After a season on RA1's I'm sucking it up and trying the new Hoosiers. Should I do anything differently with the alignment, tire pressures, damping settings, etc?

 

i'm told by the miata guys that the hoosiers like more camber than the ra-1's. but of course that's with us limited to 2.5 degrees in front, and 2 in the rear. apparantly in order to have decent longevity, you need 3+ with the rs304.

 

You may want to start out with slightly higher (2-3 psi) pressures and then tune tire pressure and alignment settings based on tire temp. and wear patterns. The one thing you will need to be aware of is that the Hoosiers are lighter and will tend to lock up quicker under braking than you are used to with the Toyos.

Good Luck!
Dave

 

Hoosiers do like more camber 2.5-3.0...but don't over do it. Depending on what your car weighs you want hot pressure to be in the 40-45 range......

 

Just curious, this is an interesting topic -

"Hoosies do like more camber 2.5-3.0" eh?

This of course refers to the static camber setting, which has nothing to do with the dynamic terminal camber when you're talking about different cars, suspension types, and where in the camber curve of the car you have you are and what your roll stiffness is.

Why not just say something like "Only you and your pyrometer and stopwatch can answer that".

FWIW, you can only put around -3.5 to -4 into the front of a stock DC2 chassis - after that you're likely to start eating CV's and/or axles since you're out of plunge.

Scott, who reminds you to remember that bushing deflection eats up a little of that plunge travel too...

 

Not if you put nice Aurora spherical bearings in the front LCA like I just did (and some hard bushings in the UCA)! Ran great this weekend, you can just feel those tires.

 

Claude,

So it felt pretty good eh?

How'd you do the LCA's rear most bushing replacement? Or did you just do the forward most one?

Scott, who's still rubberized...Mugen rubber...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote">

"Hoosies do like more camber 2.5-3.0" eh?

This of course refers to the static camber setting, which has nothing to do with the dynamic terminal camber when you're talking about different cars, suspension types, and where in the camber curve of the car you have you are and what your roll stiffness is.


Why not just say something like "Only you and your pyrometer and stopwatch can answer that".

</TD></TR></TABLE>

of course, but it's just to provide a starting point for tuning. at least both the miata and the dc2 have similar suspensions. but wait, are these for your mr2? if they are, i dunno what kind of suspension you have. so like scott said, get the pyrometer out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jake &raquo;</TD></TR><TR><TD CLASS="quote">After a season on RA1's I'm sucking it up and trying the new Hoosiers. Should I do anything differently with ... tire pressures...</TD></TR></TABLE>

From what I've seen, Hoosiers like a higher hot operating pressure. We typically start out about 5-8 psi higher cold pressures on hoosiers than on shaved RA1s. (This is for dry use.)

 

Wow - thanks for all the quick responses. Yes these are for my MR2. I run 2.5-3.0 deg negative camber all around and start at 30psi on shaved Toyo RA1's. They grow to about 38psi and show even temps across from a pyrometer. So maybe start at 32psi for Hoosiers, and check temps and pressures from there?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote">Claude,

So it felt pretty good eh?

How'd you do the LCA's rear most bushing replacement? Or did you just do the forward most one?

Scott, who's still rubberized...Mugen rubber...</TD></TR></TABLE>

I liked it a lot. Mugen rear most LCA bushing, Orijin front LCA Aurora spherical and Orijin UCA. Highly recommended, no "harshness" above that of hard dampers (I was surprised), but the bottom one was a PITA to get the bolt through. I had to grind the bolt end to a point (as in the rear suspension) or I would have died of frustration, as you have to line up 9 holes to get the bolt through the system. I had to thin down the UCA bushings to avoid the upper A-arms binding (but then again the parts weren't made by Mugen!). All Mugen rear suspension bushings. Let's you feel those tires much better, more go-kart-like. Some guys were installing R3S04's, but no one knew about setup.

Speaking of pyrometers, as the pin of my Longacre one was pushed in for some reason(or broken?) when I went to use it last weekend, I could not get to the carcass, so I tried a little $39 infra red point and shoot thermometer I picked up at Sears. It gives surface temp so much faster than the pin type, I thought it was possibly good to use to get into the ballpark of pressures and even temps across. I was getting the same readings as on my short pin Longacre, but I had to wait a lot longer for the reading on the pin one. Has anyone else ever compared (as the speed benefits of the point and shoot one has to be experienced to be appreciated, just try it)? Also who has any manufacturer advice on what temp pattern you are looking for in terms of temp evenness across the tire in terms of both pressure and camber for the various R compounds on the market.

By the way I bought some Yoko 032R Soft compound and ran them a few sessions in the rain. They were great and came up to temperature (150 deg. ) quickly on a cold damp morning. I liked them a lot for that purpose. Then I switched to my Sport Cups in the dry, since I haven't worn them out yet (but I am trying!). Looking to get the new Hoosiers next.


Modified by descartesfool at 7:20 AM 6/3/2004

 

More useful info:
http://www.hoosierracingtire.com/Tctips.htm

 

But as usual no useful info on recommended temps across the tire. Just a general statement of 2.5 to 3 deg camber and optimium hot and cold pressure and temperature range of tire in general.