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View Full Version : Close ratio VS Wide ratio?


DOOM
10-26-2012, 07:08 AM
Just ordered my T56 from American Powertrain . I had a choice between close ratio or wide ratio . My limited knowledge on this told me to get the close ratio did I do the right thing???

Vegas69
10-26-2012, 07:30 AM
I've never heard it called that but make sure you get the 2.66 first gear. With a 572, that gear is really to deep. I had a 2.87 in my car and always wanted a much higher 1st gear ratio with my 3.73. I completely understand why Mark uses a 3.25 rear gear and a 2.66 first gear.

DOOM
10-26-2012, 07:34 AM
I'm on it Todd! Am I calling it the wrong thing??? My rear is a 3.83 keep it the same?

DOOM
10-26-2012, 07:43 AM
My mistake its a 3.50 ..

Sieg
10-26-2012, 07:48 AM
Close ratio is the right ratio Mario! My under-powered gen 1 SBC with a 3.42 and T56 Mag close ratio is great. No problem with the taller 1st gear and it feels gap-less through the gears, 5-6 is the most noticeable and it's not bad. 1st gear is actually useable. I had a wide ratio in a '93 1LE Camaro and the low first gear typically created a situation of get it rolling and into 2nd asap to get business done.

I think you'll be very pleased. :thumbsup:

DOOM
10-26-2012, 07:57 AM
Close ratio is the right ratio Mario! My under-powered gen 1 SBC with a 3.42 and T56 Mag close ratio is great. No problem with the taller 1st gear and it feels gap-less through the gears, 5-6 is the most noticeable and it's not bad. 1st gear is actually useable. I had a wide ratio in a '93 1LE Camaro and the low first gear typically created a situation of get it rolling and into 2nd asap to get business done.

I think you'll be very pleased. :thumbsup:

Thanx Sieg!!! I'm new to this stuff and have a lot to learn !!

Sieg
10-26-2012, 09:20 AM
Thanx Sieg!!! I'm new to this stuff and have a lot to learn !!

You're welcome Mario.

Your 3.50 gearing should make for a very good combination. After having some time with my 3.42's I'd like a little lower gear for my little motor but 3.73's would raise the optimal cruise rpm's in 5th and 6th. I can't tell you how much I enjoy the car now, after 20+ years that T56 trans makes me want to drive it all the time. It's so good I could care less about the price and time invested in the project, the rewards are easily worth double.

I hope you enjoy it as much as I do. :thumbsup:

Flash68
10-26-2012, 10:53 AM
I'm on it Todd! Am I calling it the wrong thing??? My rear is a 3.83 keep it the same?

Close ratio vs wide ratio is the correct terminology. It's been around for 50 years. Todd's just had his head in the sand with that junk TKO. :lol:

The main reason I've seen people go with the wide ratio (2.97 1st) is for the .5 overdrive 6th gear. But those people are usually more cruising and touring oriented than performance. And with any kind of decent power level you'd likely be better off with the close ratio.

I had a TKO with a 3.70 rear gear before and it sucked.

Flash68
10-26-2012, 10:54 AM
I completely understand why Mark uses a 3.25 rear gear and a 2.66 first gear.

Um yeah... cuz he has 200+ more ft lbs than everyone else? :rofl:

FETorino
10-26-2012, 08:40 PM
Just ordered my T56 from American Powertrain . I had a choice between close ratio or wide ratio . My limited knowledge on this told me to get the close ratio did I do the right thing???

Yes you did. The WR has too low a first and too high a 6th. :thumbsup:

:cheers:

randy
10-26-2012, 09:12 PM
now on a ls2 gto swap into a car using 4.10 gears the close ratio would be the way to go also correct?

FETorino
10-26-2012, 10:22 PM
now on a ls2 gto swap into a car using 4.10 gears the close ratio would be the way to go also correct?

So chances are you are only running a 26" tire. Combine that with the low 2.97 first gear of a wide ratio and a 4.10 rear gear and your start line ratio would be way low and .50 final drive will make those 4.10s well 2.05. So you will have a first gear good for pulling trailers and a top gear for Boneville.:rolleyes: Does that sound like what you want? :mad:

JMO close ratio is the only sensible T56. :thumbsup:

A guy on another site made this spreadsheet to play around with ratios and their effect. Pretty cool, but I think some of the transmission ratios are wrong.

https://docs.google.com/spreadsheet/ccc?key=0AqPlAHiKgTwmdDhfU0NwV3BSSU95c3ZLc2VSSExzU 2c#gid=0

DOOM
10-27-2012, 06:20 AM
[QUOTE=Flash68;443219]Close ratio vs wide ratio is the correct terminology. It's been around for 50 years. Todd's just had his head in the sand with that junk TKO. :lol:

Man you guys are brutal!!!:DThanx again guys It's just getting old buying stuff twice!

randy
10-27-2012, 02:11 PM
So chances are you are only running a 26" tire. Combine that with the low 2.97 first gear of a wide ratio and a 4.10 rear gear and your start line ratio would be way low and .50 final drive will make those 4.10s well 2.05. So you will have a first gear good for pulling trailers and a top gear for Boneville.:rolleyes: Does that sound like what you want? :mad:

JMO close ratio is the only sensible T56. :thumbsup:

A guy on another site made this spreadsheet to play around with ratios and their effect. Pretty cool, but I think some of the transmission ratios are wrong.

https://docs.google.com/spreadsheet/ccc?key=0AqPlAHiKgTwmdDhfU0NwV3BSSU95c3ZLc2VSSExzU 2c#gid=0
lol wow that sums it up. i guess close ratio it is

intocarss
10-28-2012, 07:20 AM
Close ratio vs wide ratio is the correct terminology. It's been around for 50 years. That's the way I remember it

blazer1970
11-25-2012, 05:26 PM
I'm running the 2.66 1st gear in my T56 Magnum with a 4.10 gear and 28" tire.
Works great at the strip and on the highway. Just my .02:thumbsup:

gnx7
11-30-2012, 08:44 AM
The 2.66 1st gear version is what 99% of people are buying. You don't need a deeper 1st gear gear or you will simply blow the tires off and the nice thing is that 5th gear is .80 which is a closer ratio if you were to do some top speed accelleration "runs." ;)

While the .50 overdrive is nice in the other unit.... i doubt any of us are building these for commuting and the end all be all in fuel economy.

I have the 2.66 1st gear version and 3.25 gears out back. Hoping for 750rwhp/750rwtq+ on e85. Holley EFI just announced their partnership with Davis Technologies (www.moretraction.com) for a traction control module. I won't be having traction issues when trying to ramp up the boost thru the gears. It is rather affordable too. ($599 base model or $999 for a self learning fully tuneable unit) Uses a driveshaft sensor to operate.

Vegas69
11-30-2012, 08:51 AM
I prefer my right foot.

DOOM
11-30-2012, 10:49 AM
2.66 Is a done deal thanx to Todds expertise!!:unibrow: I got it all beefed up with all the goodies to handle a ''LITTLE'' more HP . Now all I have to do is get it American Powertrain has no Tremec cases ???? 6 weeks now..:rolleyes: Just called yesterday still nada!!!:mad:

Flash68
11-30-2012, 10:56 AM
2.66 Is a done deal thanx to Todds expertise!!:unibrow:

Expertise? Based on what... his TKO experience? :rofl:

JMitch19
11-30-2012, 09:41 PM
2.66 Is a done deal thanx to Todds expertise!!:unibrow: I got it all beefed up with all the goodies to handle a ''LITTLE'' more HP . Now all I have to do is get it American Powertrain has no Tremec cases ???? 6 weeks now..:rolleyes: Just called yesterday still nada!!!:mad:

I bought my close ratio magnum from D&D Driveline in Wixom, MI. I went to the Formula 43 open house back in October. D&D and Formula 43 are only about 20 miles a why from each other. I figured I could kill two birds with one stone since they are about 150 miles from me. I called D&D two days before heading to the open house and they had them on the shelf. They were great to deal with. If American Powertrain doesn't deliver give D&D a call. They told me Stielow's T56 is a stock off the shelf close ratio Magnum. I figure if his is holding up to 8xxhp I should be good.

DOOM
12-03-2012, 03:43 PM
I bought my close ratio magnum from D&D Driveline in Wixom, MI. I went to the Formula 43 open house back in October. D&D and Formula 43 are only about 20 miles a why from each other. I figured I could kill two birds with one stone since they are about 150 miles from me. I called D&D two days before heading to the open house and they had them on the shelf. They were great to deal with. If American Powertrain doesn't deliver give D&D a call. They told me Stielow's T56 is a stock off the shelf close ratio Magnum. I figure if his is holding up to 8xxhp I should be good.

Thanx Jason I'm only going to let this go on a couple of more weeks before it gets nasty... Then will be calling D&D

BHG
12-07-2012, 12:07 PM
Hey guys,
Any further insight on close or wide ratio 5 speed for a big block with 3.89's? Running 335/30/18 rear boots. Wide ratio seems to be the best choice.

Any one running a combo similar to this?

thanks,

DOOM
12-07-2012, 03:50 PM
BHG you should start a new thread so more guys can read what your asking.:cheers:

Flash68
12-08-2012, 12:07 PM
Hey guys,
Any further insight on close or wide ratio 5 speed for a big block with 3.89's? Running 335/30/18 rear boots. Wide ratio seems to be the best choice.

Any one running a combo similar to this?

thanks,

Which trans are you referring to? The TKO 600? If not, what are the gear ratios?

BHG
12-11-2012, 08:50 AM
Thanks Doom & Flash68.
I am looking at Keislers new SS700. I think I've got it cased. Crunched some numbers regarding rpm and speed.
The gear ratios are as follows:
close ratio: 2.66, 1.78, 1.30, 1.0, choice of .68 or .84
wide ratio : 2.97, 2.07, 1.43, 1.0, choice of .68 or .84

Think I was wrong about the wide ratio, will now be going with the close ratio with the .68 for fifth gear. Better to bang around town, and still have a highway gear.

JMitch19
12-11-2012, 09:46 AM
I'd do a search on keisler before you decide to spend your money with them.

BHG
12-11-2012, 11:23 AM
Ok, I appreciate the heads up man. I'm not set on Keisler by any means. What company would you recommend for a similar tranny & driveshaft?

Sorry this thread has kinda gone sideways.