TOYBARU STX Build 2.0

[Silverspeed]

Originally Posted by justinco

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.

The Racecomp T3's have 16 clicks on the HS Comp and Rebound. 6 clicks on LS Comp. I ran -2 on front LS Comp and -1 on the rear and the car felt really responsive without being harsh. It seems like the more grip you have whether it be the surface, and or tires (warm and sticky) the more compression you can, and probably should, run. Bumping up the HS Comp helps with bump control until it doesn't. I seem to have hit a wall around -5 to -6 where it just gets too stiff and the car skates.

Compression controls the unsprung weight of the car and the rebound controls the sprung weight. I read a book (see credits below) from the guy who created JRZ and his philosophy was to run less rebound and more compression. The reasoning is that running more compression and controlling the unsprung weight to "The idea is to support the outside wheel/tire in a corner instead of an anti-roll bar lifting the inside wheel, which is getting light already because of the weight transfer from the inside to the outside wheel. And of course if you reduce suspension travel to begin with then rebound has a lesser effect on handling.

That's a bit dangerous of course. If we have no suspension movement then we drive go-carts which isn't what we necessarily want. I guess the point is to use compression to control the upward movement of the suspension to the point where it's not excessive to begin with, lessening the need for lots of rebound and reducing the likelihood of lifting or heavily reducing the load on one corner.



Zuijdijk, Jan (2013-03-25). VEHICLE DYNAMICS AND DAMPING : First revised edition (Kindle Locations 2898-2900). AuthorHouse. Kindle Edition. ". He preaches running smaller bars and let the springs and dampers to control roll as it's more predictable.

[justinco]

Originally Posted by Silverspeed

The Racecomp T3's have 16 clicks on the HS Comp and Rebound. 6 clicks on LS Comp. I ran -2 on front LS Comp and -1 on the rear and the car felt really responsive without being harsh. It seems like the more grip you have whether it be the surface, and or tires (warm and sticky) the more compression you can, and probably should, run. Bumping up the HS Comp helps with bump control until it doesn't. I seem to have hit a wall around -5 to -6 where it just gets too stiff and the car skates.

Compression controls the unsprung weight of the car and the rebound controls the sprung weight. I read a book (see credits below) from the guy who created JRZ and his philosophy was to run less rebound and more compression. The reasoning is that running more compression and controlling the unsprung weight to "The idea is to support the outside wheel/tire in a corner instead of an anti-roll bar lifting the inside wheel, which is getting light already because of the weight transfer from the inside to the outside wheel. And of course if you reduce suspension travel to begin with then rebound has a lesser effect on handling.

That's a bit dangerous of course. If we have no suspension movement then we drive go-carts which isn't what we necessarily want. I guess the point is to use compression to control the upward movement of the suspension to the point where it's not excessive to begin with, lessening the need for lots of rebound and reducing the likelihood of lifting or heavily reducing the load on one corner.



Zuijdijk, Jan (2013-03-25). VEHICLE DYNAMICS AND DAMPING : First revised edition (Kindle Locations 2898-2900). AuthorHouse. Kindle Edition. ". He preaches running smaller bars and let the springs and dampers to control roll as it's more predictable.

Interesting. I'll have to read that.

When I got my TCK's for the e36, TC Kline told me to start with -1 rebound front, -1/2 rear, and compression around -8. So pretty much full stiff on rebound and then compression to adjust balance.

I remember during TnT last year with the e36, when I softened rebound to -10, the car bounced and danced all over the place, did not feel planted at all. Stiffening it up (to -1 f/r) immediately made the car planted and feel stuck to the ground (same compression setting both tests).

Need to run that same set of tests I did on the FRS to see what happens.

[Silverspeed]

This week's update.... The 1st summer solo series event for the local SCCA club was head yesterday at Pike Peak International Raceway (PPIR) autocross lot. This was a rescheduled event from a couple week ago - cancelled due to snow. The day started out pretty gloomy for the 1st heat folks and then got better for the 2nd the 3rd heaters with some sun and temps around 60. We had 164 drivers show up for this event - a whopper for a local event.

This was the 2nd event Dave Santel was able to co-drive with me. Since the last BMW event a few things were learned. First I had pretty steady understeer. Not severe, but enough to reduce cornering speeds a bit. After consulting several tuning resources I decided to reduce the front ride height by one turn on the coil-over perches. This dropped the front by about an 1/8". Not much, but I didn't think I needed to take a big swing at this because the push was so mild. I also changed the shocks just a bit adding a bit more rebound to the rear (2 clicks). Those adjustments made for a much more neutral car.

My buddy (I use that term loosely because he has been beating me like rented mule lately) Justin who I run with at both the BMW and SCCA events is usually my yardstick. Justin ran first heat in the cooler weather and without a co-driver to help. His quick time was on his 4th run with a 58.68. Since Dave is my co-driver I handicap him and make him run first. He was able to get a rerun due to a spinning car in front of him causing him to bail on his run. But on that rerun he laid down a 57.7. I was much more tentative and ran a Sunday drive like 59.9. My quick run was a 58.1 and Dave's was a 57.4. Dave ended up 5th in PAX behind the likes of Robert Thorne, Chris Dorsey and Chris Mayfield, all past and recent SCCA National Champs. We never had to touch the shocks all day, just normalized the tire pressures after every run. We feel confident in the car headed to Spring Nationals in Lincoln in a couple of weeks. Hope to see some of you out there!

Dave's quick run can be seen at the link below. I hope to get my quick run up later.

[ame="https://www.youtube.com/watch?v=kAhHh9vcmQ8"]https://www.youtube.com/watch?v=kAhHh9vcmQ8[/ame]


A few pics of the car in action as well....

[Racecomp Engineering]

Crushing it out there! Thanks for the feedback, looking forward to seeing how you do at Nats.

- Andrew

[trippinbillies40]

Andrew, the car is absolutely sublime. I'm in love with it already, and can't wait to add some air into the cylinders in a couple weeks and feel some power again haha.

[Silverspeed]

An update on last week's local event.... Timing and scoring used my 4th, and fastest run for PAX and class placement. This was not correct as X class only allows the 1st three runs to be scored, just like at a national event. So that pooped my 11th place PAX of 977 down to a 23rd place of 963. Anyway, gotta get it done in three. That's the whole idea of running X. I need to get faster in those early runs.

On another note, Myles from Racecomp asked that I provide him with a comparison between the T2's and the T3's for our cars. I did so in an email but thought it might be good to share those impressions here as well.

So I'm not much of a writer but I'll do my best to capture my thoughts on the differences between the T2's and T3's. It's tough to just to quantify the differences between the two damper sets since my set up has changed as well. The fact that I'm running much more rear spring rate this year makes a big difference - this fact is a difference in itself since the T3's have the ability to compensate for more rate - a benefit for sure. Here is a list of Pro's for both kits:

T2's
- Lower cost (than T3's, but overall a bargain for a great 2-way)
- Good initial spring rates (400# square) for Auto-X - light track duty
- Lifetime warranty
- Very good initial valving set-up provided by Racecomp - Great baseline
- Slightly lighter weight
- Ability to support more spring rate if required

T3's
- Better spring rates (450# square) for Auto-X and track duty
- Low Speed Comp adjuster simulates adding more spring - quick way to add responsiveness - improves transitions
- High Speed Comp adjustment allows for fine tuning to difference surfaces (Auto-X) or tracks - curbing/bumps
- Very closely matched performance unit to unit - this could be the same for T2's - but I never had them dyno'd
- With the remote reservoirs, should create better extended use performance, hard to say if that help's in Auto-X - but with a 2 driver car it can't hurt
- Ability to support much more spring rate - When looking at the motion ratio for the twins, IMO, this car should run much more rear spring especially for a track/auto-x car (~2.5 Hz nat freq rear, ~2 front)
- According to Chris from 3R, these are the best 3-way adjustable shocks for the money


My other experiences with the T3's
- Both the LS Comp and Rebound adjusters are very powerful in that one or two clicks make a noticeable difference in suspension performance. This, to me, is different than the T2's where several clicks were required to experience a attitude change in the car.

- Both the T2's and T3's are very streetable. With the T3's all I need to do is reduce HSC to -13 and the car is very comfortable to daily drive even with 500#+ rear springs.

- If there is one CON to the T3's other than the cost (still a huge bargain but more then the T2's) and small weight penalty, is the HS Comp adjusters are very difficult to move. Some more than others - but in general very hard to turn. I guess at least they won't move from where you set them!

Overall, now that I am getting them dialed in, I love them. I wish they had the lifetime warranty, but I understand that this is more of a track focused set and therefore they will generally be abused more than the T2's. The KW set up specs of "set everything in the middle" is probably as good as a place to start as any, but I'd probably suggest for your 450# square set up, to go a bit softer to start. I wish I had spent more time on those springs to better provide you with feedback for your buyers. I guess my initial suggestion would be to loosen up the HS Comp a bit to start. Probably -12 versus the -7 KW suggests. Believe it or not, those few clicks make a big difference in making the car more relaxed from behind the wheel. Unless you're on a perfectly smooth surface, a -7 setting for HSC is pretty abusive from behind the wheel. It just makes the LS Comp setting of -3 more digressive above 3 in/sec.

My overall 450# setting suggestions would be (referenced from full stiff):
Front - LSC - 2, HSC - 12, Reb - 9
Rear - LSC - 3, HSC - 12, Reb - 7

This would be for a STX competition car running the standard 450# springs, and with a slightly larger front bar (20mm to 22mm) and stock rear bar. If an aftermarket rear bar was used (16mm or larger) I'd remove the extra couple clicks of rear rebound.

So that was my feedback thus far to Myles. Loved the T2's and I feel very much the same about the T3's. It just took a but of testing to get them right.

[justinco]

Great info Greg! Do you remember your setup (bump/rebound) with your T2's? I am still trying to figure mine out, as you know. You run a lot softer rebound than I have with either of my STX cars, makes me wonder if I'm doing it right :p

I put 450# springs all around on my T2's from the get go. Ran them at just about default settings the first couple events (I think -7 rebound and -6 bump F/R). Car was OK with exit/on-power push, but was not stable on slaloms (rear end wanted to come around easy).

I have since stiffened up the rebound at the last event to -3/-2 F/R respectively, with bump at -6/-5. Sadly it was hard to test with varying tire/weather conditions. The previous BMW event it was similar and was OK, though I feel it could still be a lot better.

I'm wondering if I should go back to softer rebound, set the bump again, and adjust as needed with rebound. Have I mentioned I am dying for a TnT?

I'm having to re-train my brain with this car vs. my e36, as Kale from TC Kline gave me his e36 setup, which was basically full stiff rebound (-1/-0.5 clicks F/R) and softer bump (between -8 & -10 F and -3 & -5 R) and I would adjust it from there based on site/conditions.

[Silverspeed]

Originally Posted by justinco

Great info Greg! Do you remember your setup (bump/rebound) with your T2's?

I always used the Racecomp suggested set-up as my baseline (see below) and then adjusted from there. Usually if you increase spring rate your compression goes down and your rebound should increase. But you certainly can't compare T2 setting to T3's. Middle ground for the T3's would not create the same force, or even % of total force available, to the T2's. I know you know that, but I want to clarify for everyone else who may be tuning in. The 2nd compression adjuster alone throws any direct comparison out the window.

http://racecompengineering.com/instr...ingsbrzfrs.pdf

[justinco]

Originally Posted by Silverspeed

I always used the Racecomp suggested set-up as my baseline (see below) and then adjusted from there. Usually if you increase spring rate your compression goes down and your rebound should increase. But you certainly can't compare T2 setting to T3's. Middle ground for the T3's would not create the same force, or even % of total force available, to the T2's. I know you know that, but I want to clarify for everyone else who may be tuning in. The 2nd compression adjuster alone throws any direct comparison out the window.

http://racecompengineering.com/instr...ingsbrzfrs.pdf

Thanks Greg, I never even knew about that PDF. I have been going off the manual that came with my T2's which have completely different baseline settings, ugh...(-9 rebound F/R and -6 bump F/R).

Time to get a new drawing board, hah!

[Silverspeed]

It's a really good baseline set-up. I'm not sure who at Racecomp developed it, but it works well overall especially with the baseline 400# springs. As I noted, with your 450#'s you probably want to add a click or two of rebound, and maybe remove a click of compression. But that's just theoretical....

[Silverspeed]

Some better pics from the first RMSolo SCCA Summer event.

Credit for all pics attached here goes to Brendan Sobers.

[Silverspeed]

A bit of a debrief after a tough weekend....

Do you ever have that feeling that some events you're just not able to drive like you think you should? I had one of those. From my perspective Spring Nationals 2016 was a comedy of errors on my part.

Saturday started, after the 8 hour drive to Lincoln, on the test course. Dave met me there around 3 to run a few laps on the Lincoln concrete. The car felt OK. I was under driving some areas and over driving others (typical). I think this was the first time I've actually rode along with Dave and vice versa. If I can take anything positive away from the weekend it was interesting to see how someone of his caliber adjusts the car mid corner depending on how the entry went to plan. The car had it's normal power increase over Denver and it seemed more willing to rotate on throttle. We agreed to leave the car along until after 1st runs on Sunday. Our measuring stick was Justin Metz who also has a really good thread on these forums, is also from Denver and who by the way also runs Racecomp T2's (plug). We ran a bit quicker than Justin on our final runs but Justin indicated later he got a bit quicker than us a few runs after that. But we were in the ballpark.

First runs on Sunday seemed typical first runs with my car. Loose. But again we decided to just drive the car and not mess with it. Dave felt he definitely left some time out there and that he would get quicker with warm tires, but ran a respectable 57.9 versus Justin's 57.3 which put him in 1st initially. Craig Wilcox (56.8) and Ken Motonishi (57.3), both great guys by the way, made up the top 3. I was at a lowly 58.5 making several errors in key areas where being close to those key cones made a big difference - there was also a fair bit of chicken lifting as well. Dave did pick up on his second run to a 57.5 leaving him in the last trophy spot, 6th. The top guys also picked up on 2nd runs for the most part leaving the same guys in the same spots. I spun on the large showcase turn before the finish throwing that run away. Dave's last run wasn't an improvement but it probably didn't help that the steering wheel came loose somewhere mid run. His co-driver clearly didn't torque the nut on enough when installing that sweet aftermarket wheel! The world has a way of paying me back for that level of stupidity... We rushed to remove the air bag to reach the nut which also required a battery disconnection. We asked for a mechanical, but we were quick enough to not need it. But alas in the rush to get to the line I realized after the first left hander that the TC was still on. What I should have done was stop, turn it off and then proceed so at least I could have collected some decent data from the run. What I did was drive one handed for most of the run trying to urn it off with the other hand - which Dave told me after the run wasn't going to work unless I stayed under 30 mph for some time. Needless to say it wasn't a great run. It's really shocking how violent the TC messes with the brakes with it on. Overall not a good day.

After looking at some video and getting feedback from friends working course while we were running, we determined that were were really struggling putting down power coming out of turns. The plan was to reduce rear lowspeed compression several clicks to not load the rear tires as quickly. It did work, but only to a point. The car still fought early throttle application - something Chris Mayfield and I didn't fight with at last years Spring Nats. Anyway, Dave ran a 56.7 on his first run which was a very quick time, until Craig laid down a 55.5 in his Mini. Dave's 2nd run was a 57.3 which turned out to be his best and left him in 6th. Just ended the day with a 56.4 which left him just .045 out of third. Ken finished in 2nd. I ended up with a 57.2 and a really disappointing 13th out of 18. Day one really killed me, but I just didn't drive well period.

So what did I learn from the weekend? For one, I need to drive a bit harder in the fastest areas of the course. For one, I wasn't setting them up correctly, but mostly, I just wussed out and lifted in key areas where I should have made up a lot of time. The Solostorm data shows in the technical areas of the course, I run a good line and good speed. We also learned that it appears that a suspension calculator cannot correctly determine everything for you.... 10k springs are just too much for an autocross course, or at least for my car, on the Lincoln concrete and Lincoln elevation. The car was great at transitions, it had great corner entry, it was great at being able to adjust the slip angle with the throttle (drifting) but it just wouldn't put power down consistently. So the plan is to reduce rear spring rate by a fair amount and do some testing. The weekend was still fun. The weather was unusually great. No rain other than the epic storm I drove through coming home. I damn near lost my bike off of my trailer. Oh, and I learned that red Loctite should be used on important nuts. Like the one holding the steering wheel on...

Congrats to all of the trophy winners! Well done!

[renfield90]

^^TC will still turn off above 30mph. What happens is 5 seconds is a long ass time on course to try and drive one handed, and less time passes than you think.

You can still call a mechanical even if you've put the car back to working order but aren't totally set and ready to go. Just tell the grid person you had to make a repair and you'll be ready in ~60 seconds or whatever. As long as you genuinely had a repair to make and aren't trying to game the system (by waiting for the course to dry out, for example) you will get the extra time you need.

Signed,
Grid guy who worked CP and DM at 2015 nats and can tell you a lot about mechanicals

[Silverspeed]

Originally Posted by renfield90

^^TC will still turn off above 30mph. What happens is 5 seconds is a long ass time on course to try and drive one handed, and less time passes than you think.

You can still call a mechanical even if you've put the car back to working order but aren't totally set and ready to go. Just tell the grid person you had to make a repair and you'll be ready in ~60 seconds or whatever. As long as you genuinely had a repair to make and aren't trying to game the system (by waiting for the course to dry out, for example) you will get the extra time you need.

Signed,
Grid guy who worked CP and DM at 2015 nats and can tell you a lot about mechanicals

Good to know. I held the button for awhile and then said screw it... until I couldn't stand the beating I was taking from the brakes and started to hold the button again. I think it may have actually turned off just before I finished.

Another friend from CO suggested a OBD2 thingy that does the pedal dance for you after starting the car. He said it was $80. I would have paid a lot more than that for it to have it for just that one run. Live and learn. I do have to say, with TC I don't think it's possible to spin the car out. Maybe what I should have tried is to just hit the Sport button. It would have had to be an improvement!

As far as the mechanical goes, I tend to get wrapped up in not slowing the show down. I'm the guy who the day before when checking into my hotel couldn't get his key card to work at the entrance of the parking garage with two other cars behind me and had a coronary. Of course the fact that the 3rd car behind me was some jackass beeping his horn didn't help... And then it turned out to be a friend that was just messing with me.