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Looking for input on alignment for an AutoX setup?? 510


spec-bre

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Uber - ENTRY: $35.00 per person; $60.00 a couple (in the same car) - CASH Only Non-members, UFO Members may write a check.

UFO Membership $15.00 per year

 

'68 - I have not been out with SCCA, I would like to do a PCA event first. I hear they are very well run and laid back. Modifying your 510 without looking at the SCCA rule book first pretty much means you end up in OSP. The ease of modification of these cars makes such a catch 22 when it comes to classing them ... hotrod shit just doesnt groove with SCCA rules.

 

I daydream about making an auto-x club kinda inspired by LeMons racing. Instead of doing year long points battles, make it a single day - single win - setup. Give them themes and maybe organize the cars differently each time so ANYONE could come out a winner depending on the days rules. Do both times classing and peer judging stuff in parallel. (a drift group ...paint/body judging...underdog winner...most out of place car...etc). cars are numbered already and it makes voting easy. Maybe only do 4 events a year, but make them a big deal.

 

Another thing I have thought of is Handicapping in Auto-x. If you ran year long events and one person is winning every time, with each class win you add .25 sec to their best time.... forces the fast to go faster in order to keep winning. like ballast in WTCC. In a 12 event year , you would have to beat your opponents by 3 seconds to keep first at the end of the year if you placed 1st at each event throughout... I think this is a fair way to level things out and keep low budget racers interested.

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Even in VSP there are cars that get trailered in, and huge 2 second gaps between racers sometimes...cars that could easily compete at higher levels dominate there on limited tires alone....thankfully it takes showing up to every event to get somewhere in the end. so far the overdominant cars have not made it out enough to take the class from its regular competition.

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All this auto-x talk has me jonesing to get out there with you guys. Where can I find some info on this and future events in the bay area? I kind of built my car with auto-x in mind but have never been out to one yet.

 

I know at least one person that drives down from NAPA to marina for events...with a little finagle-ing you 2 could probly meet and cruise down together, makes the trip waay nicer. There are plenty of SFR events sho... just not with UFO

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Btw those camber bolts are known to slip no matter what you do....

 

What did you mean by this,,,? I am not familiar with them whatsoever... kept meaning to ask and forgetting. Are they eccentric bolts to offset the inner part of the control arm? if so.... why use them and why do they slip??? The parts pictured looked to me like they were heim jointed in the inner pivots, mine are done like this after a fashion - just lopped off the end of the arm and welded a plate with a threaded joint in it to make adjustable track and a range of motion fore and aft for the arm...

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What did you mean by this,,,? I am not familiar with them whatsoever... kept meaning to ask and forgetting. Are they eccentric bolts to offset the inner part of the control arm? if so.... why use them and why do they slip??? The parts pictured looked to me like they were heim jointed in the inner pivots, mine are done like this after a fashion - just lopped off the end of the arm and welded a plate with a threaded joint in it to make adjustable track and a range of motion fore and aft for the arm...

 

It was discussed at length on the bluebirds mailing list among veteran racers and autocrossers. No matter how tight you get it, it moves. Its just an eccentric bolt you tighten up on the arm. Look at t he pictures i posted at the top of page 2, those were pics of spec bre suspension.

 

The kind you speak of, truly heimed or adjustable arms are fine, eccentrics are crap.

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It was discussed at length on the bluebirds mailing list among veteran racers and autocrossers. No matter how tight you get it, it moves. Its just an eccentric bolt you tighten up on the arm. Look at t he pictures i posted at the top of page 2, those were pics of spec bre suspension.

 

The kind you speak of, truly heimed or adjustable arms are fine, eccentrics are crap.

 

Ok - I guess I knew that already (sort of) As I had been warned to stay away from them in any form, (hence the heimjoints) especially on the rear of the car as being gremlin inducing and not enough adjustment. wandering around would make for some good gremlins for certain.

 

...I was lucky enough to get to know someone IN PERSON (lol) when I first got my car, that knocked a lot of sense into me before I really even understood half of what I was avoiding. :thumbup: :blush:.

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Oddly enough, its quite difficult... These stick like much more spendy tires...makes no sense...

 

 

 

Ok, so a few pages back i killed half a page trying to explain this sensation, as it was something I am just starting to understand. Talking to performance "knoow it alls" and reading my book on suspension and handling gave me an idea but they make it so complex...

 

Then I got to talking to a 4x4 buddy, and his explanation was laughably simple...he said something like this....

 

OF COURSE you get more traction and less slip with a higher rear end ratio! What do you think all of us are doing with 4.44 and higher gearing? what is the whole point of the gear reduction in a 4x4 transfer case? not to spin all 4 tires, but to make them all stick when full power is applied! Hence your ability to get low end tires to hardly break away with a 4.11 rear. All the rev makes less tire rotation in total, and more crank torque is applied to fewer rotations of the wheel.

 

He said that to me while already 3 or 4 Tecates to the wind, looked at me weird like I had never seen the sun, pounded the rest of his 5th, and returned to grilling ... class dismissed. :rofl:

 

Rock crawlers thinking is so upside down that it makes things like this redundantly clear.

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  • 2 weeks later...

Well gang, I took my car to see about an alignment for autocross. I got some "base info" off a fellow vintage racing buddy and took that to the alignment shop. After swapping cross members from my other 510 (cross member only not A arms, brake fluid conflict) and completely disassembling the front for paint and new bits and reassembly I took it in. I talked to the guy and let him know what I was looking for. After a brief conversation with him I was not feeling good about his ability to get me where I wanted to be (510 was not in his system;)) we loaded it on the rack (with me in the drivers seat) and ran some numbers. After checking everything out he suggested we not do a thing.. After having everything apart and back together in my garage this is where I was at..

 

R-lft.. Camber -3.35 R-rt.. Caster -3.74

R-lft Toe 0.00 R-rt.. Toe 0.38

 

F-lft Caster +5 F-rt.. Caster +5

 

F-lft Camber -1.99 F-rt.. Camber -1.74

 

Toe .24 .24

 

I started with 35lbs in the Hoosier R6's (all I have at the moment) kept messing with the fronts but could not do anything with the understeer. One thing to note is it was 43 degrees at the warmest part of the day and there was 12+ minutes between runs so there was no chance of heating up the R comps. My 4:38 has been pulled and swapped with the 4:11. Long fast coarse that had me in 3rd by the end of 1st slalom and running out of 3rd at the light. I have a ton to learn, need some A comps, and I am going to buy or make adjustable LCA's and TC rods. 1 thing I am looking to gain from these is wheel clearance. The tires are rubbing the floor pan as well as the inner forward well on the pas side. The stops have been adjusted to limit this as well as my range of motion (which I don't like) but anywho.. That's an update on my 1st time out.

 

Also I will be removing the eccentric bolts in the LCA's. 1 slipped after the event and had the front all jacked!!

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Am I reading right? Rear Left Camber -3.35, rear right CASTER??? -3.74? (did you mean camber?)

 

First things first... Did you get shoe polish and a pyrometer? Did you use them?

 

If you were at best possible temps and using the full tire on all 4 corners, then you can start to attack swaybars and spring rates..

If you were NOT at good temps, and NOT using the tires evenly, then you may want to work on geometry more.

 

Without knowing where your bodyroll is in relation to how much tire you are using, it is hard to know how to help more than that.

 

Over stiff cars understeer for different reasons than over soft cars, etc.... stiff car with too much camber is just as bad as a soft car with too little...both will understeer. one becase it doesnt lay onto its full tire, the other because it lays over the full tire....

 

The Eccentric bolts are frikken useless, and will always slip, no matter what you do... not enough adjustment to be worth the trouble most of the time anyhow...chop off the ends of the control arms and weld in threaded heim joints...adjustable track width, and all the caster range you can ask for. Or you can go aftermarket...

 

It seems like your only solution to your rear camber without slotting the xmember, would be to raise the car a little. If you need to - just make plywood shims for the spring buckets, you can pick up the rear a little and lose some of the excess camber. Then adjust the front end for more camber at that height. (this will also help to address the rubbing)

 

Just going by what you have written.. maybe try....

(these settings may help the rubbing too)

 

Front toe - out slightly more than now

Front Camber 3-3.5 deg

Front caster 2-3deg

 

Rear camber 2deg

Rear Caster ???

rear toe - get it toed in somehow. (slot rear xmember...)

 

Pressures - about 4lbs more in the front than in the rear, as low press as you can get away with. 35 is probably too high, ask others using those tires at your events that seem competent to help you out there.

 

Most important thing is to get feedback from laps... get pics of car cornering, take notes on tires...use your polish and pyro...if you have info on those 2 things, much more accurate help is possible without being in your car.

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"Am I reading right? Rear Left Camber -3.35, rear right CASTER??? -3.74? (did you mean camber?)"

That would be Camber #'s not caster.

Not sure what the new numbers are after spring change but there is less camber now and a stiffer spring.

 

No shoe polish or P-omitor yet. 2 reasons why. 1 these Hoosier R 6's are temporary scrubs. When I get my "A" comps mounted on my 13's I'll gear up for tire tuning. 2 temps were only 45 degs and I could not get any heat in them. Less then 1 min runs and 12+ minuets between there was no chance for heat..

 

I ran it again this past Sunday and it did outstandingly better!!!! Higher temps, better gear, and stiffer rear springs made for a great time!!!

 

Here are some pics from the 1st go around

 

AC551832-E681-4A59-9000-7716A2027BF1-4949-000001CE3DFA5245.jpg

 

9C0282EF-521B-49E9-A8EB-F44A4C0F6096-4949-000001CE5B0007A8.jpg

 

0AA10B47-C6B3-43DD-AC9A-21555DC609E2-4949-000001CE5373EDB0.jpg

 

E660D1F7-E38E-47F5-BAC1-E3CE51776DBA-4949-000001CE665878D7.jpg

 

I didn't get pics of the most recent event but I do have some in car footage. I'll try and get 1 downloaded.

 

Getting ready to modify my LCA's and TC rods and then address the rear cross member.

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For some reason I see pics or vid? :confused:

Glad to see that stiffer springs made a significant improvement!

One small thing tho, both tools are useful to your goals regardless of outside temps or tires.

Use the polish to make sure you are using all the tire, then use the pyro to see where it gets used the most. Even if they never reach traction ideal temps, suspension info can still be gathered.

Geometry gremlins will carry over to other tires, and become worse in less than ideal conditions.

 

if you are overcooking the inside of the tires, or having to let out so much air @ full patch that the center temp is lowest, then you have too much camber.

 

If the inside temps are always lowest, and still roll over your outside sidewall even at high pressure, you have too little camber.

 

This is an oversimplification in some ways, it says nothing about over or under stiff cars... as you may have just experienced firsthand.

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282324_10151298550281383_1795309173_n.jpg

 

These are what is left of my Kuhmo V700s... they were dual driven last season. 88 laps in eleven events at least. Then given free to me as learner tires.... I have driven them to at least 6 events this year... chalk up roughly 40 more laps... they are blistered, flat spotted, heat cycled and un-evenly worn. Brilliant example of now NOT to use your tires...most of the odd camber wear was from the 510 that they were on before me... which WON the season in class last year in them (co-driver beat the owner... lol)

 

They were also good enough for 2nd place in class yesterday am!! Gave first to another 510, trailered in on 235/13 hoosier A6s.

 

Other cars were.... 2 Zcars on toyos and kuhmos, a 2000 roadster on Hoosier Street TDs, a dual driven Capri on A6s, a mustang on ??? and more...

 

I think I will be in the top 15% of all cars from the event ... And I think I can use the tires AT LEAST once more... :rofl:

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  • 1 year later...

First, what a FANTASTIC thread!  Quick comment on getting even tire temps and effect on handling.

 

IT WORKS AWESOMELY!

 

I was having problems with a front wheel drive car tearing the insides of the fronts out AND a 300 lb driver right behind the LF on a 2000 lb car.

 

So I set Toe and Pressure purely by temp.

 

I achieved the best compromise(linear across - one side hot outer, other hot inner) resulting in increased front grip was frankly astounding.

 

The LF is now Happy (!) even on a RH turn!

 

I have no plans to ever measure toe again on a street car.

 

Oh, and I got this far with surface temps from an optical pyrometer.

 

And I just discovered i3 FLIR's are selling for $500 on eBay :hyper:

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Old tip from the 1950s, use moisture free Nitrogen gas in your tires. The rubber will last longer due to no moisture and heat induced degradation of the casing, but more importantly the tire will run cooler, which is what you are after! Of course Helium is the ultimate "run cool" gas but that's totally impractical! It has the highest thermal transfer coefficient of all gases, that's why it's used to cool the Inertial Guidance Units of ICBMs [at least ours].

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  • 11 months later...

I ran -2 degrees front and rear last season and never used the outside edge of the tire for auto x.  The car now has a 1.1/8" front bar (up from 1"), solid mounts everywhere, spherical bearings everywhere, Byron's adjustable camber/caster crossmember plates, 1200 lb. springs in rear stock location, 300 lb. GC 280zx coilovers in front, struts shortened 1" for 300zx Tokico blue inserts, Tokico blue 510 rear shocks, 280zx brakes all around.  DPR steering box brace, idler arm bushings, offset camber plates, Ermish adj. lower control arms with adj. T/C rods pulled forward for as much caster as the threads will allow.  Powered by 1986 300zx VG30e with headers and cone air filter...all else stock.  5 speed, 3.70 Subie LSD converted to 4.44.  Ist auto x is May 17th and I am praying for good weather up here in Bozeman, Montana.  I aligned the car myself to -.5 camber all around, 1/8 toe in total front, 1/2 toe in total rear.  NO rear sway bar.  Car sits 4.5" at front crossmember, 5.5" at rear diff.  205x50x15 BFG Rivals on 200sx snowflakes +35 offset.  Bolt right up on the rear, needs 2 each 3/8" Futofab spacers with 60mm studs in front to just clear the front struts.

 

O.D.D. your posts are awesome.....much detail that is lacking everywhere else I have looked.  Thank you.

 

I will let you guys know how this initial setup works. 

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