View Full Version : Transmission reliable?

08-12-2003, 05:04 PM
I have not seen to much on this topic, but is anyone road racing a 300ft torque KA or SR ? I am wondering how well the transmission holds up to the abuse. I've seen enough guys drag racing and shifting gently to question the long term life of a tranny in a race season. Any common problems? Running a heavier oil? Thanks

08-12-2003, 05:20 PM
They're rock solid. Various people drag, drift and road race 400hp+ KAs and SRs without any problems that I've heard of. Even the synchros are quite strong, especially for a transmission designed in the late 80s/early 90s.

08-12-2003, 08:50 PM
They're rock solid. Various people drag, drift and road race 400hp+ KAs and SRs without any problems that I've heard of. Even the synchros are quite strong, especially for a transmission designed in the late 80s/early 90s.

I beg to differ!
The SR & KA trannies are reliable if you treat them right. If you treat it like I used to, a Beotch, then they won't last you long at all. I used to go through trannies every 2 years. But as a few of the members said to me, Don't man handle them which was exactly what I was doing. I would make it shift when the tranny didn't want to go into gear.

They can handle alot of abuse as long as you don't man handle the trannies. Instead treat the car like my *****, I now treat it like my baby http://forums.freshalloy.com/images/graemlins/grin.gif

08-12-2003, 09:44 PM
seriously, you werent just breaking transmissions, u were busting diffs too, i have no idea how you were doing that

must have been some incredible torque-shock, hehheh

everything ive read the SR/KA transmission is as strong as you can expect, holding up to 300+ ftlb without problems as long as your not torqueshocking or abusively shifting

ive also read that some of the higher power s15 drivers backdate to a 13 or 14 gearbox

honestly roadracing is not terribly abusive on the gearbox, and the 240 transmission tends to take fantastic steady state loads without any problems, roadracing has no torqueshocks, smooth shifting, and no sudden hard transitions...but dragracing and drifting is a lot harsher on the gearbox

there are a few guys floating around FA that have had high power KA-Ts for several years that should chime in

08-13-2003, 10:50 PM
jussa tiny bump for those big number SR/KA guys http://forums.freshalloy.com/images/graemlins/crazy.gif

08-13-2003, 11:10 PM
I would like to point out that I laid waste to an SR tranny with only 350hp drag racing on it. I did it while shifting into second.

I've seen many an SR tranny get destroyed by both drag racing and drifting. Don't go telling people they're bulletproof now... cause they're NOT. http://forums.freshalloy.com/images/graemlins/grin.gif

08-13-2003, 11:30 PM
I've seen many an SR tranny get destroyed by both drag racing and drifting.

hence components such as os giken hardened main shaft and gears are offered for serious folks http://forums.freshalloy.com/images/graemlins/wink.gif

08-13-2003, 11:43 PM
Exactly... Just like my OS Close Ratio Tranny http://forums.freshalloy.com/images/graemlins/wink.gif

08-14-2003, 12:17 AM
I've seen many an SR tranny get destroyed by both drag racing and drifting. Don't go telling people they're bulletproof now... cause they're NOT.

Perhaps it is the way you drive?

When Duy ran his 10 second pass he was running the stock transmission...


08-14-2003, 12:45 AM
but i think he is getting his 10th tranny now, ask the owner of that 10sec 240sx.

08-14-2003, 02:34 AM
It would last looong, just dont grind the gears. I think the syncros will be the firs to go and then the forks. but the forks wont go if you shift good and dont grind, and the syncros wont go if you shift good and dont grind! Dont know what youz are shifting but these transss dont like to speed shift above 7000. I dont know what that translates to in regular [censored].

08-14-2003, 02:37 AM
I dont konw why SHIFTING was censored?

08-14-2003, 03:12 AM
Granted, I know a lot of people who's transmissions have lasted the life of their cars... but I know a LOT of people with SR's and CA's here... A lot more than you see in the states. For those that race or drift, there's a good part of them who have ripped third gear out, second gear out, destroyed synchros, missed third and shifted halfway between third and fifth - this sheers off 5th and reverse but the rest of the gears will still work.

I've seen it all.

Me personally, my tranny lasted through two years of pretty bad abuse (ie: drag racing all the time) but then it gave it up right about when I bumped from 300rwhp to 345rwhp and got some good grip on the track.

I am shocked by the fact that Greaser's stock tranny holds up with slicks on there... but he doesn't drive it everyday, either. It's a track car.

08-14-2003, 06:37 AM
My point Exactly 1bad180sx, If you are are putting down the power and actually racing the often and have good traction these tranies will break. Like I said I went through them every 2 years. As for Duy's car, that car did make that passs on a stock tranny but that dam sure wasn't his first, second or even third tranny. If you are make close to 300+ to the wheels, rag on the car often, and drive daily = short life of tranny. Now Thred, what do you have? How much power are you making. Are you going by hear say, what you've seen, or are do you actually have a 240 making some power? Anybody making any power and draging hard can tell you that these trannies are far from the word "Bullet Proof".
Greaser is the only person I know who can keep a tranny held together but his method is also for a price. His method I believe decreases the clutch life greatly but he doesn't break the tranny. Its 6 in one basket/ 1/2 dozen in the other. The price you pay for High performance.

08-14-2003, 08:24 AM
me, i dont have anything done http://forums.freshalloy.com/images/graemlins/tongue.gif

im just relaying what i read from all of you, that the transmission is 'as strong as you can expect' from somthing that was engineered for a regular load of 200ftlb

that from reading for a good while (as i have a lot of fears of my transmission breaking someday) that about 300ftlb (50% increase) is about all you can do before [censored] starts to go horribly wrong....which fits into the general rule that most all auto manufacturers tend to follow of overengineering drivetrain and mechanical parts by about %50

no car ever gets incredibly strong parts unless they are 'passed down' from more intense loads

and i wanted to point out that drag racing and drifting will break drivetrain parts, period, roadracing and average strete driving is not nearly as harsh, because of exactly that there are no sudden torqueshocks, typically reasonable street tires will spin long before stuff breaks, and if you cant drive smoothly roadracing, your not going to be fast

08-14-2003, 08:37 AM
i specifically avoided terms like 'bulletproof' because its not true, but i wanted to provide a slightly more 'objective' perspective than the guy that goes through a gearbox/year and thinks they are junk, and the other dude that exclaims them as the gearbox of jesus christ himself

as an aspiring KA-T, this is information i have tried to get as good of a handle on as possible, while i am driving a more or less stock s14 for the time being, i was hoping i could offer an objective point of view from an outside onlooker

in fact some of the information about the KA transmission is what finally convinced me that it is more practical than an SR motorswap

when i refer to ~300ftlb, thats transmission load, akin to crank horsepower, not at the wheels

300ftlb to the wheels is closer to 340 crank...granted thats not quite a 15% difference, but from the information i have tried to accumulate from all the transmission posts on FA....tends to be the difference between oK if your careful and days are numbered

08-14-2003, 08:43 AM
anyway, back on topic

08-14-2003, 08:52 AM
Hell, if it's a KA tranny you're worried about, why? They're so abundant and cheap anyway.

08-14-2003, 10:55 AM
I'm on my third KA transmission, and have yet to break 200rwhp. It's all about how you treat it, my first one just had worn synchros but backed with a bad clutch I thought it was more so I swapped it. The second one scattered while racing a mustang, I lost 1st, 3rd, and 4th and eventually wound up getting stuck in the road. My third one has held up fine though, as I've learned to be a little easier on it, and I don't race much anymore.

08-14-2003, 01:14 PM
Dam Russ! http://forums.freshalloy.com/images/graemlins/ooo.gif
I at least have an excuse for my trannies blow'n. I can blame mine on the boost. hehe. Seriously, I have stopped beating on mine so much too. Tired of working on it all the time. If you don't beat on the thing everytime you get on a KA-T they will actually last. I am adapting to this practice. http://forums.freshalloy.com/images/graemlins/grin.gif

08-14-2003, 05:49 PM
Duy's videos is one of the vids that even prompts this question. He was shifting o-so-slow on some of those runs. I remember him talking about not wanting to break things.

08-14-2003, 08:55 PM
Duy and Jason broke trannies all the time. I was there when Duy broke into the 10's. They were scared as hell to launch the car out of the whole hard for fear of the tranny letting go. They are great trannies but they just wheren't designed for 300FT of torque and etc...

08-21-2003, 08:18 PM
anyone cryo treat 'em? How much will those things last if you do?

08-21-2003, 11:17 PM
I would not be suprised to hear that cryo treating them does not make a huge difference. I know subaru boys had a lot of trouble with the WRX tranny once they started making power, the gears were physically too small to really support the output.

I don't think he KA tranny would be that much different you know? imo id rather get a half dog box or something if I was really worried about the tranny. Would probably cost some bank too. 3k+