Paul TVR

I have just bought a Rover 620ti, ok bit of a come down after the TVR but I'm using it as a runabout. Question is the car feels like its a little drifting when accelerating up to 70mph, not sure if it's just me not trusting the new car but is there anything that will cause this? Car has just passed the MOT where it failed dues to brakes being out of balance but had new discs and pads all round fitted by the garage. I've yet to get it up in the air to check it out, the car has been lowered on chassis dynamics springs using standard shocks, might try and get some standard springs. Paul

I see so a tyre such as the one I had repaired which hadn't lost any pressure should be ok.

I don't have the caster or KPI on my spec sheet. this is a hand written sheet due to using the oldie ways of string boxing the car. no new fangeldangle laser equipment in the workshop. although the corner weights and linking the the palm was quite nifty. Guess they use what works for them. In truth i really admire the old school way... This is real metal Geometry combining the work from a mechanical engineer and a technician...... Although for anyone contemplating using TVR on the track we do really need to establish a steady footprint! Well as said with that set up I couldn't believe how it handled at Brands, they use the same method with their Tuscan race car and having seen that put in a very impressive run at a 12 hour race there a month before I was quite confident they knew what they were doing. http://www.topcatsracing.com/ are they people who did the work. Once the track work resumes I'll look into fine tuning if it needs it, at the moment I think the car is much more capable than I am though lol Not sure if it helps but I have a few pictures of it on the track, not sure if I can add them here though?

I don't have the caster or KPI on my spec sheet. this is a hand written sheet due to using the oldie ways of string boxing the car. no new fangeldangle laser equipment in the workshop. although the corner weights and linking the the palm was quite nifty. Guess they use what works for them.

I am desperate to ask, what set-up do you have for the car Ok I had the car set up by a company called Topcats racing who set up a lot of race Tuscan's etc. They use the old fashioned method of string boxing the car but with very good results and also corner weighted as well. The car is running Redline shocks with Nitron springs, but I can't remember the spring rates, I have a feeling they are 325 and 400 lb though. Front Camber 1.75 toe in 5 tyre pressure 22 ride height 140mm shock set 15 clicks from fully hard Rear camber 1 Toe in 2 tyre pressure 22 ride height 200mm shock set 15 clicks from hard weight 2395 Lbs 1088 Kilo wet weight with 3/4 tank fuel. The shocks were adjusted at Brands Hatch track day to slightly stiffer at the rear. Topcats added extra camber to help with the understeer and also altered the rear alignment as the rear Toe was all on one wheel. they added extra toe as they old set up would grip very well but when it broke away was very hard to catch, the new set up gives less overall grip but a much more progressive feel. the only down side to the set up is the large amount of camber causes tram lining or badly rutted roads but it is worth it as I can throw it into a corner and such greater speeds now. I don't pertend to understand much about geometry so if anything I said there is wrong I must have got it mixed up

Yes I suppose you can notice a trend, although the tyre centre I worked in (a fair few years ago now) was quite busy we could change 100 tyres over a weekend so saw quite a number of out of shape tyres but never noticed the correspondence to being repaired. Lots were mini cab tyres I presume lots of bumping up the kerb to park off the road, often others were bought in for a balance having bought second-hand tyres from a breakers yard.

The Rave4 is a perfect example.... shame no one can remove the tyres?.... We are all in a transition period with the RFT. The fitment over the pond will be mandatory on all new cars by 08 and here in the UK by 012 so this evolution is coming.... Personally i don't like the RFT but i will have to adapt and move on. I take it that's only new cars by 2012? I guess they are safer, a puncture at speed is very easy to control, having driven the mini with a flat at 40mph plus they certainly work. I noticed you said they shouldn't be repaired though? I had a tyre repaired after it picked up a screw, was only a week old and didn't lose pressure but I noticed it in the tyre.

Good!... Finally i have someone who hates the S-saver as much as me..... Like it or not the introduction is a cost saving venture and no matter what anyone says it cannot be truly safe. Have you seen how much it costs to replace those stupid skinny things though? they charge a fortune for them. I have a space saver for the TVR but can't get the roof in the boot easy even with it being so skinny so just have a couple of can's of tyre weld instead. Out of interest how do you feel about that self sealing stuff that you fill the tyres with? surely it must put them off balance having a running liquid inside?

What used to make me laugh were Fiats wearing 155/70x13's turning up with a space saver using the same rim just painted red with a stupidly skinny tyre on.

Thanks for the welcome Tony. I guess the yoke's were just a more grippy tyre, if fitting non run flats would you suggest a high tyre pressure to compensate for the side wall flex? Seeing the Mini has a 40 profile tyre the sidewalls are very small and have little give in them even on standard rubber so I guess the RFT would make a bigger difference to high profiled cars.

I've done a few track days and the best way is to start off slow and build up to a good lap, take an instructor out with you at every new track you visit. I've spun at a few in the TVR and very nearly made a big mess of it at Castle Combe due to a Cossie boiling over and dumping its coolant midway through one of the back faster corners.

I have driven many miles in a Mini Cooper S equipped with run flats, and a friend S who fitted yokohama rubber which wasn't a run flat, I can say the car handled better on a track with the non run flat tyres and also gave better road manners. Do the manufactures take the different tyres they fit into consideration when selecting the spring/damper rates? I noticed the S came fitted with Dunlop tyres originally but then move on to perrili, it seem the cars coming out the factory each week with different tyres, as the manufacturers tyre specs differ they surely don't spring the car to suit?

I worked in a tyre centre years ago and used to repair tyres, is it not possible someone had driven that tyre over a kerb or similar to snap the cords rather that the repair causing it? have repaired my own tyres and even used them on tracks after, I do check them regularly to make sure there are no problems but not had a problem with a repaired tyre yet. Saying that seen some truly terrible repairs too, some right in the shoulder where the tyre flex just pulled the repair off again, and one second hand tyre had been run flat with half the sidewall grooved out, the tyre was asymmetric and the seller had put it on backwards so the buyer couldn't see it they stuffed a tube in.