robt964

Hi chaps, here're the results from my recent 4 wheel geo session.

Ride heights with full tank + spare + tools

Front height 127mm
Rear height 243mm



On the whole the car feels alright, but the steering does feel a little darty at times. How does this setup look to you? I might increase the front toe fractionally and give it another go. Thoughts?

Cheers
Rob

Vandit

I really don't know right or wrong with regarding to alignments, so I'll share where my current alignment sits and some thoughts on how I got there.



Besides here-and-there street driving, I do a bunch of autocross in the car, so lots of fast transitions and hard, at-the-limit, tight cornering.

I told the guy I wanted as much negative camber in front as I could get (no camber plates, so I knew it wasn't much), so he ended up in the -1.8 range. Due to the bodyroll in heavy cornering, static negative camber improves cornering grip. At least that's my thought process.

On these forums, I always read that these cars like lots of caster, so I told the guy "max out the caster as long as it is even!" and I ended up around 4.3. I believe this also makes the steering weight go up.

I've always liked the idea of zero toe, so I told him "zero toe" and it ended up being slightly toe-out, which is fine. I still don't think the car is darty, in fact it still feels too slow on turn-in, but that might be a slow and/or lazy rack.

On the rear, I had been absolutely killing the outside shoulder of my rear tires, especially when the rear started getting into slip angles. Even at -1.3 it was still eating shoulders. So I went with -2.0. Again, heaving cornering w/ body roll requires more static negative = more grip, or at least that was my thought process.

The car has been a handful since I got it, very tail happy. So I took the conservative approach and went with .16 toe-in in the rear. I've only done a couple of events with this alignment (plus I switched to super grippy BFG G-Force Rivals at the same time) and now I kinda wish I would have settled for a rear toe setting closer to yours, since now the rear is really well planted unless I really try to upset the car, which is safe, but being fast requires some slip angles and rotation too.

So that was my thought process, but it might be wrong, so hopefully experts will chime in.

robt964

Thanks for your comments. I heard about the caster too and asked the guy to max them out even. Whilst one side was capable of going much higher (4?), the other maxed out about where you see them now. I forget which side it was now.
Yeah you're certainly running a lot more camber. I didn't really know where I wanted to start from so asked for the usual RS+n setup and I'll go from there. I'll drive the car for a few months, inspect the tires and increase the camber as required. Interesting that you need so much on the rears. Is the body roll down to your spring weights?

evanscott964

Hi Rob
As always with geometry it's all down to what you'll do with the car! But for a good aground set up for street and track, as Vandit said you need max castor as this reduces the amount of neg camber you need to give max contact patch during hard cornering. As a result you'll not run a set of inner edges off in a month!!
The car is a bit flighty because of too much toe in great for turn in lousy at high speed etc so I would set it at 0 total toe which again should minimise tyre weapon the inside.
The rear needs more negative camber 2-2.5* if you can get it but keep it even each side whatever you achieve. Rear toe should be 3mm overall which should be the top tolerance on the settings.
You should find the car handles better and is more neutral/stable without excessive tyre wear. Unless it is going to live on the circuit and its going on slicks this will be an ideal compromise.
Cheers
Simon.

boxsey911

Just to repeat the above.....you need more caster.

robt964

Hmm so what can I do. One side appears to max out on caster way before the other.

ras62

The rear ride height seems high for RS numbers, around 225 would be correct iirc, a slight nose down stance. Max caster should be 4+deg and dont get pulled down the more camber is better route as it doesn't suit UK roads and kills tyres. Always slight negative toe on the rear for stability. Simons advice make sense, maybe a bit less camber for a road car. Your car looks fabulous btw, top marks for all the effort you've put in

evanscott964

Yes I forgot to say the car is awesome it seems ashame to use it Ha Ha!! It should be possible to get more +castor on standard set up maybe strip the ball joints just to ensure they're testing full movement?
Simon

robt964

Thanks guys. Everything on the suspension is new and moves freely. The only thing I can think of is to slacken off all the bolts securing the front subframe to the body and try and tap the whole assembly forward with a rubber mallet. I noticed on assembly that many of the suspension parts that these bolts go through are slotted to compensate for alignment issues ?

jstyer

This is actually exactly the opposite of what is true... More toe-in helps with straight-line tracking and discourages turn in. Toe-out makes the car feel more "darty" and encourages turn-in but can also lead to a bit of a tram-lining effect.

robt964

A good mixture of information here

So from what I can find here http://members.rennlist.com/jfk964/bg_align.htm my current toe of 23' is near as damit what it should be for both RS and ROW cars?

I've just ordered a digital camber/caster gauge to try and track down where my lack of adjustment stems. I recon its gotta be subframe positioning. This tool will at least be able quantify any gains I find from jiggling things about.

jstyer

Ya, your toe numbers are right on the money. I like to set up with 0' of total toe, as I find it's a good balance between decent street manners and seems to help a bit on turn in, but your numbers are totally fine.

As has already been said, caster seems low, but there doesn't appear to be much you can do about that. I'm not too familiar with the 964 front subframe setup, but hopefully you'll be able to bump it back a bit if you'd like a bit more weight to the steering. I say you drive the s*** out of it as it sits and let us know your thoughts on your recently refurbed machine!

fuch

Found them rob I'm about +10/15 rs & set up for fast road whatever that means!!
Not darty at all.......



I think I have a fairly tame set up but it suits my limited driving skills....

GazC2

I just had mine done and the car now feels fantastic I have no figures to work to however from a visual point of view on the front I have a slight toe out,the back is toe in with a bit of negative camber, now I appreciate none of this is overly helpfull however I now have fantastic turn in but on poor surfaces you feel it tramlining occasionaly which I think were the characteristics someone mentioned earlier for me best its ever felt .

robt964

Cheers Mark, thats pretty minimal camber on the fronts. The tech told me (JZM) that at about RS ride heights it's difficult to dial out much of the camber it creates without adjustable top mounts. I have KW V3 which have a lower camber adjuster so it helped but it doesn't give that much adjustment. What shocks do you have? I'm surprised you've reached that figure but I guess mine is lower at RS+2 at the front.

How do your rears wear like with -1.5 camber each side?

Maybe I'm misinterpreting the reduced self centering caused by the caster (lack there of) as feeling slightly darty. I'll sort the caster issue in isolation before touching anything out. From what I can picture in my head, increasing the caster will mildly decrease my toe in.