BNE update: Quick Steer Roll Correction Prototype

[blkaplan]

Yeah... We thought were living in a perfect world I guess. Now, the "problem" becomes, how do we measure it reasonably?

A small amount of slotting of the 4 holes should provide for reasonable amount of ackermann change because your adjusting close to the center pivot (ball joint)

Ackermann is the toe change amount relative to fixed steering amount.

The way to check it is with a set of toe plates. Set the wheels straight and turn the steering wheel a fixed angle like 15 degrees and measure the toe on the inside and outside wheel. the difference between the two shows you your ackermann setting.

[badvlvo]

^^^ This.

You have to be patient and precise to do it, but it can be done. I haven't in ages, not since college, but it's worth the time.
I wonder if I still have the plates in the storage....

[klr142]

Honeslty that's the ONLY thing I don't like about themTotally agreed! They're AWESOME.
A small amount of slotting of the 4 holes should provide for reasonable amount of ackermann change because your adjusting close to the center pivot (ball joint)

Ackermann is the toe change amount relative to fixed steering amount.

The way to check it is with a set of toe plates. Set the wheels straight and turn the steering wheel a fixed angle like 15 degrees and measure the toe on the inside and outside wheel. the difference between the two shows you your ackermann setting.Cool, thank you sir! I'll have to give it a whirl when I have the time/tools/ability. Probably won't be for a good while and I'll probably just go back to the stock steering quickness for now.

[badvlvo]

So I had the car aligned again today. Tried it with zero toe, 1/32 in and 1/16 in. The 1/16 in eliminated some of the scrubbing in tighter turns at slow speed and still feels good otherwise. Tight turns at speed feel good. Think that's going to be the way to go.

Now it's time to top mount those camber plates and get a little more.

[klr142]

So, a good way to get the Ackerman lined up would be to:
1. Slot the 4 holes on the spacer
2. Make sure there's enough material off of the outside edge of the spacer to allow it to rotate in position
3. Stick a long bolt through the hole of the original tie rod hole to the spacer's outermost tie rod end to line them up, then tighten down the spacer.

Yes?

I was looking at Ryan's this weekend at WM2.0 and you could easily see how far his were off if you compared the outermost tie rod hole to the factory one. Other than that, three of the four holes lined up pretty well(might have worked fine), but the fourth one(towards the outside of the strut on the steering arm side, if I remember correctly) was a good 2+mm or so away from being centered. The spacers didn't need any material taken off of them on the outside edge though to just fit up in the strut assembly, like mine did.

For what it's worth.

[klr142]

Double post.

[Captain Bondo]

http://a3.sphotos.ak.fbcdn.net/hphotos-ak-snc6/196237_760580977658_19701519_40843338_5006915_n.jp g


I take it the car is in the air in that pic? With stock length struts it looks like having the car at full droop might be a little hard on balljoints too...

[wennstroma]

I take it the car is in the air in that pic? With stock length struts it looks like having the car at full droop might be a little hard on balljoints too...

While on jackstands and at full droop using the middle hole I can only turn the wheel about 1.75 turns. I haven't checked to confirm, but I think the inner tie rods are hitting the rack housing because of their downward angle. I guess if I'm flying in the air with the wheel cranked that far I've probably got bigger problems though.

Oh, and it makes my rack drip oil steadily out of the right side boot too.

[klr142]

Yes, Kenny.

[blkaplan]

So, a good way to get the Ackerman lined up would be to:
1. Slot the 4 holes on the spacer
2. Make sure there's enough material off of the outside edge of the spacer to allow it to rotate in position
3. Stick a long bolt through the hole of the original tie rod hole to the spacer's outermost tie rod end to line them up, then tighten down the spacer.

Yes?


The way they ship out of the box the original tie rod hole will line up with the factory spacer so if you do that... its your 0 point. Your going to want to rotate it from that 0 point to change it.




I was looking at Ryan's this weekend at WM2.0 and you could easily see how far his were off if you compared the outermost tie rod hole to the factory one. Other than that, three of the four holes lined up pretty well(might have worked fine), but the fourth one(towards the outside of the strut on the steering arm side, if I remember correctly) was a good 2+mm or so away from being centered. The spacers didn't need any material taken off of them on the outside edge though to just fit up in the strut assembly, like mine did.

For what it's worth.


Who's Ryan? I have been checking all the ones out the door to make sure the fasteners line up, etc... but its possible one might have slipped through. If the holes are off on his I will exchange it for another unit.

[badvlvo]

Ryan = volvoracer82.
His needed filing to line up as did mine. My set just needed a touch of the file to be right, his needed some work to line up.

Making some setup changes on my front end, then taking it to a friend who can work this ackeman correction out.

[blkaplan]

An excellent write up an Ackerman

http://www.google.com/url?sa=t&source=web&cd=1&ved=0CBcQFjAA&url=http%3A%2F%2Fwww.racing-car-technology.com.au%2FSteering%2520Ackerman4.doc&rct=j&q=measuring%20ackermann%20steering&ei=qEKKTZ6lGpKC0QG435n9DQ&usg=AFQjCNFtGKeLjDUyIJm3qWhH3aXv70BY-w&cad=rja

[volvoracer82]

Who's Ryan? I have been checking all the ones out the door to make sure the fasteners line up, etc... but its possible one might have slipped through. If the holes are off on his I will exchange it for another unit.

I'm Ryan, the only real problem holes were the ones directly over the tie rod arms and I was able to file out the minimum amount as possible and just touch up the others. they are on now and work great other than the ackerman issues, I'm using the middle hole btw. I don't need you to exchange them out unless you NEED to. I might do what Kyle was talking about, in which case it wouldn't matter if I got another set since they would have to me modified again anyway.

[blkaplan]

I'm Ryan, the only real problem holes were the ones directly over the tie rod arms and I was able to file out the minimum amount as possible and just touch up the others. they are on now and work great other than the ackerman issues, I'm using the middle hole btw. I don't need you to exchange them out unless you NEED to. I might do what Kyle was talking about, in which case it wouldn't matter if I got another set since they would have to me modified again anyway.

I dont need to exchange them, as long as you got them. I am wondering how much variance there is spindle to spindle with the machining

[klr142]

The thing is, three holes looked like they lined up just about perfectly, then only the fourth that I mentioned was "off". So, just in that procedure, the spacer needs to be rotated in order to line up better, or you can just file out the hole(s) as needed to keep it in that location. That being said, I think(can't remember now, was thinking about calling you when I was looking at them but didn't) the outermost tie rod end hole was already not in line with the factory one, before any rotating or modifying was done. Maybe some spindles are worn/bent and the factory tie rod end location is already off?

[towerymt]

The part is too precise for the volvo spindles (if it is precise, that I can't confirm). I had to grind/file on mine, and Ben said I shouldn't have to because he manually checked each spacer against two spindles. I saw the testing procedure, but this won't take every spindle into account. One of mine, the four holes were fine, but if I tried to lift it up and press against the bottom of the spindle, it wouldn't go. If I put the spacer against the spindle, I couldn't start the bolts.

On the other side, I was able to start the bolts, let the spacer hang, and draw it in with the bolts with minimal struggle. One side was a snug fit, probably ideal. The other was a no-go til I removed some material from the spacer.

How big a deal is this ackerman issue and who has measured it? What effects are you feeling when driving the car?

[klr142]

The part is too precise for the volvo spindles (if it is precise, that I can't confirm). I had to grind/file on mine, and Ben said I shouldn't have to because he manually checked each spacer against two spindles. I saw the testing procedure, but this won't take every spindle into account. One of mine, the four holes were fine, but if I tried to lift it up and press against the bottom of the spindle, it wouldn't go. If I put the spacer against the spindle, I couldn't start the bolts.

On the other side, I was able to start the bolts, let the spacer hang, and draw it in with the bolts with minimal struggle. One side was a snug fit, probably ideal. The other was a no-go til I removed some material from the spacer.

How big a deal is this ackerman issue and who has measured it? What effects are you feeling when driving the car?Your experience sounds closer to mine, but I think one bolt hole did not match up very well such as like Ryan was experiencing. Ryan's fit in the opening just right and even sat up against the outside of the strut assembly well, but that one bolt hole was a decent chunk off. I only looked at one of his struts though, didn't compare it to the other side.

The experience that you get from ackerman being off is similar to what I think you are experiencing and complaining about with your wheels being pushed out so far. When you are driving around in parking lots, or just at greater steering angle, the wheels aren't trying to make the car turn the same amount so you get the front tires working against each other. It's most noticeable when you are doing very tight turns in parking lots, etc. The car doesn't want to roll, it's as if you're putting on the brakes and you can feel the front tires skipping/skittering over the surface because they're fighting each other. I can only assume this reduces the amount of front end grip while you're driving the car because the wheels are not working in unison once you turn the steering wheel. The further you turn, the greater the fighting and less front grip.

Hopefully that helps?

[DavoS40]

The experience that you get from ackerman being off is similar to what I think you are experiencing and complaining about with your wheels being pushed out so far. When you are driving around in parking lots, or just at greater steering angle, the wheels aren't trying to make the car turn the same amount so you get the front tires working against each other. It's most noticeable when you are doing very tight turns in parking lots, etc. The car doesn't want to roll, it's as if you're putting on the brakes and you can feel the front tires skipping/skittering over the surface because they're fighting each other. I can only assume this reduces the amount of front end grip while you're driving the car because the wheels are not working in unison once you turn the steering wheel. The further you turn, the greater the fighting and less front grip.

I've noticed scrub (sideslip) with tighter turns at low speeds also, tie rods in the middle hole. Alignment sheet shows a total of +0.15 degree toe (inward). I didn't have to modify the spacers to bolt up, one did seem tight though.

[towerymt]

You have to measure Ackermann before you blame it. If you turn the wheels to full lock at the stock setting, the tires want to scrub a little. Turn them farther and...yeah.

When I tried the quickest setting briefly, I could yank the wheel and slide the front of the car at <5mph rolling around the parking lot at the shop. It was hilarious to drive and chuck, then the rear would try to step out once the front gripped.

It's easy to turn in too far or too fast. Takes some getting used to. I've definitely got front offset issues causing my problem.

I haven't looked up positive vs. negative Ackermann, but one way will have the inside tire turn farther than the outside which will help. The other way will hurt. Measure, else how do you know what you have?

[DavoS40]

You have to measure Ackermann before you blame it. If you turn the wheels to full lock at the stock setting, the tires want to scrub a little. Turn them farther and...yeah.

When I tried the quickest setting briefly, I could yank the wheel and slide the front of the car at <5mph rolling around the parking lot at the shop. It was hilarious to drive and chuck, then the rear would try to step out once the front gripped.

It's easy to turn in too far or too fast. Takes some getting used to. I've definitely got front offset issues causing my problem.

I haven't looked up positive vs. negative Ackermann, but one way will have the inside tire turn farther than the outside which will help. The other way will hurt. Measure, else how do you know what you have?

I've lost some turning radius compared to stock at low speeds due to getting into such heavy scrubbing, so it's not due to turning the wheels further. Once it starts going it vibrates the **** out the front end. I've tried different turn in rates at different speeds and haven't found a away to get around it yet. I'm running 225/45/17 Dunlop Direzza Sport Z1 Star Specs on Polaris with no spacers, -1.5 degree camber. I'd still consider it a pretty small negative to the benefits of running these.

[jay f.]

3 month bump to ask the ever popular question about the progress for the 700 series. This would be a nice compliment for my soon to arrive short coilovers you're making! :)

[boosted12a]

yeah, whares da beef! er, meat....

[St3v3]

No kit for paralell steering?

[badvlvo]

I've lost some turning radius compared to stock at low speeds due to getting into such heavy scrubbing, so it's not due to turning the wheels further. Once it starts going it vibrates the **** out the front end. I've tried different turn in rates at different speeds and haven't found a away to get around it yet. I'm running 225/45/17 Dunlop Direzza Sport Z1 Star Specs on Polaris with no spacers, -1.5 degree camber. I'd still consider it a pretty small negative to the benefits of running these.

Correct your Ackerman and this will be eliminated. My car scrubs pretty hard, but I am afraid to mess with it right now, the turn-in is great for autocross.
My car has done some down time here in Tennessee, but once I am back in CA I will be doing this along with the swap back to power steering.

[DNAsEqUeNcE]

Does this exist with the 740?

[harribert]

Correct your Ackerman.

How is this achieved?

[chirish1234]

+1

[blkaplan]

You can tune it by twisting the angle of the steering arm, you would need to elongate the holes and clearance the flange.

An idea that I was contemplating building into these but everyone was in an uproar about who would want to adjust ackermann.

[blkaplan]

Does this exist with the 740?

SOOOON!

seriously

[nathaninwa]

SOOOON!

seriously


Id be game. I havent read the whole thread, but will these level out the tierods from the rack? Mine are hella angling uphill.

[Magnum TE]

Does this exist with the 740?

We're still waiting :-(

[blkaplan]

Id be game. I havent read the whole thread, but will these level out the tierods from the rack? Mine are hella angling uphill.

YEs

[blkaplan]

We're still waiting :-(

I am having a billet prototype version made that will get sent to a carefully selected Volvo enthusiast for inspection then I will get the casting run going.


I will do a discounted preorder like last time.

[Magnum TE]

how about you be not so careful and send me one ^_^

I'll start putting away my pennies.

[boosted12a]

sweet! more money to spend!

[nathaninwa]

Im in for a group buy.

[carter]

Im in for a group buy.

Me as well. (For the 240 ones)

[blkaplan]

Me as well. (For the 240 ones)

That closed a long time ago, they are for sale now and in stock!

[idrive_MD]

Interesting read, nice looking parts. i am sure I will be refreshing this much later in the future as I start to play with my suspension, but thats much later down the road.

It was cool to see the Faro arm and the ABS protos on the first page. By the way, you can fix that tessellation of the file by scaling up your stl resolution. Most CAD programs have three settings- coarse, fine and custom. The fine setting should take care of it in most cases. Obviously some time has past since you built them, so you may have figured that out by now, but if not, there you go. You guys going to AMUG (Additive Manufacturing Users Group) this year? If so, I will be there, so let me know and we can hang out.

Also, if you ever run into an issue with your casting process, give the guys at buycastings.com a shout and they will hook you up with the right folks.

[badvlvo]

How is this achieved?


A small amount of slotting of the 4 holes should provide for reasonable amount of ackermann change because your adjusting close to the center pivot (ball joint)

Ackermann is the toe change amount relative to fixed steering amount.

The way to check it is with a set of toe plates. Set the wheels straight and turn the steering wheel a fixed angle like 15 degrees and measure the toe on the inside and outside wheel. the difference between the two shows you your ackermann setting.


It's fairly simple, but will take some time to get it right.

[klr142]

And toe plates.

[jay f.]

Maybe there is another thread, and I'm out of the loop, but did these ever come out for the 740?

[Magnum TE]

Maybe there is another thread, and I'm out of the loop, but did these ever come out for the 740?

I stopped bothering Ben about the 7/9xx roll correctors. If he doesn't produce a set soon I'm going to put in an order with Dannej
http://www.dannejdrift.n.nu/distanskit700900

I'd rather help support a turbobricker, but it seems that there isn't enough of a market to warrant more product development at this time.

[blkaplan]

I stopped bothering Ben about the 7/9xx roll correctors. If he doesn't produce a set soon I'm going to put in an order with Dannej
http://www.dannejdrift.n.nu/distanskit700900

I'd rather help support a turbobricker, but it seems that there isn't enough of a market to warrant more product development at this time.

Theres definitely a market and they are definitely gonna be made. Just in the process of getting through some other products that should free up the funds to purchase the tooling for these.

The parts are designed, just need to send out a deposit.

[Magnum TE]

I'll start stacking my dollars

[boosted12a]

sweet!

[blkaplan]

Just a heads up..... prints have been submitted to the casting co. As soon as I get pricing info I will open up a preorder / GB.

[doucheNozzle]

You just made every grandpa/grandma jizz their depends.

[towerymt]

Just a heads up..... prints have been submitted to the casting co. As soon as I get pricing info I will open up a preorder / GB.
did you go with version A or version B?

[blkaplan]

did you go with version A or version B?

version A.B

[Råda]

Just a heads up..... prints have been submitted to the casting co. As soon as I get pricing info I will open up a preorder / GB.

Nice!

[blkaplan]

Does this exist with the 740?

We're still waiting :-(

Im in for a group buy.

http://forums.turbobricks.com/showthread.php?p=4543582#post4543582