Thứ Năm, 9 tháng 2, 2017

Question about the 451's part 1

0260B4U 10-04-2004 07:43 PM

Question about the 451's
Well I know these have been run with some success in nationals
Mine are my street tire I run on occasionally. So they arent shaved.

What pressure should I run for autox?
trhoppe 10-04-2004 08:20 PM

I ran 52 front and 46 rear with success.

-Tom
0260B4U 10-04-2004 08:24 PM

Granted Im sure you have more suspension. Is that hot tempature?

Thought 50 was max psi for the tire? :confused:

Hot i ended up with bout 50 front and 43-44 rear. Front was still scrubbin(more from me overdriving the car)Rear was fine. Kept lighting up the inside tire on the turnaround and took a bit of pressure out to equalize it was getting so hot.

Should they be run hot? or spray em down between runs?
MRF582 10-04-2004 08:30 PM

with a factor of safety built in, you could easily go above 50psi. pump them up.
0260B4U 10-04-2004 08:38 PM

You felt how hot they were, guess that is another question I should ask.

When one side is much hotter than the other, shoudl you take out air to equalize or try and spray em down as best you can?
DrBiggly 10-04-2004 09:12 PM

[QUOTE=0260B4U]You felt how hot they were, guess that is another question I should ask.

When one side is much hotter than the other, shoudl you take out air to equalize or try and spray em down as best you can?[/QUOTE]
Spray it down with some water, but do not remove air. Air is for rollover, grip level, and transitional response among other things. Temperature control...uh, not so much. :)

You want unequal grip, unequal response and different amounts of rollover on either side of the car? Probably not. Also, it's plenty safe to take past 50psi. I know folks won't hesitate to autox with 60psi of pressure; it's not like the thing is going to explode. :lol: :)
rautox 10-04-2004 10:05 PM

[QUOTE=trhoppe]I ran 52 front and 46 rear with success.

-Tom[/QUOTE] :eek: ... this may 'splainsumstuff....
trhoppe 10-04-2004 10:20 PM

[QUOTE=rautox]:eek: ... this may 'splainsumstuff....[/QUOTE]
such as?

-Tom
rautox 10-04-2004 10:23 PM

[QUOTE=trhoppe]such as?

-Tom[/QUOTE]The workout my sidewalls got at lower pressures? :)
trhoppe 10-04-2004 10:26 PM

:lol:

-Tom
rautox 10-04-2004 10:29 PM

[QUOTE=trhoppe]:lol:
[/QUOTE]Ya, of the steaming pile of questions I bludgeoned KC with, I missed pressures.
:furious: :D
trhoppe 10-04-2004 10:32 PM

ooooo, so are you the new wagon owner???

First time out with them we tried azenis asphalt pressures of 42/42 and we wore some serious sidewall...

-Tom
rautox 10-04-2004 10:44 PM

[QUOTE=trhoppe]ooooo, so are you the new wagon owner???

First time out with them we tried azenis asphalt pressures of 42/42 and we wore some serious sidewall...

-Tom[/QUOTE]Yup, me :)

38/42 is where I ran azenis on my MR2, I should've known better. I'm suddenly more excited about next week's event :banana:
MNbiker 10-04-2004 10:59 PM

[QUOTE=trhoppe]ooooo, so are you the new wagon owner???

First time out with them we tried azenis asphalt pressures of 42/42 and we wore some serious sidewall...

-Tom[/QUOTE]

Yep, I'm REALLY glad I tested before Nationals - the tires need a lot more pressure than Azenis. I ended up running at approx. 48psi front & rear.

-Steve
trhoppe 10-04-2004 11:48 PM

Side note, we were 48/46 cold. The rears didn't go up a bit, but the fronts went up to 52 and we just left it.

-Tom
tuskenraider 10-05-2004 01:22 AM

Hello,

Yesterday was my third autox on these tires and I've been running 44/42 max. I'm starting to slide more in 90 degree turns or greater the higher I go, but grip more on sweepers, but with the sidewall squirming like mad. Maybe I really need to bump up the pressures and see what happens...........Would you recommend trying the 48/46 in 60 degree weather for a S-DS car with just a front sway and endlinks?
makofoto 10-05-2004 02:11 AM

Note that Tom was running 245/35/17 451's ....
trhoppe 10-05-2004 09:15 AM

at 2/32s tread depth.

I can't comment on the behavior of these tires full tread, but the size I used felt like a race tire. The sidewall "felt" stiffer and it felt like it had more grip in every part of the corner. I would think you would need MORE pressure then that on a car with just a front bar.

-Tom
tuskenraider 10-05-2004 09:22 AM

[QUOTE]Note that Tom was running 245/35/17 451's ....[/QUOTE] Ooopsy, forgot about that. I have 225/50/16's on the stock rims with full tread, I'll post an opinion after next Sunday on how it works out.
DrBiggly 10-05-2004 10:33 AM

That's a pretty big sidewall; you're definitely going to get a notable amount of squish and squirm from that. :)
0260B4U 10-05-2004 08:05 PM

Yeah im running 225/45/17 I'll put em up to 46-43 cold. See how the act this weekend

Last time I did 44-41 and ended up with 50/44-45 front rear when they were hot.

Well look for me at the Subaru Challenge.I'll be in the white scooby :lol:
Probably last place in SM....damn this deadbolt turbo.:lol:

But cant miss the silver shiny Nike hat. :cool:
04RedWRX 10-06-2004 07:12 AM

I ran 225/50/16 full tread this past weekend on my WRX. Started out with 50/40 f/r. After 2 runs front was 52 rear stayed 40 the whole day. I lowered the front to 47 for run 3, and 45 for the last run (my fastest). But to be honest I'm so new at this so I'm still trying to figure everything out. :banana:

Bruce
trhoppe 10-06-2004 09:33 AM

Bruce, are you the red car I drove during those fun runs at the Subaru Challenge? If so, what were the pressures then?

-Tom
04RedWRX 10-06-2004 12:43 PM

Yup that was me. 45F/40R cold. I didn't check them during the heat, but I'm sure they were back at 45/40 when you drove it.
0260B4U 10-06-2004 08:39 PM

Did you mark the tires to see how bad they were scrubbing? If any?

Gonna try to get 52 front hot this weekend, 44 hot in the rear wasnt scrubbing but the 50 front was. turnaround dont like me and my tires. Maybe time to learn some left foot braking.
makofoto 10-07-2004 02:04 AM

Forget left foot breaking for now ... just BRAKE early and hard enough that you don't set-up big understeer! As I've said ... you gain much more from early acceleration then late braking ... and you can't accelerate while under-steering ... :-)

And don't brake and steer at the same time ... the tires can only do one thing or the other ... well. This is something you can practice on the street ... even at normal speeds. You will be amazed at how your times will come down by slowing down! ;-)
0260B4U 10-07-2004 08:56 PM

Yeah brake and steer is where i was getting into trouble last time, got unsettled and then had to yank the wheel so hard one hadn kept coming off the wheel :alien:

Guess times will tell, 2 days till Subaru Challenge
04RedWRX 10-09-2004 08:03 PM

OK I went through a Novice autocross school today with my full tread 451's, size 225/50/16, on stock WRX wheels. It was a 30 second tight course with one of everything, sweeper, corner box, even had a skidpad for the morning runs. I ran 50f/45r all day. There were only 3 cars at a time running the course so I never got a chance to see how high the pressures went while hot, but the car felt good and I could get it to rotate when I wanted by lifting off just a bit. If I went too hard it would start to push, but again by lifting just a little, the front would grab and go.

:p
0260B4U 10-09-2004 08:43 PM

[QUOTE=makofoto]Forget left foot breaking for now ... just BRAKE early and hard enough that you don't set-up big understeer! As I've said ... you gain much more from early acceleration then late braking ... and you can't accelerate while under-steering ... :-)

And don't brake and steer at the same time ... the tires can only do one thing or the other ... well. This is something you can practice on the street ... even at normal speeds. You will be amazed at how your times will come down by slowing down! ;-)[/QUOTE]

Well did what you said today at the challenge, that and ran a higher pressure

Braking str8 rather than through the boxes and eyebrows gained me at least a 2-3 gain over last weeks times(same course for the challenge just rolling start and alot more open)

Ended up with like 51F 41R but I barely even heard my tires chirp. Even on the turnaround where I was lighting up the inside tire before. Getting used to the setup more also. Car feels great. And with the higher pressure the tires were barely scrubbing at all. But I think that goes with me driving a little smarter.

Went form a 57.440 clean(best run, rest had at least 1 cone)
55--- was the only time I seen passing the finish. But I hope the rest are are arod the same area

Far as I know all 4 clean runs. But got robbed on the last run. Said I was O/C. 3rd section of the back slalom.
Think with my consistancy I would have made it to the SuperStar Challenge.
I was disapointed to say the least. Except when I was stock and spun out I have NEVER been O/C. :(

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