2021 STU Discussion
May 13, 2021, 10:35 AM
#78
Luckily for me, between SCCA and local Time Attack series we have plenty of local events on a bi-weekly basis with lots of participation that helps me scratch the itch as I do this more for fun.
Yall have fun out there.
Last edited by DaWorstPlaya; May 13, 2021 at 12:31 PM.
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LV///R (May 13, 2021)
May 14, 2021, 09:27 AM
#79
Yea I count about 6 of my friends from Colorado. With my mediocre level of driving it's not worth my time to travel long distances for auto-x.
Luckily for me, between SCCA and local Time Attack series we have plenty of local events on a bi-weekly basis with lots of participation that helps me scratch the itch as I do this more for fun.
Yall have fun out there.
Luckily for me, between SCCA and local Time Attack series we have plenty of local events on a bi-weekly basis with lots of participation that helps me scratch the itch as I do this more for fun.
Yall have fun out there.
So who out of those CO drivers should we be most concerned about?
Give us some insight, haha.
May 14, 2021, 01:12 PM
#80
They're all very talented drivers and are usually fighting for top spot in STU locally, anyone of them could do well given the course and conditions. In terms of raw talent, personally I would pick Brian Kelly and Jon Kuo. You can check out the local Colorado SCCA region results if you are curious.
Here's a link to the last 2020 summer event from last season.
https://www.rmsolo.org/event-results...-0927_full.pdf
And the 2nd Summer event this season:
https://www.rmsolo.org/event-results...-0509_full.pdf
Here's a link to the last 2020 summer event from last season.
https://www.rmsolo.org/event-results...-0927_full.pdf
And the 2nd Summer event this season:
https://www.rmsolo.org/event-results...-0509_full.pdf
Jun 2, 2021, 11:20 AM
#81
Spring Nationals is complete! The plan was to have a codriver for at least 2 days...that didn't happen. I also didn't bring my tire blankets which would have at the very least, helped a bit considering most of the days were cool, cloudy, windy. Live and learn.
Day one (Friday) - I simply wasn't getting my eyes up in the right places, especially in the SE corner of the course. Absolutely left a good bit of time in a series of turns that I couldn't get right. I was approximately 8 tenths off Michael Carpenter's 1st place time.
Day two (Saturday) - ran the course in the opposite direction with minor changes at the start/finish. Car felt great. My third and final run I screwed up a couple corners and thought the run would be a wash. At the very end of the course, I nicked a cone in the final slalom. Come to find out, that run would have been fast time in STU for the day. After reviewing my logs, I absolutely left multiple tenths out there - so my butt dyno still works properly at least. Finished 2nd overall in STU. Pax'd 24th and would have been quite a bit higher if not for that last slalom cone...-_-
Day three (Sunday) - The tiredness and fatigue was setting in. I deal with fatigue on an almost daily basis and knew doing this for 5 days straight was going to be an absolute challenge. Rain was nearing by the time we started. Getting it done on the first run was probably going to be crucial. It was cool, cloudy and we were running in the 2nd heat. The a052's just didn't get any heat into them until a handful of turns. Laid down a fairly slow time all things considered. The 2nd run, sprinkles were coming down but the ground was dry. The first series of turns at the start, allowed you to get a good amount of speed coming into the first slalom. I was on the limiter A LONG time before entering the 1st slalom. Needless to say the whole way through, and the 180 sweeper after, my evo was sputtering. If i hit the gas, nothing happened...and I was tempted to pull off the course. I hit the gas another time just to see, and sure enough, she came back to life and I finished the run. Thankfully I did as that was my fast run for the day. 3rd run was completely wet/rainy so there wasn't much of a chance to drop time. And I didn't. I was sitting in 4th after day 1.
Day four (Monday). The nicest temperature wise of all the days down there. Unfortunately, I absolutely struggled. I was considering heading home Sunday evening as I was simply out of it mentally. I got bumped out of the trophies into 5th. The most frustrating thing for Sun/Mon is my datalogger wasn't working at all.
Either way, I feel like the rear of the car isn't probably setting/sticking in the slaloms still. Granted, I found out that I was running super low compression for whatever reasoning and I think this could have played into the loose rear. I'm going to possibly try to make some changes for the next Lincoln points event in a week and a half. Kevin was nice enough to allow me a fun run in his evo with a square setup. I had much more confidence in his car in the slaloms than mine. I may switch back to a square setup, or at least do a comparison again. The problem is, if I try to run a 285 square setup, these JRZ's can't get high enough in the rear to allow that combo to fit....I was thinking of going back to possibly a 265 A052 or try the 275 CR-1....
The STI's that were competitive were on 255 A052s (Carpenter was on 17" wheels and in 3rd gear for most of the 4 days)....Michael Carpenter's STI is John Hale's old car....and he and his co-driver are not slouches. He was 1st overall PAX after day 1 of the 1st event.
https://www.scca.com/articles/201509...r-1-fast-notes
Day one (Friday) - I simply wasn't getting my eyes up in the right places, especially in the SE corner of the course. Absolutely left a good bit of time in a series of turns that I couldn't get right. I was approximately 8 tenths off Michael Carpenter's 1st place time.
Day two (Saturday) - ran the course in the opposite direction with minor changes at the start/finish. Car felt great. My third and final run I screwed up a couple corners and thought the run would be a wash. At the very end of the course, I nicked a cone in the final slalom. Come to find out, that run would have been fast time in STU for the day. After reviewing my logs, I absolutely left multiple tenths out there - so my butt dyno still works properly at least.
Finished 2nd overall in STU. Pax'd 24th and would have been quite a bit higher if not for that last slalom cone...-_-Day three (Sunday) - The tiredness and fatigue was setting in. I deal with fatigue on an almost daily basis and knew doing this for 5 days straight was going to be an absolute challenge. Rain was nearing by the time we started. Getting it done on the first run was probably going to be crucial. It was cool, cloudy and we were running in the 2nd heat. The a052's just didn't get any heat into them until a handful of turns. Laid down a fairly slow time all things considered. The 2nd run, sprinkles were coming down but the ground was dry. The first series of turns at the start, allowed you to get a good amount of speed coming into the first slalom. I was on the limiter A LONG time before entering the 1st slalom. Needless to say the whole way through, and the 180 sweeper after, my evo was sputtering. If i hit the gas, nothing happened...and I was tempted to pull off the course. I hit the gas another time just to see, and sure enough, she came back to life and I finished the run. Thankfully I did as that was my fast run for the day. 3rd run was completely wet/rainy so there wasn't much of a chance to drop time. And I didn't. I was sitting in 4th after day 1.
Day four (Monday). The nicest temperature wise of all the days down there. Unfortunately, I absolutely struggled. I was considering heading home Sunday evening as I was simply out of it mentally. I got bumped out of the trophies into 5th. The most frustrating thing for Sun/Mon is my datalogger wasn't working at all.
Either way, I feel like the rear of the car isn't probably setting/sticking in the slaloms still. Granted, I found out that I was running super low compression for whatever reasoning and I think this could have played into the loose rear. I'm going to possibly try to make some changes for the next Lincoln points event in a week and a half. Kevin was nice enough to allow me a fun run in his evo with a square setup. I had much more confidence in his car in the slaloms than mine. I may switch back to a square setup, or at least do a comparison again. The problem is, if I try to run a 285 square setup, these JRZ's can't get high enough in the rear to allow that combo to fit....I was thinking of going back to possibly a 265 A052 or try the 275 CR-1....
The STI's that were competitive were on 255 A052s (Carpenter was on 17" wheels and in 3rd gear for most of the 4 days)....Michael Carpenter's STI is John Hale's old car....and he and his co-driver are not slouches. He was 1st overall PAX after day 1 of the 1st event.
https://www.scca.com/articles/201509...r-1-fast-notes
Last edited by LV///R; Jun 2, 2021 at 11:50 AM.
Jun 2, 2021, 05:00 PM
#84
That's a great datapoint though, especially on concrete where Hoohoos are usually dominant, and without having a ton of runs in the car on this setup.
Unrelated - getting close to pulling triggers on wheels.
I want to make sure I'm not missing any obvious 18x10 options
* Enkei RPF1 - 18x10 +38 https://enkei.com/shop/wheels/racing/rpf1/
* Enkei NT03 - 18x10.5 +30 seems like the closest?
* Advan RGIII - 18x10 +35 - https://www.evasivemotorsports.com/s...143-offset-35/ - $600+ per wheel though
* Wedsport TC105X - 18x10 +35 - this is where I'm leaning currently - I like the idea that the rears would either not need a spacer or need a tiny one
It seems like 18x9.5 and 18x10.5 are very popular but there are less 18x10s.
I just don't think I can do RPF1s again. They are great wheels and best bang for the buck and all that but this would be my third set... then again I could use the savings to get them painted something goofy, bright orange again, lime green, a nice bronze perhaps.. dunno. Just want to make sure there isn't some other wheel option that makes sense.
Jun 2, 2021, 05:50 PM
#85
Do you have pictures or something that describes this? Curious as I would guess the Motonzz and JRZ are pretty similar.
Also Josh Luster's old car. I hate that thing
That's a great datapoint though, especially on concrete where Hoohoos are usually dominant, and without having a ton of runs in the car on this setup.
Unrelated - getting close to pulling triggers on wheels.
I want to make sure I'm not missing any obvious 18x10 options
* Enkei RPF1 - 18x10 +38 https://enkei.com/shop/wheels/racing/rpf1/
* Enkei NT03 - 18x10.5 +30 seems like the closest?
* Advan RGIII - 18x10 +35 - https://www.evasivemotorsports.com/s...143-offset-35/ - $600+ per wheel though
* Wedsport TC105X - 18x10 +35 - this is where I'm leaning currently - I like the idea that the rears would either not need a spacer or need a tiny one
It seems like 18x9.5 and 18x10.5 are very popular but there are less 18x10s.
I just don't think I can do RPF1s again. They are great wheels and best bang for the buck and all that but this would be my third set... then again I could use the savings to get them painted something goofy, bright orange again, lime green, a nice bronze perhaps.. dunno. Just want to make sure there isn't some other wheel option that makes sense.
Also Josh Luster's old car. I hate that thing
That's a great datapoint though, especially on concrete where Hoohoos are usually dominant, and without having a ton of runs in the car on this setup.
Unrelated - getting close to pulling triggers on wheels.
I want to make sure I'm not missing any obvious 18x10 options
* Enkei RPF1 - 18x10 +38 https://enkei.com/shop/wheels/racing/rpf1/
* Enkei NT03 - 18x10.5 +30 seems like the closest?
* Advan RGIII - 18x10 +35 - https://www.evasivemotorsports.com/s...143-offset-35/ - $600+ per wheel though
* Wedsport TC105X - 18x10 +35 - this is where I'm leaning currently - I like the idea that the rears would either not need a spacer or need a tiny one
It seems like 18x9.5 and 18x10.5 are very popular but there are less 18x10s.
I just don't think I can do RPF1s again. They are great wheels and best bang for the buck and all that but this would be my third set... then again I could use the savings to get them painted something goofy, bright orange again, lime green, a nice bronze perhaps.. dunno. Just want to make sure there isn't some other wheel option that makes sense.
I would start here in reference to my issues in the past year or so: https://www.evolutionm.net/forums/mo...l#post11904857
I've already had JRZ install extended shafts in the rears. They told me there's nothing else I can do to get any further extra height out in the rear. I fit the 265 A052 on the 18x10 +35's without issue with the lengthened shafts. The JRZ's don't have separate height and preload adjustment, say like the Ohlins R&T. Thus, you're quite limited to making drastic ride height changes. With 285's, I'd absolutely have to raise the rear at least another 1/2" - 1" I'm guessing. Depending upon if I'd go the CR1 route (are they even legal for competition this year? I totally am drawing a blank now) or the RT660. Why the A052 doesn't come in a 285/30/18 is beyond me!
Volk makes some 18x10's in the TE37 variants... $$$$$
I'm partial to your wedsport offering. The 18x10 +35 just works perfect out back. I run a 20mm spacer up front from what I recall, but the rear needs no spacer. That with rolling the rear fenders, will easily fit a 265mm A052. With the right ride height and camber, you can squeeze on the 285mm RT660 as Doug has proven. I believe the CR1 in the 285mm variant runs slightly wider than the RT660 just as a heads up for anyone considering it.On another side note: After looking at my Solosotorm data on the Saturday course, I possibly left an extra 8-9 tenths of time out there vs sections in my first two runs as well. Possibly a 54 flat... I realize I have to take that with a grain of salt, but there were obvious mistakes. Frustrating in ways, but also encouraging that this car could absolutely throw down, if the driver can pull their head out of their ***.
Jun 2, 2021, 06:43 PM
#86
There is an easy button for getting rear droop if your shocks are too short which is common on the JRZ and MCS shocks. Flip the rear lower arm. Its offset for an underslung mount but if you put a urethane or other solid bushing in that shock mount hole it works out great. Its one of the necessary things to deal with on my billet uprights since we connect to the lower arm yet that also controls geometry. Flipping will give you about 20mm more droop IIRC at the wheel.
Interesting to hear youre too loose. On 295 A052s or A7s Im only loose on first runs when fronts come in but rears are still cold. And Im of course much stiffer in rear bias. Where are you at with pressures and camber?
Being loose in slalom would lead me to think you are back down with rebound forces or have some bind somewhere. Is it loose steady state? If you watch some of my runs on my youtube I'm not loose at all and exterior vids just show the rear yaw's around slaloms driving them as aggressive as I can.
Interesting to hear youre too loose. On 295 A052s or A7s Im only loose on first runs when fronts come in but rears are still cold. And Im of course much stiffer in rear bias. Where are you at with pressures and camber?
Being loose in slalom would lead me to think you are back down with rebound forces or have some bind somewhere. Is it loose steady state? If you watch some of my runs on my youtube I'm not loose at all and exterior vids just show the rear yaw's around slaloms driving them as aggressive as I can.
Jun 2, 2021, 07:16 PM
#87
There is an easy button for getting rear droop if your shocks are too short which is common on the JRZ and MCS shocks. Flip the rear lower arm. Its offset for an underslung mount but if you put a urethane or other solid bushing in that shock mount hole it works out great. Its one of the necessary things to deal with on my billet uprights since we connect to the lower arm yet that also controls geometry. Flipping will give you about 20mm more droop IIRC at the wheel.
Interesting to hear youre too loose. On 295 A052s or A7s Im only loose on first runs when fronts come in but rears are still cold. And Im of course much stiffer in rear bias. Where are you at with pressures and camber?
Being loose in slalom would lead me to think you are back down with rebound forces or have some bind somewhere. Is it loose steady state? If you watch some of my runs on my youtube I'm not loose at all and exterior vids just show the rear yaw's around slaloms driving them as aggressive as I can.
Interesting to hear youre too loose. On 295 A052s or A7s Im only loose on first runs when fronts come in but rears are still cold. And Im of course much stiffer in rear bias. Where are you at with pressures and camber?
Being loose in slalom would lead me to think you are back down with rebound forces or have some bind somewhere. Is it loose steady state? If you watch some of my runs on my youtube I'm not loose at all and exterior vids just show the rear yaw's around slaloms driving them as aggressive as I can.
I did already flip my arms which did help, but only so much. (Thanks to your advise from another post I saw).
To clarify, I'm on the staggered wheel/tire setup currently. 295/11" Front 255/10" Rear. It's truly hard for me to put in words. My car doesn't feel as planted in the slaloms as say a square setup. Anyone else who's driven the car has mentioned the same thing, that slaloms aren't it's strong point currently. Especially even if you get even slightly behind in them, it just wants to get out of sorts out back. I can NOT be aggressive in the slaloms or the rear will bite me. Steady state sweepers feel very neutral with a good amount of lift off yaw if needed. I have no complaints there to be honest. Never even a hint of understeer.
I'm running around 30-32 PSI up front and similar out back. -4.75 F / -2.50 R for camber. 0 toe all the way around, since I drive it to and from to Lincoln currently.
Keep in mind, every single day was cool out. I didn't have a co-driver, nor tire blankets. They would have a entire car blanket and use that prior to even their first run.
My thoughts/options going through my head are the following, and I'd appreciate criticism if need be:
1) go back to a stock rear bar (currently on a ST suspensions adjustable rear - full soft)
2) up the rebound/compression out back. I was running around 3 - 5 clicks from full soft for whatever reasoning the whole weekend.
3) possibly go down in rate from 1000lbs to 900 or 800?
You're more than welcome to take her for fun runs at Nationals when the time comes. I'd love any sort of input.
Jun 2, 2021, 07:58 PM
#88
Wow, so even flipped you dont have enough droop. Thats pretty bad and Id say a pretty substantial design flaw from JRZ. Ive been annoyed with MCS also cause of that similar issue. Its like the got a stock shock and assumed X length lowered so shortened the shock X amount, but with a ~0.73 MR its a ~1.35x effect at the wheel. Its a shame, so many that have made Evo supensions just phoned it in and never came back to fix it after the fact 
Hard to keep straight who's doing what these days but forgot about you trying the stagger. One reason lifting a tire works when going square is because we're able to make the outside wheel match the fronts work given weight/tire ratios. So you with a smaller tire are just making it harder for the rear in that case. To make that work, you'll probably need to go softer in spring and/or bar to keep stability. Remember, once you lift a wheel the bar has done what it can and its only adjusting how fast it gets to max load. Do you know if you're lifting much?
Everyone has their preference but I prefer a confident car so would take a little pushy over too much oversteer. If you can find that perfect balance where it dances then thats the magic, but you need to have confidence the rear is stable in slaloms for sure. I would drop 100lbs in the rear to see how that feels.
Front camber seems maybe a tiny bit high but probably not too far off. Pressures seem low. I run pretty much everything in the 35-38 psi up front over the years with the exception of BFG R1-s that oddly wanted less pressure. Ive tested mostly on hoosiers but found A052s are really similar acting, but lower pressure "feel" faster and more forgiving but more pressure on data shows more lateral grip. They just become sharper and easier to go over that limit. Its worth trying 38-40 psi for a few runs. Do it for more than one run though, you'll have to recalibrate your feel to it.
Balance wise it sounds like you're close, it doesn't take too much to shift things back to stable in slaloms. Hard to say though if the shocks are causing and issue, if shocking tires with hitting droop limits, or have some other bind.
Hard to keep straight who's doing what these days but forgot about you trying the stagger. One reason lifting a tire works when going square is because we're able to make the outside wheel match the fronts work given weight/tire ratios. So you with a smaller tire are just making it harder for the rear in that case. To make that work, you'll probably need to go softer in spring and/or bar to keep stability. Remember, once you lift a wheel the bar has done what it can and its only adjusting how fast it gets to max load. Do you know if you're lifting much?
Everyone has their preference but I prefer a confident car so would take a little pushy over too much oversteer. If you can find that perfect balance where it dances then thats the magic, but you need to have confidence the rear is stable in slaloms for sure. I would drop 100lbs in the rear to see how that feels.
Front camber seems maybe a tiny bit high but probably not too far off. Pressures seem low. I run pretty much everything in the 35-38 psi up front over the years with the exception of BFG R1-s that oddly wanted less pressure. Ive tested mostly on hoosiers but found A052s are really similar acting, but lower pressure "feel" faster and more forgiving but more pressure on data shows more lateral grip. They just become sharper and easier to go over that limit. Its worth trying 38-40 psi for a few runs. Do it for more than one run though, you'll have to recalibrate your feel to it.
Balance wise it sounds like you're close, it doesn't take too much to shift things back to stable in slaloms. Hard to say though if the shocks are causing and issue, if shocking tires with hitting droop limits, or have some other bind.
Jun 3, 2021, 05:16 AM
#90
Wow, so even flipped you dont have enough droop. Thats pretty bad and Id say a pretty substantial design flaw from JRZ. Ive been annoyed with MCS also cause of that similar issue. Its like the got a stock shock and assumed X length lowered so shortened the shock X amount, but with a ~0.73 MR its a ~1.35x effect at the wheel. Its a shame, so many that have made Evo supensions just phoned it in and never came back to fix it after the fact
Hard to keep straight who's doing what these days but forgot about you trying the stagger. One reason lifting a tire works when going square is because we're able to make the outside wheel match the fronts work given weight/tire ratios. So you with a smaller tire are just making it harder for the rear in that case. To make that work, you'll probably need to go softer in spring and/or bar to keep stability. Remember, once you lift a wheel the bar has done what it can and its only adjusting how fast it gets to max load. Do you know if you're lifting much?
Everyone has their preference but I prefer a confident car so would take a little pushy over too much oversteer. If you can find that perfect balance where it dances then thats the magic, but you need to have confidence the rear is stable in slaloms for sure. I would drop 100lbs in the rear to see how that feels.
Front camber seems maybe a tiny bit high but probably not too far off. Pressures seem low. I run pretty much everything in the 35-38 psi up front over the years with the exception of BFG R1-s that oddly wanted less pressure. Ive tested mostly on hoosiers but found A052s are really similar acting, but lower pressure "feel" faster and more forgiving but more pressure on data shows more lateral grip. They just become sharper and easier to go over that limit. Its worth trying 38-40 psi for a few runs. Do it for more than one run though, you'll have to recalibrate your feel to it.
Balance wise it sounds like you're close, it doesn't take too much to shift things back to stable in slaloms. Hard to say though if the shocks are causing and issue, if shocking tires with hitting droop limits, or have some other bind.
Hard to keep straight who's doing what these days but forgot about you trying the stagger. One reason lifting a tire works when going square is because we're able to make the outside wheel match the fronts work given weight/tire ratios. So you with a smaller tire are just making it harder for the rear in that case. To make that work, you'll probably need to go softer in spring and/or bar to keep stability. Remember, once you lift a wheel the bar has done what it can and its only adjusting how fast it gets to max load. Do you know if you're lifting much?
Everyone has their preference but I prefer a confident car so would take a little pushy over too much oversteer. If you can find that perfect balance where it dances then thats the magic, but you need to have confidence the rear is stable in slaloms for sure. I would drop 100lbs in the rear to see how that feels.
Front camber seems maybe a tiny bit high but probably not too far off. Pressures seem low. I run pretty much everything in the 35-38 psi up front over the years with the exception of BFG R1-s that oddly wanted less pressure. Ive tested mostly on hoosiers but found A052s are really similar acting, but lower pressure "feel" faster and more forgiving but more pressure on data shows more lateral grip. They just become sharper and easier to go over that limit. Its worth trying 38-40 psi for a few runs. Do it for more than one run though, you'll have to recalibrate your feel to it.
Balance wise it sounds like you're close, it doesn't take too much to shift things back to stable in slaloms. Hard to say though if the shocks are causing and issue, if shocking tires with hitting droop limits, or have some other bind.
I don't believe I'm lifting a rear, but I'll make sure to have someone watch next weekend to confirm. Agreed, I just don't know for sure how that rear is going to respond, which is absolutely not giving me any confidence in the slaloms. Most of the cones I hit now are slalom related it seems.
The front camber is probably a tad much. I feel like that's why I can get away with such low pressures. If I go higher, say 33-35, There's a good 1/8" to 1/4" of outer tread that seems to not be in contact with the ground after the run. Also, I have rubbing issues behind the front tire on the sideskirt area. I'd assume taking some of that negative camber out, would increase the rubbing.
The car definitely seems close for sure! I'm going to try messing with the shocks this coming weekend as well as a stock bar (and/or disconnecting it if need be) this weekend. If that doesn't work, I'll go down in rate to see how that tames things down.
I appreciate your insight!!!
