2015 STU Discussion!
Thanks! You had some good raw times in B Street yourself 
Going into Nationals, my co-driver (RichJ) and I were hoping to be close to the trophies; we made some changes a few weeks before Nationals (spring change, re-tune for 100 octane, alignment, some lighter parts) and the last event before Nationals gave us confidence that the car felt the best it had ever been. We also took some TnT runs and were noticing that Rich wasn't far off other competitors in STU/STR on the TnT course so that also gave us a confidence boost (I didn't drive well on the TnT course on either day, but Rich's times gave me confidence that the car was able to lay down some decent times as we are usually pretty close time-wise).
We were also the only car in the class on the Rival-S (brought RE-71Rs for rain though); we put 10 runs on the RE-71Rs a few weeks before Nationals, we felt that they were better under braking and they were more "crisp" than the Rival-S, but the BFG was very close in those categories (RE-71Rs were mounted on 9" wheel, BFG on a 9.5" wheel) and was a lot more forgiving if you went off the edge or made a mistake. Also, at Lincoln, we didn't think OPR had much, if any, of an effect on the tires (only the rear tires had OPR) though it did rain a lot so there wasn't a ton of OPR built up on the courses between days; picked up a decent amount during practice course runs and on Thurs/Fri but a few circles in the OPR removal area got rid of it all on Friday morning.
Going into Nationals, my co-driver (RichJ) and I were hoping to be close to the trophies; we made some changes a few weeks before Nationals (spring change, re-tune for 100 octane, alignment, some lighter parts) and the last event before Nationals gave us confidence that the car felt the best it had ever been. We also took some TnT runs and were noticing that Rich wasn't far off other competitors in STU/STR on the TnT course so that also gave us a confidence boost (I didn't drive well on the TnT course on either day, but Rich's times gave me confidence that the car was able to lay down some decent times as we are usually pretty close time-wise).
We were also the only car in the class on the Rival-S (brought RE-71Rs for rain though); we put 10 runs on the RE-71Rs a few weeks before Nationals, we felt that they were better under braking and they were more "crisp" than the Rival-S, but the BFG was very close in those categories (RE-71Rs were mounted on 9" wheel, BFG on a 9.5" wheel) and was a lot more forgiving if you went off the edge or made a mistake. Also, at Lincoln, we didn't think OPR had much, if any, of an effect on the tires (only the rear tires had OPR) though it did rain a lot so there wasn't a ton of OPR built up on the courses between days; picked up a decent amount during practice course runs and on Thurs/Fri but a few circles in the OPR removal area got rid of it all on Friday morning.
I just picked up some Red Line 75W140 NS fluid and a bottle of friction modifier for my re-stacked rear differential.
The plan is to start with the NS fluid and just a tiny bit of friction modifier, then to maybe add a bit more friction modifier as desired to dial in the right amount of lock-up for our courses.
The rear diff re-stack and big rear bar have gone a long way toward getting handling where I want it, but I'm still spending what feels like an eternity waiting to apply throttle in the long sweepers because I just push if I do. A little bit of rotation on demand would have made all the difference at my last few events.
Interestingly enough, I do get the right amount of on-throttle rotation for my first run out in the morning, where the tires and surface are still cold. But once things start gripping, it goes back to just pushing on throttle.
The plan is to start with the NS fluid and just a tiny bit of friction modifier, then to maybe add a bit more friction modifier as desired to dial in the right amount of lock-up for our courses.
The rear diff re-stack and big rear bar have gone a long way toward getting handling where I want it, but I'm still spending what feels like an eternity waiting to apply throttle in the long sweepers because I just push if I do. A little bit of rotation on demand would have made all the difference at my last few events.
Interestingly enough, I do get the right amount of on-throttle rotation for my first run out in the morning, where the tires and surface are still cold. But once things start gripping, it goes back to just pushing on throttle.
I just picked up some Red Line 75W140 NS fluid and a bottle of friction modifier for my re-stacked rear differential.
The plan is to start with the NS fluid and just a tiny bit of friction modifier, then to maybe add a bit more friction modifier as desired to dial in the right amount of lock-up for our courses.
The rear diff re-stack and big rear bar have gone a long way toward getting handling where I want it, but I'm still spending what feels like an eternity waiting to apply throttle in the long sweepers because I just push if I do. A little bit of rotation on demand would have made all the difference at my last few events.
Interestingly enough, I do get the right amount of on-throttle rotation for my first run out in the morning, where the tires and surface are still cold. But once things start gripping, it goes back to just pushing on throttle.
The plan is to start with the NS fluid and just a tiny bit of friction modifier, then to maybe add a bit more friction modifier as desired to dial in the right amount of lock-up for our courses.
The rear diff re-stack and big rear bar have gone a long way toward getting handling where I want it, but I'm still spending what feels like an eternity waiting to apply throttle in the long sweepers because I just push if I do. A little bit of rotation on demand would have made all the difference at my last few events.
Interestingly enough, I do get the right amount of on-throttle rotation for my first run out in the morning, where the tires and surface are still cold. But once things start gripping, it goes back to just pushing on throttle.
What RSB are you running?
Construct, curious how your rear alignment looks? I took sweepers into more of a triangle shape, which allowed for full throttle on @ apex, boost moments later, rotation kicks in, and point & shoot..
My IX RS in STU trim I ran about -1.19* camber, zero toe... I had the 24mm WORKS bar, on the middle setting and it seemed to be quite happy... as much as our cars could be in steady state cornering.
My IX RS in STU trim I ran about -1.19* camber, zero toe... I had the 24mm WORKS bar, on the middle setting and it seemed to be quite happy... as much as our cars could be in steady state cornering.
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From: Why do they always call the Evo the Dark Side?
^- and -1.5 in the rear was definitely too much for me on concrete @ Toledo. Even with 800 lb/in springs and the shocks maxed out, I had to jack up the tire pressure substantially to get the car to turn.
We're running a bit more than 1.5 in the rear of Jimmy's car... but the springs are also a fair amount stiffer than 800lb. The car handles pretty neutral on grippy concrete, but was pretty loose on the Lincoln practice course.
^I agreed with that until I tried it....having good shocks with the rebound + compression turned down for the drive to/from events helps a bunch 
FWIW, my old setup (550f/550r, PSS9s) felt ok on asphalt (low grip) but was always ridiculously pushy on any sort of concrete surface (Marina Airport and Crows Landing). However, I was running Dunlops on the old setup (ZII and ZII SS) until we tried the Rival-S in June (on concrete, made no setup changes) and the car was actually rotating a bit and understeering noticeably less. The spring/shock changes we made later that month (and again in August) made it even better.
In retrospect, my setup while running the Dunlops was probably way off and as a result the front of the car would push everywhere. The Rival-S on their own made the car a lot easier to drive but the spring/shock change was the biggest reason for the improvement in handling, IMO.
FWIW, my old setup (550f/550r, PSS9s) felt ok on asphalt (low grip) but was always ridiculously pushy on any sort of concrete surface (Marina Airport and Crows Landing). However, I was running Dunlops on the old setup (ZII and ZII SS) until we tried the Rival-S in June (on concrete, made no setup changes) and the car was actually rotating a bit and understeering noticeably less. The spring/shock changes we made later that month (and again in August) made it even better.
In retrospect, my setup while running the Dunlops was probably way off and as a result the front of the car would push everywhere. The Rival-S on their own made the car a lot easier to drive but the spring/shock change was the biggest reason for the improvement in handling, IMO.
Last edited by Jim3142; Sep 28, 2015 at 10:58 AM.