Can't Decide: 4.10, 4.30 or 4.56 Gears

[67Satty]

I need to replace my 3.91s because they are howlers and want to change the ratio while I am at it.

What I am looking to do is knock off a tenth or two from my ET in the 1/8 mile without driving myself crazy on the 30 mile freeway drive to the track.

Driving it to the track is pretty much the only time it is on the freeway. Other than that, I cruise around town where the speed limits are anywhere from 25-55 mph.

My current best 60 foot is 1.70 and current best ET is 7.86 in the 1/8. Combo is in my signature.

4.30s are kind of an oddball, hard to find ratio these days, that's why I'm considering going up to a 4.56. I don't know if 4.10s will be that different than a 3.91.

Right now it has 27" tall D.O.T. slicks, when these wear out I'll probably go to 28" or 29" tall non-D.O.T. slicks to increase my footprint a little.

The way things are going in SoCal, I don't think this car will ever go down a 1/4 mile track.

Here's a gear ratio chart I found:

http://www.alloyusa.com/gear-ratio-calculator

Thanks for any opinions to get my off the fence and order something!

 

[WileERobby]

I agree, 4.10 won't be that much difference. You can do the 4.56's & play with tire diameters to dial in your RPM's thru the traps.

 

[Roadbird]

X2 go for the big gears and enjoy, I would!

 

[Budnicks]

yeah 4.56:1 & the 29" tire would be a great idea

& biggest change/noticeable difference

 

[67Satty]

I found these Richmond 4.57s for a good price in a 10 spline pinion so it would save me from having to spend money on a different yoke.

http://www.summitracing.com/parts/rmg-6900611

But I've been seeing stuff online about Richmonds being loud and having a whine to them. Anyone hear have first hand experience with them? Are they to by avoided, I can deal with a little noise.

 

[SUPERSTOCKRACER]

4.56 is too much gear with that size tire. Motive makes a 4.30 and that would be plenty for your combo. 4.10 will feel better than your 3.91. i made the switch and it helped alot
so i would try and find 4.30 gears IMO.

 

[67 B-body]

4.56 is too much gear with that size tire. Motive makes a 4.30 and that would be plenty for your combo. 4.10 will feel better than your 3.91. i made the switch and it helped alot
so i would try and find 4.30 gears IMO.

X-2!
4.56:1 is STEEP!!!!
4.10 you'll still notice a difference, 4.30 will be a BIG difference.... I have used 3.91's, 4.10's and 4.30's in my 69RR......
I have 4.10 in my 67 Satellite....... I could use a Tiny bit more..... I think 4.30's would peak me out in the 1/4 mile. I have been itching to give another set a try, .... I rev to 7,000 rpm though.

 

[MikeyT]

I think 4.56 and tall tire would work, but just cause I am an odd ball.... Tell me about the rest of the combo? Auto/ or stick? Suspension mods..

Mikey

 

[383man]

I can tell you I run 4.30's with a 30 x 9 tire. I cruise the highway at 60 mph turning about 3200 rpm. I would not go with the 4.30 with the 27" tires. If you can go with atleast a 29 tire it would not be real bad. I drive 45 miles one way to the track with my 63 and I enjoy the drive almost as much as racing it. Its nice when I am done racing and watching everyone crawling under their trailers tying their cars down all I have to do is put more air back in the rear tires and then drive on home. I bought my 4.30's from Jegs anout 6 to 7 years ago and they are Richmond gears. I set them up myself and they are not noisey at all. It may have a tiny noise but if it does the exh is louder because I dont hear any noise from my rear. If you stay with the 27 tire I would not want to go over 4.10's like that. Good luck whatever you decide. Ron

 

[HT413]

4.56's with the 27" tire gives you 55mph at a hair more than 3100 rpm. 29" tires knocks it down like 200rpm. I'd say it's doable if you dont mind doing 55 to the track and back - small price to pay I say.

 

[67Satty]

I think 4.56 and tall tire would work, but just cause I am an odd ball.... Tell me about the rest of the combo? Auto/ or stick? Suspension mods..

Mikey

Trans: 727 with 9.5 Dynamic 4200 stall, Transgo TF-2 shift kit
Rear suspension: 3400 # SS Springs with adjustable snubber, Monroematic Dodge pickup shocks (long enough), pinion angle set 4 degrees down
Front suspension: 90/10 Calvert shocks, 318 w/AC torsion bars
3600 pounds without driver as weighed at landfill scale (I weighed myself on it and it was accurate).

Future plans (very near future):

Weiand Tunnel Ram with 2 1850 Holleys (just need to buy linkage, fuel line, etc...)
28" or 29" slick for increased footprint

*1/8 mile ONLY* - currently shifting into third right at the stripe with 27" tires and 3.91s.

I don't mind cruising in the slow lane at 60 mph for an hour on the way to track.

 

[MikeyT]

I bet you pick up 2 tenths on the short end, going to a manual valve body in the tranny over the transgo tf-2. I guess I would go with 4.10's and a 28 inch tire... Just my opinion.

Mike

 

[cryplydog]

satty,i like taller tires and higher gears. you didn't say what rpm you wanted to cut through the traps at. I like 3 to 4hundred rpm past red line in high gear. good luck

 

[WileERobby]

4.56 is too much gear with that size tire. Motive makes a 4.30 and that would be plenty for your combo. 4.10 will feel better than your 3.91. i made the switch and it helped alot
so i would try and find 4.30 gears IMO.

Are you running 1/4 ? I would agree if he was,but he wants to knock off a tenth or two in an 1/8. I don't know if a 4.10 would do. Just a thought.

 

[67Satty]

1/8 Mile ONLY for this thing right now.

MikeyT, so you are saying a manual valve body could be good for another couple tenths off compared to my Transgo TF-2 - even if I'm shifting manually? I've been wondering about if a manual valve body has an ET advantage all other things being equal.

If so, I'll switch to one when I put the T-Ram on to keep things simpler.

 

[MikeyT]

67satty,

I have tried both transgo tf-2 kit and a MVB and felt my manual valve body shifted quicker and more precise and I was able to gain about .15 on the short side which translated to .3 on that top end(1/4 mile of course). I will hunt up the time slips if you want even more precise info... However it sounds like you hit the stripe going into third, in this case, on top of valve body, if you are set on changing gears too. I would go. 4.30 with a 30" tire

Mike

Mike

 

[383man]

Forgot to say that with my 4.30's and 30" tire I also use a Dynamic 9.5 converter that flashes about 4200 at the track. And I really like how that converter drives and works at the track. Ron

 

[Budnicks]

Trans: 727 with 9.5 Dynamic 4200 stall, Transgo TF-2 shift kit
Rear suspension: 3400 # SS Springs with adjustable snubber, Monroematic Dodge pickup shocks (long enough), pinion angle set 4 degrees down
Front suspension: 90/10 Calvert shocks, 318 w/AC torsion bars
3600 pounds without driver as weighed at landfill scale (I weighed myself on it and it was accurate).

Future plans (very near future):

Weiand Tunnel Ram with 2 1850 Holleys (just need to buy linkage, fuel line, etc...)
28" or 29" slick for increased footprint

*1/8 mile ONLY* - currently shifting into third right at the stripe with 27" tires and 3.91s.
I don't mind cruising in the slow lane at 60 mph for an hour on the way to track.

Hence my suggestion for the 4.56:1 gear & 29" tire suggestion... A 4.30:1 gear & 29" tire will only be a less than only 50rpm {3216 vs 3163rpm} differences than what you have now, not a very big change at all, hardly worth it @ 65mph, compared to 3434rpm with 4.56:1 & your base now should be around 3163rpm w/3.91:1 gears & 27" tires now @ 65mph, that's only 371rpm higher difference @ 65mph, similar to a 27" tire & 4.30:1 in RPM, to the 4.56:1 & bigger tire footprint... If you get what I'm saying... IMHFO it would help your 60ft times & get you into 3rd gear faster for more MPH in the 1/8 mile, IMHFO you have plenty of converter 9.5"/4200rpm to run a steep gear like that, especially with a taller 29" tire, it's a kind of heavier car @ 3400# it will help to move the car out of the beams much easier too.... It's not like you have some $30k 600ci engine combo with "gobs or torque" or 1000hp & 450cfm flowing aluminum heads, ladder-bars/4 Link & coil overs, trailering it everywhere or much lighter car, were you can run a higher 3.91:1-4.10:1 gear ratio to take advantage of the gobs of Torque & not hurt your ET, anywhere near as much... Also it would probably work better with the tunnel ram set up also, especially with the steeper gears, it would get you into the power band/RPM range of that induction combo, much quicker... As you probably well know, the 1st 330ft is everything in the 1/8th mile... Opinions will vary vastly, I'm sure... Good luck either way, no matter what gear & tire you choose... There's a pretty good book worth getting for a base line set up or just to read Mopar Performance book ,"Chassis" 9th edition #P5007160, it has some proven combos, from some great racers & Chrysler Engineers, with similar type set ups, kind of old school stuff, "some what outdated" & not really for the full on race car set-up, with a 12 pt cages, 15x33's & Lencos etc., but some great proven & basic easy combos... But there are some more race specific combos too... Good reference book for especially a lower cost, minimalist operation.... You don't need to reinvent the wheel, it's already been done & proven, by guys like Tom Hoover.... Have fun

 

[67Satty]

I like a lot of what you are saying Budnicks, especially about the first 330 feet being everything in the 1/8 mile. Also, doing as many torque multiplication tricks as I can to get this heavy 3600-pound car moving in the first 60 feet. I almost feel like I need to exhaust all these tricks first before worrying about more HP and better flowing heads.

I've got the MP Chassis book and thanks for the remainder to look up some of the proven old-school combos.

 

[Budnicks]

I like a lot of what you are saying Budnicks, especially about the first 330 feet being everything in the 1/8 mile. Also, doing as many torque multiplication tricks as I can to get this heavy 3600-pound car moving in the first 60 feet. I almost feel like I need to exhaust all these tricks first before worrying about more HP and better flowing heads.

I've got the MP Chassis book and thanks for the remainder to look up some of the proven old-school combos.

Anytime, I hope some of it might actually help too...LOL...