SN-95 Mustangs are another car where you do the counterintuitive thing and add a big front bar to reduce understeer. Works because you are reducing camber loss and enabling more usage of the contact patch and that ends up being a stronger influence than the increased loading from the swaybar on the contact patch.
Its a good lesson on addressing suspension as a system and not one part at a time in its own bubble.
In reply to Apexcarver :
It’s a good thing my challenge car came with an Eibach front sway then.
74CS
New Reader
1/30/19 9:14 p.m.
In reply to Javelin :
Nothing so far (other than tow hooks for track event) Planning on a few AX and a Feb 8 track event at Sebring to learn the car "bone stock". Thinking I'll wait until about March to take next step.
On this episode I tackled changing the headlight units out to get the car fully functional. It's a pretty wild piece of engineering!
I signed up for AutoX school in 3 weekends. I likely won't have the challenge mustang ready in time so I will take the Boxster on Conti sports. They ought to be okay for this purpose but not awesome.
Javelin
MegaDork
2/11/19 12:23 a.m.
AnthonyGS said:
I signed up for AutoX school in 3 weekends. I likely won't have the challenge mustang ready in time so I will take the Boxster on Conti sports. They ought to be okay for this purpose but not awesome.
They'll be good enough for AX school anyway. You can learn what you need to and not worry about setting FTD.
Javelin
MegaDork
2/11/19 12:24 a.m.
So the winter storm "Maya" threw a big snow-covered frozen wrench into my plans and postponed annual tech for SCCA until the weekend of the BCA autocross, reeking havoc on our schedule. I made an update video explaining it all.
In reply to Javelin :
Same here. I've had a nice box of new brakes for my Miata sitting in my house for like three weeks now. I was hoping this weekend would be good.
I'm hoping to make it out to that BCA event but it's the day after my friend's wedding so there's a good chance I'll be sleeping in...
In reply to thatsnowinnebago :
It's going to be the first ever event on the all new South Paddock, so it could be fun. I just can't squeeze it in any more with tech on Saturday.
Question for the autocross guys - what size tires? Do I square the wheel width? Wider by a bit? Widest darn thing that will fit??? Remember, up front I only have -0.3* of camber...
Javelin
MegaDork
2/24/19 11:25 a.m.
Well I went to Annual Tech for the SCCA and PCA, passing both. I also put over 150 miles on it in one day and just stayed in front of the next winter storm. Next up is tires! Ordered 235/40 and 275/35 Bridgestone RE71Rs.
I went with stock sized Conti ECS for now. AutoX school next week. I need to check brakes / fluids.
On street tires, we ran 235 F/265 R but on R's we tried 255/275/285 fronts and always had 285 rears. You definitely lose steering feel as you go wider in front but wider does reduce understeer. I guess it's gonna depend on what you're doing for sway bar and alignment but the 235/275 set up should be a good start.
Javelin
MegaDork
2/24/19 11:33 p.m.
AnthonyGS said:
I went with stock sized Conti ECS for now. AutoX school next week. I need to check brakes / fluids.
I can't wait for your feedback on how you like it!
Javelin
MegaDork
2/24/19 11:41 p.m.
loosecannon said:
On street tires, we ran 235 F/265 R but on R's we tried 255/275/285 fronts and always had 285 rears. You definitely lose steering feel as you go wider in front but wider does reduce understeer. I guess it's gonna depend on what you're doing for sway bar and alignment but the 235/275 set up should be a good start.
I've been running 275's on the front of my Cobra with more camber than the Boxster (-1.5* instead of -0.25*) on 9" wheels and hate them. They are "squishy" and really numbed the steering feel. It is most apparent in any quick transitional work like slaloms. I really liked the crispness of the 235's but ended up with 255's because they were fastest despite loss of feel. Granted that has a different suspension setup and way more front bar, but it was still data to consider so I figured the 235/275 setup would be a solid place to start in order to baseline the car. If there's a lack of front end grip after adding a bar I'll start stepping up sizes.
How did height play into your data points? The 235/275 combo is 0.3"/0.3" taller than stock, but the 245/285 combo is 0.7/0.6" shorter than stock.
Javelin
MegaDork
2/28/19 10:20 p.m.
Finally! It had to brave yet another snowstorm, but the Boxster finally has new tires:
I went with Bridgestone Potenza RE71R in 235/40/18 (F) and 275/35/18 (R). Interestingly, one back wheel has been cracked and welded back together, but done professionally. The tire shop didn't have any concerns with the repair, but I wonder how "legal" it is for autocross?
I also got fresh numbers and class letters from Autocross Digits. I've been using iZoom for 10 years, but got a lot of recommendations for Autocross Digits, so I gave them a try. Pretty happy with the quality out of the box and the swiftness of having them made and delivered.
Javelin said:
Finally! It had to brave yet another snowstorm, but the Boxster finally has new tires: New Episode
I went with Bridgestone Potenza RE71R in 235/40/18 (F) and 275/35/18 (R). Interestingly, one back wheel has been cracked and welded back together, but done professionally. The tire shop didn't have any concerns with the repair, but I wonder how "legal" it is for autocross?
I also got fresh numbers and class letters from Autocross Digits. I've been using iZoom for 10 years, but got a lot of recommendations for Autocross Digits, so I gave them a try. Pretty happy with the quality out of the box and the swiftness of having them made and delivered.
if the offset and width are still factory then you have nothing to worry about at all. you have 7mm of variance from the stock offset to work with.
In reply to spacecadet :
Offset and width haven't changed at all. It was a crack in the barrel that was welded. The tire shop said it looked very professional inside and out and had no concerns. Balanced fine.
Taking yellow boxster to autocross school saturday and event sunday. Since it’s damp out with chances for showers both days Conti ECS’s should be fine. If I had rear wheels I’d have sticky tires for this and my 996.
I won CS out of 6 and 2nd in S2 index out of 11. 22/81 overall.
Not bad for my first ever event in the car.
Codriver won S2 ladies and was 3rd fastest female on the property. 42/81 iirc? I'll update when the results are up.
Car did great! Taking it to karaoke now.
In reply to Javelin :
Awesome start. The car is easy to drive fast, right?
Wow. Just, wow. I feel like I'm about 10 seconds faster than I usually am. This car is stupid good. Like 4th fastest raw time of the entire morning session run group fast. And it's barely even been set up and it was my second event with it.
This is going to be epic.
Glad you had a blast. I stayed home with kiddo since she had the flu. I couldn’t leave my wife to take that on solo.