Limit of Stock b16a gearbox shift speed

[Scholzey]

hey guys, i was going over some of my datalogs from some of the quarter mile races i have done, and was curious as to what a fast shift time would be, or how fast a b series tranny can be shifted.

at the moment i have a stock b16a gearbox with origional synchros and a sprung clutch, i also use a no lift to shift switch on the clutch.

i was looking over the datal logs and the fastest i saw from clutch out to clutch out was about .25 sec

now if i get these speeds, is there any point in getting a short shifter or unsprung type clutch or anything like that?

also a note, at about 165 000 km on the stock synchros and a bunch of fast shifts starting at 150 000km, the third and fouth gear synchros now miss at fast high rev shifts. very annoying.

i'll be putting in a new set of syncyros soon to fix the problem, which i think is going to be quite costly, but it has to be done.

let me know what you think guys. if anyone has hondata i've uploaded the logs for peeps to look at.


to check shift time i looked at injector duty cycle, my clutch swith sets a lower rev limit, there for cutting injectors as soon as the clutch is touched, and wont start them again till clutch is fully out.

cheers

[turbotegs]

hey there, i had a quick look at some of my logs and my clutch out to clutch out time is usually sub .1 sec. my clutch switch is set so that it turns on exactly as the clutch disengages so the pedal is about half way down so this could explain the quicker times than yours, but more than likely i would put it down to the clutch. when i had my competition single plate clutch i couldn't change as quick and it eventually got to the point where i was missing gears, i also thought it was synchros and pulled the gearbox down to check and it all seemed fine, i then changed to the twin plate as i could see that the single had been slipping and there has been no problems with missed gears since and i can definitely change quicker.

just a thought.

cheers bruce

[Scholzey]

hmmm does your clutch grip till it disenguages? i would like to set mine like that, but i fear the revs will jump as it starts to slip from taking the weight off the clutch. also i am using a brake switch, which i can only set to switch like a brake pedal does, so it switches at the very start of travel. what setup do you use?

[turbotegs]

i'm using an adjustable pressure sensor switch in the clutch line, so you can adjust according to line pressure, which in turn allows you to adjust what drive is on when ignition/fuel is cut.