MAZMAD'S Track car (and Driver) build

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Suspense
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Re: MAZMAD'S Track car (and Driver) build

Postby Suspense » Wed Apr 10, 2013 11:38 pm

What tyres this time?

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Re: MAZMAD'S Track car (and Driver) build

Postby mazmad » Thu Apr 11, 2013 7:52 am

Will drive down Saturday, not sure what time...after my daughter's hockey.

Yeah I think if you have standard ratio - unless you have massive mods and torque - 2nd is probably right. What kind of diff do you have?

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Re: MAZMAD'S Track car (and Driver) build

Postby evil_weevil » Thu Apr 11, 2013 9:51 am

Ive got the standard LSD as mine is a clubman.
whatever ratios that are haha
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viewtopic.php?f=73&t=62834

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Re: MAZMAD'S Track car (and Driver) build

Postby mazmad » Thu Apr 11, 2013 11:09 am

Hey Spence - kumvo v70s. Very happy with the Toyos, as I have been driving to and from the track but limited on sizes. First preference would have been yoko's but can't get them in a 225/45/15.

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Re: MAZMAD'S Track car (and Driver) build

Postby Hellmun » Thu Apr 11, 2013 8:48 pm

I always found 3rd perfect for T8. I was on 225/50/15's and a 4.1 on my 6 speed. That said 2nd came into use on T10 for me. Be mindful a locker is going to give you a lot of understeer on turn-in. My clutch-pack is chronic for it... without enough power I think it'll be slower than a torsen if you can stop the wheel lifting.

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Re: MAZMAD'S Track car (and Driver) build

Postby mazmad » Fri Apr 12, 2013 8:31 am

Hellmun wrote:I always found 3rd perfect for T8. I was on 225/50/15's and a 4.1 on my 6 speed. That said 2nd came into use on T10 for me. Be mindful a locker is going to give you a lot of understeer on turn-in. My clutch-pack is chronic for it... without enough power I think it'll be slower than a torsen if you can stop the wheel lifting.


3rd would be perfect ... with a little more torque. :D

Thanks for the info re diff. More understeer is not what I am after, just starting to eliminate it. So how do I stop the wheel lifting? Other than go in slower.

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Re: MAZMAD'S Track car (and Driver) build

Postby Hellmun » Fri Apr 12, 2013 11:54 am

Depends why it's lifting, what shocks/springs/swaybars/endlinks do you have? I had tein monoflex 7/6kgmm, 24mm front bar on full hard with 0 preload, 16mm rear on middle hole with preload removed.

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Re: MAZMAD'S Track car (and Driver) build

Postby mazmad » Fri Apr 12, 2013 3:53 pm

I have PSS9s, standard end links, pretty sure they are 24mm sways set full hard front full soft rear. Preload on the sways? Don't understand how that is controlled.

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Re: MAZMAD'S Track car (and Driver) build

Postby Hellmun » Fri Apr 12, 2013 11:48 pm

You adjust them by not having standard endlinks :mrgreen:

Too much rear swaybar is the usual reason a rear lifts, it transfers too much weight to the front but your actually running less than I was unless your bar is preloaded so it engages earlier. Wonder how much flex is in your car, I was running a whole bunch of bracing on mine and I could run much more rear sway bar and still have neutrality compared to any of the other guys at the track.

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Re: MAZMAD'S Track car (and Driver) build

Postby mazmad » Sat Apr 13, 2013 7:36 am

Thanks good tip will look into end links. Racing Beat or Whiteline? Only standard bracing but that is a lot.....any small bump that is what I catch underneath.

It is a conundrum :D Handling is superb otherwise don't want to reintroduce understeer.

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Re: MAZMAD'S Track car (and Driver) build

Postby evil_weevil » Sat Apr 13, 2013 8:28 am

Put standard rear sway bar in?

Mark, what are your thoughts on my car using 3rd for both fish hook ad last turn?
Looking for an SVT motor for this:
viewtopic.php?f=73&t=62834

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Re: MAZMAD'S Track car (and Driver) build

Postby Boyracer » Sat Apr 13, 2013 9:22 am

Tomorrow try disconnecting the rear sway bar and see what happens.
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Re: MAZMAD'S Track car (and Driver) build

Postby Hellmun » Sat Apr 13, 2013 5:46 pm

mazmad wrote:Thanks good tip will look into end links. Racing Beat or Whiteline? Only standard bracing but that is a lot.....any small bump that is what I catch underneath.

It is a conundrum :D Handling is superb otherwise don't want to reintroduce understeer.


The 949 ones are much cheaper and look strong, whiteline are like $190 and are basically the same as the 949... Racing beats weren't very beefy from memory though I've never heard of them snapping.

Chris I've barely dríven any 5 speeds other than while training so I'm not sure whether it's worth it. Only 5 speed I've dríven hard I can think of was Tony Williams car for one session and I'm pretty sure I didn't use 2nd at all. He had a modified head and cams though and so it was nice and torquey motor, managed a 1:12:99 first and only session having a bit of fun and not really trying (quick car that was a hot session in the afternoon). Pretty sure he had a 4.3 though and 205/50/15's D03's. If I was you'd I'd just measure the rev drop for each gear, then work out how far below that 3rd puts you, if it's not far I'd stick with it. I found second useful for T10 but only because I do a very wide line, tighten the entry and drop to second and then power out to the outside under throttle changing to third mid corner. Found a few tenths increasing the lap distance but increasing the entry speed to the straight. I'd have to go through my old logs but it was repeatably faster for me with 6 speed, 4.1 diff and 225/50/15's. If I was running stock height tyres I'd probably go 3rd but from memory I got down to 4500rpm in 3rd so 2nd became viable. The time I did a 1:09:35 was using 2nd at T10 but 3rd at T8... I don't think that's uploaded. I definitely have a bunch of sub 1:10 laps on my account still though, it was a regularity I kinda got very very distracted in trying to catch David Hammon in a 180kwish SE... I did right at the end :mrgreen:

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Re: MAZMAD'S Track car (and Driver) build

Postby Hellmun » Sat Apr 13, 2013 6:00 pm

Boyracer wrote:Tomorrow try disconnecting the rear sway bar and see what happens.

An incredibly large amount of understeer but the rear wheels staying firmly on the ground I'd guess?

Rear swaybar takes away the independance of the rear wheels so as soon as you hit too much weight transfer the rear wheel will lift. You can remove rear bar but then you'll have to compensate for the understeer when you don't transfer weight off the inside rear to the front. I'd first try stiffening the dampers (all 4 corners a few clicks) to reduce the total amount of movement in the body during cornering so the sways contribute less. Depending on where your at now I found that there were big changes in stiffness in the monoflex as you go down into the stiff range (if measure in number of clicks off full hard). Makes sense as you choke off the fluid movement it goes back up the digressive curve so gets much stiffer at a high rate. A change from 5 off full hard to 4 off full hard on my front end was enough to almost completely stop wheel scrub with my 225/50/15's for instance.

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Re: MAZMAD'S Track car (and Driver) build

Postby mazmad » Sat Apr 13, 2013 6:08 pm

Yep good ideas, easy enough to fiddle with the rear sway so will give that a go, though not sure i will do it tomorrow.

I am thinking of another set of wheels (especially if I do the 1 hour's or 300) and was leaning towards 6ul's again so if i do i will grab those links Mark.

But I have to say, these 2 recent failures have got me nervous, especially if I shoehorn in more horses sometime this year. More power then bigger tyres all stresses the wheels more.


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