Suggestions For Geometry For Road Rally Car

[philfingers 5]

Ok here's the spec

 

Mi16 engined 205

 

Bilstein adjustable coilovers with gravel springs and inserts, fully adjustable (BakerBM prototype- individually adjustable for castor and camber) rose jointed top mounts. Rosejointed (adjustable) bottom arms. 309 shafts (so I can run a little wider on the track is required.

 

rear is std torsion bars and gravel dampers. Changed back from 21mm bars and 23mm ARB as I found this too hard in the lanes, i prefer a slightly softer suspension.

 

ride height needs to be sensible, I have a figure of 345mm for the front in my head (centre to lower of the plastic arch trim). Camber I was thinking 1/2 to 3/4 neg. Toe, usually i set paralley but I'm open to suggestions.

 

I have my own castor/camber and tracking gauges.

[philfingers 5]

Well I re-fitted by Bilstein gravel setup and these are the nice shiney (under all my grease!) new BBM fully adjustable top mounts.

I set camber to approximately 0.7deg negative and toe to parallel

These new (prototype) BBM mounts are lovely piece of kit, I added grease nipples as I'm a bit anal in that way. Anal grease is good :-)

They use the correct PTS spec bearing, which is big and last ages, even better to grease it regularly. Only real downside is that the gap created by the adjustablility (you can't have your cajke and eat it!) will throw up the crud from the wheel into the engine bay so in the interim I've put a 200mm disc of flexible plastic between the top mount and the upper sping pan.

 

 

 

 

 

They look way out towards the wings but the rose jointed bottom arms have the joints screwed right in!

No idea what the track is but it's wide! Compared to the 309 arms and std 309 front legs I've been running on the car in the interim I had to wind both TREs out 7 3/4 turns!

[brumster 135 1 Cars]

Phil,

 

Your car sounds pretty sorted, all I can think is maybe a smidgen for negative camber but for road rallying you might prefer it the way it is.

 

Have you considered getting it down to the chap round the corner from Andy B? He's ex-ralliart and for a couple of hours labour, he set up my new Reigers and set the entire geometry, and the car feels night-and-day different in steering feel (it had never been set up properly), he also spotted a bent rear pin (bonus!). Mind you if you've got your own gear and are confident in using it, I guess you could do it all yourself.

 

I'm guessing one big benefit you'd find is the dreaded ProFlex on the back; mega difference on the jumpy/bumpy stuff. If you can hold out, I might sell mine at the end of the year/next year just so I can put consistent Reiger all the way around, but I'm in no rush to get shot of it yet to be honest...

 

P.S. Yeah, they do look way out don't they!? Nice bit of kit, though

Edited March 22, 2010 by brumster

[philfingers 5]

thanks. You can see the little M5 cap head on the insert I used the refill the inserts with gas. Holding pressure for about a month now. Easy to get to tho if they need some more!

Out of interest what did he set your toe to?

You can't do a lot with the rear beam other than check it's aligned correctly i guess and check for abnormalities like the stub pin. I picked a new stub pin up on ebay the other day actually for £15 with P&P, which isn't bad. You can't buy them seperatly as far as i know. I had the back break clean off one stub pin recently. Must have been cracked a while as it was rusty.

Haven't driven the car yet, looks nice tho :-)

[jackherer 543]

Castor value depends on PAS or lack thereof IMO. I built a car, the red shell we got from you in fact Phil, with a Xsara VTS 2.4 turn rack with power steering and we run a hell of a lot of castor on that, I don't remember the exact value but it works very well. We have had that shell on a 4 wheel laser alignment rig BTW, its the straightest I have ever seen!

[brumster 135 1 Cars]

I'm at half a degree toe-out at the moment. I've fiddled a lot with toe-in/out in the past, parallel just has me pinging from hedgerow to hedgerow on full power

[philfingers 5]

I'm at half a degree toe-out at the moment. I've fiddled a lot with toe-in/out in the past, parallel just has me pinging from hedgerow to hedgerow on full power

you could always just retard the ignition if it's too much a handful!

 

I'll maybe try toe out a little then. I know Craigb was on about it a while back.

 

glad the Red shell worked out Kieran, so much work to reshell a car. On hindsite it's a better shell than the one all my nice bits are bolted too!

Edited March 22, 2010 by philfingers

[Dazza 4]

This threads just up my street at the moment as I also have the Geometry and suspension Hat on .

 

Also using the fully R/J'd lower arms and ecc top mounts and R/J/td track control arms with New GGA's in between.

 

I have been advised on the following albeit I also have not finished bolting it altogether yet and I dont have the most experince with this particular area.

 

2/2.5d-NC

4d-Cstr

Toe setting 0 -.5 out

 

Rear 1.5/2d-NC

Toe-0

 

Iam just going to set it to this and book on a local track and take my guages ?

 

Ps Looks V nice ....

Edited March 23, 2010 by Dazza

[philfingers 5]

Dazza, what are you using it for, track work?

I'm not sure about camber for track work but 2deg should be in the right ball park.

I may well try the 1/2deg toe out that Brumster is using

[Dazza 4]

Yes Phil My 205 GT16 is a pure Trackcar , way to much of a handful for the roads now.

[Craigb 2]

!

 

I'll maybe try toe out a little then. I know Craigb was on about it a while back.

!

 

What tyres are you running Phil , and do you have a lsd fitted .

 

the reason being , with A035's , i found that any more the .75 deg negative camber and the inner edges were gone in no time.

Also the toe out was to compliment the LSD , I can't remember what the setting was , posssible 2mm toe out . That made the car so much more stable , rather than darting around under power. the additional castor that the top mounts that Andy Baker made for me made the car turn in better than any car I've driven .

 

Hope this helps

 

Ps when are you out next? its the VK this weekend

[philfingers 5]

What tyres are you running Phil , and do you have a lsd fitted .

 

the reason being , with A035's , i found that any more the .75 deg negative camber and the inner edges were gone in no time.

Also the toe out was to compliment the LSD , I can't remember what the setting was , posssible 2mm toe out . That made the car so much more stable , rather than darting around under power. the additional castor that the top mounts that Andy Baker made for me made the car turn in better than any car I've driven .

 

Hope this helps

 

Ps when are you out next? its the VK this weekend

 

Can be gravel or road. I don't want (and don't believe you need) anymore than 3/4deg neg for road rally use on tight muddy lanes. I want the tyre square to the road to maximise braking really.

 

Yes, TranX on 25/30lb and 45/45 ramps.

I set my castor to midway and haven't checked it TBH. Where is yours further back or forwards from the central position. The beauty of these new BBM top mounts is you can adjust castor and camber independantly; only i haven't used the feature yet!

Edited March 24, 2010 by philfingers

[sam jfm 0]

i run about 2deg toe out