Project rebirth, FRS - STX and trackday/TTD log

[redlined600]

After seeing the lack of bump travel in the front I wanted to try and see if adding more would help. I ordered 949 Racing camber plates. They will add about 20mm of bump travel in lieu of droop that I don't need. However they don't have a radial bearing, which is a feature I liked on the Vorshlag plates. I'm not married to either at this point, but it's hard to imagine not wanting the extra bump travel.

This shows the change in stack height


Installed

[redlined600]

Last one before the next trackday.

I got the thermocouple mounted in a front pad to monitor temps. Should be interesting.



Hitting Road America next weekend, I fully expect to keep with the theme of being slower still in a straight line but overall lower lap times. Plus I've been hearing good things about the new track surface.

[RedReplicant]

The Xidas come with Torrington bearings on each corner, I suppose that is the exchange for the radial bearing.

[redlined600]

Originally Posted by RedReplicant

The Xidas come with Torrington bearings on each corner, I suppose that is the exchange for the radial bearing.

That makes sense although I had them on my Miata Xidas and never once found them in working order.

Maybe when I get back I'll see if I can get the radial bearings from the vorshlag plates to fit on the 949 racing camber plates to make a bastard super plate.

I'm curious to hear your feedback on the Xidas.

[autoracer86]

Originally Posted by redlined600

Last one before the next trackday.

I got the thermocouple mounted in a front pad to monitor temps. Should be interesting.

So what sort of temps are you hoping you're below ?

[redlined600]

Originally Posted by autoracer86

So what sort of temps are you hoping you're below ?

I don't really have any expectations other than gathering data. I'm also going to use rotor paint as an additional data point.

The goal is to help inform future brake decisions.

[redlined600]

Lots of thoughts after this weekend at Road America.
First the bad, I made it 2.5hrs from home and my wife sent me a pic of my data logger sitting on the counter. :-( I made due with a phone app but not ideal.
Second, track time could be summed up with one word, traffic. Too many incorrectly grouped cars led to very few clean laps.

Now the good. The new track surface was awesome, super smooth everywhere with a couple weird spots. Braking into 5, the good spot is along the rumble strips. I'm used to cutting straighter across the track but this was more upsetting to the car. I suspect this might go away once the track rubbers in a bit more. There is also a little hump just after the apex in the kink. Nothing dangerous, but it's there.
New wheel and tire combo worked great other than my fender liner got a little loose at one point and rubbed through.

The track never disappoints in the scenery department

A buddy grabbed this shot, car was looking good


Brake data: Pulling the temp from the front pad, max. temps.
Session 3: 1652*f
Session 4:1685*f
Session 1 day 2: 1582*f
This probably explains why I wasn't getting along well with the ST43 pads as they start to fall off around 1200*f
Wear rate : One data point, but based on this event I recoded brake wear at 1.25mm per hr of track time. Which means for a typical day (5 sessions x 20 min) I would expect about 2mm of wear. Put another way, I would expect a set of pads to last 4-5 days.

Day 2 ended with a broken axle (I think), some pretty crunchy noises coming from the outside drivers rear wheel.

I had very few clean laps and just couldn’t pull one together for a new PB. I was feeling pretty bummed about this and started second guessing the move to 17x10s. Once I got home I was able to compare data across platforms and things looked a bit better. If I looked at individual sectors I was faster at pretty much every corner and the same or faster at the end of all the straights. I’m not big on theoretical lap times but the data tells me if I could have put together a clean lap without traffic it absolutely would have been faster. I’m still not super happy but it at least put things into perspective for me.

[autoracer86]

Thanks for sharing the brake temp data. Very helpful !

[redlined600]

Originally Posted by redlined600

Day 2 ended with a broken axle (I think), some pretty crunchy noises coming from the outside drivers rear wheel.

Back to my previous post, this was a weird one. Turns out it wasn't the axle or the wheel bearing. Apparently when I replaced the studs I didn't install the drum brake hardware correctly and it decided to disassemble itself on track. When I removed the drum everything literally fell out. $23 hardware kit and I'm back in business.


I took a second to radius the bottom edge of the splitter. This one is not long for this world so I just went at it with an angle grinder.


I think optimally the splitter could be about an inch lower, however that isn't straight forward to fab.

Blackhawk farms in two weeks!

[redlined600]

Hit up Blackhawk Farms this past weekend. Other than being hot as balls it was a blast.
Car felt great and had no issues all weekend.
I did more monitoring of the brakes and learned a couple things. Blackhawk is hard on brakes because it's constant on/off without long straights. Peak temp. was higher here than Road America. Average was over 1800*f and the highest I saw was just under 2000*f.
Also of note, despite the brake temp. being higher the wear rate at RA was about 30% higher per time on track. After tracking wear for 2 events the wear rate is averaging 1mm per hour. I'm strongly suspecting that once the K-swap is done brakes will become an issue.

I didn't take any pictures but grabbed a few vids.
Mixed it up with this C5 for a good chunk of the weekend.

Threw my gopro in my buddies car and he followed me for a couple laps. He has a gutted 318ti with S50 swap. We're about even through the corners but with a 30hp and 5 million ft/lb torque advantage he murders me in the straights. Either way it was a lot of fun and a cool view of my driving.

I think I'm pulling the plug for this year to try and get the K-swap done.

[redlined600]

Follow up from the last post, here is the rotor paint, >1400*f on the rotor and back of the pad. Calipers were in the 650-800*f range.


Spent some time on the swap. Of course I broke an oil pan stud, then doubled down and broke the ez-out off in it as well. Luckily I was able to drill from the back side, push the ez-out out, re-drill and triple down with a larger ez-out. No threads were damaged.


Put the superdamper on. I had a adapter made at send-cut-send to hold it while I torqued it down. I'd be more than happy to loan it out if anyone needs it. I did use a torque wrench once I had it snugged up.


My Kpower intake was an older version that still had draft on the bolting surfaces, these are well documented to lead to broken bolts. The new ones have flat faces at the bolt holes. It took some creative fixturing on my little hobby mill but I was able to mill all the bolting locations flat.


Only thing left is a brace for the intake manifold and the motor will be ready to go.

[RedReplicant]

Glad you went ahead and milled them, one of the other KSwaps broke all its manifold bolts a few weeks ago at a Colorado NASA event.

Curious what you come up with for a brace

[autoracer86]

"Calipers were in the 650-800*f range"

That sounds really high. Most of the indicator stickers I seen for calipers don't even go to 600F

[redlined600]

Originally Posted by autoracer86

"Calipers were in the 650-800*f range"

That sounds really high. Most of the indicator stickers I seen for calipers don't even go to 600F

The overall front brake temps are concerning for sure.

In regards to the caliper paint, it's possible I'm getting bad data. I can try again with stickers and see if there is a difference, however given the temp of the pads and rotors, as well as the difference in rear paint color, I'm inclined to believe it.

Once the swap is up and running I'm leaning toward going with the performance package Brembos. The disks are larger/thicker, pads are cheap and the bias is correct. I just wish the pads were thicker.

I also have some ideas to modify the heat shield to allow more air into the center of the disk without going to a full ducted setup.