The Getrag F23...How Much Can It Take?
 

I've been pouring over the numerous threads around here regarding turbocharging/supercharging, etc. I'd be lying if I said I wasn't interested in exacting some power via a turbo kit in the near future.

However, although much talk around here is geared towards whether the engine can take the power, it seems that very little discussion has gone into whether or not the transmission can. Now I'm not talking about the clutch. We all know that the stock clutch is nowhere near sufficient to handle the type of power a T/C or S/C can throw at it. So I'm fine with upgrading that.

My only problem is, after digging around for some info on the F23 transmission, it is said that it is only rated to handle 155 ft-lbs of torque. Now with some of these turbo kits pushing torque numbers into the mid 200's, are these transmissions really going to hold up to the additional stresses that are brought into the mix?

Also, if they aren't strong enough, what plan of action would be needed to ensure that your not going through synchro's every month, or blowing input shafts on a regular basis. Would you need to take it to a transmission shop and have it rebuilt with stronger internals? And is this even available at this time?

Just looking to start a little discussion on the other side of the fence. The engine reliability has been discussed at ends, but again, I've heard little about the transmission. Anybody with experiences of their own or any knowledge, please chime in :)

Thats a really good question..

I would say as for reliability under the stress of the T/C or S/C there hasn't been enough people out there that have had them for that long to see what it does to the transmission. I recall looking over css.net and there are only a select few 2.2 and 2.4 with S/C or T/C.


But nonetheless, a great question.

yea i was wondering that too..

and another thing i was wondering is why the auto tranny put into the 2.2's is rated to over 300ft-lbs but the manual is only 150? i didnt get it. if 150 is correct than that means we are already at the highest amount of torque it can safely handle

i think it's stupid, but for some reason i don't doubt that.

I wish I knew.....this is one thing stopping me from supercharging

In cavalier/sunfire world this trans is living behind 11 second cars . Give Bill Hahn a call , their sunfire which runs 11's , uses a stock F23 . From all Ive been able to observe , it takes substantially more power reliably than its factory ratings . Of course an able clutch , proper mounts and good driving go a long way too .

I actually Emailed Getrag today about that very issue....hmm great minds think alike. As soon as i get a response i will be sure and post it...i also inquired about if there is an AWD in the works that could be used on the cobalts :-D

awd requires a diff in the back.

my f23 holds up fine. 12k miles @ 9psi and holding strong. Even the clutch as a matter of fact...sure it slips when I punch it in 3rd in the upper rpms a little bit, but i'm impressed with how long it has lasted.

yes the auto trans does holds must stronger than the 5spd..odd..but tis true. they shud of put the ss/sc tranny in the 2.4..imo

yes....i know that AWD requires a diff in the back...but thats why i asked the company about any plans to develop an AWD system for our cars....meaning tranny, diff, transfer case, and rear diff....

ive been told by a couple people that had the auto tranny past 400hp without problems... have also heard that the auto tranny was built for a v6 car but slapped on ours... someone also showed me a performance gm tranny that is auto.. dont no if i still have the email.. havnt checked in awhile.. yea hahn has pushed those trannys pretty hard but in the right way... wheel hop, burn outs, improper treatment all have a play in tranny life.. if they can do 50 passes on a 11 second ion with our type of tranny and not have problems, that says a lot.. mounts would be a definate.. better tranny fluid i would assume for lower temps.. any cooling mods that would work on the tranny should be done...

i am auto and i am in the process of turboing my car within the year.. funding it aint my biggest problem, its the fact of A: tuning B: not toasting the tranny or making one wrong mistake to toast the motor..

i have a friend around where i live who knows quite a bit about tuning so i am good there if all goes well :)

Go buy a 2nd gen eclipse:lol:

the tranny is called: 4t65e

there is a site that builds parts for them as well for cars with high hp... they have parts to watch the line pressure and to regulate it.. looks awesome.

well i know the sunfire that adam races has 500+ whp and if he is using a manual then thats another one that is past the 155 mark lol but he showed me his dynos and i talked to him alot about it and i didnt know it was a stock f23. maybe someone try to get bill on here to answer some more if hes not too busy

Go search the cavalier forums for more/better answers. They've used and abused longer then the Cobalt 2.2/2.4 have even been out for.

Bill was just talking about this in his GT35r thread for the SS/SC's . Durability was brought up with the F35 trans , and he said he wasnt worried one bit , because its stronger than the F23 that their Turbo sunfire was using without problems . Its a HUGE thread , so youll have to dig :D

The 4T45E automatic used behind the current Ecotec's is rated to a maximum 221 ft-lbs engine input torque which is different than the maximum gearbox torque rating (the older 4T40E was only rated to 190 ft-lbs max engine torque). The 4T45E is also used behind some of the pushrod 60° V6's and also the new HHR SS (which is why the HHR SS is torque managed to that level when you choose the automatic).

Getrag F23:
http://media.gm.com/us/powertrain/en...Getrag_M86.xls
http://media.gm.com/us/powertrain/en...23_M86_MG3.doc

Getrag F35:
http://media.gm.com/us/powertrain/en...08_GME_MU3.xls
http://media.gm.com/us/powertrain/en...08_F35_MC2.doc


HydraMatic 4T45E:
http://media.gm.com/us/powertrain/en...8_4T45_MN5.xls
http://media.gm.com/us/powertrain/en...45_MN5_ME7.doc


Now keep in mind that the engine input torque ratings are just what GM has done durability testing to and may not indicate the maximum torque they will take. There's other factor that determine the rating such as vehicle weight which if means if you placed the same transaxle in a lighter car it may take more power since the loads might not be as high on the internals. It's quite possible to see some transaxles take over twice their rated input torque but you can bet they will have accelerated wear and some won't last as long as at the durability tested levels. Then there are other designs that won't tolerate much over their rated levels and when abused/pushed may have differential failures, gear set problems, bearing deflection failures, etc.

lets just hope if i push 300 to the wheel my auto tranny wont drop lol... if so i will look at the higher model that i can get put on the car and get tuned with the emanage ultimate if i go that ruite..