7 replies to this topic

[Hebby73]

I'm wanting to run my Vtec mini on 13 inch wheels, I've not swapped the final drive gears from the stock b18c4 that I've got, is there just one final drive that everyone uses ? What does it come out of ? I'm guessing it's from another Honda ? Or do I have to do some swapping gears about to get things to work ?

[joakwin]

I think for the b engine they get the 3.7 Watson final drive at 500quid

[Hebby73]

So are these custom made ? I thought that they would just be taken out of another gearbox from say another Honda & swapped over, maybe by putting different sized bearings or something...I know very little regarding gearboxes so please forgive my ignorance

[joakwin]

Watson has them made

Their is a few other companies that make them as well but mostly for group buys


The d series honda swaps have gears that could be used from other honda cars, the civic cx vx has a 3.25 and 3.7

But no stock honda gears like those for the b series engine, all aftermarket

[Kam]

As joakwin mentioned the Honda B series gearbox has the worst selection of final drive gear ratios and it is a shame you can't use the ratios from the D series as they are better suited, but then again they made them for Honda and not Mini 

 

I don't think vauxhall, suzuki, rover etc have as much of an issue for final drives - its a Honda thing 

 

Here's a wiki guide on Honda engines, the Honda gearbox guide/ratios is at the bottom just so you have a heads up

 

Wiki clicky for ratios

 

And a gear calculator to play with once you're armed with all your info

 

Ratio clicky 

 

As mentioned, over here you can pick up a 3.4 or 3.7 final drive which will help massively, you can get them from Geoff Watson - clicky

 

Geoff's one are known to 'whine' on deceleration, bothers some but not me as its adds mini character to me, its not straight cut sound by any means but still adds a nice touch, they whine as they are not lapped in

 

Across the pond you can get one from Jamie who does lap his in, there is very minimal whine from his ones, but you pay a bigger premium, throw in shipping, possible customs charge, clicky for Jamie 

 

What ratio you need is a preference thing

 

[Hebby73]

Brilliant info there many thanks, it's hard to say what's right for everyone as everyone will want different things from there own cars, I'm wanting to use mine on the road for a Sunday thrash & the odd track day. Will have s better look a calculator for the gear ratios to see what speeds would be expected in each gear, I don't want to be flat out at only 70mph or something silly like that, or need to be constantly dropping down two gears to get the thing moving at speed from say 60mph in top gear, or a huge gap from 1 gear to the next.again, thanks for all your help 👍

[Hebby73]

Or alternatively can you just swap complete gearboxes ?
Does the b-series box got the d-series engine ?

[Kam]

You can use any B series box you want and its a simple plug n play but unfortunately you can't use the D series box on a B series engine but you can use the B series box on a D series engine - confused? good

 

There is an adaptor plate made for the B series box so it can be used with other engines like D H F, the H2B is the most popular and one I was looking at, so basically you buy a H block (2.2 prelude) and use the adaptor plate so you can use your B series box and retain them ratios, problem is with the plate added it alters the engine positioning (height angle) quite a bit (in mini terms) so fitting it even in a clubby would be a mission. The adaptor plate is also made for the D2B and F2B, they didn't bother making the D series adaptor plate as the B series box is far superior for ratios (and strength allegedly) for the Honda fanboys so everything is >2B

 

In mini terms they don't get us so don't cater for us 

 

For what ratios you need thats a toughie to answer as you say people want different things, my sunday thrash has turned into now wanting a nice sedate sunday quiet(ish) drive but with the odd sunday of hooliganism 

 

I've given up on trackdays, at least taking them seriously, a set up for fast road vs track that someone is comfortable with both ways just don't happen, theres always something to fettle with so base the majority of the build on its use and don't get too downhearted if the other takes a bashing

 

With the standard honda ratios (not much in difference between the boxes overall for mini terms) running on 13's you will find 1st gear not always usable, more so if your gas pedal is basically an on/off switch, you need as much movement on the pedal as possible to help where it can, starting in 2nd might seem like an easy way out but if you want four gears then keep the a-series in 

 

Out on the road some have found cruising at 70 sitting in 5th the revs are around 4500-5500 - nice, again this all differs with not just tyre diameter but aspect ratio as well

 

You can get custom final drives to throw in the honda box but they ain't cheap, but they do make the difference between enjoying it and not enjoying it so effectively buying it and finally using it as intended or selling up altogether as you are tired of how it runs, if you are running smaller size wheels than Honda intended this is important 

 

The calculator will help you to work out the difference between the standard ratio, the 3.4 and 3.7 FD and how it suits your need if you feel you need it, you really do not want to build it to then find out you can't plant your foot and get the revs going into the ground

 

End of the day if its wet or damp outside then yes it can be spin city in most gears but then again this is based on throttle control, you can drive it normally in the wet in all gears including 1st

 

I could spin my 1275 with full throttle in 1st in the dry and that was only a stage 3, any car without traction control will light up the tyres if you plant your foot in 1st, I was using either pirelli 145's or yoko a539's back then and the yoko tyres are still on the car now and I bought some falken 145's (pirelli p3000 discontinued) and I can pull away in the wet in 1st with no spin and plant 2nd and get no spin whatsoever unless I turn the wheel, in the dry I can only spin in 2nd if I aggravate the car (turning wheel wildly) obviously the 145's will break traction much easier than the 165's...  

 

However my gears (3.4FD) are quite long (would prefer longer) but then again I take this car on long trips inc abroad and its sits nice on the motorway, loud but does its job, but having long gears can go to waste if you don't have the power to boot, I had this 3.4FD with the b16 and it can feel empty but was smooth to drive, having shorter gears won't make your engine feel empty but you will be annoyingly changing gears, having more power b18c4 (and torque) to boot over the standard b16 does make the difference of whether it feels empty in gears

 

Its all fun trying to find the answer