just another sunroof-less ZHP autocross STX build and events chronicle
Originally Posted by GoGators
Video of my best driven laps from Dixie Solo National Tour.
You will see that I have not solved the pushing condition encountered anytime I am not stomping on the brake to turn. Car just pushes coming out of every turn. any tire screech you hear in the video is front tire... (mic is under the hood)
Currently I am running the struts/shocks at 'fairly loose' . the frnt sway bar is set to middle section and the rear bar to less stiff.
the car felt pretty well balanced before I added the rear camber bars and LSD... so.. I want to keep the rear camber I am currently running (~3.2 deg) bc I am killing the outer part of the tire tread less than I was at stock rear camber. so, I reckon, I am going to try and loosen the rear (since I cant think of a way to get more grip up front) by stiffening the sway bar and more tightening up the rear shocks.
open to suggestions....
Sorry man I've been busy.
I think you have to remember that National events are all top caliber drivers. Don't over think it, they are all there because they're good.
Are you positive you're not riding on bump stops?
Typically it's not good to adjust the other side of the car where you don't have issues, in this case that will be the rear. It's a good temporary fix, but I'd still keep on looking at the front.
What's your front spring rates in relation to the rear?
Also, thought process on why you think you're too low pressure up front? Where is your rollover?
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Project STX: TCKline Racing l APEX l Vorshlag l Eibach l Hawk l Schroth l BMW Performance
Yea, reckon if you are willing to drive several hours for 5 minutes of seat time, you better be good!
the subsequent event I put a camera on each of the front wheels, see post on page 4 (~3/23/15), after the nationals video. tire is rolling a lot...
springs are F500/R550.
agree, front grip is certainly the problem. next event is in ~3 weeks. going to run the front bar at full stiff (a change from medium). video mentioned above shows outside tire coming to atleast zero camber, possibly positive.
also going to put a bit more front toe out in the car. when I have done that in the past, it distinctly helped turn in. figuring if I can atleast get the car into the corner, that will minimize the understeer impact!
video from Sunday's event in Gainesville FL (JAXSOLO / buccaneer region scca).
changes from the last event, in an effort to reduce prevalent understeer, went from med to full stiff on front sway bar, increased front tire pressure by ~3 psi, increased front toe out from ~0.5* to ~1.0* total toe out.
car definitely turned better. still tends to understeer, but the turn in felt much better and it didn't fight the sweeping turns as much as it has there in the past. pretty happy with this setup. looking at tire deflection in the video, I still want to increase the front tire pressure a bit, ran ~38-39 psi on sunday.
overall though, I really didn't get one really nice pass. had some operator error in all of them. i think i should have been able to shave at least a full second off my best clean time. ended up 7th of 20 in STX, there were ~15 BRZ/FRS in STX on sunday. the 6 cars ahead of me were all BRZs. PAX overall, i was 24th of 96.
well.... bit the bullet and bought another set of front springs. got 550lb/in coils to replace my ~450lb/in coils.
also looks like I can gain about another 3/16" of inboard movement of the strut top by further elongating the 3 holes retaining the camber plates. after that, the nut/threads of the top of the strut should be touching the inner part of the strut top opening on the fender, thereby maxing the possible neg camber..
will get it put back together this week for a local event on sunday.. the question will be were to set the sway bar, considering the new springs and bit more camber. probably going back to med or maybe soft....
video from local autox on sunday. finally... finally, dialed out the understeer that has plagued the car. it took new front 550 springs (removed 450s), backing off the front sway bar and adding more front camber (now at ~3.5 deg) by carefully filing the holes and grinding the strut top nut.
now I need to adjust the rear a bit, now that the front is gripping. probably going to go back to soft on the rear bar.
mic is located underhood, hence you wont hear the rear tires letting go...
Good thought on the rear alignment. After my wavetrac LSD issue.... I now have an open diff back in, so I set the bar to less stiff. once the LSD is back in, might try more camber again, previously, when I increased rear camber it made the car even more prone to understeer... but, now, it might not. current alignment in the rear is to factory spec.
Saturday night / sunday morning was our annual night autocross... wasn't a great a night for me. I ran in the second heat, after I worked timing in the first heat which fried my brain and I lost sense of the course. finished 5th of 9 in STX (once again, BRZ/Frs-ed to death), 18th overall of 43 raw time and 15th overall PAX. adding to the distraction was a torrential rain just after my second pass, so passes 3-5 were all in the wet. additionally, local cops showed up in force at pass 4, causing another delay until they were convinced we were authorized to be on the deactivated runway and not a gang of very well organized street (runway) racers....
visibility isn't as bad as the video suggests... though, the dark certainly adds an element of confusion and lack of perception...
Did a couple things I don't typically do at the Gainesville raceway test/road circuit.... stayed on the tarmac and moved up (20th raw to 11th PAX) in adjusted/indexed (PAX) time instead of moving down.... It was quite soupy out there from the heavy rain on Saturday, you can see some of the mud-slicks that folks went off into..
Ran the car with my spare differential. my ZHP diff is back from machine shop after sending my wavetrac unit back for warranty repair... but I haven't installed it yet...
only managed a fourth in STX... as usual behind a few AE86s and ahead of many!! audio is from inside the cabin, baby seat tie down was rattling around and I presume the seat was flexing (not sure what else could make those noises)...
last run I dropped tire pressure a bit and I think that is the way to go. ran 37 F and 38 R. sway bars are at loosest setting and I could tell coming through the slaloms, but turn into the 90 deg corners felt much better.
Originally Posted by GoGators
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