the car looks hawt on the ring, eric. btw please check your PMs.
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rear end gets light, how can i fix it?
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Originally posted by jlevie View PostHave you had the car corner weighted and the coil overs adjusted for corner balance?
The nervousness of the rear end could be just a weight imbalance or the brake bias could be wrong, or both wrong.
Originally posted by kilgojr View PostJim is a better source than I am with car set up...what pressures are you running with the Azenis? Have you tried to set the front sway bar stiffer so that it has a greater tendency to push the front through a corner?
I'm not sure, but the fact there is 30mm of difference from stock in track width front to rear could cause some issues....Jim, enlighten?
With the stiffness of your swaybars (car in general) and BIG brakes with no ABS you are going to have an oversteer tendency anytime you get on the brakes when the car is not fully settled.
Originally posted by Jean View PostWhat Jim said, and also not having a rear sway can also help "settle" the rear end.
I believe Wider rear track = understeer, wider front = more towards oversteer if the car was neutral.
Do you have true coilovers in the back or is the spring/shock in the stock e30 location?
I knew that wider tires in the rear would created understear, but track does the same? huh
no true coil overs. they are just E30 M3 H&R coil overs that are non adjustable exept for ride height.
Originally posted by jlevie View PostThe first thing I'd do is to adjust the coil overs to corner balance the car. If the rear is still nervous, I'd stiffen the front sway to shift weight to the rear tires. If that isn't enough, I'd add weight to the center of the trunk. Somewhere along there the oversteer under power should be conquered. If the rear is still nervous under braking, stiffer springs up front are an option as would be twiddling the front to rear brake bias.
I'm sure my brake bias is off. how do you test/adjust this? I have a bias adjustment knob that i'm going to install some time, i just have no idea how to tune it, so i haven't bothered yet.
Originally posted by Dave View Postthat sounds like a LOT of neg camber in the front. Not saying it is a factor on being "loose".
Jim (as always) has good ideas on how to address that.
and i agree, Jim gives me lots to think about!
Originally posted by SkinnyVT View Postwhat spring rates are you running?Originally posted by Massive Lee View PostHi Eric
It seems your rear end is too stiff. Could be the spring rate, the swaybars, the shocks or tires.
Also, a car that has too much front brake can have a twitchy rear end under braking. But also if the rear brakes are too strong. Let me know if you still run the OEM brake pressure valve. Front SL6R/332mm and rear SL4R/310mm is the ideal set-up with stiff suspension and stock pressure valve.
Lee
right now i have the stock pressure valve still, and i believe those are my disk sizes. I'll have to go measure them again when i have the brakes off.
Originally posted by Wh33lhop View PostThere's a reason lots of guys run no rear sway bar.
As everyone else has said, Try stiffening up the front sway or loosening up the rear (depending on if you want more or less overall roll stiffness, if the rear is dancing around you might want to give the rear some more compliance).
Car looks fucking awesome by the way.
Originally posted by 87e30 View PostSo I know nothing about tracking cars and the above responses all seem helpful, but just thought I'd ask about this.
Can I just throw out the idea of a rear spoiler? Or is 100mph not fast enough to give any benefit?
Originally posted by Erick View PostSorry, I dont have much to contribute to this thread. But I'm massively jealous.
If I buy another set of rims do I get a free ride around the ring? :p
Originally posted by JeffRR View PostWhat ride height are you running? Its very possible that you are bottoming on the jounce bumper, which would show itself as nervous/busy on the offending axle.
Make sure that you aren’t bottoming and then work on balancing with spring / bar adjustment.
I think you mentioned that your having trouble with a crest as well, that’s a rear shock issue. The rebound damping isn’t allowing the wheel to drop fast enough, soften up the rebound damping on your rear shocks. This should help with the crest as well as the tendency to OS under braking. The wheel just isn’t dropping.
Have fun at the ring
Originally posted by Gnarles View PostI don't have anything to contribute about your problem, but do you have any pictures of your bumpsteer spacers? I am interested in how you have that setup.
Originally posted by Wh33lhop View PostMmmmmmmmmmmmm, lack of bumpsteer. :)
Originally posted by daniel View Postthe car looks hawt on the ring, eric. btw please check your PMs.
thanks again for all the ideas guys! i'm going to try a few simple things mentioned in this thread and over at Bf.C. I'm taking my friend up there Wednesday, so well see how she does!
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Eric,
To check for bottoming, Just crank up the rear spring perches to increase the ride height and run a lap. That's pretty easy and quick and will tell you if your running too low. Make the height adjustment pretty big, maybe an 1" at the wheel, so its noticable, you can always dial it back.
With no adjustment on the shocks, give the brake bias a try like others have mentioned. This isn't going to cure the busy / nervous feel but at least you won't be fighting the brakes as well.
(Lee can comment here since he is Mr. Brake)
With the bias valve installed, start off by doing some limit straight line stops and adjust the bias so that the front and rear lock up about the same time or even with the front locking up 1st. This will at least get you in the ball park, as you get more comfortable with the bias control you can adjust for track, set-up and load conditions.
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Great, let us know how it goes and take many pictures at the ring if you can!
I can't even imagine living close enough to the ring arghhhh! :)Mtech1 v8 build thread - https://www.r3vlimited.com/board/sho...d.php?t=413205
OEM v8 manual chip or dme - https://www.r3vlimited.com/board/sho....php?p=4938827
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well Mr hammer worked great since the wheels didn't rub once on the rear fenders (metal part). the rear end felt much better as well, however there are still two corners in the track that feel quite unsettled. One is where there is a crest in a hill right at the apex of the corners, so i understand why it gets light there. the other one is the one i described a few posts up where there is a kink right in the middle of a pretty heavy brake zone.
Now i'm fighting a coolant issue. today was warmer than before, and the temps rose almost into the red. a blown motor means S50 swap so i'm not too too concerned, but it definetly took my concentration away from the track as i was checking the guage often. you can see this in a few spots in the video my friend took.
The car also got pretty greesy a few times under braking. I don't know if it's the azenis getting overheated, or the brakes getting mushy, but doing 3 laps in a row (10 minutes waiting in line each time) the car didn't feel as good.
I also found out that i can't check tire pressure at the local gas station (i have no air) with the turbine covers:hitler:
finally, my buddy took a video on one of the worst laps i've ever done. but it's AVI so i can't get it to play the vid part, just sound. can i upload it to youtube?
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I'll have to guess it's probably your tires (unless your pads/fluid is old?), even in Autox when I did back to back runs (fun runs at the end of the day) they get worse and worse as they get HOT quickly.... can you get a tire temp. gauge? The one you point at the tire and read the temperature?
YouTube should accept .avi , try and play it back with VLC on your computer.Mtech1 v8 build thread - https://www.r3vlimited.com/board/sho...d.php?t=413205
OEM v8 manual chip or dme - https://www.r3vlimited.com/board/sho....php?p=4938827
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So my buddy is a dork at the beginning. I am no way a master, especially with this lap that has to be one of my worst! I also get pretty nervous before each lap, so i'm not in super serious dick mode, just nervous.
From the beginning until about 2 minutes in i'm worried about high coolant temps.
1.42 checking coolant, wrong gear
2.42 worried about smashing into the lotus. the car was really alot closer than it looks in the vid!
3.01 had to slow down a bit for the lotus
3.57 carried too much speed after thinking about my first pass in a braking zone the corner before. this is also where the car got a Little greasy
4.14 real greasy here, i was pretty nervous actually
4.22 this is the corner my rear end gets light under braking. i actually had to counter steer in this vid, but you can't really see it.
4.41 I wasn't sure where this biker was after i passed him so i stayed left. car was still greasy so i got flustered, entered the corner early and went WAY wide. usually i take this corner pretty fast and it's one of my favorite, but i totally butchered this one. after this corner i slowed myself down because i was now unsure about the car and about myself.
7.19 i need more power!
at the end, look at how many cars are backed up. if those cars weren't there, the coolant temps wouldn't rise, and i could have packed a ton more laps in. after every lap we waited about 15 minutes in the traffic jam... sucked.
ok, after all the lame excuses here is my lap
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Kuddos to your passenger/friend/slave who was holding the camera. Hopefully he was not looking thru the camera. That's a recipe to be sick within a minute.
Good work (even though I was about to puke on my keyboard, staring at the shaky camera work)
LeeBrake harder. Go faster. No shit.
massivebrakes.com
http://www.facebook.com/pages/Massiv...78417442267056
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