Project GTR (zed replacement)

Monster · Post by **Monster** » Wed Aug 01, 2012 8:55 pm

This is the pic I mentioned abover (among others) that show the amount of deformation of the slicks in the corner. Interested in peoples thoughts...

Opentrack track day Snetterton 300 July 26th 2012 by Opentrack Track days, on Flickr

Monster · Post by **Monster** » Mon Aug 06, 2012 8:58 pm

So, has anyone got any thoughts on this? randomly made up or based on knowledge?

Post by **Stuart** » Mon Aug 06, 2012 9:14 pm

My only comment would be that your car will be producing an awful lot of 'G' at that point, with the weight transfer, the speed and the mechanical grip your car 'makes'. I have no first hand experience of driving on slicks mate, so I'll be of next to no use with performance characteristics on a GTR. I'm not surprised that you can see tyre distortion as that energy has to go somewhere; I always thought that the tyre movement was the thing that produced the heat, that in turn produced the grip?

It may be worth sending Logan (Blacky) a PM as he runs slicks on his sprint EVO

Tommy · Post by **Tommy** » Mon Aug 06, 2012 9:18 pm

Would you expect the deformation to be better or worse on track tyres? I have photos of my old M3 on track tyres with similar amounts of deformation. I have no idea whether a slick would be similar or different though.

Post by **Stuart** » Mon Aug 06, 2012 9:31 pm

Trying to remember old conversations with Pete (ex-Avon tyres support) I am sure said that slicks are crossply's not radial's, so the comparisons between slicks and 'normal' tyres may not be so relevant........unless I am talking out of my arse of course

Monster · Post by **Monster** » Mon Aug 06, 2012 9:34 pm

you mean Pete Rosenberg?

Post by **Stuart** » Mon Aug 06, 2012 9:41 pm

Yeah........was nervous about mentioning his name on your thread

Your query forced me to do 5 minutes of homework, so I have checked up and Avon do both crossply and radial. The crossply is more prone to stretch, apparently.........but is supposed to be more forgiving and communicative (all third hand knowledge)

I'll get my coat

Tommy · Post by **Tommy** » Mon Aug 06, 2012 9:57 pm

I did a bit of research too. Didn't find anything on deformation though. Only that slicks require more camber and totally different pressures to track tyres. Also that Dunlop slicks have a softer wall than others.

Monster · Post by **Monster** » Tue Aug 07, 2012 8:29 pm

Haha, well I'll let you off this time Stu!!

Yeah I'm pretty sure the Michelins are radials although they aren't here so can't check at the mo.

Tommy, You're right fella, def run different pressures and the amount of grip/performance characteristics is very dependent on the pressures. I wound in a load of extra camber on the front as the first time out I knocked the shoulders out of the slicks on the old settings.

It's an area that I too don't know much about but is very complex so I need to learn. Steve ran the same michelins as mine on the Supra and the michelin guy (at a race meet) did a few calculations based on the wieght/power of his car and suggested what pressures to run and apparently it improved it a lot.

However, still not convinced how much they're hanging off the rims is ideal... Might have to make a few phone calls

Monster · Post by **Monster** » Fri Aug 24, 2012 6:41 pm

So a quick update although not much to report. I'm moving house so despite my best efforts the GTR isn't getting as much use as I'd hoped. I've already had to cancel my OT day at Donny on the 31st due to threats of move dates, very annoying!!!

Anyway, got a few jobs done. I think the reason it was spitting diff oil out is that the breather valve thing was getting hot and not operating properly. Prised it off and greeted to a psssshhhhhhh noise so obviously not venting. Originally tried removing it and running a length of pipe but the smell of diff oil in the car was very strong so have replaced the OE plastic bit with a metal one so fingers crossed that works.

Also added some massive spacers to the bonnet in an attempt to reduce the folding up of the front as spotted in all the excellent pics from Snett. I'm not sure if this will work but hopefully will help until I get a more permanent solution - sourcing an OE bonnet catch aswell as the pins, or maybe venting the bonnet. Some pics:

I'm not keen on the fact that this is a bit of Drift look rather than track, however, I'm not unhappy with how it looks, reckon it's quite tough