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Drag trans brake and bump box

Off Topic Discussion

If it's not really about tuning or wiring. Then it belongs in here.


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Hello,

im new in drag racing, so i have several inquires regarding the trans brake and bump box. First whats the difference between both, im planing to run the car on motec m800 ecu my gear has a trans brake built on it, im planning to wire the trans brake button into the ecu to switch antilag on. But what is a bump box? Will i need it? And can i tune the ecu to get the same result of a bump box or i need to fix a hardware?

thanks

The "bump box" is used in staging to 'bump' the car forward to bring it into position.

I would guess it is some means if momentarily releasing the brake to allow the car to inch forward.

Ah, seems I was right - good summary of it here - https://www.youtube.com/watch?v=XIznnpUR6sQ

What i understand from the video is that the bump box is used for the driver to release the transbrake and apply it again in a fast time for the tree to know that he entered the final stage. What i dont understand is can it be tuned or a hardware should be installed? I already have wired my transbrake button into the ecu and tuned it to apply the 2step.

also can't it be done manual? By releasing the transbrake button and applying it again?

thanks

With the trans-brake engaged, and the engine running under boost/with power applied, any momentary rease of the reverse band will jump the vehicle forward as hard as a launch.

Because the car reacts so violently, and quickly, to the release, it has to be released and re-engaged VERY quickly, too quickly for most people to do it accurately and fast enough. I would expect, in theory, a momentary contact switch could get the job done (unfamiliar with the electrical packaging of it) but by using a programmable timer it can be done with more consistency and without the driver being part of the equation - for example, if a 2" jump/bump is a 2mS release it is practically impossible to judge that manually with consistancy... you don't want one bump to be 2", the next 7" and the next 3" because you can't get it right each time.

Thanks gord, any idea how can i wire the push button to cut the transbrake? Im planning to set a timer as the m800 has a built in timer, which is enabled when the push button is pushed for a set time and resets after the set time ends.

'Fraid not - you may find the ECU just needs a momentary contact switch* to activate the 'bump' in it's software, after that it is just down to getting the delay where you want it for the amount of 'bump' you want.

*Going to be down to a bit of RTFM, which is always fun.