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.


------

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

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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.

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.

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.

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...

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

I only have only one spin out on 'em, too.

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

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

exspensive hobby. wish i had your kind of cash . 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

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 ...
Andy

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.

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

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

expensive hobby. wish i had your kind of cash

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 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.

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....

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

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

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.

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...

KT

I'm going out on a limb...don't saw it off.

Rear sway bar...no wheel spin.

KT

high rev-ing /6

no torque

Just some very subjective observations from my vantage point watching Nathan's car and those tires.

1. Maybe on a bad day his car is putting out 115 rwhp, my butt-o-meter says its a little more. His car has more pull than my 220hp Boxster at low speeds and that was with my 270 lbs in the passenger seat.

2. I have had the pleasure of lining up behind Nathans car on grid and his starts are something akin to an out take from The Fast and the Furious - full wheel spin for a good 10 feet. He is also not shy about exiting some slower corners with those tires blazing occasionally. ...Trekkor you must have a video somewhere of one of those starts.

3. Now for thoses pics of demolished tires - yes they were terribly corded, but Nathan forgot to mention the drift competition at the end of the day at Marina that really knocked that rubbber off the tires. ...some of us were watching those festivities as we were changing our tires.

4. From my ride with Nathan at Marina, greasy wasnt the feeling I felt as we went into corners. The grip felt similar to my A3S04s which only have about 30 runs. They were still sticking better than my Yokohama's.

It will be interesting to see how much Albert (the other 1.8 AX driver) and I get out of these tires since we cant really spin our rear tires like the more powerful cars. I think mine will last the rest of this year. Alberts is a two driver car so he will know very quickly how long these last. I also believe he ran quite a few fun runs at Marina so he is likely got just as many runs on his tires as mine after just 1 event. I have never driven any of Kuhmo's r compound tires, but I can say these tires make a big difference from my Yokohama's. I had a chance to run the tires back to back and the Hoosiers were easily worth a second over the Yokohamas.

I agree with Nathan on pressures. I have been having good luck running about 28 psi with my A3S04s. I'm going to try 26 next AX.

I picked up my A3S04s for $109 per tire from RS Racing on sale. I already have 30 runs on them and they easily have more than 3 more AX left. So my cost factor wont be as bad. Problem is that even with slicker tires Nathan will still go faster than most of us. I'll just go from a full 2-3 seconds off the pace to about 1 or 2. I'll probably be down around $5 to $6 a run if I only go 70 runs. Its worth it to me until somone comes out with a better or equal tire that lasts longer. I wonder if the AS05s are any better? They sure do feel stickier and from what I hear are supposed to have better feel.

QUOTE (Randal @ Jul 27 2005, 05:12 PM)

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.

yeah, it's fast for a 2056, and it has a fairly wide power band. starts at 3.6k and goes all the way to 6k, where i shift. trekkor's car is quite a bit faster flat out, but i can out-torque him in the tight stuff slightly cause he doesn't keep his engine on the cam.

Nathan,

The Hoosier AS04's are worth a minimum of 1 second over Yokohama A032's at the Big Track, Willow Springs. The Yoko's last almost twice as long however. I have burned up a set of Hoosiers at a two day race and TT event. They are without a doubt sticky....

Dan

QUOTE (grantsfo @ Jul 27 2005, 05:48 PM)

3. Now for thoses pics of demolished tires - yes they were terribly corded, but Nathan forgot to mention the drift competition at the end of the day at Marina that really knocked that rubbber off the tires. ...some of were watching those festivities as we were changing our tires.

yup. i thrased 'em at the end of the day. 914's sure are hard to drift, but tons of fun! they were only showing cord after the timed runs. they were showing steel belt after the drift session.... i hate drifting as a sport, but that was about the most fun i've had in the 914....

and i launch with a little wheelspin...

Nathan,

I found my Kumhos wearing as your tires even with -2 camber. Raised the pressure till noticed pretty even wear - they also stuck better as they warmed up.

I will loan you my pyrometer if want to measure tire temps and play with tire pressure.

Iwill not be at the next few AXs but if you or sombody can pick it up in Gilroy you are more than welcome to use it.

Ken

QUOTE

he doesn't keep his engine on the cam

Uh-hem...can't keep it on the cam. Not with this trans.
When we're doing 28 MPH you're ready to blast off at 3500rpms in 2nd.

I have to wait til the motor comes up to 5000rpms to catch you...You shift at 6k at 48 mph while I wait 'til 7300 rpm's and get to 59mph.

It seems to even out though, as we were .25 seconds apart at the end of the day.

Say "one...one...thou...sand" It's just the "one", over a 52 second run.

Now, if I had an "C-F-I-M-Q" a/x box...Ooooho, you'd know.

KT

i didn't mean it as a slight at all, trekkor. it does even out i think -- although i'd use more 1st gear if i were you. i know you're right on my heels!

I know you weren't diggin' on me. Just the facts of my powerband

The last two a/x's have been get it in 2nd and go!

Let's do a fundraiser to get you another set of Hoosiers

KT

Toyo RA1s are going for around $120 but they arent going to stick like a Kuhmo or Hoosier. In reading the AX boards I have heard early A3So4's had a problem with a lack of tread on shoulders that Hoosier corrected in later batches. I cant find the A3so4 on sale anywhere now.

They, Hoosier, also indicate that if your car has less than 3 degrees of neg camber and you run lower than reccomended pressure that patch (stire shoulder area) you show in the picture wears more quickly. So guess that means I'll be wearing that area as well since I'm not close to 3 degrees. Albert better make some changes soon!

A3s05's and V710's are supposed to wear better. Found the V710 for around $140. The Yoko is on sale at Tire Rack for $136. Have you thought about Hoosiers race compound tires? I thought those felt almost as good as the autocross compound. Just took a few turns to get them heated up.

ha! yeah, albert better get himself an alignment!!! grant and trek -- how are your tires wearing across the tread? for what it's worth, i think you could both put use more camber, as well. if you don't want to hack up your car, rich bontempi has the tarret plates/monoballs for $450. fair price. i have about a degree more neg camber than both of you, and i still wore them down on the outside shoulder.

ken, thank you for the kind offer. maybe when i mount up the new tires.

when i'm ready, i'm leaning towards the 710s... seem to be the best stick for the dollar -- plus they're robust enough for track use.

QUOTE (nebreitling @ Jul 27 2005, 08:46 PM)

ha! yeah, albert better get himself an alignment!!! grant and trek -- how are your tires wearing across the tread? for what it's worth, i think you could both put use more camber, as well. if you don't want to hack up your car, rich bontempi has the tarret plates/monoballs for $450. fair price. i have about a degree more neg camber than both of you, and i still wore them down on the outside shoulder. ken, thank you for the kind offer. maybe when i mount up the new tires. when i'm ready, i'm leaning towards the 710s... seem to be the best stick for the dollar -- plus they're robust enough for track use.

Mine look good so far - fairly even wear pattern.

I think Grant's wear will be better because he has a "square face to side wall" profile using the 15 x 8 rims.
At least thats what I found with my Diamond wheels Only put 10 runs on them and took TTOD by 2 seconds. Hassan blew everybody away. Next event I had the Kumhos backon the car and he said What the hell happened to the car? Like driving on ice.
Well aside from more gas in the tank and a turn up on rear springs. Won't doth at again.
I ran 32 PSI and found lots of grip and even tire temp/wear. 1.7 degrees - camber front (all I can get even with Welt camber plates) and -2 at the rear.
I think the wider wheel contributes to that.
Uh yea the fenders needed some serious bending to get them in.

QUOTE (Joe Ricard @ Jul 28 2005, 05:58 AM)

I ran 32 PSI and found lots of grip and even tire temp/wear. 1.7 degrees - camber front (all I can get even with Welt camber plates) and -2 at the rear.

Most of the posts I've seen in this thread make me think you guys are running the Hoosiers with too low pressure. Instead of using the rubber compound for grip, you're increasing the rolling resistance which is giving you grip but probably slowing you down from the times you should be running. The Hoosiers work best with more air than other brands of tires, but they need to get heated up to work, which I know is difficult on AX. If the 32# that Joe states here is cold, I think that is about right. I don't AX so I'm just talking from my knowledge of Hoosiers in general.

that's what i keep thinking, drew. i'm sure my tires would have lasted longer with more air pressure, but i keep coming back to the fact that i consistently ran my fastest times at around 27-28 psi -- hot.

so i don't know

btw, up until the very end, my tire wear appeared to be quite even across the width. this thread is making me think that perhaps the key is to fine tune your camber settings in order to put down a large contact patch, as opposed to letting the tire 'deform' into a large patch with low pressures.

QUOTE (nebreitling @ Jul 28 2005, 07:09 AM)

that's what i keep thinking, drew. i'm sure my tires would have lasted longer with more air pressure, but i keep coming back to the fact that i consistently ran my fastest times at around 27-28 psi -- hot. so i don't know btw, up until the very end, my tire wear appeared to be quite even across the width. this thread is making me think that perhaps the key is to fine tune your camber settings in order to put down a large contact patch, as opposed to letting the tire 'deform' into a large patch with low pressures.

And get wider wheels. the contact patch is really affected by the width of the wheel. keeping the tire from being pinched by a narrow wheel make the tread face round.
Just don't get UGLY ones.

My tires are wearing quite well.
The fronts have more wear, but the treadwear indicators are clearly visible.
The rears have those "track worms".
You can tell that I've been on the hard right handers just by looking at them
The last three a/x's have all been clockwise with high speed rights at the end.

Here's a shot of my tires:
o=outside
i=inside
rf=right front
lf=left front

KT

i was just thinking that exact thing joe. the 205 width on my 4 lug fuch wheels, and the somewhat "balloning" effect must contribute heavily to sidewall roll. my next step will be to disconnect the rear sway and see how much further i can confuse things. my car was very loose in the rear, sort of predictable, but time/ momentum was lost going off throttle a bit to keep the rear from coming completely around.

k

Here's the rears.

Can you see the rubber that has been pushed across the surface of the tires?

KT

QUOTE (rhodyguy @ Jul 28 2005, 08:11 AM)

i was just thinking that exact thing joe. the 205 width on my 4 lug fuch wheels, and the somewhat "balloning" effect must contribute heavily to sidewall roll. my next step will be to disconnect the rear sway and see how much further i can confuse things. my car was very loose in the rear, sort of predictable, but time/ momentum was lost going off throttle a bit to keep the rear from coming completely around. k

Yea on the advice of an "old guy" here I did that too. Disconnected the rear bar. then just took it completely off.
Now the inside rear tire stays in contact with the surface much better.
The tail can still get loose if the shocks are stiffened up. Probably need more front bar. I'll be tuning this during my school this weekend. Should be my last event on Kumhos.

Has anyone tried the Hankook DOT AX slick (Ventus Z214) yet? They seem to be very comitted to motorsports with a full range of competition tires.

Here is a link to a place selling the DOT AX slick

http://www.aimtire.com/typ_tire.asp?ObjectID=6605

i guess i'll need to pointedly ask someone to note what the "shape" of the car looks like in certain sections. other than the "wow. oh crap" factor while driving, it's hard to know what's going. but then the "it looks good kevin", makes others more competitive. running on other than street tires should put people completely dif class. just a set of carbs bumped me into improved.

k

QUOTE (Joe Ricard @ Jul 28 2005, 07:49 AM)

And get wider wheels.

my wheels are 6.5" wide. true, they're a little under 'ideal', but they seat the rubber quite well.... n

I don't follow all the "remove the rear bar" talk.

I never spin the rear tires.
There's one course where the cars go down into a banked turn and then back up onto course. You can get airborne a little if you come out fast. All the fast cars do that though, bar or not.

My car is super flat in the turns and rotates- very predictable. I can't imagine ever removing the rear bar.
If it's not twitchy now. Removing the bar won't improve it.

Tell me something.

KT

trek -- your tires look good. but you're not rotating them?

i haven't noticed your front wheel lifting lately, trek -- has anything changed? ditto, grant. am i lifting?

n

btw trek your car stays unbelievably flat.

QUOTE (trekkor @ Jul 28 2005, 09:07 AM)

I don't follow all the "remove the rear bar" talk. I never spin the rear tires. There's one course where the cars go down into a banked turn and then back up onto course. You can get airborne a little if you come out fast. All the fast cars do that though, bar or not. My car is super flat in the turns and rotates- very predictable. I can't imagine ever removing the rear bar. If it's not twitchy now. Removing the bar won't improve it. Tell me something. KT

It depends on the rear roll stiffness relative to the front roll stiffness. If you have a large front bar relative to the rear, and/or stiff torsion bars compared to rear springs, you won't have the problem with the rear lifting. I bet you have a large front bar.

It's all in the combo!

Andrew

QUOTE

not rotating them?

Not yet. I'll move the rears to the front for the next session.

After Zone weekend I'll have them re-mounted, inside-out.

QUOTE

i haven't noticed your front wheel lifting lately

Shoulda came to RR.

QUOTE

your car stays unbelievably flat.

Thanks and thanks to Brad for the set-up!

KT

QUOTE

I bet you have a large front bar.

31mm...



KT

QUOTE (nebreitling @ Jul 28 2005, 09:09 AM)

i haven't noticed your front wheel lifting lately, trek -- has anything changed? ditto, grant. am i lifting? n btw trek your car stays unbelievably flat.

I know I could use a little heavier spring in the back - say a 200 lb rather than the 175 lb springs I have currently. I think that would give me nicely balanced car with my current front swaybar. I believe that would keep the front wheel on the ground and help me get around some of those slow corners better. I still have plenty of adjustment left on my front bar to counteract the heavier springs. I also have plenty of firmness I can dial into the front if the car gets too twitchy.

I havent seen your car lift a front wheel for awhile Nathan.

Back to the Hoosiers I checked mine again becuase all this wear talk had me worried and they look really good to me.

QUOTE (trekkor @ Jul 28 2005, 09:07 AM)

I never spin the rear tires.

That goes without saying