My impressions of a 3.55 gears vs. the stock 3.06

[Super T]

By popular (sorta) demand, I'm going to give a somewhat brief and long overdue review of my gear experience.

I had a 3.55 gear mounted in a Dana44 rear end with custom halfshafts and driveshaft. This came to become the Track Killer from CMJ... unfortunately, they're gone, and so is the rear end I was promised, and so is your opportunity to buy one. However...

The gear gave the car so much more grunt it's ridiculous. In a nutshell, it increases the amount of force the tires deliver to the pavement... by about 16% in this particular case. You can feel every last pound of that, too. At the track, I was blazing 305x18 drag radials into 2nd gear if I wasn't careful. On the street, it was smoke-on-demand. No question, the difference is very large, and very appreciable. It's damn good fun!!!!! Not sure what it would take to hook - the 600hp club must feel the same way. More practice I guess!

I had the gears for about three months. I only had weekend custody of the car (which is when I drive it anyway). Several trips to the track and lots of street and highway driving - about 3500 miles worth total. Granted, that's not enough to speak to the longevity of the rig (which you can't buy anyway so that would be irrelevant), but it's enough to get a good feel for it. First of all, a one-piece driveshaft at that length vibrates, period. I never had any worries about failure, but there was a nice massage feature at about 67 mph and again at about 130 (harmonics). Stay out of that range, and it was fine. So if you're going to upgrade your driveshaft, keep it 2 pieces.

There was also a little bit of whine from the gear but it really wasn't bad - and I'm picky about that kind of thing. One of the coolest things was how hard the shifts kick you in the ass, both up and down. Some of that probably comes from the way they were shimmed and the fact that I went to solid diff. mounts, but still. Downshift in autostick and you REALLY get slowed down (I thought it was awesome).

Mileage decreased about 0.5mpg... really not bad at all. RPM's increase by the same 16%, so you spin a little higher on the highway. I would be in the 2300 range a lot of the time. Even there, between my engine, tires, exhaust and the gear, you could still have a civil conversation without too much trouble.


Overall, I think a gear is an AWESOME mod for the money, if you can install it yourself. If you're paying someone else, I've seen it cost anywhere from $600 to $1200, so at that point consider going on the bottle instead. I also wouldn't do the gear w/o doing the axles. The labor overlaps and I honestly think if you didn't break stock axles before, you will w/ a gear. But for the true racer in you, WOW is it awesome. If you want to spend most of your time on the street and just put a little pep in your step, maybe stick to something more along the lines of a 3.23. That's 6% more force to the ground than a stock SRT.

[ujokin2]

Thanks for the review !!! Hmmm this is sounding more interesting now.

[Heavy H.P.]

Id like to do 3.55 in my R/T but idk

[bklynmag]

You mentioned a few trips to the track. Did you notice a net difference to the before and after times?

[Super T]

You mentioned a few trips to the track. Did you notice a net difference to the before and after times?

Discovered a weakness in my tune (car bogs like nuts off the line). 60' times were actually slower when I hooked than when I spun... Soooo I personally did not, I'd be lying if I said I did. That's on my list of things to get taken care of before Spring.

HOWEVER, so long as the car is running right, you can't not improve your times at the close end w/ a gear. Due to the way gears work, you get more torque but less speed... so don't expect your trap speeds to go through the roof but your ET's should definitely improve.

[Junior]

Great breakdown, bud.

[street hooligan]

yea, same. great info, i think a 3.23 would be a great viod!

[bklynmag]

Discovered a weakness in my tune (car bogs like nuts off the line). 60' times were actually slower when I hooked than when I spun... Soooo I personally did not, I'd be lying if I said I did. That's on my list of things to get taken care of before Spring.

HOWEVER, so long as the car is running right, you can't not improve your times at the close end w/ a gear. Due to the way gears work, you get more torque but less speed... so don't expect your trap speeds to go through the roof but your ET's should definitely improve.

Tks. Sux you didn't have enough time to sort it all out and got nothing for your time/efforts.

[Super T]

Tks. Sux you didn't have enough time to sort it all out and got nothing for your time/efforts.

Yeah I'm bummed I couldn't pull a great time out of it. I should be getting times very similar to jaak, the hardware is all there and the car goes once it's gone. But it stutters bad, you can feel and see it lurch, drop the bumper, then take off like a raped ape. I've ruled out hardware problems.
And yeah, I'm definitely pissed I have nothing to show for close to four months and 3,500+ miles of "try to break it!" on my car. Didn't expect a freebie in the beginning but shortly thereafter it was promised. But hey, what's a promise among "friends" (had considered us that for a while)... apparently not much. Whatever. John's a great guy and he's still around and on to bigger and better things, at least something good came outta that place ;-)

[Johnparts]

I ran the Track Killer in my car after they pulled it out of Todd's car and the difference was Night and day with even a stock car as far as Butt dyno numbers. I tried everything I could to make sure Jeff fufilled his end But in the end there was nothing I could do I guess. I'm sure we will see something again that makes the track killer look like poop but until that day comes I am at least glad I was part of that even though the CMJ experience as a whole sucked.

[ujokin2]

For "me" this is totally still confusing even though I have tried to read through all those threads on the gearing by hemiwagon and other knowledgeable folks .... is that with a 426 stroker...the torque is there... but with the 3.55 gear does that mean I will be able to put more of that "torque" to the ground initally? .... or go with another gear to get higher MPH at the end.

[Super T]

For "me" this is totally still confusing even though I have tried to read through all those threads on the gearing by hemiwagon and other knowledgeable folks .... is that with a 426 stroker...the torque is there... but with the 3.55 gear does that mean I will be able to put more of that "torque" to the ground initally? .... or go with another gear to get higher MPH at the end.

Think of it this way... gears are kind of like levers... sort of...

You have two gears of different sizes... kind of like on a lever where you push on the long end and end up w/ a lot more force but less movement on the short end. That's why prybars all have a drastic "L" shape, after all.

You spin the pinion gear with a certain torque and at a certain speed. Let's look at that torque - measured in foot-pounds, right? Well, you take that and divide it by the radius of the gear and you get straight-up pounds of force. That's what you're applying to the ring gear... so now you take that and multiply it by the radius of the ring gear, and there's your new torque. In other words, where F is force, T is torque, 1 is the ring side (input) and 2 is the pinion side (output):

T2 = T1 * R2/R1

You'll notice that R2/R1 IS your gear ratio... so you can see, that a higher gear ratio gives you more torque on the ring gear (and therefore more torque to the tires).


Speed works kinda the opposite, long story short, we'll use W for speed (traditionally it's a lower-case omega, which looks like a curvy lower-case "w"... don't ask me, I don't make the rules)...

W2 = W1 * R1/R2

This one works the opposite of torque, you sort of divide by the gear ratio instead of multiplying by it... so the bigger the gear ratio, the slower the axle turns for a given driveshaft speed. But remember, it's turning w/ more force.



So the bottom line is that the increased torque to the tires gets you going faster, faster (better acceleration). Now it means your top speed is limited - but none of us are maxing our cars out in the 1/4 mile so it's not so much of a concern.

[Super T]

I ran the Track Killer in my car after they pulled it out of Todd's car and the difference was Night and day with even a stock car as far as Butt dyno numbers. I tried everything I could to make sure Jeff fufilled his end But in the end there was nothing I could do I guess. I'm sure we will see something again that makes the track killer look like poop but until that day comes I am at least glad I was part of that even though the CMJ experience as a whole sucked.

I know you did what you could, I've told you 100 times but just for public record:

I do not hold John responsible in any way for anything negative that happened at CMJ... in fact, I think he's the only reason anything positive ever happened there.

[gremlinsteve]

did you ever get to run it at a track? what gear was it hitting at the stripe? what tire?

steve-o

[lallend]

One of the coolest things was how hard the shifts kick you in the ass, both up and down.

That alone, raises the fun factor to a whole new level...