TKO transmisson suggestions

Sicarius428 said:

Thanks for the suggestions. My car is a daily driver when its dry. I do need the freeway overdrive since work is about 20 miles from home. My consern is really first gear... I would hate to end up with too much first or too little... Strength is more of a perk because I doubt I will ever reach 500 lbs of torque. The stock T5 gear ratio would be closest to the TKO 500 correct? Kevin

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Since you will be going with stroker, you will have plenty of torque down low. Also factoring in the highway cruise preference; the tko 600 2.87 first gear option shouldn't be a problem getting moving and the slightly better .64 OD option should be a better bet.

The trannies are essentially the same construction. The problem is when you go with a more shallow gear, the load carrying capacity decreases. If you look at the very first T5 trannies, they had a 2.95 first gear. the WC T5 trannies from 86' up came with the 3.35 gearing. These had an inherrent problem with being over-powered and not holding up, so when the T5Z was released, it had more capability AND it went back to the 2.95 option because it holds up better.

The same holds true with any gearing setup but in this case the tko 500 versus the tko 600 gearing ratios.

Tko 600

I am happy with my TKO 600 and .64 od. First gear is perfect any taller ratio would be like a big truck. The .64 OD gives me good hiway cruising @ 2200/70 mph so I am happy with that. Big drop between fourth and fifth though don't think I will ever get past fourth in quarter mile.

mike0227 said:

Big drop between fourth and fifth though

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Yes it is, if you ever land up in a highway race, it does have great effect on things.
It drops you right out of the powerband unless you shift at 6200rpm.

I have a TKOII w/ .82 OD & a 3.73 rear end.

The .82 gear is great for acceleration but you will lose top end. At 100mph on 5th, you will wish you had a 6th gear. I'm thinking of dropping the rear end to 3.55's.

Very interesting discussion.


I think that ultimately there is no right or wrong gearing. It comes down to personal preference.

For example my car is my Daily driver and i drive it 35 miles each way to school. I have HCI, 3.73s and stock T5. Aliate is right about the T5s gearing being so disproportioned, 1st is steep, second is ok IMO and then 3rd is kinda long, 4th is way to long. See all those jumps makes racing kinda hard. When i get the tranny im gonna want the TKO600 with 0.64 OD. i need 5th for the highway, and 1st through 4th shouldnt be partitioned such that when i shift im not to far into my power band or to far below my power band (in RPMs). Theres more to racing than just the final gear ratio.

Treachery said:

I have a TKOII w/ .82 OD & a 3.73 rear end.

The .82 gear is great for acceleration but you will lose top end. At 100mph on 5th, you will wish you had a 6th gear. I'm thinking of dropping the rear end to 3.55's.

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Yeah, i calculated it out.
And if you use a 26 inch tire.
Based on a car that will run to 5500 rpm with 3.73 gears you can goto about 140mph,
If the car is capable of 6200rpm (most are not) it could goto 155mph, which is still a bit low.