Major clearance issues

[Dave Freeman]

Well my brakes look fantastic, and they sort of work, need more bleeding to get the best from them. But the biggest issue is that I had new front hubs and bearings and then Andy Clements popped in on Friday to check the suspension set up. We found that the castor angle was 9mm out so we duly put in washers where needed and although they are not spot on they are much closer to the proper dimension, the car drives so much better and does not wonder across the road. Straight as a die. So the car is now as good as it could be but why do the front tyres now rub on the body work. on turning the wheel about 15 degrees the first part of the tread rubs on the arch about where the lower valance meets the wing, this small piece of body work is seperate and is rivetted to the main body and acts to support the valance.

I have now removed this (for the moment) but also find that the main body where it finishes needs grinding back about 15mm. I will put some pictures to explain but the inner wing needs grinding back. so what stress points are around this area, I have no option but to grind this away. I have raised the suspension but it makes no difference.

so the question is that the new disc assembly must push the wheel out by about 12mm and setting the castor must make it worst, any thoughts chaps, be nice to know the reason. The grinder will come out at the weekend, its driveable but I need to be careful do not want to wreck the tyres.

DAVE

[andydclements]

Dave, does that mean it's rubbing on the front of the wheel where we spotted it was pretty close? Is it when turning the wheel out it catches? I wonder if the new hubs have moved the wheel out a bit further.

[Dave Freeman]

Hi Andy the answer is yes, the rubbing is quite bad, its major cutting time, or the option is back to the old discs or buy new wheels. I favour the grinding.

[andydclements]

Is there no option to move the hub face in (machining it ) so that the wheel is further towards the centre line of the car?

[Dave Freeman]

Good point Andy, its worth considering, not sure how much this would need to be, I will take a look tomorrow night to see what else could be done.

Dave

[andydclements]

Worth measuring the distance from the inner (relative to car) edge of the inner bearing to the outer edge of the new disc centre section (where wheel mounts) compared to old set-up where wheel bolted to hub.

[Dave Freeman]

will take a look Andy, cheers mate

[red vtec]

Dave,

I seem to recall reading that the newer bodies had a different setup in the wheel arches i.e more space, hence why the older cars can rub when fitted with bigger wheels

This is posted from Lotus Esprit World may have some relevance to you, I know your wheels are bigger..

Question:

I wonder if you could help me please.

I have an '89 Esprit SE and I have fitted the S4 five spoke alloys to it. They are fitted with one of the recommended tyre options, ie front 215 40 17 and rear 245 45 17 Goodyears.

Could you please let me know the suspension geomotry setting for my 89 SE and also for the S4 so that I can make any modifications necessary to castor/camber etc.

Many thanks,

Reply:

Dear Mr.

I recommend you retain the SE suspension geometry as follows:

First set the car by ballasting to a mid-laden ride height of 170 mm below the chassis front crossmember, and 170 mm below the rear lower link chassis brackets;

Front

Camber; minus 0.2 degrees

Castor; plus 1.0 degrees

Toe-in; plus 0.1 to plus 1.9 mm overall.

Rear

Camber; minus 0.5 degrees

Toe-in; plus 1.5mm each side

The S4 models used power steering and were able to run a greatly increased castor. Wishbones front and rear were also changed to allow revised geometry which will not apply to your SE.

I recommend you purchase a Service Notes manual from your dealer under part number B082T0327J.

I hope this information helps.

Yours sincerely,

Dave Massey - Technical Service

Senior Technical Author

Lotus Cars Ltd., Hethel, Norwich, Norfolk. NR14 8EZ.

Tel: +44 (0)1953 608247

e-mail: dmassey@lotuscars.co.uk

Chris

[rocket63]

Sounds like the offset may have been affected, perhaps in relation to the new hubs and the adjusted castor? Doesnt take that much to create this issue, plus your car is lowered into the bargain Dave?

[rogerch]

Is there no option to move the hub face in (machining it ) so that the wheel is further towards the centre line of the car?

Not forgetting the rim still has to clear the calliper.

[andydclements]

Sounds like the offset may have been affected, perhaps in relation to the new hubs and the adjusted castor? Doesnt take that much to create this issue, plus your car is lowered into the bargain Dave?

The increased caster has actually decreased the issue, as it's achieved by moving the top ball joint rearwards it gives more clearance at the front. I wonder what it would have been like as it was.

I'm thinking it has to be that the wheels have moved outwards too far, probably not an issue if it was on standard wheels, but the wider tyres are probably just not compatible with the new brake disc& hub set-up unless there is some modification elsewhere.

[rocket63]

Ok. Well the known quantity is the wheels. They have not changed since before, so its a process of elimination. Have you thought of putting a standard set of wheels on the front, just to sense check where you are ?

[CHANGES]

If at any point during the upgrade of the brakes, the mounting flange (hub face) has moved outward. Then . the swinging radius of the wheel centre will have extended. This in turn will have extended the distance that the outer edge of the wheel/ tyre wiil move fore and aft in the wheel well during steering rotation.. A comon problem when wheel spacers are fitted.. This in turn means the original geometry angles will not apply and a compromise should be found...On the esprit fouling the wheel well is quite comon when larger 17'' wheels are fitted to pre S4 cars.... I belive the drop link on these cars was different to better centralise the wheel to eliminate this issue along with some heal board modification to stop tyre rub.....The original design did not leave enough room to carry out this type of upgrade without modifying other areas to facilitate.....

Conclusion ....have geo set up perfect.....then get the grinder out and relieve the tight area's.... or machine the wheel inner face to reset the original offset for car. ( the later beware of clearence on calipers.)

enjoy

Dave. L

[andydclements]

With Dave's current ride height at the front (not sure if it's lowered evenly front to rear) we couldn't get correct caster, it was at the Lotus recomended limit of spacers + a little bit and still only half the camber it should have.

[CHANGES]

It maybe worth grtting the ride height sorted and all the other geo then reset. A good starting point before chopping away with the grinder... It will certainly handle a lot better aswell.

It may still need some grinding then , but it will be a lot easier knowing it will be perfect when done...

Dave L

[andydclements]

How is it going Dave?

[rogerch]