gearbox

PerformanceAutoworks · Post by **PerformanceAutoworks** » Tue Jan 31, 2012 4:51 pm

littlefeller wrote:all manual boxes fall out of vtec between shifts in 1,2 and 3 but stay in vtec between 3, 4 and 5, some only between 4 and 5,

Theory and reality .... which is best..... only one way to find out....

Fiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiight !!!!!!!!!!

I can only assume that you've come to your conclusions with the manual boxes by using 7k as a shift up point?
I can honestly say the only H22 manual gearbox car that is even close to having the "fall out of VTEC" issue is the ATR...1st to 2nd especially...you absolutely have to be spot on with your shift point and a slick shift needed also to keep it on the boil. This is more to do with the ATR's higher VTEC engagement point than the ratios of the box however. H22a8 Ludes have the same ratios and don't suffer.

Post by **Vtecmec** » Tue Jan 31, 2012 6:24 pm

When my lude was an auto, it never dropped out of vtec on full throttle, ditto now it's a manual. When shifting, I never touch the beginning of the red line.

littlefeller · Post by **littlefeller** » Tue Jan 31, 2012 11:20 pm

yep was using 7000rpm as a shift point and a 5250rpm vtec start point

is now wondering if there is a difference between auto boxes

Vtecmec wrote:When my lude was an auto, it never dropped out of vtec on full throttle, ditto now it's a manual. When shifting, I never touch the beginning of the red line.

which box? where does yours red line? where does your vtec start

but even with a shift point of 8000rpm and vtec @5250 the m2b4lsd box is still 4mph short of vtec between 1 and 2, its very small though perhaps nobody notices it

with vtec @5000 it would be fine

sorry theory will always win

Post by **Vtecmec** » Wed Feb 01, 2012 8:34 am

I never shift any later than 7k, I've had 5 and 5.5K VTEC engagement points with different ECU's. The current manual box is from a 2.0 (M2J4?), though I'm pretty sure the guys on here will confirm that other boxes are ok too.

I think the theory is letting you down.

littlefeller · Post by **littlefeller** » Wed Feb 01, 2012 9:06 am

it isnt theory, its mathamatics taken from a list of gear ratios, the ratios could be wrong though unlikely as these have been going around for quite a few years. ok your box - 1st @7000rpm 35.3mph, 2nd @7000rpm 64.3 so if at 7000rpm in 1st (35.3mph )then shift to 2nd you would need to do traveling @ 50.5 for vtec @5250rpm could you check something for me please, next time your driving @ 60mph in top gear have a look @ the tacko and let me know what rpm you are doing, these figures are based on std wheel sizes, would be intresting to cross check the ratio chart. for the ratios for the 2.0 m2j4 box to be correct on the chart it should be reading 2850 rpm @60mph in 5th

speeds for 5000rpm 1st 15mph, 2nd 27mph, 3rd 39mph, 4th 51mph, 5th 63mph, does this look about right?

A1ex · Post by **A1ex** » Wed Feb 01, 2012 9:27 am

little feller, your maths isn't adding up.

7000prm in second is 64.3 mph but 5000rpm in second is 27mph.

if you take 64.3 and divide it by 7 you get 9.18 mph per 1000 rpm, you times that by 5 and get 46mph at 5000rpm.

Edd · Post by **Edd** » Wed Feb 01, 2012 9:57 am

I can't hit vtec in 5th legally....

littlefeller · Post by **littlefeller** » Wed Feb 01, 2012 9:59 am

oops my typo, 1st @5000 25.3, 2nd @ 5000 46 3rd @5000 65, 4th is 86 5th is 105
originals should have been 3000rpm

my fail

i changed the spreat sheet box to 3000rpm thinking it would be easyer to cross check then i forgot

littlefeller · Post by **littlefeller** » Wed Feb 01, 2012 10:02 am

Edd wrote:I can't hit vtec in 5th legally....

you could in the isle of man

Edd · Post by **Edd** » Wed Feb 01, 2012 10:19 am

littlefeller wrote:
Edd wrote:I can't hit vtec in 5th legally....
you could in the isle of man

Ha ha, good point!