Hoosier AS04 thoughts and impressions, i just corded a set... Options

[nebreitling]

Hoosier AS04 thoughts and impressions

because i know a lot of you guys are running them right now, below are my thoughts and impressions. YMMV

i snagged a set of these up at the beginning of the year at closeout pricing -- something like $118/tire -- and have run them at AX since. although these tires would normally be out of my budget (183/tire), i couldn't pass up this deal.

these were mounted on my street-mod car, app 1900#s w/out driver weight, pretty hot cammed/carbed 2056cc ~115 rwhp, 205/50 on 15x6.5" wheels. they are wider than a typical 205, but pulling fenders is part of the fun.




first off, they are obviously a fairly major competitive advantage. although the new kumho 710s appear to be just as fast (and wear better, at that), i'd estimate that the hoosiers were worth .5 to 1 sec over victoracers or yoko A032's, all things being equal.

WEAR

they were competitive for 6 events. at my 7th event, they went off, showed cords, and were just generally unpredictable and quite less grippy, although they turned in and transitioned just about as well as they did when fresh. honestly, i'm surprised they gripped as well as they did for having cords showing! you can drive them hard up to the end!

do the math, though. after shipping and mounting these things, i had a little over $600 in them. at ~60 minutes of life, that's $10 per minute. ie each run you take costs you $10. clearly, you don't drive these on the street.

RUNNING THEM IN

if i were to buy these again, i'd have them heat cycled to try to get them faster out of the box -- and to try to extract more life out of them. definitely: you want to run them in as hoosier suggests -- heating them up slowly and them dismounting them and letting them rest for a few days.

my tires were not as fast my first event as they were my 2nd, 3rd, etc. my 4th and 5th events, they were at their peak. or maybe i had just figured out how to drive them (more later).

TIRE PRESSURES

When i first got these, Randal told me to run 'em low. Hoosier recommends 40+psi for these tires on a light weight car.

Randal is right.

i ran my hoosier AS04's low (against factory suggestions) -- they had more mechanical grip, but didn't set turns or transition as quickly. they also gave slightly poorer feedback and were trickier to control at the limit compared to more 'reasonable' pressures. but this resulted in undeniably quicker times, and would hook up in a fast sweeper like a slot car.

i found that 26-28 psi was a nice trade-off, although randal mentioned to go as low as 24. at my 7th event, i ran them between 23-25 just to try to get some good rubber in the contact patch -- not just corded rubber. felt *different*, but certainly gave me better grip in the fast sweepers.

CAMBER

i run lots -- particularly up front. more than any other 914 in my class in my region.

while most of the older books i've read say to adjust camber until you reach an evenly distributed tire temp, hoosier suggests to run neg camber sufficient to heat up the inside more than the outside. while this will wear them more quickly, they'll perform better.

even given my alignment settings, the tires wore quite evenly across their width. despite these settings, and despite a liberal use of power-induced wheel-spin (which will heat up and wear the inside edges of the Rear tires), i still corded the outer edges -- not the inner. this is probably an indication of the effects of AX on tires more than alignment settings or drivers' style, but still says something to me.

a caution, however: you can go too far with neg camber -- particularly in the rear....

TIRE BEHAVIOR

these tires turn in and transition like a motherfucker. you can ATTACK slaloms. absolutely phenomenal -- and loads of fun!

while they have excellent latitudinal grip, they have LESS than ideal longitudinal grip IMHO. easy to spin, easy to lock up during braking. little warning, also, so it takes some experience to know where the braking threshold is.

they DO NOT like a high slip angle. keep it well under 10%, for sure! (do some measurements on how far the wheel needs to be turned to get your front tires to turn 5%, 10%, 15%, etc., and you'll start to gain a feel for quantifying slip angle. you need to do measure this stuff anyway to check castor settings.).

because of their phenomenal turn-in, it's easy to gain a false sense of confidence with their ability to keep up with your input. you HAVE to drive tidy with low slip angles! if anything, these tires were worth a $600 investment JUST to teach me about how to drive a given slip-angle.


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again, these are just my subjective impressions -- YMMV -- but i hope there are a few points in here to help some of you guys kick ass on these tires! please feel free to debate, reiterate, or disagree with this.

nathan