meBlaise

Hey everyone. I'm new to HPDE in a car this year after lots of motorcycle experience. Already WAY happier having switched over, once I got fast enough to slide the bike things just weren't as much fun for me.

At the moment my car is very easy to drive (understeer-biased) but I can tell that the front tires need way more camber not just because of the push but also pyrometer readings. It's been my DD/street fun car since ~2010, thus the mild setup.

Complete details:

Chassis:
'92 NA 1.6 - 2557lb with 210lb driver and 2/3 tank fuel. Presently has PS/AC, full interior, etc.
No Aero work, using hardtop
V8Roadsters frame rails
Blackbird SD rollbar

Drivetrain
Stock 1.6
Torsen 4.3 from '99

Brakes
NA8 Calipers/Brackets
GLOC pads: 10 Front, 8 Rear
New lines (not stainless)
no ABS

Suspension
Polyurethane bushings
FM Springs (gen1). No sag or bumpstop-slamming issues that I've noticed.
FM Rear Shock Mounts with included bump stops
FM "Improved" 10mm front bump stops
Tokico Illuminas Set to 4 (of 5) all around
Pinch Weld Height: 5" front 4.75" rear
Stock sway bars
Present Alignment Numbers: From flyin miata recommended #s:
Front: -0.9° Camber 5.0° Caster 0.06° Toe
Rear: -1.5° Camber 0.06° Toe

Wheels/Tires
15x8 6UL +36mm offset
Yokohama AD08 205/50/15
Had to bend/mold fender liners due to rubbing under heavy cornering

Things I have sitting in a box or on order:
Halo Seat, 6pt harness, RB #54107 sway bar, RB Brace kit, ELBJs, wilwood adjustable prop valve.

OK, back to what the car does and what it doesn't do. I've played around with hot tire pressures and right around 34psi hot the AD08s seem to exhibit much better wear. Here's an example of them around 32psi:



And 34psi:



Pyrometer (probe type) reading deltas at 34psi hot on outside front tire were: 0 (Inner) 0 (Center) +15 outer. I had this written down but lost my notebook so it's from my memory. I am 100% certain I had inner and center temps extremely close once I came up from 32 hot (then it had a slight drop to center) but the outer edge was cooking still due to lack of camber. So basically it's the opposite of the ideal gradient I read on the 949 pyrometer page. Ack.

As for actual felt behavior, the car is very easy to drive as it's quite understeery. I've noticed that I'm starting to trail brake the car instinctively just to get it to rotate on slower corners, on turn 9 at NJMP thunderbolt I'll give it a little left foot to get it to turn in. On faster turns I'm just stuck setting it and letting the front plow. That part is not fun and I'd like to fix it. I'll play around with my friends in similar miatas and I'll catch them on the brakes or in transitions but in steady-state turns they're running away from me on similar tires and then of course in the straights as I'm underpowered/overweight.

All I'm looking to do for now is to bolt on my ELBJs and big sway bar so I can run lots more front camber without changing the bias so much that the car impedes my learning. I'm also OK with spending more money on parts if it would be productive/helpful at my skill level (roughly 10 seconds off of SM pace at NJMP thunderbolt - 1:47s vs 1:37s). I have already budgeted and am running every event I can reasonably drive to within ~6 hours of Philadelphia so buying parts will not impact seat time. I spoke to emilio for a bit last night and I'm well aware that there's no way to get the suspension 'right' without playing with things... just looking for a good baseline so I can learn not just to be a better driver but learn basic racecraft.

Given that I've bought a halo seat, I'm also OK with running a more aggressive than dual-duty alignment. Let's be honest, I'm unlikely to drive it much on the street anymore especially now that I bought a Silverado to tow it to the track...

Thanks!

hornetball

iTrader: (4)

Beyond getting front camber with the ELBJs, seems like your next step would be coil-overs for more adjustability (for example, your rake is backwards). That'll let you dial out the push. It seems like you're already doing all the right things, including talking to Emilio. Also seems like you're way ahead of the learning curve for being new to HPDE. You understand tire temps and how/why to use trail braking. Maybe that comes from your time on motorcycles.

IMHO, the basic Xida CS is the best suspension deal around by a good margin.

meBlaise

Yeah - I'm OK with spending the coin on Xidas but didn't want to overcomplicate things while I'm learning how to drive. After all, I'm 10 seconds off spec pace. I want the car to be easy to drive and neutral, then just do LOTS of seat time to get fast.

Any suggestions on how to set the alignment at the shop? My initial thoughts were to:

1. Have them set max camber in front that can be attained evenly (assuming this will be ~2.1 as -0.9 was most we could do last fall - 949 lists about 1.2 degree extra with ELBJ)
2. Set rear camber to 0.5° less.
3. Use recommended dual-duty toe #s: Zero front. 0.06° rear. 3.5-4.0 caster.
4. Head to the track and see how it does. Run front bar on stiffer setting to be safe to start. Next outing is on the 25th so it's not far off.

Also, I will remeasure pinch weld heights with me in the car.

hornetball

iTrader: (4)

Rule of thumb is run the front with ~0.5 degrees more camber than rear to get a more neutral car. Toe and caster mainly have to do with turn-in, high speed stability and steering effort. Front bar full stiff is easy to soften if you find yourself pushing.

Beyond that, you probably need suspension. One of the things that may really be holding you back is spring rates (not sure what the rates on the FM's are). You're running pretty low. Combine a low ride height with soft springs and you're likely riding on the bump stops a lot. It's better to be riding on properly damped springs in the turns.

meBlaise

Thanks man. Glad to see my guesses aren't totally off-base.

Published rates are:

No idea if this is accurate still for Gen1 Springs. I've emailed them to ask exactly changed between the generations.

Edit: From FM:

flier129

iTrader: (7)

First post in race prep and it includes this?







Onto actual response.....

Looks like you're already going towards a more aggressive alignment, which is definitely needed. Those springs are super soft even for the AD08s, +2 on Xidas (800/500 if you decide to go with a super200 or r-comp)

What track have you run/plan to run? Where are you located?

meBlaise

Thanks man! I now see that it's hard to get any insight without providing as much info as possible. I got an earful from emilio last night bc I figured he'd rather NOT hear everything and tried to ask a general question. Pretty clear now that you gotta give all the info!!!

I'm in Philadelphia so I'm super lucky as I have NJMP (two great tracks) 45 minutes away. I'll run basically every event I can there, next one is the 25th so the only things I really want done by then is the seat/harness and alignment/frontbar.

I ran pocono double infield this past saturday but I didn't love it. Nobody did.

Driveable for me:

NJMP (duh)
Pocono (meh)
Summit (have run everything but Shenandoah on a bike)
Thompson (would be new)
Watkins Glen (would be new)
Lime Rock (would be new)
Pittsburgh (never run full course since they added the northern part)
VIR (Only run north section on bike)

As far as Xidas, wouldn't it be better to continue to learn on the softer setup? I'm not opposed to spending $2k on coilovers although it does seem a little nuts on a $1500 track car.

I'm also open to running Super200s like an RE-71 or an R-comp like an RC1 but again, I'm interested in learning not necessarily setting lap records. Since it can rain out here I'd rather not use a tire that only works in the dry (that's the case for the RC1 right?).

icantlearn

Definitely get new suspension. Its best to learn to drive the car with a better suspension setup. Im saying this because it changes the car completely. So most everything you got used to with the stock setup its going to be thrown out the window, turn in, mid corner balance, and corner exit will all be different to your current setup. So get seat time on a good suspension setup. Xidas are 1000% worth the coin.

As for as tires go, stay on a street tire for as long as you can. You want a tire that will let you exhibit oversteer more easily. R-comps and some super 200 tires tend to be snappy when they beak loose. Street tires feel like you are gliding out of traction if that makes any sense.

Hope this helps.

Bronson M

iTrader: (1)

My suggestion would be a set of endurance 200tw tires, RS4 /VR-1. You'll get 8 to 10 track days out of them instead of 4 to 5 out of the super 200's, and they are a little more forgiving to drive. I wouldn't go with stickier rubber untill you stiffen up the spring rates. Plus to fit 9" wheels you need the coilovers. Do the 9" or even 10" wheels, no reason not to.

If you haven't read through the DIY ebay coilover thread you should. A used set of Bilstein and a set if 800/450 springs Are pretty amazing for the money spent, I have less than 500$ in mine. They are no exida but they're a huge step in the right direction and you can easily get most of your money back out if them when you are ready to spend stupid money on shocks.

meBlaise

Alright guys. Had car aligned last night after getting the ELBJs on.

New Numbers:
-3.0 Front Camber
5.0 Front Caster (had requested 4.0 per 949 page, oh well)
0 Front Toe

-2.5 Rear camber one side, -2.0 on other (I was dealing with a local chain and while the tech was working on it really hard the service manager basically kicked him off the job because he kept taking time on it and because 'NOT FACTORY SPECS').
.06 Rear Toe

Added the 54107 RB front bar, currently set to the softer setting as I need new endlinks to reach the stiffer one. Also installed RB brace kit.

Soft top has been removed and I will be removing AC/PS this weekend. Radio is also out.

Tonight I'll bolt in my halo seat and 6pt harness. HANS and compatible helmet have arrived. Will be at NJMP Tuesday and report back with impressions and pyro readings.

Thanks everyone!

meBlaise

Alright!

Quick report here, only got 3 sessions last night as it was an after-work special. NJMP thunderbolt.

Car is WAY more neutral. Way, way, way more neutral. I can no longer drive it like it's FWD! My 2nd lap out matched my previous best which was a huge surprise when I saw it.

Extra camber helped immensely. Duh. Have so much more grip that after dropping 3 seconds off my times I know there's still several more left in it. VERY VERY happy.

Pyro readings on the FL tire were ~147/130/135 at 34psi hot so I bumped it to 36 which moved it to ~145/135/130ish. Rears were still happy at 34. I didn't look at pyro stuff too carefully as I was concentrating on learning to drive with the seat/harness/hans.

After my last session I got in the car and the clutch pedal did nothing. Had to start it in gear from a stop at every light and match revs to get it home. That was rough.... that will be the last time I drive to track. Hitch goes on truck ASAP.

Thanks everyone!

Goingnowherefast

iTrader: (1)

I just want to say that I literally just put in an order for Xidas after reading this thread. Like you I am a beginner, but also seem pretty confident with my ability to set up the car via current pyrometer and stop watch readings. I thought the Xidas would be some unobtainable setup left only for pros but this thread convinced me to sell my soul for Xidas

meBlaise

It's $2k, it's not really my soul. After all, this *is* an expensive hobby.

Very much looking forward to your impressions.

Goingnowherefast

iTrader: (1)

I just payed $16K in student loans yesterday, so it's added up to selling my soul haha. I'll be sure to post them, I actually have an almost identical setup to you and am almost running SM times. I was recommended 800/500 springs and the 54104 Front sway w/ 14mm rear. Will certainly give me impressions/lap times

x_25

Wait until you try them even just on the street. I have not had time to get to the track with my set, but man, they are doing everything I could ever want on the road.