TOYBARU STX Build 2.0

[Silverspeed]

I participated in another local event last week with mixed results. I foolishly signed up for our "X" class and in doing so was assigned to run first heat. Heat being the operative word. Like in none. It was 30 degrees when 1st runs started. In X only the first 3 runs count, and we only got 4 anyway, but the tires didn't get any heat until 3rd runs and even then they were just warmer than ambient temp.

Nonetheless I got beat by my co-driver as usual. This time David Santel who was 3rd at Nats last year in his own twin. The other STX guys crushed us by like 2 seconds running in 55 degree weather and some sun. Dumb move on my part to not run with them. There are some really good local STX guys (look for Justin Metz's build elsewhere on these forums) and another good driver in a well prepped car is Chad Lipscomb. Hopefully both of these guys will do Nats this year as I think they will place well.

Anyway on to what I've been doing recently with the car. Not a whole lot to be honest. I ordered a set of DIF rear control arm bushings as it came to light that my SPC rear arms contained illegal joints where they attached to the center of the car. It's not a bushing, but a spherical joint, making it illegal for SCCA ST competition. Who knew. Anyway the car desperately needs to be aligned since having the new coilovers installed. But since I needed to replace the LCA bushings it didn't make sense to do that. It will be aligned before the next event.

I did want to check where I was wight wise so I borrowed a set of scales from a friend. I'll get the corner weights finalized during the alignment but the pics below show the before and after from when I have the car weighed before I added the Sparco seats and the Grimmspeed strut brace. It appears I've dropped 57 lbs. I believe there were a few other differences between the two weights (fuel, trunk mat) but the seats were certainly worth 50 lbs., maybe a bit more.





One more, or four actually, to be added this week...

[CB762]

Originally Posted by Silverspeed

One of the exhaust upgrades referred to in the previous post arrived today.

This is the same header and overpipe I have been using, just with Swain Tech's White lightning coating.

Attachment 130960

Note the nice welds on the V-Band by Granby Truck Shop.

Attachment 130961

How much did you pay to Swain Tech (less shipping)? I've my headers shipped there and wondering what should I expect.

TIA!

[Silverspeed]

Originally Posted by CB762

How much did you pay to Swain Tech (less shipping)? I've my headers shipped there and wondering what should I expect.

TIA!

I cannot find my receipt, but as I recall it was $270 for the header and overpipe. Don't hold me to that.... but I'm pretty sure that's what it was.

[Captain Snooze]

For what it's worth.
I had 6k/6k springs with the Eibach bar kit. Car was flat but I could feel the cross talk. Went to 9k/10k springs (AST dampers) no bars and liked the independence. Sold the ASTs (sob) and am back on the 6k/6k springs with no bars. Yeah, the car rolls more but I much prefer that to the cross talk.

Because compromise.

[Captain Snooze]

Originally Posted by Silverspeed

One more, or four actually, to be added this week...

Attachment 134102

Would you please tell me what tyres are they?

[Silverspeed]

Bridgestone RE71R's. 245/40-17 size.

[Silverspeed]

DIF inner LCA bushings came in this week for my SPC arms. I need to get them installed before getting the car aligned next week. Being that these are Delrin I don't expect any difference between the stock SPC inner bearing and the DIF bushings. As I mentioned before... crazy price for these things, but as with any business it's a balance of engineering time + manufacturing costs + materials vs. potential sales. Well made pieces though and I'll be legal now. No one can "throw paper" at me for a 13th place trophy dammit!

[DocWalt]

^^ lol 13th place trophies FTW I was in a foul mood...

[Silverspeed]

Originally Posted by DocWalt

^^ lol 13th place trophies FTW I was in a foul mood...

Ha. I wish I could get any kind of trophy at Nats.... Great car. Not so great talent. Maybe this is my year! Even a blind squirrel finds a nut eventually. Right?

[Silverspeed]

The car was aligned at 3R yesterday by Chris Mayfield. To say it was messed up due to the installation of the new RCE T3's and the DIF rear LCA bushings is an understatement. The car was soooo much better driving back from 3R than the drive in. Very stable, no longer following every dip in the road... The car tracks straight down the road without the need for constant corrections. Nice.

Here are the results from the alignment/corner balance. Note the weight is a bit higher (2616 empty) as I again had too much fuel in the car (1/2 tank) and the heavier exhaust on the car (+ 8lbs). Going to try a bit less front camber (~ .4 degree less than I have been running) for the early events this year. We'll see what the tire temps show, but Chris feels that the RE71's like, or at least can deal with, a bit less camber.

[justinco]

Hey Greg, just stumbled across this thread. I'll txt you tomorrow, need to pick your brain about your Sparco seat install...got my mounts/sliders/etc and curious how you handled all the airbag/seatbelt sensor non-sense.

[Silverspeed]

I haven't submitted any updates for awhile... But I have participated in two local events since my last post and while I haven't prevailed in either I think I'm making some progress. I've run a couple BMW club events (lot's of fun and usually 8 runs per event, 4 morning + 4 afternoon) which are great for TNT sessions.

For the 1st event I ran the WRX bar in the rear and the Whiteline front bar in the middle position (one side stiff, one side soft).For the morning runs I used a stiffer set-up for the shocks than I had in the past with the idea that I would work up to 3R's recommendations based on the dyno data. The car felt good overall. I was running brand new Re71's so the first couple runs were a bit slick. Tight in some spots and loose in others. By the 3rd (we only got 3 in the morning) run though, it felt pretty good. Maybe a bit skittish but OK. I was down to the current fast STX guy, Justin, by about 7/10ths.

In the afternoon I went full on stiff closely following 3R's suggestions. The car was very skittish especially through the couple of higher speed sections of the course. I was 4 wheel drifting a bit in several spots. Fun, but not fast. The tires were definitely getting better though. We got all 4 afternoon runs (the afternoon runs are the ones that count) and I ended up behind Justin by 6/10ths. He was 6th in PAX and I was 14th out of 80. I learned that the 3R specs would probably be great on a smooth road course but a bumpy autocross lot created some issues for that stiff of a set-up.

This past weekend was the 2nd BMW event for 2016. The weather wasn't great. Cold and overcast with rain on the way. I tried a much softer set-up for this event. Stock rear bar, Whiteline front bar at full soft and the shock baseline I have derived from using a suspension design calculator + 3R's shock dyno plots + what I have learned so far from previous events with the Racecomp T3's. This baseline set up is quite a bit softer than 3R's recommendations and softer than KW's as well. The car felt good out of the gate. A bit more roll but quick and smooth. Even with the cold tires and weather (50 degrees - cloudy) I was able to be aggressive with the throttle coming off the turns. The last two runs of the 4 morning session saw a bit of a corner entry push show up. I lowered tire pressures on the front by a couple pounds and added a click of low speed compression but the push stayed. It was worse in the slow corners and it might have been a driver error and I was pushing pretty hard getting in. Overall I was happy with the car. Due to rain I never got my afternoon runs but based on the morning runs I was a bit quicker than my fellow STX competition. Justin wasn't there but another quick local friend was and I think I beat him by a tenth or two. I think of the non-BMW group (BMW drivers get a softer PAX) we would have been 2nd and 3rd behind another SCCA racer with a Audi TTS. AWD was a bonus in the cold I think.

So the current baseline for the Racecomp T3's looks like this (all settings referenced from full stiff):

Front - LowSpeedComp -3 HighSpeedComp -10 Rebound -8
Rear - LowSpeedComp -2 HighSpeedComp -11 Rebound -7

Adding a click of LSC helps the car react quicker to direction changes without hurting bump performance. Higher traction surfaces can allow for more LSC.

It takes several clicks of HSC to feel the affects of how the car deals with bumps. The thing I've experienced so far is that it's harder to tell the difference when adding HSC, but when you reduce it, especially several clicks, you can feel a difference in both how the car handles bumps and to a lesser extent in transitions.

I have yet to really play with rebound a whole lot yet. That seems counter-intuitive as rebound is usually the go to shock adjustment for dealing with handling ailments. I plan to play a bit with rebound this weekend as there is a rescheduled SCCA event this weekend. Dave Santel will be co-driving this weekend as well so I can get some feedback from him as well. I do think the final rebound setting will be a bit stiffer than the baseline, but only by a click or two depending on if the push I experienced is real, or driver induced. I'm thinking it is the latter...Unless Dave feels otherwise I'm going to try to stop futzing with the car and just drive it. Spring Nats in around the corner...

[Silverspeed]

I run Hawk Street/Race pads on the front with StopTech drilled and slotted rotors, and Hawk HP+ pads on the rear using stock rotors. I used to run HP+ pads on the front of the car but wanted to try something that was hopefully less dusty, noisy, and less abusive to rotors. The Street/Race pads were not that solution. Don't get me wrong, they bite great and are a huge improvement over the stock pads. Honestly they feel just like the HP+'s. I really think they are the same pad.

I had a discussion with a friend at a recent event about the stock pads and he mentioned that he was thinking of upgrading. I mentioned what I run and that an pad upgrade is a real cheap way of making some time up on course. I told him I still had a used set of HP+'s in my shop and I'd give them to him after I took at look at my current pads to be sure I no longer needed the HP+'s. Once I get to the shop I first took a look at the boxes for each set. The part numbers are very similar. I suppose they should be, but based on my experience the pads are essentially the same. Same bite (great), same dust and noise (not great at all). But then I took the pads of the car...



I've noticed recently that my brakes haven't been as effective as they once were. Usually the first run of the day contains one episode of applying the brakes and feeling like the bite just isn't there. After that they work great for the rest of the day. I never had that type of issue with the HP+'s and stock rotors. After having my discussion with my buddy about possibly giving him my old HP+'s to try I decided it was a good time for a brake inspection. I was shocked to see the pitting I had on both pairs of Street/Race pads. I don't track the car and don't think I'm overly abusive to the brakes so I don't believe heat is the issue. The only difference between the HP+'s (which were used in the same way for approximately the same period of time) is that the Street/Race pads were used exclusively with the StopTech rotors. Maybe the cross drilling is eating the pads up? BTW the rear HP+'s look fine as well - as noted, always used with stock rotors. Needless to say my buddy isn't getting my HP+'s as they're back on the car after some preparing of the rotors.

Wondering if anyone else has experienced pad wear like this?

[justinco]

Originally Posted by Silverspeed

So the current baseline for the Racecomp T3's looks like this (all settings referenced from full stiff):

Front - LowSpeedComp -3 HighSpeedComp -10 Rebound -8
Rear - LowSpeedComp -2 HighSpeedComp -11 Rebound -7

I wanted to be there Saturday, but I'm going on 2 weeks out of town for work, and needed a day off while at home for a couple days

How much adjustment do those have? 16-18 clicks?

My RCE's are only double adjustable but I have been running the rebound between -4/-6 and compression between -6/-8. I try to set the rebound where the car feels responsive enough then tune the balance with compression. Not sure if that is the right way to approach things but has worked on my last 2 STX cars

Still need a good TnT to do some testing, bummed it was cancelled this weekend Anyways, see you Sunday.

EDIT: Never seen that on brake pads before, odd.