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View Full Version : Auto-X and tires...


HaLo
09-06-2003, 09:37 AM
Well... I can't be competitive in the SM class with Bridgestone Bald Potenzas. Last weekend, we had a rapid course. The kind of course that you hit 65-70mph (120kph) with no really tight turns. The kind of course you'd need power AND grip. I had the power, but I had no grip. On a 50 second course, I'm 3.5 seconds back of the leader.

Next year, I'm getting some R's...

Here's a few pics:

http://www3.sympatico.ca/oktayy/pmg/01.jpg

http://www3.sympatico.ca/oktayy/pmg/02.jpg

http://www3.sympatico.ca/oktayy/pmg/03.jpg

http://www3.sympatico.ca/oktayy/pmg/04.jpg

http://www3.sympatico.ca/oktayy/pmg/05.jpg

http://www3.sympatico.ca/oktayy/pmg/06.jpg

thx247
09-06-2003, 11:30 AM
Maybe something a little less bald? Azenis?

240racer
09-06-2003, 11:26 PM
The potenza's didn't like the yoko sticker and were treating you like a traiter. Maybe you should run yoko's if you are going to have a yoko sticker :-) I don't see Ferrari wearing yoko stickers and they seem to win on "bald" potenza's. looks pretty good though, no tires off the ground not gripping or anything. how much boost did you run in the event?

HaLo
09-07-2003, 01:07 AM
Oh... Maybe that's why... ;)

Actually, the Yoko sticker is there because they sponsor all our events in the area and it is "polite" to them that we shove some stickers on the car for pictures... :) Next year, I'll probably run A032R for Auto-X and ES100 for street.

As for boost, I was running 10 psi. Had so many problems with the car that weekend. First, I came there with a faulty hydrolic clutch system. Clutch was soft, hard, stuck to the floor. I took out the damper box the day before and bleed the system. Nothing changed. I order a new slave cylinder from Nissan, hopefully that will fix the problem. So my 1rst run was screwed up. I was fighting with my car. In between my 1rst and 2nd pass, my e-fan broke. So I ran my 3 last runs with no e-fan. Managed to get better times, but it kept bothering me.

I also believe I'm scared of my car. Too much power, little grip, very nervous engine. I can't seem to be able to floor the pedal on straights and to take the corners more agressively. I brake early, accelerate late... I hope I'm going to shake that off next year because it annoys me a lot.

MovinUp-1
09-08-2003, 08:37 AM
Originally posted by HaLo
Next year, I'll probably run A032R for Auto-X and ES100 for street.


run those A032Rs and you'll still be behind in grip compared to a kumho or a hoosier, especially since you're in canada. The A032R is a harder compound and will really show it's deficiency in cooler weather. the only time i've seen those tires work better than a kumho or hoosier is last month at the divisional in houston. Our tires were getting too hot so we had to wet them down between runs. The yokos that another guy was running were getting enough heat in them to work and therefore had a little advantage. It was 98 degrees with a heat index of 112. Don't know what the track temp was exactly but I imagine it was pretty hot.

sykikchimp
09-08-2003, 09:36 AM
a Roll bar and harnesses would do wonders for your confidence.

HaLo
09-08-2003, 09:46 AM
Originally posted by MovinUp-1
run those A032Rs and you'll still be behind in grip compared to a kumho or a hoosier, especially since you're in canada. The A032R is a harder compound and will really show it's deficiency in cooler weather. the only time i've seen those tires work better than a kumho or hoosier is last month at the divisional in houston. Our tires were getting too hot so we had to wet them down between runs. The yokos that another guy was running were getting enough heat in them to work and therefore had a little advantage. It was 98 degrees with a heat index of 112. Don't know what the track temp was exactly but I imagine it was pretty hot.

Really? What about the RA-1?

Keep in mind that we have some events in the rain... :)

HaLo
09-08-2003, 09:47 AM
Originally posted by sykikchimp
a Roll bar and harnesses would do wonders for your confidence.

I was thinking of getting a reclinable "racing" seat like a Corbeau CR1 to start with... hopefully it would help a lot.

MovinUp-1
09-08-2003, 09:50 AM
same deal with the RA-1. The RA-1 is the spec tire for the camaro mustang challenge road races. Some guys report running an entire season on one set of those. That should tell you that they're no good for autocrossing. Don't worry about the rain. The kumhos are still good in the rain when they are new. If it rains, you will slide around, simple as that. If it's dry, you will be slower than you're competition if you're not on kumhos or hoosiers.

HaLo
09-08-2003, 10:15 AM
Originally posted by MovinUp-1
same deal with the RA-1. The RA-1 is the spec tire for the camaro mustang challenge road races. Some guys report running an entire season on one set of those. That should tell you that they're no good for autocrossing. Don't worry about the rain. The kumhos are still good in the rain when they are new. If it rains, you will slide around, simple as that. If it's dry, you will be slower than you're competition if you're not on kumhos or hoosiers.

I see... I had my mind pretty set on the Yoko's... However, your insight might change my mind. :) Thanks again. :)

Would running street tires in rain be more acceptable than running Hoosiers? And what model of Kumho's are we talking about?

MovinUp-1
09-08-2003, 10:26 AM
it depends on the conditions. If the majority of the track is covered in standing water then the street tires would be better. if the track is just wet then kumhos would be better. The kumho I am talking about is the victoracer or Ecsta autocross tire. yokohama did just come out with a softer compound for the A032R. Grassroots Motorsports is testing them on a Mini Cooper S at the National Championships this week. It'll be interesting to see what they think of the new tire.

HaLo
09-08-2003, 10:36 AM
While we're talking about tires, what's the difference between a heat-cycled tire and a regular R tire?

sykikchimp
09-08-2003, 11:04 AM
another point is that the yoko's are MUCH more expensive than the Kumho's.

Get a harness, and s14 seats. Just having the harness will hold you in the seat better, and increase your ability to drive the car in a more controlled manner.

Since your auto-xing even a 4-point harness would help dramatically.

HaLo
09-08-2003, 11:46 AM
Originally posted by sykikchimp
another point is that the yoko's are MUCH more expensive than the Kumho's.

Get a harness, and s14 seats. Just having the harness will hold you in the seat better, and increase your ability to drive the car in a more controlled manner.

Since your auto-xing even a 4-point harness would help dramatically.

Shouldn't a 4-poit harness be used with a roll-cage? I heard things (may not be true) about running 4-point without cage being more dangerous..

MovinUp-1
09-08-2003, 11:54 AM
The 4 point y-type harnesses are fine for what you are doing, you don't need a cage to use them. A heat cycled tire has been brought up to it's ideal operating temperature and allowed to cool back to ambient. This is done because the compounds have more grip once they have been heated one time. Too much chemistry to go into. IMO, it's not worth paying the extra money tire rack wants for heat cycled tires unless you plan on running them at nationals without using them beforehand.

HaLo
09-08-2003, 12:00 PM
Originally posted by MovinUp-1
The 4 point y-type harnesses are fine for what you are doing, you don't need a cage to use them. A heat cycled tire has been brought up to it's ideal operating temperature and allowed to cool back to ambient. This is done because the compounds have more grip once they have been heated one time. Too much chemistry to go into. IMO, it's not worth paying the extra money tire rack wants for heat cycled tires unless you plan on running them at nationals without using them beforehand.

Understood. How would you fix a 4 point harness?? on the rear STB? What about the two other points?

sykikchimp
09-08-2003, 12:47 PM
two lap straps bolt to the rear seat floor bolts.. shoulder belts can be attached to the rear seatbelt mounting points.

Check this:

http://www.soloracer.com/harnessbelts.html

240Dave
09-08-2003, 01:07 PM
Originally posted by HaLo
Shouldn't a 4-poit harness be used with a roll-cage? I heard things (may not be true) about running 4-point without cage being more dangerous..

It's only bad if you roll the car...not something likely to happen at an auto-x.

HaLo
09-08-2003, 02:14 PM
Originally posted by 240Dave
It's only bad if you roll the car...not something likely to happen at an auto-x.

It's funny because I've seen it happen in the last Auto-X event I did... :eek:

sykikchimp:

Basically, I have to drill the floor in order to install the 2 lower points of the 4-pt harness while my 2 shoulders points should both be on the rear shoulder point of the rear seatbelt?

I thought I could use both lower stock points for the 4 point harness and the strut bar for the higher points. Would that work?*

And what about the 3 point harness? Is that any good?

sykikchimp
09-08-2003, 02:51 PM
If I was to use a 4 point, I would mount the two lap belts to the exsisting bolts that hold the seat rail in the back. Maybe use the exsisting seatbelt bolt on the right side of the driver.

I would mount the 2 shoulder belts to the rear seatbelt lapbelt mounting bolts. Where the little latch peice that pop through the rear seat are attached to the rear deck.

You could use the rear seatbelt mounting point from the c-pillar (hatch frame rail), but I hear it being kind of at an angle allows it to slide around a little while your wearing it. Doesn't hurt to try both ways.

The 3-point will work just as good as the 4-point. Just easer to install.

I wouldn't mount the belts to the STB, because it's not meant to hold you if you do hit something. Say you have an encounter with a concrete based light pole.. I wouldn't trust the strut bolts to hold ****.

HaLo
09-08-2003, 02:56 PM
Originally posted by sykikchimp
If I was to use a 4 point, I would mount the two lap belts to the exsisting bolts that hold the seat rail in the back. Maybe use the exsisting seatbelt bolt on the right side of the driver.

I would mount the 2 shoulder belts to the rear seatbelt lapbelt mounting bolts. Where the little latch peice that pop through the rear seat are attached to the rear deck.

You could use the rear seatbelt mounting point from the c-pillar (hatch frame rail), but I hear it being kind of at an angle allows it to slide around a little while your wearing it. Doesn't hurt to try both ways.

The 3-point will work just as good as the 4-point. Just easer to install.

I wouldn't mount the belts to the STB, because it's not meant to hold you if you do hit something. Say you have an encounter with a concrete based light pole.. I wouldn't trust the strut bolts to hold ****.

Thanks a lot. Apparently, the Schroth belts are mounted to the stock seatbelth points. front lower and rear C-pillar for 3-point and rear lap belt for 4 point. I believe I'll get the 3-point and try it from there. Also might find some s14 cloth seats instead of my s13 leather seats.. that should help too.

hurleyboi514
09-10-2003, 12:23 AM
im pulling out of auto'x for track schools instead. more money, but it'll be good. ill probably go to a few though to keep my skills up. i do pretty well, usually one of the top 3 on street tires. there is a pesky WRX and my room mates SER that get in the way alot though. its nice to see the 240's getting into it though. there are a few local drifters that go to them for some skill improvement. thats always nice to see! :)

HaLo
09-12-2003, 09:26 AM
sykikchimp:

I followed your advice and got some s14 seats..

I can't believe what a difference only the seats make.. Can't wait for my harness to come in! :)

http://www3.sympatico.ca/oktayy/DCP00793.JPG


http://www3.sympatico.ca/oktayy/DCP00794.JPG

sykikchimp
09-12-2003, 01:02 PM
They made a big difference for me too.. they have much better side bolstering.

just a heads up, but you loose about 1-2" of leg room with the s14 seats as long as the lapbelt at the right rear corner of the seat is there. The s14 seats hit it.. the s13 didn't. You have to install the manual seat belts (s14 or Canadian s13) to gain the space back.

probably not an issue for you, but it is one I thing I plan to do.. I'm 6'4" though.. so leg room is a comodity

EDIT: Nevermind.. I just noticed you already have Manual belts.. DAM CANADIANS!! lol :D

AceInHole
09-12-2003, 01:27 PM
does anyone remember the old S13 seat modification that used to be on the 240sx.org site?? i pulled the seat covers and foam off my s14 seats and noticed that you can *sorta* do the same. just used a large crescent wrench and a pair of pliers to bend the frame of the seat in slightly. Tried to get it so I could fit into the bolstering a bit "deeper". Kinda works. Some people actually notice the difference, some don't (basically... it helps ever so slightly).

I should've done a writeup on it but it's way too easy to do....

hurleyboi514
09-12-2003, 02:21 PM
you can get a sparco speed for like $250. it helps SO much. like you dont worry about sliding around, u just drive. my seat was one of my favorite mods! and it looks damn cool, it shows u mean buisness! ;)

HaLo
09-12-2003, 02:39 PM
sykikchimp:

Lucky us that the auto belts are illegal in Canada. The don't pass safety inspections. :)

Ace:

A friend with a S14 did it with his car and it makes a big difference too. I plan to do it on my S14 seats too. They are a tiny bit wide. (I'm on the skinny side. ;) )

hurleyboi514:

Considering I paid 250CDN (~180$) for both seats, I believe I got a steal. I plan on getting 1 Bride seat with rails in the long run. For the moment, those S14 seats will do it. :)

Halz
09-14-2003, 05:50 PM
I have a lame little write up of how I installed my 4 point harness without a roll-cage, for autocross

http://members.dslextreme.com/users/awaher/240sx/harness.html

AceInHole
09-14-2003, 06:40 PM
Originally posted by HaLo

Ace:

A friend with a S14 did it with his car and it makes a big difference too. I plan to do it on my S14 seats too. They are a tiny bit wide. (I'm on the skinny side. ;) )

Well, even my 250lb friend on the "heavy" side noticed and liked the difference :p

It's still not a racing seat, but at least any amount better than stock is good.