Da Groj

Good eye professor. His car is very low. We talked about that. He likes it that way and doesn't want to raise it.

Loren wrote:What I'm seeing in this video sort of "feels" like you're bottoming out the rear suspension, which spikes the rear "spring rate" to infinity and causes snap oversteer. Too low in the rear? Too soft in the rear? Blown shocks in the rear? Lack of bump stops in the rear?

Native wrote: His car is very low. We talked about that. He likes it that way and doesn't want to raise it.

It's too low and too soft.

As much as I dislike it, it looks like I need to raise it until I can find some stiffer springs or afford better coilovers. The current spring rates are 7k front and 6k rear, which isn't super bad, but it's not super good either, and they're only height/preload adjustable.

So I guess I'll raise it a half inch all around and mess with the camber and sway bar later. I will be getting it realigned after I raise it, though, just back to the current settings.

Loren wrote:I honestly don't remember what tire pressures we run in that car. Ben has a notion, and it seems to work okay.

The comment wasn't meant to be what you think it was. Have you already forgotten that you were suggesting I run my tires at 28 PSI at the last open event? I didn't take the bait, but you shouldn't be concerned about my degree of competitiveness. Unless I sort out my driving I am no threat. Until I get that Eureka moment my times are always going to be slower than yours. The thing is you never know when that Eureka moment will happen.

I didn't forget, I knew where you were coming from.

You ran essentially the same time that Ben ran at this event, which was only about 2/10ths off of me. You're a lot closer than you think. Are you sure you don't want to try 28 PSI?

Almost timely...the Insight video for 3/12...

https://vimeo.com/159221942

Vimeo Comments: Final tricks...RE71 fronts at 24, rears at 31. Used D-S to start, then to L after a few seconds. Haven't been using L for awhile, which has been a mistake. This appears in the instrument panel indicators. Also note the pedal to the metal (reading of 91 for Tps) on the lower, green OBD display. Wish I had a little more room to modulate...but it's mostly on or off...

B

Cloud498 wrote:

Loren wrote:What I'm seeing in this video sort of "feels" like you're bottoming out the rear suspension, which spikes the rear "spring rate" to infinity and causes snap oversteer. Too low in the rear? Too soft in the rear? Blown shocks in the rear? Lack of bump stops in the rear?

Native wrote: His car is very low. We talked about that. He likes it that way and doesn't want to raise it.

It's too low and too soft.

As much as I dislike it, it looks like I need to raise it until I can find some stiffer springs or afford better coilovers. The current spring rates are 7k front and 6k rear, which isn't super bad, but it's not super good either, and they're only height/preload adjustable.

So I guess I'll raise it a half inch all around and mess with the camber and sway bar later. I will be getting it realigned after I raise it, though, just back to the current settings.

Tyler, if I looked it up correctly, your springs are 392 lbs/in front, 336 lbs/in. My springs are 504 lbs/in front, 336 lbs/in rear. I don't think your rear springs are too soft if you don't adjust them too low. I have my car adjusted to 4.5 inch front, 4.25 inch rear measured at the pinch welds. My recommendation is to raise your ride height to no lower than mine or up to 4.75 inch front and 4.5 inch rear because you have softer front springs. The reverse rake (front higher than rear) will calm your rear end during transition, you can adjust it up if you don't like the feel. Remember to ballast the driver's seat with your weight before measuring ride heights, I prefer measuring at the pinch welds instead of the more common hub to fender. Here is a link to some very good info: http://949racing.com/miata-race-alignment-info.aspx

BTW, 3.5 degrees of negative camber isn't enough up front on my car according to my tire temps.

Joe is all alone in his M class.
Someone else will mess with him....right? Where are all the M guys?
Don't make an S class guy mess with him.

jev61 wrote:I don't think your rear springs are too soft if you don't adjust them too low. I have my car adjusted to 4.5 inch front, 4.25 inch rear measured at the pinch welds.

It would seem I'm too low to have the correct rear preload, but I'm currently at 4.5 inches pinch weld height all around. That's on my smaller diameter DD tires (185/60r14 vs my 205/50r15 star specs). I think NBs are lower from factory, so I may not have as much suspension travel available at the same ride height as an NB; I may need to get NB top hats to increase the coilover travel.

Loren wrote:Too much bar tends to react "instantly". When you turn in, the bar reacts NOW, and your problem shows right then. What I'm talking about (and what I'm seeing in the video) is more of a problem WAY after turn-in... like middle-of-the-turn-around...

Just watched my video again, and I think the reason it got loose in the turnaround was the crest in the runway. Not sure about the near spin right after that. It looks like maybe it started to slide right as I was about to shift the weight back to the other side. I don't feel like I'm hitting the bump stops, but if it's just barely hitting them I might not feel it.

I'll have to look at the rear suspension next time I switch to my autox wheels and make decisions based on what I see.

Cloud498 wrote:

Loren wrote:Too much bar tends to react "instantly". When you turn in, the bar reacts NOW, and your problem shows right then. What I'm talking about (and what I'm seeing in the video) is more of a problem WAY after turn-in... like middle-of-the-turn-around...

Just watched my video again, and I think the reason it got loose in the turnaround was the crest in the runway. Not sure about the near spin right after that. It looks like maybe it started to slide right as I was about to shift the weight back to the other side. I don't feel like I'm hitting the bump stops, but if it's just barely hitting them I might not feel it.

I'll have to look at the rear suspension next time I switch to my autox wheels and make decisions based on what I see.

I don't feel my bump stops engage either. When I had the car too low and had a rear sway bar, the car would spin easily.

The dialogue above, between Tyler, Loren, Steve, and Joe, is a good example of why we like Autocrossing with Fast. Folks are helpful. It's nice. Thanks.

Just for fun, I'll post my most ridiculous run of this event. Seems like when I push harder I suck more. Finding that balance can be so elusive. Hope it's worth a laugh.

https://youtu.be/ewbVgJbG4ew

If your suspension is working right, you shouldn't feel bumpstops engage, at least not unless you are off-roading. Should be a smooth transition to "full stiff" as the car settles onto the stops.

Yer welcome, Dave. And thank you, too!

Native wrote:If your suspension is working right, you shouldn't feel bumpstops engage, at least not unless you are off-roading. Should be a smooth transition to "full stiff" as the car settles onto the stops.

Assuming it still has bump stops. If they're rubber dust, then it's a smooth transition to "kart suspension", and it'll go around pretty easily.

cloud498 wrote:...I think the reason it got loose in the turnaround was the crest in the runway.

If that crest unsettled the car, then your suspension's not working right -- there's just enough crown in the runway to drain water off, and it's not that much of a transition. Wouldn't have done to have B-26s spinning out because they didn't land right on the centerline....

Blue_Heron wrote:The dialogue above, between Tyler, Loren, Steve, and Joe, is a good example of why we like Autocrossing with Fast. Folks are helpful. It's nice. Thanks.

Just for fun, I'll post my most ridiculous run of this event. Seems like when I push harder I suck more. Finding that balance can be so elusive. Hope it's worth a laugh.

https://youtu.be/ewbVgJbG4ew

I would add another vote to check the bump stops. If I remember correctly when I drove it it was great but it did have a "snap lose very fast" feeling on some but not all the turns. Kind of like my car did on the old bump stops.

tdinfl wrote:

twistedwankel wrote:
Tony you really manned up to get second away from Sam and the Datsun AWD this time.
I was able to get a practice 47.06 later with a passenger but just couldn't get my zags and zigs sorted out on return lane by myself.....damn tires squealed like pigs all the way home.
Congrats on getting some actual points again with a sticker!!
Doug

Thanks Doug, I felt good about it. Had fun, and posted my best overall finish with FAST. You might have to reconsider that tire decision!

TD

Tony. I had a long talk with my tires. They won't give up the 7/32" after 5 events. They said they'd ream you a new one with 6/32" if I stood on the gas and got them there.
So I will drive like I did when I was 68. They are still 7/32". Driving like I did when Jimmy Carter ruled 55 would probably make you shiver. Maybe one day we'll drive in the same heat? I'm not longer distracted by family and can drive again?