84 replies to this topic

[steah]

well honestly (not sure if you've looked at the project thread) i thnk im going for a minor engine, then sorting a ford box conversion (been done numerous times) dont need a huge budget, but at this point after all the flaws being pointed out the gearbox being sequential is the least of my worries, i can put up with a normal box, its not any problem for me, just my mates who cant drive, so their loss really... and wow 110 bhp! what if i threw a turbo on that bad boy?

[Cooperman]

To get 110 bhp from an A-series requires very careful engineering and is quite expensive as the parts needed are high-quality and not cheap.

A turbo-ed 1275 can give around 125 bhp, or more if built correctly.

Is the car for competition, if so what type/class of competition?

[steah]

its not for competition, its just the fact its a formula styled car, so it needs enough power to make use of all the downforce, check out the project thread and youll see what i mean http://www.theminifo...he-mad-project/

 

otherwise it just adds drag and no handling gains, need enough power to make use?

[CCX]

If you plan on making a formula car out of carbon fibre, I would budget far in excess of £50,000. Carbon is incredibly expensive to work with, the engineering skill and knowledge required would be immense. Plus, if you want downforce, it's not just a case of sticking a big wing on it. There's an awful lot of design work required. With all that expense - building a carbon single-seater - I'm not sure they'd be much point in putting an A-series in it. It would probably be cheaper to stick a 1000cc bike engine in the back than to upgrade an A-series to those levels of power. And also, good luck getting a Formula-style car through an IVA test. Really, unless you have a fortune to spend on this, it's not realistically achievable to build something like your sketch out of carbon.

Edited by CCX, 08 July 2014 - 01:45 PM.

[steah]

Well yeah, I know about prices and stuff, but honestly its not that bad, we rethought a lot of it, and decided we were more or less gonna build a spaceframe out of steel or ally, we have been thinking about it and have finally got a grasp on the price, maybe changing it is a good idea we'

[steah]

Ve basically decided to build our own ariel atom more or less now, with a busa engine probably and f1 styling, so we toned it down quite a lot haha

[mini93]

Really, you cant run a sequential system on a normal gearbox with runs syncromesh, the syncromesh is there to spin up the dog teeth (of which there are many on a regular box) by running a sequential shifter your there to cut down on time which you are off the accelerator pedal.

 

When driving a sequential boxed car, the gearbox runs without this syncromesh, the dog teeth are wider, stronger, under cut and there are fewer of them, often around 4 on the circumfrance of the gear, with matching quantity on the engagment ring. By having fewer dog teeth you are given a more positive location for the teeth to engage one another upon shifting meaning in essence, you can flat shift, meaning you can change gear without having to depress the clutch pedal. You simply have to lift off the accelerator slightly and very quickly, this will slow the gearbox down just enough to disengage the under cuts on the dog teeth (which are there to stop it coming out of gear) and you can shift. This is where the time is saved on track, any moment your not on the power time is lost.

Trying this with a syncromesh gearbox will simply damage the rings and teeth in the gearbox and you will likely not even finish a race. To finish 1st, 1st you have to finish!

 

A sequential gearbox is better still, sensors on the gear lever, or in the gearbox depending on the manufacturer means that as soon as you start putting load on the gear lever the ECU cuts spark to the engine for a very short space in time so you can stay flat on the accelerator and the ECU does the work for you.

This is another reason I dont think it can be done on a mini/A-series unless mega bucks are spent.

 

There are companies out there which can supply fuel injection which will allow this to work on an A-series, companies which will supply a bespoke 'box but this is far too expensive. The better option which you appear to have already clicked onto is using a Bike engine which come with a sequential box standard and fuel injection

[MIGLIACARS]

A while ago I was a photo of a quaife/swiftune 6 speed sequential box.

 

cannot remember were i saw it can some help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Dan]

Are you thinking of the Australian conversion?

[Tupers]

Steve Harris had a couple Quaife 6 speed sequential boxes for his hill climb cars that were built in auto cases. I'll try and find the pictures I took of one at his auction. 

[David Reid]

You need to ask why do you want a sequential, the answer for a track car should be reduced shift time. With a semi auto, even tip converted using a mini autobox will slow and rubbish so don't bother, even if you did get it to work the transmission loss of autos is massive and you would find yourself with a slow track car. Stick to the known ie 4 speed sc gearbox for the track you need nothing else.

Reference twin rads, again think "why would you need them", the answer is only if you could not cool your engine with a single rad, as twin rads are heavier and hold more water than a single, again slowing down your track car.

Hope this helps

[MIGLIACARS]

Steve Harris had a couple Quaife 6 speed sequential boxes for his hill climb cars that were built in auto cases. I'll try and find the pictures I took of one at his auction. 

Yes sorry it is harris motor sport I saw            not swiftune!!!!!!!!!

 

Ive found the pics now.

So you have one do you have you had it in a car yet!!!!!!!!!

[MIGLIACARS]

You need to ask why do you want a sequential, the answer for a track car should be reduced shift time. With a semi auto, even tip converted using a mini autobox will slow and rubbish so don't bother, even if you did get it to work the transmission loss of autos is massive and you would find yourself with a slow track car. Stick to the known ie 4 speed sc gearbox for the track you need nothing else.

Reference twin rads, again think "why would you need them", the answer is only if you could not cool your engine with a single rad, as twin rads are heavier and hold more water than a single, again slowing down your track car.

Hope this helps

Im hoping that it will be stronger than a 4 speed as with the power I now have I think! the dogbox I use will be up against it

 

 

[David Reid]

 

You need to ask why do you want a sequential, the answer for a track car should be reduced shift time. With a semi auto, even tip converted using a mini autobox will slow and rubbish so don't bother, even if you did get it to work the transmission loss of autos is massive and you would find yourself with a slow track car. Stick to the known ie 4 speed sc gearbox for the track you need nothing else.

Reference twin rads, again think "why would you need them", the answer is only if you could not cool your engine with a single rad, as twin rads are heavier and hold more water than a single, again slowing down your track car.

Hope this helps

Im hoping that it will be stronger than a 4 speed as with the power I now have I think! the dogbox I use will be up against it

 

 

 

 In my understanding the space in a standard casing is limited so 5/6 speeds compromise gear width thus strenght, at least that was my understanding from when I looked at them last, things could well have moved on and I wait to be corrected

 

I think your  also taking my comments slightly out of context, this guy is going to be lucky to have a 100bhp and has limited funds a sc 4 speed is going to be far better than the mini autobox with tip conversion he was thinking of.

[The Matt]

He also wants to run the engine longitudinally, so the Mini/Metro autobox would be useless to him anyway as it's transverse mounted.