i have a t5 rebuilt with a cfdf will it hold up to powershifting, (shifting as normal but not letting off the gas when depressing the clutch so you build r`s then dump it) everytime i race someone they do it and they either beat mme by a hair or i barley beat them.

 

If you do a quick search on the forum here, you'll find the resounding answer to that question is no, it won't hold up to powershifting for long at all, especially running a 350 motor. That T5 will be grenaded in short order. You should follow your own advice in your signature and invest in either a T56 or a Tremec TKO if you want to powershift without worrying about breakage.

 

i speed shifted an eaton fuller with no trouble

but yea it will tear up that t-5 pretty fast.......good built autos are best for racing like that IMO

im not sure, but maybe putting a better clutch in it may help that

 

Your best bet would be a better tranny.
Also it depends on what you consider powershifting.
Me personally I don't do that.
However I do launch my car at 5,000. When I shift, I start pulling out of 1st, hitting the clutch at the same time. About the time I am in N I let off the gas.
About the same time that I hit N, I am crossing the friction point.
As I go into 2nd, I start letting the clutch out again, and floor it.

I can also do this without crossing the friction point. Usually don't when I am racing though. Generally my clutch pedal hits the floor, just cause I don't want to start bringing it back up a fraction of a sec to soon and not make it in gear.

With all that in mind, it's not all how you shift, it's how you take off, what RPM your at when you shift, how hard you hit the gas when you do shift, and how quickly you let the clutch out.

I will also add a thought. When I bought my car I bought it to race it. So if I blow the tranny or engine, I really don't care. It's just going to suck that I can't drive it untill I get it fixed.
When I dump my clutch, I could almost sidestep it, and get the same result. Just don't quite like to do that. But point being the clutch comes up quick.
I thought I destroyed my clutch the first day. Looks and works great though. I also have a stock 305.

 

"Powershifting" - they way you explained it(which seems to be the comon theory of it) will kill a T5 in short time. Case flex is their death, and by shocking it on every gear change you stress it much more.

I shifted mine clutchless, but that seems to be a lost art. No lift, no clutch, just shift. There are a few ways to do so with a stock type trans. 1) You can set a rev limiter right at your shift point. Basically, when you "bump" the limiter, the engine has a slight moment of free-wheel and you can click right into the next gear. 2) (my way) is to do it by feel. My motor made peak power around 6800, but I shifted around 7200, as high as 7600 some times. Shortly after coming past peak power, there is an almost free-wheel state and you can again click right into the next gear.

The bottom line will still be a broke T5, as although I never broke one during a shift, I shattered many under power in the 3rd gear(the most comon failure).

 

Have to agree with kcb on the sidestepping bit. I learned that lesson the hard way years ago when I was a punk teenager. I had a Hays 3 finger clutch and a Muncie 4 speed in my 69 Camaro back then. I just slipped my foot off the side of the clutch pedal at around 5k to launch in 1st gear. BAM!!! Must've fractured some of the teeth on the countergear, because just a few days later, 3 teeth broke off it, and I was driving it pretty mellow when they decided to let go. Sidestepping severely shocks the entire drivetrain, so wherever the weak link is, it's gonna give. It's also extremely hard on the clutch and the u-joints. I also know all too well about letting up the clutch just a fraction of a second too soon. I can't tell you how many times I'd miss 2nd or 3rd and overrev the **** out of the motor while the gears are grinding! Of course the old Muncies have the clunky, external shift linkage, and the synchros are quite notchy, not to mention the thick 90wt. gear lube, so it's even easier to miss a gear with one of those. Considering how tough those trannys are, if you can break one of them, it's 100 times easier to break a T5! Btw, the better your clutch is, the easier it is to break something else, since a racing clutch that's working properly doesn't allow any slippage to soften up the shock to the rest of the drivetrain.

 

dang and i thought me and a friend of mine were to only ones.....people go crazy when you do that with them in the car

i also like to fools that say you cant power brake a stick.........

 

Back in my college days, we were filming a quick vid of a buddies built TSI passing under full boost. I was camera mand, riding in another guy's Prelude. He was talking all this crap about how good a driver he is, blah, blah, blah, so I asked, "then why do you use the clutch?" He goes into this speal about how hondas won't slick shift, etc, etc. - Long story short, I get stuck driving the prelude back, as this guy wants to ride in the Talon and I rip 4-gears in the turd passing them with my left foot on the dash board. My buddy driving the Talon had tears rolling down his face he was laughing so hard when we got back. The prelude owner wouldn't even talk to me, just got in his car, slammed the door and left.

Muncies and strong don't go in the same sentence. I know the old schooler's think they're the shizz, but they also think there is nothing better than camel hump heads. My first car was a '69 Z28, we took the 302 out and put an aluminum headed, roller 427 in. I never hurt the "rock-crusher" in low, but if it chattered the tires going into 2nd it would roll the entire clutster shaft out the side of the case and dent the floorboard in. I split 4 or 5 cases in about a 4 month span. - I didn't run any syncro's and I had a long shifter. Mine would shift clutchless as smooth as silk. You had to double clutch to downshift w/o syncro's though. Kinda like driving a Mack truck. The final fix for it was a modified 18 spline Chrysler "crash box".


anyhow, back on topic - T5's won't last under much abuse. Shock is probably the most abusive thing you can do.

 

Never had the opportunity to test out a Muncie behind a big block motor. They've held up great behind my SBC, but the torque of a rat motor is another issue altogether!