5MT failure from power

[bnguyenbb6]

I understand that user error is the main cause of death of transmissions and that there are a handful of guys running huge turbos on stock 5spds but I would like to hear about failures from power. Just rolling onto it, and breaking a gear.

 

I floor my car pretty much everyday even in the heat(100+) but I granny shift all the time(even at the drag strip. dumb? yes but my tranny survives). My fastest shifting is still pretty slow, babying the tranny.

 

How many have broken gears just from power?

 

I'd like to hear the "unsuccessful stories" lol, not "it should be good for..."

Thanks!

-Brian

[NSFW]

ATP 3076, 22-23psi peak boost, never dynoed yet, so far so good.

 

I'm upgrading to 6MT soon for a variety of reasons... uncertainty about the 5MT's robustness is one of those reasons.

[bnguyenbb6]

lol, thats my turbo of choice if I upgrade. I'm getting a motor built and the only reason why I'm not doing rods and cams(so cheap that I should) right now is the fact that the next weakest link isn't my rods. Its my tranny, I just don't know how much it will hold though.

 

I'd love to have a 6spd, they're pretty bullet proof apparently...

[Rick]

I would like to know this as well before I switch to E85 with my 68hta setup. I don't slam gears when I drive so I'm hoping it will last.

[bnguyenbb6]

The fact that no one(only the few that have not seen this thread) has broken one tells me that no one really knows. Much like the common "400whp" is safe on the stock block...well only a handful of guys on here are running larger than 20g's so that is not true.

[NSFW]

One guy here has broken one, but now I've forgotten who or how much power...

 

But for the most part, I agree. There's not enough info to really say where the limit is.

[Balrock]

Silverstar toasted his 5MT with E85 and 68HTA. He has since moved to a location that does not have E85 and he is very sad, but not his trannie.

[Legend]

No issues here with my 5mt on moderate power. It's seen at least 20 runs at the dragstrip. 73k miles, 343whp/390tq.

[Code]

I think j255c took out his tranny right after building his motor. Iirc he dynoed around 350 whp. I don't recall the circumstances under which it failed though, so it could have been some catastrophic event.

[Rick]

Silverstar toasted his 5MT with E85 and 68HTA. He has since moved to a location that does not have E85 and he is very sad, but not his trannie.

 

Him and I have almost the exact same turbo setup which is why I have been hesitant to run E85.

 

I was with Silverstar at the local dragstrip last year, and man that guy can drive. He was on his second transmission at that time, and before he moved I helped him with his third 5mt install. Needless to say he is very hard on his transmissions.

[StoplightAssassin]

I think j255c took out his tranny right after building his motor. Iirc he dynoed around 350 whp. I don't recall the circumstances under which it failed though, so it could have been some catastrophic event.

 

he was doing a 3rd or 4th gear highway pull

 

kevkel50 broke gears at stg 2

[bnguyenbb6]

So...silverstar broke his from torque or from user error?

 

j255c was the only one I remember that has broken a gear from rolling onto it...I wish some more guys would speak up. I also wish there was a cheaper solution than PPG gears or a 6spd swap .

[LittleBlueGT]

So...silverstar broke his from torque or from user error?

 

j255c was the only one I remember that has broken a gear from rolling onto it...I wish some more guys would speak up. I also wish there was a cheaper solution than PPG gears or a 6spd swap .

 

I have done 100s of 360 wtq roll ons in the winter months. No problem so far.

[j255c]

it blew up on a 375 wtq 350whp 93 pump gas rolling pull in 3rd gear. This is on a mustang dyno. It also made numerous dyno pulls at >400wtq on my meth map. Zorko(zorg??) also blew up his 5 speed. If you're making more than 360wtq I would not trust it in the long run. I also had a 6 puck clutch which is much harsher on the transmissions than a street disk clutch. LBGT I dont know what clutch you had but my standard street clutch could not hold 370wtq at all.

[bnguyenbb6]

j255c- you're talking about 360wtq on a mustang right?

[LittleBlueGT]

LBGT I dont know what clutch you had but my standard street clutch could not hold 370wtq at all.

 

I was holding 350-360 wtq for 3 years with my Bully Clutch (think slightly better then ACT, but not much more holding power). I did drive easy on the transmission though.

 

It started to slip in 4th gear runs a few months ago, I am now putting in one with even more holding power (still full-faced kevlar, but different diaphram)

[j255c]

j255c- you're talking about 360wtq on a mustang right?

 

Yes, my pump map made 375 wtq and 350whp on 93 octane at around 23psi. It was out of injectors >4th gear.

 

On my Meth+ Pump Map I made 400wtq and 380whp on the mustang.

 

On a dyno dynamics this was 424wtq and 420whp.

[bnguyenbb6]

Holy crap...thats way more power on a Dynojet...lol

[Rick]

So...silverstar broke his from torque or from user error?

 

j255c was the only one I remember that has broken a gear from rolling onto it...I wish some more guys would speak up. I also wish there was a cheaper solution than PPG gears or a 6spd swap .

 

 

Silverstar didn't break his from user error, he just drove the car hard. The day I was with him he ran a 12.0 sec quarter mile with a 68hta and e85 setup.

[kevkel33leg05]

I blew mine at stage 2 levels but drove it very hard. The 5mt will take a beating though IMO

 

http://legacygt.com/forums/showthread.php/can-someone-send-me-link-stronger-gearsets-99749p3.html?highlight=kevkel33leg05