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

[nebreitling]

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[nebreitling]

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[J P Stein]

The obivious question is ....how much is "more camber".
and how much pressure? Looking at the tires, it "appears" that you don't have enuff of either.

I ran 225s for a season (with 2 drivers) and they had the lines left.....but the outer edges were getting thin. This was on low grip asphalt however. -2 deg camber & around 30-32 hot.
I tried pressures 26 to 39. At 26 they stunk...and at 39.
The 30-32 range gave me the best combo of grip, turn-in & braking.

Guys in heavier cars were getting 30-40 passes out of the 04s which is why Hoosier jumped quickly to the 05s.

[nebreitling]

i think their wear pattern was a result of the low pressures that i ran them at -- and not camber.

i'm running significantly more than -2.

[J P Stein]

I will admit the comparison is a bit of apples/oranges
with the most prominent difference being the different surfaces we run on. You were undoubtly getting more lateral grip than I
which would cause more roll over ....fed by the low pressure.

Still, the best measure for pressure is heat across the tread.
Your results speak highly of your set-up, tho. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[ottox914]

I too grabbed some of the "close out" SO4's, and am running them on 15 x 7's, under stock fenders, with about 1.5 degrees neg all the way around. I emailed hoosier, they suggested 40-42 psi cold, adding another 2 or so psi for the limited camber!!! Tuning tire pressures by heat across the tread, this weekend, on a 90degree day, best I could get the tires up to was mid 90's for temps, and ended up running 21 front, 23 rear for even temps across the tread!?!? This is in my DSP car, 2200# with me and 1/2 a tank gas. Finished 9th overall out of 105 gridded. The last run at the lower pressures with a little front koni tweek was the best feeling of the day. I would totally agree they grip in the corners better than in a straight line. Hard to launch w/out wheelspin, and even worse early this season with 50 and 60 degree air temps...

[Trekkor]

I am going to re-mount mine inside out after the next three events and watch the wear on the fronts compared to the rears.
The fronts are wearing much faster, so they'll rotate to the rear before long.

I have three events ( 29 minutes ) on mine already and they still look great and really grip. All lines and wear indicators are clearly visible. I'd guess 30-40% worn (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

I only have only one spin out on 'em, too. (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

These tires are super forgiving for me. I can feel when they are about to break loose and I back off.
If I miss it and the car starts to lose it, the tires will catch if I don't upset the car any further.

I run them at 28 psi front and 29 rear.
On 5.5" rims (IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif)

By far the best tire I have run.
Started on street Yok's, TW 420
Falkens, TW 200
Yok's A032R, TW 60
And now the A3S04's with a treadwear of 40.

Grant runs 'em, too so it'll be interesting to hear what he thinks.

KT

[rhodyguy]

exspensive hobby. wish i had your kind of cash (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) . so, new skins or street tires for the rest of the season? interesting data and impressions. the rubber loss on my potenzas, skid pad/track in lancaster and 1 ax was sort of alarming. i don't think rotating them will buy much extra life.

k

[SirAndy]

i run my R250 goodyears at 17 and 19 lbs ... i might go even lower than that next time. lower pressure makes the ride feel more "squishy" but they actually stick better ...

my camber settings are completely off tho, way too much in the front and not so much off in the rear.
the R250 like less camber ...

FWIW ...
(IMG:http://www.914world.com/bbs2/html/emoticons/driving.gif) Andy

[Randal]

QUOTE

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.

My experinece: If I brake in a straight line and completing my braking before inducing a (smooth) turn it seems to work wonders.

Keeping the car as settled as possible also seems to result in less "brake induced spining," and heavens knows I've got the record for those, i.e., lots more than Trekkor.

The other solution we found is making sure the car isn't on the loose side.

Brad blew me away one day. I was out there racing and in one particular corner I was backing off to control the "loose" handling of my car. Brad asked me about it and I told him I thought this was the speed I was going (always fast you know!). Well we slid the sway bar back about an inch and the loose situation went totally away. I kept going faster and faster in the same corner all day. Never did find the limit.

My feeling, that I will leave to Brad to explain properly, are that those sudden high speed spins, where the car just goes away without warning, are induced more from incorrect suspension settings than the tires.

Actually pretty complicated stuff.

[ppickerell]

Nathan,
Do you run those on stock wheels with no flare?

[nebreitling]

QUOTE (rhodyguy @ Jul 27 2005, 04:39 PM)

expensive hobby. wish i had your kind of cash (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

(IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif) HA! that's the best! i'm a grad student -- i take a salary from stanford for my research and teaching, but i'm clearly out under budgeted for this dumb sport... hell, my car is built 90% out of used parts and other people's spares. BUT, i can live cheap, and i have an understanding girlfriend (IMG:http://www.914world.com/bbs2/html/emoticons/wub.gif) you'd laugh if you saw my budget. it's like 40% car...

QUOTE

so, new skins or street tires for the rest of the season?

good question. i don't know. if i can scrape up the $$, i'll spring for a set of 710s -- but circumstances require me to put my cash elsewhere for the next few months. i've got some very tired victoracers, but i'm saving those to tear up at the track next week. also have some VERY crusty hoosier RS03's, but i wanted to save those for DE as well...

might just run my street tires for a while. although i'll miss being competitive, my driving could use a lot of refinement. i want to spend time focusing not necessarily on winning, but on reading the course -- and then hitting every single damn apex on every single damn run i take.

[nebreitling]

QUOTE (Randal @ Jul 27 2005, 04:50 PM)

QUOTE 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. My experinece: If I brake in a straight line and completing my braking before inducing a (smooth) turn it seems to work wonders. Keeping the car as settled as possible also seems to result in less "brake induced spining," and heavens knows I've got the record for those, i.e., lots more than Trekkor. The other solution we found is making sure the car isn't on the loose side. Brad blew me away one day. I was out there racing and in one particular corner I was backing off to control the "loose" handling of my car. Brad asked me about it and I told him I thought this was the speed I was going (always fast you know!). Well we slid the sway bar back about an inch and the loose situation went totally away. I kept going faster and faster in the same corner all day. Never did find the limit. My feeling, that I will leave to Brad to explain properly, are that those sudden high speed spins, where the car just goes away without warning, are induced more from incorrect suspension settings than the tires. Actually pretty complicated stuff.

by *easy to spin*, i meant easy to spin them on a launch or coming out of a corner. throttle spin. tear-out. you know, longitudinally....

but i agree with you about the suspension stuff: these tires will find any deficiency in your suspension settings...


pp: i run these under stockish (pulled) fenders on 15x6.5" rims. i think they're too wide for 5.5" wheels, but Trekkor's running 'em that way....

[Randal]

Are there any of the cheap last years Hoosiers still around?

[nebreitling]

someone said that tirerack had 'em -- but i couldn't find them...

[Randal]

QUOTE

by *easy to spin*, i meant easy to spin them on a launch or coming out of a corner. throttle spin. tear-out. you know, longitudinally....

That motor of yours really does rock. I could never break my tires loose coming out of a corner when I was running 205's.

[Trekkor]

I just checked R&S Racing, where I got mine and they're gone.
R&S

QUOTE

they're too wide for 5.5" wheels, but Trekkor's running 'em that way....

Thatz cuz ayeeem koo-koo... (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif)

KT

[Trekkor]

I'm going out on a limb...don't saw it off. (IMG:http://www.914world.com/bbs2/html/emoticons/unsure.gif)

Rear sway bar...no wheel spin. (IMG:http://www.914world.com/bbs2/html/emoticons/hide.gif)

KT

[nebreitling]

high rev-ing /6

no torque