Keisler 5 speed - which OD gear to buy?

[Culprit]

I'm looking for input from the folks who have made the Keisler 5 speed swap.

I'm buying my Vette a Keisler 5 speed for Christmas (shhh, don't tell - it's a secret).

But which gear ratio should I go with? Current engine is the L-82 (220hp) and I'm planning/saving for a ZZ-4 (350ish hp) in a couple of years so any of their hp ratings will more than suffice - that isn't a factor. Rear diff is 3.70. Right now their available options are:

-----------------------1st------5th
TKO-500 (550hp)------3.27-----.68
TKO-600 (650hp)------2.87---.82 or .64
Current BW T-10 CR---2.43

First question: is the gap between the 1:1 4th gear and a .64 or .68 5th gear too much for practical highway speeds (we can't always drive at 90+)?

Second question: I don't think I will have traction problems with a 26 year old L-82 (220hp), but is the 3.27 1st gear in the TKO-500 version of Keisler's tranny too much when combined with my 3.70 rear and a planned ZZ-4 in the future? (street car with street 15in tires) Not only looking at traction issues, but also general drivability around town and stop lights and parking lots etc.

Right now I'm leaning towards the TKO-600 with 2.87 first gear and .64 5th gear. What advice do you Keisler owners have to throw my direction?

Semper Fidelis,
Culprit

 

[Eddie 70]

http://home.comcast.net/~eddiengerry/MOV00235.MPG

This is a short video of my car on the interstate. I got the .68 OD version of Keislers tranny. I have a 3.36 rear gear and I am running 255/60/15 tires. It runs about 2000RPM @ 80MPH.

 

[norvalwilhelm]

I have a Tremec TKO which has the 3.27 first gear and I think it is too low. I do have the .68 overdrive and I love it.
I would go with the TKO 600 and .64 overdrive.
I did a Tremec swap for a guy with a 73 in July and it took a weekend but if pressed it could be done in a long day. This was not a Kessler swap so I had to cut the crossmember out and make a removable one but overall the job is really easy. Cutting the driveshaft is no problem for a shop, costs about $150. The rest is just a little fabricating.
You will really like the tremec with it's overdrive.

 

[BeaterShark]

I like the TKO-600 over the TKO-500 because of the better gear spread. I really don't like he 1-2 spread on the TKO-500 (5500 RPM in 1'st to 3300 RPM in 2'nd). Also, the 3.27 1'st will be practically useless under decent amount of throttle with a 3.70 rear gear and no slicks.

To me it's a no-brainer; go with the TKO-600.

Now for the OD gear. I drive much more at 40 - 50 mph (city) than at 70-80 (hwy), so I'd make sure I could use the OD at 45 mph. For this, you will have to do the math and figure out when YOU want the OD to be available.

Here are some base numbers to start with. Assuming a 27" (stock) tire and a 1:1 ratio with a 3.70 rear gear, you will be going 21.7 MPH for ever 1000 RPM. This will show you the equivelant 4'th to 5'th gear RPMs at a few speeds. So, lets run some numbers:

at 86.8 MPH:
1:1 = 4000 RPM
.82:1 = 3280 RPM
.64:1 = 2560 RPM

At 65.1 MPH:
1:1 = 3000 RPM
.82:1 = 2460 RPM
.64:1 = 1920 RPM

At 43.4 MPH:
1:1 = 2000 RPM
.82:1 = 1640 RPM
.64:1 = 1280 RPM

If it were me, it would be a tough decision, I can't even say right now which I'd go with for sure. I would be trying some 4'th gear 1300 RPM driving to see how my engine liked that RPM for cruising.

 

[Robin7TFour]

hmmm, do i smell a deal on a used 4 speed?

R

 

[bossvette]

I have the TKO with the .68 in my 76 since 2000 and love it, but I have a 383 with TPI which is built for torque and will pull low RPMs It actually handles 45 mph in 5th better then the stock engine did in 4th or even 3rd.
The OD trans swap works best with a modern FI setup where the engine works well at low RPMs
a rear swap to a 3:36 would help you with the OD trans
Craig sr

 

[Culprit]

Thanks for all the input guys. You all seem to be nudging me even further in the direction I was leaning. I'm definitely going with the TKO-600 due to the first gear ratio, and I'll most likely go with the .64 instead of the .82 OD gear - but like bossvette suggests, I'll do some driving in 4th at low RPM's just to make sure before I place the order.

Any other words of advice about the Keisler swaps that I should know before I get started? What clutch disk do y'all recommend? Since this is a street car with original L-82, I'd have to have a good reason to go with something other than OEM style stuff.

 

[bossvette]

check out this site, its where I bought mine from flywheel to yoke complete ran me about $2700 I believe 4+ years ago. Mine was before the offset shifter so I made a new shift plate.

http://www.fortesparts.com/

Culprit if you are running a L82 you could save yourself a lot of money by using a Tremec 3550 the TKO and newer 500/600 would be overkill talk to Mike at Fortes he has been doing the Tremec swap longer than anyone out there.

 

[Culprit]

bossvette - just saw your edit. I think I'll read up on the 3550 - didn't know that was an option.

 

[BeaterShark]

The 3550 will most likely force you to re-gear (1'st = 3.27), putting your total cost more than a TKO-600. From what I remember the TKO-600 is about $200 more than a 3550.

Also, I don't believe Keisler offers a 3550 kit, so you'd have to do some fabbing.

 

[bossvette]

http://www.fortesparts.com/ give these guys a call, they were the first to offer the tremec for Chevys.

 

[SMR 67]

I like the TKO-600 over the TKO-500 because of the better gear spread. I really don't like he 1-2 spread on the TKO-500 (5500 RPM in 1'st to 3300 RPM in 2'nd). Also, the 3.27 1'st will be practically useless under decent amount of throttle with a 3.70 rear gear and no slicks.

To me it's a no-brainer; go with the TKO-600.

BeaterShark, I have a '67 with a 383 stroker and 3.73 rear that specs out at 415hp (Holley 750, MSD, Hooker headers, etc.). I'm seriously considering a Keisler 5-speed and read with interest your reply to Culprit that a TKO-500 would be practically useless with his 3.73 and only 350hp (if he goes with the ZZ-4). Is this because the TKO-500 acts like a 4.84 in first gear (per Keisler conversion chart) but only a 4.24 with a TKO-600 (.64)? I'm not planning on putting slicks on the car and don't think there's a big difference in fifth gear (only 4mph), but my thought was to maximize power off the line with the TKO-500. I know it would still be a beast off the line with the TKO-600 (.64) at 4.24 in 1st, but why not take advantage of the higher gear ratio? Also, what do you mean by the TKO-600 having a better gear spread? Any other advantages to the TKO-600 in this scenario?

Thanks in advance for your input.

SMR 67

 

[SMR 67]

Thanks for all the input guys. You all seem to be nudging me even further in the direction I was leaning. I'm definitely going with the TKO-600 due to the first gear ratio, and I'll most likely go with the .64 instead of the .82 OD gear - but like bossvette suggests, I'll do some driving in 4th at low RPM's just to make sure before I place the order.

Any other words of advice about the Keisler swaps that I should know before I get started? What clutch disk do y'all recommend? Since this is a street car with original L-82, I'd have to have a good reason to go with something other than OEM style stuff.

Culprit, I'm also seriously considering a Keisler 5-speed and posted a reply to BeaterShark with some questions. I was just wondering if you got your 5-speed and if so, which one and how is it? I also have a 3.73 but with 415hp and trying to decide between the TKO-500 and TKO-600(.64).

Thanks,
SMR 67

 

[BeaterShark]

First, I want to say that I've drooled over an OD tranny for a long time and probably the reality is that there is not a large real-world difference between the two trannys. But, if you are doing it, why not do it right?

BeaterShark, I have a '67 with a 383 stroker and 3.73 rear that specs out at 415hp (Holley 750, MSD, Hooker headers, etc.). I'm seriously considering a Keisler 5-speed and read with interest your reply to Culprit that a TKO-500 would be practically useless with his 3.73 and only 350hp (if he goes with the ZZ-4). Is this because the TKO-500 acts like a 4.84 in first gear (per Keisler conversion chart) but only a 4.24 with a TKO-600 (.64)? I'm not planning on putting slicks on the car and don't think there's a big difference in fifth gear (only 4mph), but my thought was to maximize power off the line with the TKO-500. I know it would still be a beast off the line with the TKO-600 (.64) at 4.24 in 1st, but why not take advantage of the higher gear ratio?

I don't really know where the 4.84 and 4.24 numbers come in, but I guess it is Keisler's way of "equating" it to a Muncie. Instead of those, let's look at the effective (tranny x rear) gear ratios for each tranny in 1'st:
TKO-500: 12.2:1
TKO-600: 10.71:1
Muncie M20: 9.40

This is the multiplication of torque that is being provided by the tranny and gears. IMHO, 10:1 is just about as far as I would go on a street car. Going much over this will give alot of wheelspin in 1'st under hard accel with street tires. I currently have 3.36 rear gears with a M20 giving me an effective 8.47:1 and I still have traction problems in 1'st gear under WOT.

Also, what do you mean by the TKO-600 having a better gear spread? Any other advantages to the TKO-600 in this scenario?

I'm talking about the RPM drop when shifting. Using percentages, the trannys have the following % drop during the shifits:

 	 M20		 TKO-500		 TKO-600
 1-2 shift 75%		 61%			 66%
 2-3 shift 78%		 68%			 68%
 3-4 shift 68%		 75%			 78%

So, if you shift at 6000 RPM for a 1-2 shift, you will drop to the following RPM in second:
TKO-500: 3633
TKO-600: 3951
Muncie M20: 4476

IMHO, the TKO-500 just drops too far down on this shift.

I really don't care that much about the 3-4 shift since you will already be going close to 100 mph, and the only time I get there is at the 1/4 mi track, but both TKOs are good here.

Again, I have probably over-thought this subject.

 

[SMR 67]

Thanks - I appreciate the info. I'm going with the TKO-600 (.64). Keisler has a 6-8 week delivery time - sounds all too familiar. But it will be worth it in the end. I'll let you know how it is.

SMR 67

 

[bossvette]

Thanks - I appreciate the info. I'm going with the TKO-600 (.64). Keisler has a 6-8 week delivery time - sounds all too familiar. But it will be worth it in the end. I'll let you know how it is.

SMR 67

6-8 weeks I had mine in less then a week and just got off the phone with Mike at Forte's he has them in stock.

 

[SMR 67]

What's the difference between what Forte's does and what Keisler does? Is Forte's customized / bolt-in like Keislers? Keisler's turnaround time is actually only about a week, but they're saying that Tremec is backlogged, thus the long wait.

 

[bossvette]

What's the difference between what Forte's does and what Keisler does? Is Forte's customized / bolt-in like Keislers? Keisler's turnaround time is actually only about a week, but they're saying that Tremec is backlogged, thus the long wait.

I bought everything from flywheel to yoke from Fortes and modified my crossmember myself the offset shifter was not availabe and I made a new shift plate. Fortes gets their transmissions from Tremec with a hardened GM input shaft at the time I bought mine they were the only ones doing it; give them a call and talk to them

 

[lnirenberg]

My car is finally setup right and I got a quick test drive with the new Keisler TKO500 before it started to snow. Holy s***, I can't believe it's the same car. The 1st & 2nd gear pull was amazing. I must say the shifter throws will take a little getting used to as it has a much tighter throw pattern than the Muncie. I think any rear much lower than my OEM 3.36 would render 1st gear useless as the final drive would be too low to do much but spin the tires. I can't wait 'till spring.