Ackerman on the 22

[dbizzle5]

Has anyone worked out a way to increase the ackerman on the 22?

The front outside wheel wen turning has way to much lock and is almost parrallel with the inside wheel.

This problem I think is the main problem with the 22 causing it suddenly hook during the corner as soon as you come off the power and the weight transfers forward. Ive tried everything else setup wise to try and compensate for this but nothing really solves it.

Just wondered if anyone had worked out a way to solve this as I cant!

[Frecklychimp]

Agree totally dude, thats why the rear end loses traction... there is nothing but inline or trailing Spindles to adjust steering.

Have seen Ellis Stafford on another car use carbon plates mounted where ballstuds go on spindles to give extra options, but with the steering on 22 being linear it will be hard to get anything to work ratio side to side wise like a radial bellcrank steering system operates.

I was chatting to Tom from Akula and we worked out that it would be possible to fit rear pivoting bellcrank steering on the chassis as there is enough room once rack is removed and there are posts to use as pivot points i you remove the plastic tapered sleeves... just need someone handy enough to make the parts!

When my 3D AutoCAD drawing of 22 is completely finished i'll be able to play with the design.... but its been 6mths so far cos it takes forever when doing half hour at a time.

[Frecklychimp]

Actually just wondering if curved turnbuckles/links would be able to give it a different Ackermann ratio enough to help?

With it having linear steering reaction, unless you change the toe in/out drastically it will be hard to get different response with wheels side to side against each other.

I'll get some graph paper out and the calculator and have a play... good fun engineering!

[dbizzle5]

haha! youre a much cleverer man than me! lol If this cud get sorted then the 22 wud be awsome. I still like the car and its only really been an issue on high grip astro. On carpet and at your place indoor it was fine.

So just adding new holes to the spindles isnt the answer? I was hoping I could just make a carbon plate to move the holes further back/forward on the spindles.

[Frecklychimp]

It may give you enough to dial out the snatchy feeling but unless i do some proper maths i can't work out the differences in angles... tbh i can't be bothered with maths tonight anyways!

Sure you can understand what i mean with linear and radial? with linear the ratio between wheels doesn't change across steering action, on other cars with bellcranks they have a radial ratio which changes how far and angle the arm is positioned during its sweeping motion, which changes the ackermann between wheels... 22 doesn't do this, the change between wheels is in the spindle pivot lengths and distance of mounting points on castor blocks which gives the angle of turn.

I've got a bloke that does Carbon cutting so may be able to get some different shapes with hole patterns knocked up for us to play with.

If you have spare spindles then get the drill out and give it a go buddy

I've always known its the front end giving the issue with mid corner sliding/grip loss but adding weight more towards the rear and using minimal front camber to allow the back to roll and rear tyres dig in helps as long as you are smooth with throttle in corners.

never bothered with it as my driving doesn't warrant designing new parts and i am used to it enough not to be an issue.

High bite tracks it is always awesome as you tend not to use steering as much

[dbizzle5]

Ahha! Ive just moved the castor blocks backwards and put the 2mm spacer at the front which has reduced the angle of the outside wheel. I think u have this done already.
Hopefully this will be enough.

[Frecklychimp]

Yeah that does help matey

I've been messing around with mine on the bench, going to drill my spindle ball stud holes further into the lever part and try it... it should give the outside wheel less travel and it looks like inside wheel will still reach lock stop, although not a lot of room between turnbuckle and back of spring.

not trying it Sunday cos i think it will weaken spindle too much and i need as many points as poss this year!

You ran that gear diff yet? that completely changes handling so its like driving a different car.

try running -0.5 to 0 camber on front with -2 on rear, makes the snatching less severe but does induce understeer on turn in, but with Nick's pistons the car squares up quicker so you can afford to let back end roll more.

tbh the biggest improvement was being very smooth with throttle and trying to keep on throttle as much as possible as it stops weight being thrown forwards and backwards all the time

What ride heights are you running?

[dbizzle5]

Been testing the gear diff. Tried 2k first and it was wank really! went upto 5k and was better but then chucked my ball diff back in and it was just better. More consistent through sweepers on power. Im sure the gear diff will be good but wiv these other issues I thought id just chuck the tried and tested ball diff for this weekend and try it again soon. I reckon Id probably go to 7k to start next time though. 21mm ride height all round at the mo.

[Frecklychimp]

found the same with gear diff on lighter oil, car swayed too much when putting power down, liked it at yours in wet and on frost so its staying in.

I run 18mm all round, on a 1/10th car 3mm higher makes a massive difference to roll centres and C of G, give it a whirl!

shame there won't be any track time before Regional cos it'd be interesting to see what you think of my set up... you'll thrash me Sunday but thats not down to the cars!

Only thing i found running at the very wet Snowman rd was my front end going light at higher speeds... only thing i'd changed was bodyshell to the phat rocco, but G speed after Sunday should help with downforce on front

lap time wise i was surprisingly hustling you on that last qualifying run at Arena X (yeah tell me it was your slowest run!), but that was probably cos Nanobytes are faster at Grantham IMO, purely cos they work better on the wooden bits than Schueys.

[Gnarly Old Dog]

Just throwing this into the mix for you guys.

Have you tried the 30 degree front kick plate from the 22T?

I've found that running this combined with zero degree caster blocks really mellows the front end of the car out and makes it feel as if it's got more grip coming out of the tighter corners?

You can see there's less skewed roll at high speed when the front end can tuck under the outside front wheel a little bit on high speed corner entry so for me, the 30 deg bulkhead has really smoothed the car out.

directionally, if you felt that the 25 deg angle was smoother than the 20 deg taped wedge then the 30 degree block feels almost twice as smooth as the difference between the 20 and the 25.

Just throwing in here in case it helps - there's often more than one way to skin a cat :-)

[university_dave]

Originally Posted by Frecklychimp

I was chatting to Tom from Akula and we worked out that it would be possible to fit rear pivoting bellcrank steering on the chassis as there is enough room once rack is removed and there are posts to use as pivot points i you remove the plastic tapered sleeves... just need someone handy enough to make the parts!

Funnily enough I've got a design worked up and costed - I just need to do some more analysis of the ackerman angles to see what effect it will actually have on the steering.

I'll try and find the time to have a look at it this week - been a bit busy with another project recently...

[Frecklychimp]

Originally Posted by Gnarly Old Dog

Just throwing this into the mix for you guys.

Have you tried the 30 degree front kick plate from the 22T?

I've found that running this combined with zero degree caster blocks really mellows the front end of the car out and makes it feel as if it's got more grip coming out of the tighter corners?

You can see there's less skewed roll at high speed when the front end can tuck under the outside front wheel a little bit on high speed corner entry so for me, the 30 deg bulkhead has really smoothed the car out.

directionally, if you felt that the 25 deg angle was smoother than the 20 deg taped wedge then the 30 degree block feels almost twice as smooth as the difference between the 20 and the 25.

Just throwing in here in case it helps - there's often more than one way to skin a cat :-)

Nice one Gnarly, you've saved me a test session... plus i swapped 30deg out of 22T to 25 deg for the reverse reasons, so got everything needed to bolt on

Get the feeling it won't be tomorrow as its looking to be damp and/or cool so won't be a lot of front end grip giving any issues anyways!

Good work Tom, i'm game for trying it if you get it done as i've been pretty settled with my set-up for a while, so easily notice small differences... plus have a couple of cars so back to back testing is a lot easier (having a permanent test venue to play with helps too !)