Transformer arrives in Colchester

**Strat Fan** · 13-04-2016, 14:15

Originally Posted by Lancialulu

Used a firm in Colchester that specialise in track hardware - mostly drifting.

The biggest change is in tyre pressure up to 28 front 30 rear from 22 all round. Castor wound back to 4 degrees, 1.5 deg camber on front, .7 on rear, and parallel toe rear and 2 deg toe out front.

Was a bit mystified until I drove it and found it delightful (not a delightful handful). We will have to see. The overall comment was nothing much is going to remove the twitchiness until I source different tyres as the super soft TB15's will always tramline due to their stickiness......

Sounds like the perfect settings for a drift car.....
The proof will be in the driving but be very careful, I've worked on a number of high performance mid engine cars & your settings contradict what those companies used.
295 section TB15's are the tyre I'd fit to the back of the 15" wheeled GP4 Strato's replica, the stickiness of the tyre I think is irrelevant to the twitchyness.

**strat24v** · 13-04-2016, 19:27

Craig, how's about asking Mr Comas what his tarmac settings are?

**Lancialulu** · 13-04-2016, 20:29

Craig

its the sticky 235 TB15's on the front that make it twitchy not the rears... Can you recommend a standard compund 15 gp4 tyre front and back. Noted I trye to drive carefully. It is early days but I am persauded to live with this until alternative tyres can be found at which point I will set the front differently.

Tim

**Strat Fan** · 13-04-2016, 21:59

Michelin TB15 215/55/15's have a nice big compliant side wall which shouldn't cause any issues. At the temperatures you are running on the road then I doubt the tyres can really be classed as sticky. Guy runs a wider squarer front tyre which should yield more issues than yours.
Have you actually taken the time to remove the damper & check the bump steer? You have mentioned a number of times that you have altered the front castor. Are you aware that each time you alter the castor you should then double check the bump steer as castor adjustment alters the relationship between the steering arm & the steering rack which in turn provokes bump steer. About 4 pages ago we covered the subject of twitchyness & the subject of bump steer was raised. If you are now happy with your ride height, toe settings & tyre pressures then can I suggest you actually check the bump steer before buying new tyres to replace the ones that plenty of others here run with out issue.

**Strat Fan** · 13-04-2016, 22:13

Originally Posted by strat24v

Craig, how's about asking Mr Comas what his tarmac settings are?

I'm sure Mr Comas has better things to worry about than me calling him up to ask what his suspension settings are!!
As we have covered earlier in the thread a car which is set up for competition or drifting will often have more aggressive settings such as toe out which help to promote turn in (track car/rally car/drift car) &/or instability (rally car/drift car) in the interests of ultimate times or visual flamboyance. A road based Strato's replica should be set up for performance & handling but with a concession for compliance & safety, ie stability under braking & predictability when cornering.

BR

**gtmpaul** · 13-04-2016, 22:44

Can I just chip in on this one,
What Craig is saying on castor is what I have found during my rebuild.
When the front suspension was put back together without springs, it gave me an chance to check the bump steer through the full stroke of the damper, I checked the bump steer and as you start putting on more caster the toe in to toe out change was huge.
At the moment I have reduced the caster and raised the rack on shims.

Paul

**Lancialulu** · 13-04-2016, 22:49

Originally Posted by Strat Fan

Michelin TB15 215/55/15's have a nice big compliant side wall which shouldn't cause any issues. At the temperatures you are running on the road then I doubt the tyres can really be classed as sticky. Guy runs a wider squarer front tyre which should yield more issues than yours.
Have you actually taken the time to remove the damper & check the bump steer? You have mentioned a number of times that you have altered the front castor. Are you aware that each time you alter the castor you should then double check the bump steer as castor adjustment alters the relationship between the steering arm & the steering rack which in turn provokes bump steer. About 4 pages ago we covered the subject of twitchyness & the subject of bump steer was raised. If you are now happy with your ride height, toe settings & tyre pressures then can I suggest you actually check the bump steer before buying new tyres to replace the ones that plenty of others here run with out issue.

Craig

The old hands at GBH Motorsport (and incidentally Longstone) classed these tb15s as sticky and Bob at GBH road tested the car and said the twitchiness was down to the profile and compound of the front tyre which I beleive is correct. For avoidance of doubt the twitchiness is felt on a notmally smooth tarmac no bumps. I have driven the car puposefully over uneven road surfaces and apart from tram lining there is no apparrant bump steer. I still wish I could find normal compound tyres to fit.....

Tim

Ps in case you were wwondering GBH stands for Geoff Bob and Herindoors....

**Sando** · 14-04-2016, 08:06

Can I have your TB's?

**Bernard** · 14-04-2016, 08:50

I have run TB15's and TB5's in competition (front 205-215/40x15 and rear 295-335/35x15) and can say that there is NO "twitchiness" whatsoever.......... TB 15's are great in the wet giving excellent grip.... however during a dry 20minute race the tread did rip off in lumps (this was my mistake only having a set of wets available to me at the time)
For short dry stages they were great, giving good grip off the line and not getting too hot and ripping tread off during a 8 mile tarmac stage..... IMHO great tyres