Track-prepping my Ultima: help please!

[Alex Wagner]

Hi guys,

I'd apreciate your advice and experience on track-prepping:

I have bought a 1996 Ultima Sports (yellow with green stripes, ex martinlaw, ex John Castle). The car is in a street configuration and has proved really agreable on road but ill-adapted for heavy track work. To make the car perfect on track I would like to upgrade tyres, brakes, suspension, geometry. For this I am willing to sacrifice road-useability. ;-)

TYRES:
Existing tyres are road tyres: 225/45-16 and 315/35-17. I am going to change for road-legal track tyres (R-compounds).
- Are these sizes the widest that will fit without rubbing? Or can the fronts in particular be 245 instead of 225?
- I have found Toyo R888 and Kumho Ecsta V70A in the existing front and rear sizes. What would be the advantages of each?
- I don't like understeer and I'm comfortable dealing with oversteer: may I order medium compound for the front and hard for the back?

BRAKES:
The brake discs and callipers all need changing (a stone has grooved a front disc, a rear disc is cracked, plus the callipers are seizing) and I'm keen to specifiy the most powerful possible as a replacement (I'm used to an RS Porsche on big reds, so I've been spoiled by fantastic braking!).
- Given the 16" front wheels, what's the biggest disc/calliper set I can fit?
- Is there an AP Racing kit for the Sports? If not what would you recommend in terms of discs and callipers?
- What master cylinders should I specify in accordance?
- What brake pads should I specify? (for track use - I don't mind if they squeal on the road and don't work well when cold)
- What would I fit for the mecanical handbrake? I don't need the car to pass MOT (I'm in France on English reg), so may I have a system compatible with a separate handbrake (for resale) yet not fit one (to save money)?

SUSPENSION:
Existing shockers are by AVO. They are adjustable. Even of the hardest setting they are softly sporting: very pleasant on the road but unprecise and lurchey on the track. Car dives a lot too, with the chin spoiler raking the ground under heavy braking.
- Should I simply have the AVO dampers revalved?
- Anyone know the percentage distrution front/rear of the 970Kg weight? (to specify to get the dampers revalvled)
- Should I also change the springs?
- Is there an INTRAX kit for the Sports? Does it present advantages? Are they adjustable? I have found a set for sale on piston heads. Would I also have to have these revalved for heavy track use?
- In terms of firmness, I'm looking for something similar to a Porsche 964/993 CUP.
- I'd like to order a full set of bushes. Is Nylatron best for my use? Would rose joints be unacceptable on the road?
- Is there an anti-roll bar kit? I was surprised to see none on the car...

GEOMETRY:
- Existing geometry is road-biased: there is no instability or tramlining at all. On track the steering gets very heavy at high slip angles, which prevents me applying the correct lock and causes a spin. There is no centering action (on a long constant motorway bend, the wheel can be released and the car maintains its turning without trying to center) - maybe this is linked to the steering being very heavy during slides (no centering action).
- I'm considering 3° of negative camber on the front and maybe 1° on the rear (the rear tyres are very wide...)?
- I'm considering a bit of front toe-out? How much? Would some rear toe-out create excessive oversteer?
- Can I adjust caster? Should I set it at maximum positive caster?
- I'm confortable with some oversteer, I don't like understeer, and I accept some tramlining. What would you recommend for the ultimate lap time?

Thanks very much for your advice. I apreciate it! The car has great potential as a track weapon. It just needs upgrading in tyres, brakes, shockers and geometry.

Alex

Edited by Alex Wagner on Monday 16th March 13:57

[Wilder]

Hi, firstly, Tyres:
I have not used the Khumos, but I have the R888 Toyos fitted to my GTR.
They are the best tyres I have used on any car, and the grip is simply staggering.
Add to that, the fact that they are a soft sticky compound even when cold, yet after 2K miles and a couple of shows performing burnouts, I still have around 4 mm of tread left (at least). These tyres give decent grip even in the wet, but as with any track day tyre use the power with caution.
If you can increase the width of the fronts it will certainly help you counter any potential understeer (especially if you are lookinng to increase the power).
You can either get offset wheels from a company who deal with Ultimas on a regular basis such as Image, or you can have the bodywork arches cut away to assist wider wheels/tyres as I have done.
Once you have uprated your springs (you may or may not have to change the dampers as well), the one thing I would recommend above all, is that you take your car to have a professional corner weighting setup.
This is simply THE most important requirement for any serious track car, as when its done the cars handling will be transformed.
My own car handled like a Viking longboat on a track when I first got it. I would go as far as to say it was a death trap, but Phoenix Motorsport of Accrington Lancs (who also set up Chewys Ultima for racing) transformed the car in 1/2 a day.
You can play guessing games from now till X mas, but get the professionals to tell you what it needs rather than throw money at what may not be whats required.
Its far cheaper and certainly gets better results than anyone can do at home or at a garage that is not a specialised chassis/suspension specialist.
Go to a garage who deals with racing car setups for customers and you will find all your answers there.
I hope this helps.

Edited by Wilder on Sunday 15th March 17:17

[Boosted LS1]

Don't know about an ultima but I once dialed toe out into a car and it was almost deadly.

[F.C.]

If you want the steering to centre you will need to dial in some caster,
Take it to a specialist outfit. I should not cost too much to sort.

[srreck]

My experience on track.

Tires.....Kumho V70
Suspension....NITRON 2 way + track springs + antiroll bar
You will need to ad extra downforce at the front for high speed on track.
With 16" at front you can fit 315mm from AP and CP5000 series calipers. Or ask Richard/Ted if the 320mm from the GTR are good for you.

Enjoy the car.

[wherzmespana]

Toyo R888 are a must - mine have done about 25 trackdays and still have tread left (and I give the car real abuse!) - they give massive grip in the dry. I am running EBC yellow stuff pads and once bedded in and warm they give massive stopping power at a price that is stupidly cheap. I set up the suspension and geo myself, but have heard good things about Phoenix so probably the best way forward. It will be interesting to see how you get on with fuelling - surge is a real issue. Also, is the car dry-sumped - if not, you could be looking for grief - good luck with it all!

[LuckyP]

wherzmespana said:

....mine have done about 25 trackdays and still have tread left.....

Whhoooaaaahhh 25!!! And still tread??? That is some going - what's your secret???

[UltimaCH]

Probably not trying hard enought.... I would get throught a set of PZero Corsas per weekend on certain abrasive tracks, but never more than two weekends of racing on other more normal surfaces.

Edited by UltimaCH on Monday 23 March 21:23

[wherzmespana]

The tyres are a regular source of amazement - I had an Exige before and that used to eat tyres. I am still staggered at how much abuse in terms of late(sometimes too late!) braking and powersliding you can give them and they just take it. The rears have only got a couple more left in them in reality. I put it down to my excellent homemade steering and suspension set ups!!!Even if I only got a handful of days out of them, they are worth every penny.