Trying to get the 3200-lb moving a bit quicker and to let the converter climb a little faster to see if it just "frees the combination up a bit".
Just wondering what gear you guys with small blocks in 3200+ lbs are running. Pretty basic 406" .640 lift cam, 1000 cfm alky carb, 1.80 low and 31" rear tire.
1.47-49 sec. 60' now but feels like it labors trying to get to shift point. RPM hangs right on 6100-6150 for about .9 then starts climbing.
Tried timing, smaller carb, the normal stuff. I just feel it would be even better if it geared deeper.??
Thanks.
Jok

Does not say what converter you have but it seems like it may be too low.

For Super Pro bracket racing I like a dip in the rpm graph. It's traction control, kinda like shifting to second gear after flash stall.

Three trips to Orlando, two working on fuel mixture, it's only just a matter of time now, for a break through.

1.69 low x 3.89 gear 28 x 10 tire 3475 lbs

I went from 4.86 to 5.13 in my car. I did it to get it to react faster off the footbrake.

My car weigh 3260, sbc 406, with a 29.5 inch tire. Sixty foot low 1.3s, high 1.2s.

I feel it helped my car in terms of consistancy, and picked up .01-.02 in the sixty foot.

What ET?

I'm running only a 4.33 gear, 30" tire. Otherwise similar combo. Converter flashes around 5,800 and holds about 1.5 sec. I started with a 4.56 and the 4.33 is only about .01 slower at 60' and the remainder of the run basically the same. I can get through the 1/4 at a tick under 7,200 with the 4.33. Really no options to run 1/4 anymore.

I know folks running ~5.3 gears with 30" tires. They do some nice wheelies which is very tempting, lol.

Something is wrong.

I've gone 1.35 60' with 4.56's and a 30" tire, 1.40-1.42 with a 'glide and 4.11's @ 5200 stall.
3250# 406

The converter is a BTE 8", We leave between 3500 and 4500, flash stays the same and the pull to shift is similar.
I guess another question is the heads an older set of Brodix-1 (I think?). Old enough there are no mounting holes on the front of the heads if that indicates age and design. Intake is Brodix and the runners seem to come up into the intake more than I see on Victors, etc.

What RPM are you shifting at and trapping at

Shift a 7000- goes through 1/8 at about 6600 when the throttle is kept down. Never been on 1/4 mile with the S10.

Swap to the 5.29

If it's methanol, it needs higher (highway) gear ratio Super Pro bracket racing.

To make your gear ratio the same as mine - effective gear ratio, it would be a 4.33, taking into account your taller 31" tire.

new tire (yours) / old tire (mine) x ratio (mine) =new ratio

Jok, I agree, go 5.29 if 1/8 mi. You want finish line rpm closer to max hp rpm.

It’s possible to loose a little stall rpm at launch switching to larger gear #. Don’t rule out a converter adjustment.

Late last year I went from 4.40 to 5.14 at 2840# and was 1.49 moved to 1.40 . I re-stalled from 6100 to 6450 starting line flash in very best late fall air, and ended up 6250 is very worst summer air this year. My car completes shift to high gear @ 7025 and finish line 7150 - 7250

Removing the 2 step rpm and using the TB it’ll stall @ 6600

quote:

Originally posted by markemark:
Jok, I agree, go 5.29 if 1/8 mi. You want finish line rpm closer to max hp rpm.

It’s possible to loose a little stall rpm at launch switching to larger gear #. Don’t rule out a converter adjustment.

Late last year I went from 4.40 to 5.14 at 2840# and was 1.49 moved to 1.40 . I re-stalled from 6100 to 6450 starting line flash in very best late fall air, and ended up 6250 is very worst summer air this year. My car completes shift to high gear @ 7025 and finish line 7150 - 7250

Removing the 2 step rpm and using the TB it’ll stall @ 6600

The only reason you're coming to those conclusions is because of the 1.49 low gear you're enjoying.

In low gear, your effective gear considering your tire diameter in comparison to mine, is the same.

Put a 1.80 low in it, your conclusions will change.

The way it is now, you're enjoying the best of both worlds.

Load (methanol) in low gear and after the shift and rpm at the stripe. Same effect as an inefficient converter (load).

This message has been edited. Last edited by: Mike Rietow,

Thanks guys. I will consider your inputs and talk to a couple converter companies to see what they have for ideas.
Have a great winter.

quote:

Originally posted by Toad1:
Thanks guys. I will consider your inputs and talk to a couple converter companies to see what they have for ideas.
Have a great winter.

Actually with a 1.49 low MarkeMark car has the same effective gear ratio as my car does in low gear, factoring in the tire and 1.49 low gear ratio. In high gear he'd need a 4.44 rear gear to have the same effective gearing in high gear, as my car. But he has a 5.14.

So he's got the best of both worlds, or in other words a inefficient converter in low like my car does, and an efficient converter in high gear, unlike mine with only a 3.89 rear gear, to his 5.14 gear.

So what that means for high gear is, if MarkeMark crosses 7150 @ 113mph his converter slip will be 13- 14% 5.14 efficient converter.

My car at the stripe 113mph 3.89 gear, the converter will be slipping 23% 6950 rpms inefficient converter.

3300lb with 1.80 and 32.5 tire i have a 5.67 gear. Leaving at 4200 shift at 7,000 and finish line at 7,300

quote:

Originally posted by C Hodge:
3300lb with 1.80 and 32.5 tire i have a 5.67 gear. Leaving at 4200 shift at 7,000 and finish line at 7,300

MPH?

109

quote:

Originally posted by C Hodge:
109

Converter slipping 12-13%. I have a PTC like that one. 8"