New RT615s

Wheels, Suspension, Brakes & Tyres questions and answers

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phatMX

Postby phatMX » Tue Sep 05, 2006 4:07 pm

hey that could be it... though not sure how the suspension is setup on the mx5's I know my rx7 I had 3.2 deg on the rear (due to lowering) and that couldnt be changed (could but i wont explain) I run about a standard height, the front bar just sits too low and hits everything when its on a lower ride hight.

phatMX

Postby phatMX » Tue Sep 12, 2006 9:26 pm

Okay, got back from the trackday and the RT615's were okay. Better times than previous but my rear end was very loose. I'll have to take the car to Fulcrum and get them to fix it up. Corners 1 and 2 felt a lot slower than previous, i think i was only making up time when braking as I could brake a lot harder now. As for the tires, I tired running 29psi cold which was about 31hot and it was wriggling all over the place felt very squirmy. I chatted to ASE05 and he said he felt the same and noticed an improvement with more air so I pumped it to 35hot and it felt a lot better. Others out there, have you tired racing with more psi to compare results to the lower psi?

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ASE05
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Postby ASE05 » Tue Sep 12, 2006 10:35 pm

Yep, agree with phatmx, the RT-615s suck bum at anything below 35psi :!:

@ 32psi hot, it had AMAZING snap oversteer and I had a pretty major loose @ 120km/hr into turn 1 at this pressure. Couldn't hit turn 1 at any more than 120-125km/hr.

By the end of the day I was running around 38psi hot all round and was able to enter turn 1 @ 135-140km/hr :shock: There was still oversteer but easlily controlled and actually quite fun. Pitty I only fixed this in the last two sesions of the day. I guess I know for next time!
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kula
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Postby kula » Tue Sep 12, 2006 10:55 pm

wow

thats weird

i run my 615s at about 26-28 psi...
any higher and they felt crap.. but maybe i havent tried over 35..

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ASE05
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Re:

Postby ASE05 » Sun Oct 01, 2006 4:19 pm

kula wrote:wow

thats weird

i run my 615s at about 26-28 psi...
any higher and they felt crap.. but maybe i havent tried over 35..


Anyone think that wheel diameter could have anything to do with variations for tyre pressures? I'm running 205/40/17's and @ 32psi hot I could feel 'em rolling around on the sidewall and had a good spin the next lap.

A mate went to do a skid pan day and was told to arrive with AT LEAST 40psi in 'em cold!!?? That's for a F6 Typhoon though so maybe the weight was a factor in their suggestion.

I've also noticed that after a couple of track days that the they aren't as good on the road as when I first got 'em. The tyre fitter had 40psi all round and went for a spin throught Mt Nebo etc and it stuck like sh*t to a blanket. I'm now finding that unless there's heat in 'em there is no rear end grip.

Grrrrr, too much info and too little knowledge on how to apply it :oops: !
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phatMX

Postby phatMX » Sun Oct 01, 2006 5:36 pm

ASE05, I had 38psi when i picked mine up. I found the ride too harsh, I've kept it at 35 now and it seems fine for road. As for grip I think mine have gotten better with age although I have found the limit so even in my NA i can get the arse out. You've probably just started to push it harder... See how they go next track day :D

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Re:

Postby ASE05 » Sun Oct 01, 2006 5:53 pm

phatMX wrote:ASE05, I had 38psi when i picked mine up. I found the ride too harsh, I've kept it at 35 now and it seems fine for road. As for grip I think mine have gotten better with age although I have found the limit so even in my NA i can get the arse out. You've probably just started to push it harder... See how they go next track day :D


I'd like to think I was pushing harder but a best of 1:31 on the National @ QR with the RT615s VS the standard Toyo Trampio Vimode half shagged netting a best of 1:29.50 have got me thinkin' :!: I was hoping to dip into the high 1:28's as a minimum with the RT's

I'm finding the RT's are too sensitive to pressure/temps vs. the stocko's :shock:

Again, I'm learning as I'm going so I have probably missed something :roll:
Sing that song, puff all night long.......


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