vtec q

littlefeller · Post by **littlefeller** » Sat Aug 04, 2012 9:12 pm

ok i should remember this but i dont, does anyone know the min speed for vtec activation?

bristol_bb4 · Post by **bristol_bb4** » Sat Aug 04, 2012 9:16 pm

19mph

hmm i think anyway? did do loads of reading up on it before, its either that or 25mph im sure

littlefeller · Post by **littlefeller** » Sat Aug 04, 2012 9:30 pm

thanks, either is good.

ziyaan · Post by **ziyaan** » Sun Aug 05, 2012 2:06 am

1st gear tops out about 32/5ish which is at 7800 sort of

YouTube · Post by **Sailor** » Sun Aug 05, 2012 9:49 am

... which means that vtec cuts in in 1st at about 20mph.

littlefeller · Post by **littlefeller** » Sun Aug 05, 2012 9:08 pm

thats cool, for some reason i had 18-19mph in mind but couldnt remember exactly, i fairly sure the last time i googled it i got quite a few different points like from 16mph to 26mph but couldnt remember the exact speed,i will have a play around with my spreadsheet and get an idea what speed a m2b4 is doing at 5000rpm. though i read somewhere that the vtec point changes depending on throttle position

littlefeller · Post by **littlefeller** » Sun Aug 05, 2012 9:36 pm

think i need to refrase the question, what is the min speed the ecu has to see to allow vtec, thats better

for an m2b4 5000rpm is 25mph but the ecu will allow vtec lower than this but i dont know how low.

littlefeller · Post by **littlefeller** » Mon Aug 06, 2012 11:19 am

ok found it, its 14-16mph

bennyboy · Post by **bennyboy** » Mon Aug 06, 2012 11:32 am

IIRC correctly, vtec needs three factors to activate:

Oil pressure, engine up to temp
Speed over 11mph I think
Throttle - needs a certain amount, though I can't remember what

Put it this way, mine is set at 3800, and I'm over that when cruising in 5th on the motorway, but it doesn't engage until I put my put down, giving it that third criteria.

littlefeller · Post by **littlefeller** » Mon Aug 06, 2012 11:57 am

on an m2b4 box 15mph would be correct for no vtec in 1st with the delimiter and vtec @5000rpm, with 11mph it would be able to vtec. so it must therefore be somewhere between the two. think at 14mph and vtec @5000 it could just do it, but then maybe there is a zone rather than an exact speed, again this may take into account of throttle possision maybe.