Strengthening an auto trans?, Is this possible? Just wanna weigh out my options Options

[UndecidedPC9397]

I heard from a friend of mine from my old work you can install titanium gearing into an auto trans, but sounded clugy but interested me so wanted some feedback on this, thanks.

[JozhGoober]

While I guess that would be theoretically possible, that much titanium would be prohibitively expensive (we're talking tens of thousands of dollars) and wouldn't actually do anything for strength. Pure titanium is only about as strong as steel, but it's much lighter.

Why would you want to strengthen an automatic transmission? I assume drag racing? Otherwise the E153 is a incredibly strong manual transmission, and it bolts right on.

[UndecidedPC9397]

While I guess that would be theoretically possible, that much titanium would be prohibitively expensive (we're talking tens of thousands of dollars) and wouldn't actually do anything for strength. Pure titanium is only about as strong as steel, but it's much lighter.

Why would you want to strengthen an automatic transmission? I assume drag racing? Otherwise the E153 is a incredibly strong manual transmission, and it bolts right on.

Mainly because its more precise shifting and swaps arent looking to be in my favor, and I had a feeling of as much with the titanium. Like I said, sounded cluegy. but are there parts in the auto trans that could be strengthened for if I wanted to lets say turbo on low boost? and how much can the auto withstand naturally out of the box?

[Bitter]

You would install a shift kit and run a more robust external cooler.

[mandrek]

You would install a shift kit and run a more robust external cooler.

i have not seen a shift kit for the A-246E (7afe auto trans).... or auto-computer hacks... are there any out there.. i have not been able to come up with any in my research..

[mandrek]

While I guess that would be theoretically possible, that much titanium would be prohibitively expensive (we're talking tens of thousands of dollars) and wouldn't actually do anything for strength. Pure titanium is only about as strong as steel, but it's much lighter.

Why would you want to strengthen an automatic transmission? I assume drag racing? Otherwise the E153 is a incredibly strong manual transmission, and it bolts right on.

Mainly because its more precise shifting and swaps arent looking to be in my favor, and I had a feeling of as much with the titanium. Like I said, sounded cluegy. but are there parts in the auto trans that could be strengthened for if I wanted to lets say turbo on low boost? and how much can the auto withstand naturally out of the box?

there are a few things that you can in theory do the strengthen any trans, and these would to autos as well.. depending on how far into it you want to go....

Getting to the guts of the trans, you can get the gears: shot peened, and or cryo treated. both of these essentialy work the metal to make it stronger.. are they end all solututions? no, but it will help..

there is also a process called " Isotropic Superfinishing" which puts a micro polish on all the contact serfaces.. this is esspecialy helpful for saving the syncros and in the long run will be good for over all health of the trans since the point of this is to remove as much friction as posible. reduced friction on the contact serfaces of the gears = easyer enguagment, smoother running of the syncros and also reduced heat genarated from the operation of the trans..

found that this company does both of these as a two step process. the site covers the details of what is involved much better than my quick summery here.

Other than that as for the auto specific, i have always heard that you can get a stall converter as an upgrade to the torque converter.. i dont know much more than that as far as those go.. i know that the 4 spd muscle cars do this for drag racing, but the rest i am unsure as to what (if any) benefit it would offer a DD car.. or how it would effect drive abillity or even how that works differently than the stock torque converter.....

There are ''shift" kits which (from my understanding) replaces the valve body in the auto trans to shortens how long the auto takes to shift..

some piggy back and stand alone ECU's allow you to access the trans computer, from what i here it will usually allow you to change shift points and or how long you "hold" a gear depending on load.. IDK i am sure that the specifics are based on what trans is in question... but i have to admit that, again, i do not know more than that.

last but not least, (as Bitter pointed to) is cooling. Heat is the number one killer of automatic trans. and there are a few way to tackle this.. first an for most, is the addition on top of, or complete replacement of the stock trans cooler. (i know that for the 7afe it is built into the rad, dont know about the one for the 5sfe (may even be the same)). A good idea is to also install a trans temp gauge, that way you have a way of knowing what is going on!!! then at last there is also the fluid that you are using!!! in an auto trans, the fluid is multi-tasking like an Octo-mom working out, feeding the kids, and working all at the same time!!!! MOST auto trans have the fluid acting as a hydrolic fluid (function on all of the clutches, valves, and torque converter. used as a lubricator for the gears, all the valves, clutches AND the diff. AND used as a coolant for all the components as well!!!!! so selecting a good trans fluid should be the first thing you should do when you are about to abuse an auto..

personally i went with a stand-alone radiant-style cooler. (since i got a non-auto godspeed rad. to replace my cracked OEM one) an AEM temp gauge to monitor operating temps and also see if i need to install a termastat controlled fan over the cooler.. (since it has a digital readout [great for quick reference during or just after a race] an analog color coded LED "needle", and an additional 5V out-put to give the ability to data log!!!). and for fluid i will be going with royal purple's MAX-ATF.... did some poking around and it would seem that it will work well for what i need it to do.. (the fluid is primarily designed to stay cooler longer, provide better lubrication, and have better resistance to viscosity break down under hard load.) i selected to go this route for my auto since i auto cross the car, and will be going boosted later on (about a year from now).

As for how well the auto trans will hold up?? IDK, but IIRC OOBI had a boosted 7a (stock)auto, and said that he never had any problems with it..


hope this helps!

[Bitter]

You would install a shift kit and run a more robust external cooler.

i have not seen a shift kit for the A-246E (7afe auto trans).... or auto-computer hacks... are there any out there.. i have not been able to come up with any in my research..

I think transgo makes one.

[RobbMeeX]

^They do.

Break it first, then see what you need.

I personally suggest bypassing the stock rad cooler in the event your internal radiator cooler has a leak. (The day after I converted mine, we had a dodge come in the mixed the coolant and ATF) I bought an Eclipse radiator cooler for like $10 or so at the pull-a-part.

I switched to Mobil 1 ATF. Mobil makes the T-IV (3309) and says it will work in its place. I'd use T-IV if I didn't use synthetic.

The transgo kit is probably just going to adjust the firmness. The plus side of a really firm shift is that its a quicker shift. Less time slipping the clutch discs means less wear. You achieve this by shimming the accumulators. You can apply more pressure for more hold, but also you can overdo it. I'd like to look into how to adjust the shiftpoint electronically, but I'm too busy to tackle it on my daily. In essence, you apply 12+ on the solenoid and it shifts.

I admit I don't understand stall at all, but a torque converter does it

[mandrek]

found this

looks like it "should" work for the 95+ 7afe's A-246E auto trans as well..

[Bitter]

Wow, that price came down. They were $150 when I owned my 7A auto. You can email Transgo to ask them if it would work with the A246-E or check valve body part numbers on toyodiy to see if they use the same valve body.

[JasonTX]

http://www.levelten.com/Toyota_Transmissions_s/48.htm

these guys used to do custom made kits fr any tranny. dont know if they still do. also their super expensive

[UndecidedPC9397]

Thank you guys for all this info, gonna need an hour to get a grasp on all this lol And I have the 5sfe so did the 7a an 5s share that trans or were they different? im still just a little confused. and oh much hp did that boosted 7a have? (if you can recall the numbers)

[njccmd2002]

just out of curiosity, why spend $$$ on a weak tranny, for a weak engine. Unless you are putting a 3sgte and using auto, makes no sense to make the tranny stronger.

they are a dime a dozen, that if they break, you put a new one. my .02

[Bitter]

Thank you guys for all this info, gonna need an hour to get a grasp on all this lol And I have the 5sfe so did the 7a an 5s share that trans or were they different? im still just a little confused. and oh much hp did that boosted 7a have? (if you can recall the numbers)

I don't think they do. Not sure what trans the 5S uses.

[mandrek]

just out of curiosity, why spend $$$ on a weak tranny, for a weak engine. Unless you are putting a 3sgte and using auto, makes no sense to make the tranny stronger.

they are a dime a dozen, that if they break, you put a new one. my .02

good point. but how "cheap" the A-246E is in fact one of the reasons why it makes it a good idea to do some of these upgrades..

the "weak tranny" as far as i know is fairly robust, and looks to be able to take but only a bit to make it be able to safely manage boosted, or raced 7afe/4age/4agte/4agze/7age/7agte's
interesting fact that i came across is that the fluid in the auto tranny should be flushed and changed approximatly every 30K miles. thought i doubt that many people do that..
also this IS in fact a rather niche section of the celica performance community.

personaly i chose to stay with the auto, rather than go to a manual. on this project 7afe since it will end up being my DD/ week end racer.
i have been auto-crossing my 7a-auto celica for about 2 1/2 years. and the longer first gear is GREAT!!! for the club auto-X'ing that i do. and then there is the sh!t D.C. traffic that i have to deal with on a regular basis. so for me the choice to keep the auto was simple..

I am sure that for others, the the choice to stay with an auto will be on similar grounds. and i am well aware that the majoraty will want to, or just, swap to a manual.

also , anything more than "regular" driving, will put additional stress on the auto trans, and there for would be smart to do a few upgrades to make sure that you are not going to have to prematurely replace a trans.

my target for the 7a will be 300WHP.. will i hit that , probably not, or any time soon.. but i figure that with a few choice mods the auto trans can be made to handle that power, with out crapping out on me every other day...
And there are other advantaged to using an auto for a boosted car.. by the very nature of the auto; it will be easier on the rest of the drive-train, due to the torque converter allowing a smooth engagement of power, and handling a solid place for slipping. no worry of shocking the trans on a bad shift, or miss shift, or improper throttle load wile shifting; as you may encounter on manual trans.

the list of mods that i would like to do to/for my lil auto would go like this:

*better trans fluid> going with Royal purple's Max ATF (all around ++)
*dedicated trans cooler> got a radiant style. (gives better heat handling of the auto trans, and radiant that way it does not have to be mounted in direct air stream.)
* auxilery trans fluid filter>Got a magnifine in-line duel media filter that uses a massive magnet for ferrous particulates, and low micron for other types of particulates. (this will offer better protection for the trans over all, AND extend the service cycles on the changing of the trans fluid (about 10K miles more)
*the shift kit is a new find for me, but defiantly on the list of later on.. > later phase of modding the trans( reduced time "shifting" should make racing the auto a bit more predictable, perhaps less loss of power during change over, and over all better performance.)
*Limited slip diff> i know that this is not something that most would think of doing for an auto, but the realized performance gains on the track should/would make it worth wile.. now as to if there IS an LSD that will fit the A-246E is another question all together, but i have hopes that a C-series lsd may fit.. and the only addition stress that would be realized from this mod would be excess heat, which should be handled by the already upgraded cooler.

this list of mods (whit the exception of the LSD) would cost not too much considering the yielded benefits. and can all be transferred over to another trans should this one "not make it". but the whole point is to make the trans have a drastically reduced susceptibility to catastrophic failure. and handle the increase load.

this trans regularly goes for about $250. and does makes it not a HUGE pain to replace should you break it. so in concept you can go off and mod the car with out fear of needing to find a hard to get trans quickly, or a more expensive trans cheaper...


as for not going with the cryo or iso process, i just don not believe that it is needed for anything other that a race prepped trans.