Advice on close or wide ratio T56

[triplecap]

63' Belair Wagon, 481" W motor, might be around 550HP/550TQ, 9" rear with 3.89's and about a 28" tall tire. Might see one auto cross event and one trip to the drags per year... mostly going to be for getting groceries and carting the kids around school/practice. The engine will be mostly done by 6000 rpm. Kinda leaning towards the wide ratio as the 1st gear will be fun, and I have enough torque to pull it in the other gears that I don't need to keep the R's way up. For those with a wide ratio - are you pretty happy with the ratio spread or do you find yourselves wishing it was a bit closer? And for those with the close ratio - are you constantly shifting? I don't want something that requires me shifting 3 times before I get to the end of an intersection.

Thanks in advance,
Eric

[Lonnies Performance]

I have a close ratio with a 27.5" tire & 4.10's.
First gear is pretty short, even shifting it at 6500.

Unless I was under powered or very heavy, I do not think I would like a wide ratio trans with more than a 3.73 gear.

[65 drop top]

99% will say get the close ratio

[BobinFL]

I agonized over this choice as well. My car is roughly 3600+ pounds with a 3.31 rear and 27" tall tires. With the close ratio T56 that gives me roughly the same gear multiplication is first gear as the original 2.20 Muncie and a 4.11 rear. I only have a SBC, so dont have the torque you have. The other consideration is the upper gears. My 5th is a perfect around town OD gear, with 6th only useful above 65 MPH, but again, a lot of that is due to the engine size and cam range. It is less than happy below ~1400 rpm when you roll on the throttle in 6th. I think with your extra gear and torque the close ratio will work great. You might find with your rear ratio the wide ratio first gear is too low, almost like a granny gear.

[mikedc]

I abandoned ideas of a Tremec 6spd because they don't make a wide ratio (for the lower 4 gears) with normal spacing.

The "close ratio" gives you all four gears spaced tightly.

The "wide ratio" gives you the first 3 gears spaced tightly, and then a wide gap from 3rd-to-4th.

If you don't want the first few gears to be spaced tightly . . . you're out of luck. No amount of messing with axle gears will fix that.


Tremec's 5spds don't have this problem at all. Both of their ratios (1st-to-4th) are spaced normally.

[triplecap]

I appreciate the input guys, thanks!

[Reckn8]

Just took out our close ratio and put in a wide ratio. Much better for regular street driving!

[anguilla1980]

I would say it depends where you live in relation to how many street lights/stops you have to deal with and if there are freeways or just highways.

[triplecap]

I'm in SoCal... while there are plenty of freeways it will mostly be stoplight to stoplight in suburbia. I want to do one Power Tour once with my pops but that won't dictate the gear ratios.

I would say it depends where you live in relation to how many street lights/stops you have to deal with and if there are freeways or just highways.

- - - Updated - - -

How much HP/TQ are you at, and what rear gear?

Just took out our close ratio and put in a wide ratio. Much better for regular street driving!

[TANKMASTERJ]

You just made my day that you removed a close and swapped for a wide. Since. I just dropped 4500 flee a wide
I got an LS7 650+ hp 55/+ torque and 4.11s. Haven't driven yet but someday....

[parsonsj]

The key to making the close-ratio work is to use a "normal" rear gear. 3.25 works very well, and gives great street manners along with enough "legs" to work on the track.

[Hotwire]

You can use this calculator to help decide which way to go. You can input gears, tire sizes, and trans gear ratios. At the bottom there's a cross section chart where you can see mph/gear/rpm. Helps to tell what you'd be cruising at going down the road. Also you can compare different gears/tires/trans gears, helped me to visualize my shift rpm changes when downshifting. You can print out your results and carry them with you, helps when you first switch the trans in.

https://www.blocklayer.com/rpm-gear.aspx

I'm a bit out of the loop on what's considered the close and wide ratios. I'm running a TUET2066 T56 out of a 05 GTO, 3.73s, and 25" tall tires.

1st 2nd 3rd 4th 5th 6th Rev
2.97:1 2.07:1 1.43:1 1.00:1 0.84:1 0.56:1 2.90:1

I'm having to shift into 4th in the 1/8 mile to get over 90mph, haven't had it to the 1/4. At some point I may go with a taller tire or 3.42 gear. As of now I can use all odd or even gears. Start out in 2nd, 4th, 6th, etc. It's an all around good setup for cruising, country roads, city driving, autocross, etc.

[Kenova]

I have the close ratio Magnum (2.66 1st gear) behind a torquey 400 SBC. The rear end is an 8.2 with 3.32 gears.
It pulls well from a stop but I think the 30lb. flywheel and torque from the engine have more to do with that than the trans ratio. Around town I'm usually restricted to the first three gears, occasionally slipping into 4th in the forty zones. On the highway I usually cruise in 6th at 60 mph @ 1600 rpm. Lower than 60 I need to drop down to 5th gear. The engine and I would both be happier with 3.73s, mostly because of where the revs and speed limits match up.
As for the gear ratio spacing I think it is perfect. With each shift the rpm drop is less with the revs landing higher in the engines torque/power curve when the load is increasing. The time between 3rd and 4th is a lot less than the time between 1st and 2nd. Ya gotta be on yer toes.:naughty:

Ken

[68Formula]

As far as trans ratios go, if you compare to autos they aren't that far apart. Honestly with the weight of the wagon, you'll be better off with the 1st gear of the wide ratio. Good drag launch and easier take off in street driving.

Secondly, with autocross, having gears close together means a lot of shifting. Depending on the track layout can cost time. Sounds like you have the torque to utilize the midrange rpm coming off corners and winding out to the next transition. With the wide ratio, you'll probably be only using the first 5 gears at the most around town, and only use the 6th for highway.