low 1st gear
 

Is the car 50/50 or better?

Re: questions about low 1st gear
 

The 4L60E gives heavy cars like my ImpalaSS a great 60ft time.
Car uses the heavier Locking Converter works good for 1-2 Shift.
First Gear is 3.09

D

Re: questions about low 1st gear
 

Larry the car is 53/47

Re: questions about low 1st gear
 

A 3% swing will make a big change. That is a summer of a little here and a little there. It's real cheep and it works. You can always add weight to make it 50/50, but its more fun to watch the car improve with a little bit of work.

Re: questions about low 1st gear
 

How much does increasing starting line ratio effect wheel spin?
My 3,000lb Camaro had 29x10.5W Hoosiers and 4.50 rear gear with a turbo 350 with stock 2.52 st gear. Put a set of 29.5x10.5W MT and the 60' and et dropped off. looking at 5.13's as even with the 29 hoosiers it could use a little more RPM at the stripe. Car only runs 1/8th.