Wilder

I run a 98 993 C4S with Turbo sways, PSS9s, 18 x 9/11 CCWs and Falken Azenis 615s in 245/315s.

Last weekend I ran the last PCA AX in the cold, pouring rain. I did okay but could've done better and would like some feedback.

What is the best setting for my PSS9s? The information I've found is that 1R, 3F should work well for an AWD in a hot track. What about wet? Do I want the same ratio but in softer settings (i.e. 7R, 9F)? And what if it was just colder but not wet? 3R, 5F maybe?

What tire pressure? I ran 34F/36R cold which is what I run on the street. I took it up to 36/38 but the car felt more planted at 34/36 so I took them back down. In the past I've ran 32/34 cold in warm weather.

Also, I don't know that the very wide tires and light wheels helped much in the cold rain. What are the best widths in the rain? Should I be running 205/245s on 17s?

Are heavier wheels better in the rain? A friend was running 19" RUFs on street tires (don't know what brand) on his stock 993 C2. RUFs are very heavy and he got FTD. Could've just been good driving but it was his first AX (or so he said) and I was 2 secs behind him.

TIA

AllanJ

Hey Louis,

Can't help you with PSS9 settings, but I lower the tire pressures when in the rain. It's the only way I can soften my suspension a bit to help. Also, I bleed the pressure down between each run. Just setting the tire pressure once at the start of the day is a good way to make sure I'm sliding around in the afternoon.

When driving in the rain it's all about driving the right line and being smooth. That's where you'll get back the most time. Any sudden movement (brakes, gas, steering) will result in tires sliding on you and that's slow. Be smoooooooooooth out there.

Come out to the UBCSCC slush series over the winter and I'll be happy to work with you. We need more Porsches there!

Cheers,

Wilder

Even though I logged better than average times during the morning, they should've been better given the car I was driving. I'm sure screwing around with my PSS9 settings and not running proper tire pressures contributed to slower times but clearly I need more seat time and technical information. There was a book on AX that was mentioned here a few months back. I'll do a search and see if I can find it. Aside from that, thanks for the offer and yeah, I'll take you up on it and come out with you to UBCSCC for more training. When's the next event? Is there a website?

BTW, I'm in Calgarly right now. I've got to be up early for this....http://www.allenbergracingschools.co...ols-oneday.asp

lowside67

Louis, we run into each other all over the place.

I run 4psi less in the rain than I do in the dry on my streets and 3psi less on the r-comps in the "damp".

After a ton of testing, I actually dont touch my shocks between wet and dry, any deviating from where they are in the dry seems to be counterproductive in the wet.

www.ubcscc.com/slush.shtml

Those are the dates for your test sessions

-Mark

sechsgang

pshhh...who cares about time??? go slide!




On a semi serious note...agreed with smoothness...seems to always be the key...just especially so with autox...which FWIW...I'm horrible at because I always do the first part of my post...

Wilder

OMG, I'm so in...http://www.ubcscc.com/gallery/main.php?g2_itemId=4614

Actually, I met this guy and he instructs ice racing, which sounds awesome and I might just have to try it out this winter.

KenJ

Was the book "Secrets of Solo Racing" by Henry Watts? I think his main mention of AXing in the wet is that the rain is a great 'equalizer'... that cars that wouldn't get close to you in the warm, dry weather may surprise you in the rain... however, the C4 is pretty hard to beat in rotten weather.

Also, aren't there too many variables? For me, just having plenty of tread to dispurse the water is the best bet. Also, your lines might have passed through more standing water.... your runs may have been in harder rain... your particular tires may not be as good in wet as others.... etc.


kj

Wilder

I can't remember the name of the book but I agree with the comments. Porsche FTD went to a 993 C2 and non-Porsche FTD went to a VW GTi. There were pleanty of faster cars including a 997TT and a Mustang 5.0.

As per the above, part of the reason for my post is that my AWD should've done much better than RWD Porsches. I did better than average but a few RWDs got better times and I suspect it has more to do with tire pressures, suspension settings and tire widths than with my lines or whether I ran in more rain than my counterparts.

Tire pressures and suspension settings can make a huge difference in AX and I made changes to both of those variables which I think may have negatively impacted my car's performance. Truth is, I'm just learning how to adjust my PSS9s and I dialed them incorrectly. I also listened to the wrong advice on tire pressures and ran them too high. Just trying to get it right for next time.

AllanJ

Hey Louis,

Yes, tire pressures and suspension settings matter, but driving the right line matters a ton. Let me give you one example which I see people doing all the time.

Sweepers

More often than not, at an autox I'll see people driving too far into a sweeper. What I'm getting at isn't just the particular line they take around the 180 degree sweeper, but how far they drive beyond the sweeper. If you took their line and moved the entire thing closer to the inside of the sweeper, they can be driving too far by 10 feet. 10 feet there and back for a total of 20 feet extra per sweeper.

Now figure that those sweepers were driven about 30 mph. Crunch the numbers and now you're in the neighborhood of 0.5 seconds wasted for each sweeper.

With your recent course, IIRC a single lap had three sweepers (I'm not talking about the endurance portion of the day). So....a fellow could've wasted 1.5 seconds by driving 10 feet beyond where he should have for each of those sweepers. Like I said, I see it all the time. Also note I'm completely ignoring the aspect of the correct shape of their line - whatever line they are driving, right or wrong, they are simply driving too far.

There are many, many more examples of where time is lost on the course. I'll show you more of these when you come out to the UBCSCC slush series.

Cheers,

Wilder

Agreed, however, my problem is that my line was okay. I was actually taking the first sweeper very well from the beginning (drove far to the right and started breaking/turning early, making the farthest cone my apex and the gate after turn-in my exit point, thus taking the sweeper quite fast) and so-so on the second (too far right) but corrected after lunch.

I requested station 4 and was on track duty first thing in the morning because I knew that was the key turn on that course. I watched mistakes being made over and over throughout the morning and knew what not to do by the time we switched. I did my very first run on my stock settings and got one of the best times (1.51 on the very first run when FTD was 1.48). I then switched my PSS9 settings and tire pressures and it all went down hill from there. IIRC, I got between 1.52 to 1.54 for the remainder of the day. This is the first time I don't progressively improve my times at AX and why it seems so obvious to me that my not-so-great times had more to do with tires and suspension than with my driving. In fact, I haven't changed the settings yet and my car still doesn't feel right. It feels like I've got it on full hard in the front and full soft in the rear.

Notwithstanding, I'm fairly newb and my lines can only improve so I'm looking forward to your help at UBCSCC. I'm going to Scan this afternoon to get some help on setting my suspension as I don't have the manual for them.

Thanks for the input Allan, I really appreciate it.

AllanJ

Yeah, your times should be getting better, especially after your first run so whatever you did with your PSS9's and tire pressures, don't do that.

Re: your quote above, you need to be careful how much wider you make your arc. Like my previous example, you need to watch the extra distance you add to your line. Driving wider to make a shallower arc to carry more speed is one thing, but you need to make sure that you are gaining enough speed to more than make up for the extra distance you are driving.

I didn't drive that course so I don't know what I'd be doing at the far sweeper, but I just thought I'd mention that point. Often in autox, driving the extra distance (that people often try) is the wrong thing to do. You won't have enough time at a higher speed to make up for the extra distance.

Cheers,

Wilder

Agreed. Going wide worked well for the first and furthest sweeper but I initially applied the same idea to the second sweeper and I was clearly wasting track. Danny pointed this out to me and I tightened up my line which worked very well.

This past Wednesday I was doing this: http://www.allenbergracingschools.co...ls-gallery.asp. I'm looking forward to using what I've learned.

Paul E. Dodd

Louis,

Keep in mind that your C4S is actually like 95% RWD until the rear end starts to slip. So I'm not sure how much an advantage you should expect until conditions get really crappy. In moderate conditions, you may only feel the front drive kick in once you've already overcooked it anyway. In really bad conditions, I would expect to see a bigger advantage if everyone is having traction issues.

Paul

chris walrod

If you run into Allen Berg, tell him I said 'hello' ! He was one of our customers when he owned a pro Atlantic team a few years back. He is a super guy!

Wilder

Paul, thanks and yes, I'm well aware of the power transfer ratios. We were autoXing on heavy rain. My pants were soaked up to my knees and there were puddles with 2"+ of water. Not surprisingly, the FWDs took FTD (that being a Dodge Neon and a VW GTI). I got good times but there were 993 C2s that got better times than I did. That coupled with the fact that I had the variables noted above, are the reasons for my query.

Chris, will do. You're right, he's a great guy and runs a good program. I'm looking forward to taking further instruction from him. It was a blast.