Autocross Alignment Specs

Suspension, including wheel, tire and brake.
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jeffball610
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Autocross Alignment Specs

Post by jeffball610 » 14 Feb 2018 20:17

I'm late in posting for help since I'll be installing parts and aligning the car tomorrow, but I thought I'd ask anyway. Most people will likely tell me to run the DQ specs, but things have changed since those days.
I'm running Experimental Engineering spring and shock setup f/r with Top End Performance camber plates. Many people know these parts and how they work. I've already installed Futofab's rear camber/toe brackets and have their 1.125" sway bar up front and I'll be installing their control arm/TC rods tomorrow. I plan to use the camber plates to add caster and use the control arms for camber. Is that advisable? I've heard that I should run as much caster as possible and most specs only ask for 1-1.5* of negative camber. I'm looking to run an autocross setup even though the majority of my miles are on the street. I would like to be a little aggressive so I can push the crappy tires I have (Exclaim UHP 205/50/16) until I need stickier units. I know I'm throwing out a lot of info here, but I'm trying to get as much info back as I can. Thoughts?
1972 Datsun 510
7-bolt 4G63T, EVO 9 pistons & rods, Garrett GT3076R, "Flipped" Stock Intake Manifold, Toyota R154, Z31 R200 w/ CVs

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bertvorgon
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Re: Autocross Alignment Specs

Post by bertvorgon » 14 Feb 2018 20:43

Your tires will in some ways determine what CAMBER is best. CASTOR, which if you run quite a bit, indices NEGATIVE camber on turns, this of course is good. Quite a bit I would say would be from 5.5 - 6 degrees of Castor. Most of us Vancouver guys run 5.5 as our base setting for castor.

Make sure the alignment shop gets it EQUAL ( castor)on both sides, otherwise the car will feel "funny", been there.

Chalk the tire sidewalls to see how the roll over onto the tread edge is doing, that test is still valid no matter what.

At the peak of my Solo career, I ran 6 degrees, which makes steering very heavy at slow speed, but on tight course, can sure help with under steer ( if your set up favors that balance. ) Also makes the car crazy stable at high speed, AND, at the slaloms, I found if I lightly let go of the wheel on tight turns, the steering comes back faster by itself that trying to reef it back, due to the self centering effect of high castor. It really does work!

Usually the castor comes from the T/C rod and camber from the top hat on the strut "camber" plate. How you get there, may not be an issue, the results is what matters.

I run a full Solo/Hillclimb setup on the street...WORKS AWESOME!

Make sure you have YOUR weight or equivalent in the driver seat, for all settings. If your car does NOT turn in well, depending on how serious you are, you can try running ZERO TOE, or a hair toe out, this will sure help the car turn in but be a bit wandery on the highway.

Make sure you run some toe in on the rear, this is what really transforms a 510. Go back and read the SUSPENSION thread if you have not already.

Decide on what average fuel load you want to run, as all this weight distribution does affect your static settings.

You can play with tire pressures to fine tune over/understeer characteristics too. Make sure you write all things down, then when you make a change, you will always have a baseline. Try to change only one thing at a time after you try the car at the first event. That way you will have an idea of what really made a change.

Until you drive it and then give some feed back, it will be hard to say how your spring package and shocks are all working together too, again, re-read the suspension thread. As the springs are part of the "roll control" and weight transfer, which handling is all about, it may take you a couple of events to figure out what it may need.

keep us posted.

keith
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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icehouse
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Re: Autocross Alignment Specs

Post by icehouse » 14 Feb 2018 23:18

I agree with everything Keith says. The only thing I'm going to add is. Don't get to crazy with front toe out, unless you plan on tons and tons of autoxing I would stick with zero to a touch of toe in. Same with the rear. Don't go crazy on rear toe in unless you plan on it being a dry day autox car. Keith is correct it does help a ton but I daily drive my car and it does weird things on crappy wet roads where they seal the cracks. When one rear wheel slips on the smooth patch tar, the wheel with the traction can straighten itself out. Feels odd and if you aren't going to race no sense dealing with it. Frank hates how it feels on his car, I told him to go back and set it to factory toe settings. He didn't...

O also make sure your rear crossmember is solid mounted. That dumb flip the washer trick IMO doesn't work, it does limit the movement but not 100%. I switched to solid bushings a was amazed the difference!!! Way louder but I don't mind. My daily commute is only a few miles.


Good tires and time behind the wheel will make you way faster then any suspension setting.

22 1st-3rd place in the unlimited RWD track X I've been going to for about 2.5 years now. They do from 0-3 per month depending on the season. I try and go to them all.


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"People don't like it when shit doesn't match their rule of thumb." Sam

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bertvorgon
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Re: Autocross Alignment Specs

Post by bertvorgon » 15 Feb 2018 06:11

Re: the toe out suggestion.

I only mentioned it as this was before we figured out that most of the springs available at the time, were just plain too soft, so upon toss in to a corner, there was just inherent understeer as the weight transfer loaded the outside front corner with too much body roll. At the time also, tires were not what they are today and turn in was sluggish to say the least.

Most of today's true street legal race tires are way quicker in slip angle and turn in.

Jeff is right when he says "Seat Time"! That will let you know what the car is doing at the limit of both your driving capability and the cars. That is when you make the really educated decision of what to change..if anything.

As we all learn, tires are the biggy when it all comes together. You cannot ever be competitive no matter what great STUFF you have thrown on the car, if you try to run Sears Roadhandlers.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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duke
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Re: Autocross Alignment Specs

Post by duke » 15 Feb 2018 06:33

To reiterate what Jeff and Keith have said, TIRES!

I personally run a similar setup to those guys, with the exception being I run a good deal more camber. I run 3.5* in the front and 2 in the rear. This results in even temperatures across the tire after a run. However, I run either Hoosier A7's or a UHP street tire. The added grip of these tires cause the car to roll more, which requires more camber when compared to a lesser performance tire. I have driven my car a couple of times with some generic tires with a similar setup and it is SCARY. It's amazing what good tires do not just for ultimate speed, but also predictability a break away characteristics.
Duke Schimmer

'72 2-Door 510
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icehouse
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Re: Autocross Alignment Specs

Post by icehouse » 15 Feb 2018 07:57

Keith, I only mentioned what I did and used Frank as an example because what people say they want and what they really want is sometimes way way different haha. Turns out when Frank says he want to "race" that doesn't mean come to the track, it actually means downshift on the freeway. Which is lame!

Duke, I so want to try A7's!! I'm getting closer. The rear suspension stuff will allow me to fit them on 13's. So excited!!!
"People don't like it when shit doesn't match their rule of thumb." Sam

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Re: Autocross Alignment Specs

Post by bertvorgon » 15 Feb 2018 08:02

Hah, I realized I did not say what camber I run, and like Duke, I have found that 2.5 -3 is good with sticky tires. I am running 2.5 right now ( front) and get good temps across the tread face.

Same with the rear, the loading is so great with sticky tires that they need that camber in the real world. Pavement surface too affects how the grip goes. We used to run on and old concrete WW2 runway, insane grip but it did eat tires if you slid a lot.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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Re: Autocross Alignment Specs

Post by funwithmonkeys » 15 Feb 2018 15:25

I have mine set close to the above but with more camber in the front. I have about 4 in the front and about 2 in the back. I run the same tires as Keith but I like a slightly lower tire pressure. 5.5 caster also. Coming out of corners you just have to let the wheel slide in your hand, you never have to turn it back to straight. On the A048's the turn in is sharp and the back is predictable and feels like it is glued down. Tires are the biggest difference you will feel right away. I have tried a few and nothing can ruin the confidence in your car more than a tire that doesn't feel right.
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icehouse
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Re: Autocross Alignment Specs

Post by icehouse » 15 Feb 2018 17:10

So could you guys run a little more caster to get away from so much static camber? My BMW buddies run more caster then stock, they basically max it out. Steering effort would go up for sure, I personally want to try electric power.
"People don't like it when shit doesn't match their rule of thumb." Sam

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Re: Autocross Alignment Specs

Post by bertvorgon » 15 Feb 2018 19:21

For me, that is correct. I am also talking when I had the car setup in it's most competitive solo mode, 6 degrees of castor. If you just sit in the car with that amount of castor and turn the steering wheel say hard left, you can see the fender RISE as the wheel goes to extreme negative camber, THAT is why the steering gets so hard as you are literally lifting the car on one side, with the steering wheel. I would rather have heavy steering parking any day, and have the car so able to turn in and bite with a large castor setting.

My G35 runs almost 8 degrees of castor as a factory setting ( power steering of course ) and that thing turns in like my 510. Look at many of todays cars like my G35, BMW, Mercedes, when you see them turning tight, the outside front wheel really leans over, to the inside of the fender well....that is the high castor setting.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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jeffball610
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Re: Autocross Alignment Specs

Post by jeffball610 » 16 Feb 2018 19:01

Ok, so things didn't go as well as expected. I tried to use my camber plates to add caster, but ended up adding positive camber that I didn't feel the control arms could undo. (I have a second way to mount them I'll try at a later date)
Due to this, trying to get 5 degrees of caster wasn't happening. My 205/50/16 tires are too big for the stock fenders being pushed that far forward using the TC rods. After nearly destroying the passenger fender, I redid the alignment with only 3 degrees of caster. I can dial more in later, but felt this was acceptable and very safe.
Next issue was the fact the control arms push the tire out further and somehow made it lower. The tire was rubbing the fender and needed to be rolled a bit to clear. I have my camber plates at full negative and dialed in a total of 2.5 degrees of negative camber with the control arms. (I had about 1-1.5 degrees negative with just the plates)
Toe was set at zero just to see what it's like and I can adjust from there. I have lots of room on the TC rods for more caster, and I think I'm being conservative with the adjustment on the control arms.
The good news is that I learned a lot and I have a baseline to work from. I think I can still use the camber plates to add caster and keep from moving the tire forward. I just need to flip them around the other way. The control arms also seem to be about level, if not slightly pointed downward, with the ground. The steering arms line up well and there shouldn't be much bump steer.
I left the rear alone since it was set up when I put the brackets in a few months ago. It's about 1.5 degrees of negative camber and about about .15" of toe out. (I think)
My particular setup is making it more difficult to use other people's settings. I'm running S12 V6 struts with Z31 5-lug hubs. My 16" wheels have a +35 offset with a 10mm spacer and stick out much further than the rear. However, I need the extra 10mm to clear the strut housing.
On a side note, the Futofab stuff fits great and is super high quality. My only complaint is the tight tolerances. The lower control arms mount to the stock crossmember with, what can only be called, a pressed fit. I'm sure it needs to be tight, but it was a bit tough to get installed. I'll post pics later when I get more time.
1972 Datsun 510
7-bolt 4G63T, EVO 9 pistons & rods, Garrett GT3076R, "Flipped" Stock Intake Manifold, Toyota R154, Z31 R200 w/ CVs

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Re: Autocross Alignment Specs

Post by funwithmonkeys » 16 Feb 2018 19:36

I had the same issue with my fenders. When I got the front end redone on my car after an accident I got them properly trimmed so they look almost stock but let the 205 tires clear with ample room for more caster.
You can see them here in my build thread.
viewtopic.php?f=3&t=26048&start=495
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Re: Autocross Alignment Specs

Post by icehouse » 16 Feb 2018 21:40

You gotta get smaller tires. Those are massive. Your gearing has to be crazy tall.
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bertvorgon
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Re: Autocross Alignment Specs

Post by bertvorgon » 17 Feb 2018 06:47

You do NOT want to have toe out in the rear!!!!!!! You may find you have a over steering car with both a narrow track on the rear plus toe out.

And as Jeff said, gearing is one of the best ways to get performance increases and tall tires are not the way to go.

At this point I guess you just need to drive the car and lets us know the feed back.
"Racing makes heroin addiction look like a vague wish for something salty" - Peter Egan

Keith Law
1973 2Door Slalom/hill climb/road race / canyon carver /Giant Killer 510
1968 Vintage 3HP Mini Bike
1971 Vintage 13' BOLER trailer

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jeffball610
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Re: Autocross Alignment Specs

Post by jeffball610 » 17 Feb 2018 17:24

Tires aren't really my concern right now with a 2.0L turbo motor and an R154 transmission. My R200 has 3.54 gears and I'm on the hunt for a 3.7 LSD. I'm happy with my 2500rpm @ 65mph. Although smaller tires will help with some clearances, width is what I'm most interested in. Either way, I can't get anything wider under the car right now. I've got enough clearance that the tires don't rub under most circumstances. Tomorrows autocross will tell what the next step is.
1972 Datsun 510
7-bolt 4G63T, EVO 9 pistons & rods, Garrett GT3076R, "Flipped" Stock Intake Manifold, Toyota R154, Z31 R200 w/ CVs

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