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Cal-look/High Performance => Technical stuff => Topic started by: Brown-nose on May 14, 2020, 17:42:09 pm



Title: Rear toe
Post by: Brown-nose on May 14, 2020, 17:42:09 pm
Seems like lots of differing opinions in the rear.. toe in/out. I know Gene Berg said must have toe out, but I've searched and read on here a lot of guys running toe in ?

I'm just setting mine now. Street car, swing axle. More of a straight line safety than in the Twisties as it's nose down, arse up stance.

Gimme your input ! Thanks


Title: Re: Rear toe
Post by: Jimbosmith on May 14, 2020, 19:07:22 pm
Hi, im going to be in the process of resetting mine as im redoing the whole rear section of the car.

I have found this write up that im going to be following for alot of things.
https://www.aircooled.net/vw-drag-racing-suspension-type-1-aircooled-volkswagens/

"Shoot for 1/16-1/8″ rear toe in for a nice stable (safe) ride."


Title: Re: Rear toe
Post by: PPRMicke on May 15, 2020, 16:26:23 pm
There are some things to keep in mind
Like what happens to the rear wheel when the car is going
When the car wants forward at the start then the rear wheel wants to push what happens then with the t gearbox
  The box wants to forward
 The wheel turns and you get to out
On a race car
Then you have the chassis does not have flex Then you can have other wheel angles
On a daily driving car it is good to have a little to in


Title: Re: Rear toe
Post by: Brown-nose on May 15, 2020, 16:31:28 pm
Thanks. I did go for a little toe in and it seems more stable. It is a street car so want to be safe. I'm still open to all opinions as I will get it professionally aligned in the near future.


Title: Re: Rear toe
Post by: richie on May 15, 2020, 17:56:07 pm
1/8th toe in on both cabrios and the white 67 :)


Title: Re: Rear toe
Post by: Garrick Clark on May 15, 2020, 18:04:52 pm
Make sure the spring plate doughnuts are good, If there's play in them ,driving forward can alter the 1/8 setting.


Title: Re: Rear toe
Post by: Brown-nose on May 15, 2020, 18:58:22 pm
Thank you. 1/8 toe in sounds good.

I just replaced the spring plate rubbers with GWD upgraded rubber. Seem like a quality item and in between stock and the red polys in terms of hardness


Title: Re: Rear toe
Post by: Martin S. on May 16, 2020, 17:25:18 pm
Local suspension guru around here, Lanner Khan told me to set the rear toe to all the way back in the slots for a lowered car, and for a slammed ride to grind a bit more room in the slots to gain even more toe-out.
I did that on my runner 68 and noticed a difference right away. The car felt more stable in the wind and on uneven pavement.
After doing that I had the car in for an alignment. The printout said I had about 1/8" total (1/16" per side) toe out, with the axels all the way back.


Title: Re: Rear toe
Post by: Brown-nose on May 16, 2020, 19:37:45 pm
Many ways to skin a cat !


Title: Re: Rear toe
Post by: Martin S. on May 16, 2020, 20:49:40 pm
The best thing is to try it yourself. It's such an easy thing to play around with.
Gene Berg's tip of using a piece of welding rod to measure from the axel to the door jam was maybe a useful idea.
In the ACNet article he stressed how important it is to have the sides even, and unless your car has been to an alignment shop you wouldn't know if they are or not.
Mark where they are now with a file, then try moving them all the way back and do some driving and see what you think.
If you decide to move it, do that before getting an alignment so you can see how close they are.


Title: Re: Rear toe
Post by: Brown-nose on May 18, 2020, 19:01:40 pm
Thanks. I used the string parallel method so i'm fairly happy it is even side to side. Ultimately i will get it checked proffessionally. The string method is a bit time consuming to just try out a test change. But I am interested to see what the car likes...


Title: Re: Rear toe
Post by: Bruce on May 19, 2020, 12:46:02 pm
..... set the rear toe to all the way back in the slots for a lowered car, and for a slammed ride to grind a bit more room in the slots to gain even more toe-out.
This is wrong.  The guys that are super lowered (with swing axle) have a huge amount of toe-in.  By lengthening the slots, they are just reducing the unwanted toe-in.  It doesn't matter how long the slots are, they still have toe-in.  That's why some will weld extensions onto the spring plates.


Title: Re: Rear toe
Post by: Martin S. on May 20, 2020, 13:02:42 pm
I’ll add the original reference from the Berg bible just in case you forgot what he wrote or have never read it.
He explains what Bruce talks about with the fully lowered suspension going toe in due to the geometry and of course he’s right!


Title: Re: Rear toe
Post by: 63 ripper on May 20, 2020, 19:58:50 pm
I have limit straps and the bump stop rubbers. I have the berg book
and understand his point about making sure the toe is the same side to side, hence why I used the parallel string method rather than just total toe.


Title: Re: Rear toe
Post by: Martin S. on May 20, 2020, 23:04:28 pm
I know the string method is popular, but I'm too much of a klutz to tell 1/32" or 1/16" with a string. Tried it, didn't work and I know cuz I went and got it checked and found out the real measurement. Here's my printout from after I pushed the axels back all the way. I'm assuming specs are toe-in and a negative number means toe out. I'm guessing the specs are wrong and actually from a 2001 VW.
If you get lucky maybe your alignment guy would do the rear, so ask around and see if someone has the patience and time.
Mine is out a bit showing 1/32 left and 1/16 on the right, then 0 on the left and 1/16 toe out on the right in the last check.

Anyway, if anyone else gets theirs done I would appreciate seeing the printout please!


Title: Re: Rear toe
Post by: Bruce on May 23, 2020, 10:46:39 am
When looking at the readings, I have to ask what the resolution is on the readings.  I bet it's +- 1/32".  In other words, the error on your car's readings are + or - 100%.


Title: Re: Rear toe
Post by: Martin S. on May 23, 2020, 16:29:21 pm
Good observation Bruce, thanks for pointing that out. Note that from the first test to the last test the reading was out 1/32” (30 thou). That made it apparent the tolerance of the alignment rack is probably 1/32” or close to that.
At the same shop I had my stock 71 Bus aligned and we saw the results have exactly the same error.
I’ll attach the printout from that as well for reference.


Title: Re: Rear toe
Post by: jim martin on September 11, 2020, 05:21:21 am
Hey hope everyone is ok in your end of the earth.
Doing some post reading and always like this topic of
Stability and alignment.
This topic is in my opinion one that is never really understood and to many
Just end up copying something some one else said to do .
Step 1 is really understanding what the measurements mean and
Step 2 is putting your chassis through its complete range of motion
And watching what changes and how it effects alignment specs,
Once you do this you will be very suprised what you thought was good really
May be the cause of your stability issue ect.
I’m lucky that I have access to great equipment But before I drove the car to the shop
I made some home alignment tools to do some checking at home to see if in fact my alignment
Has drastically changed and was the cause of my top end wandering.
I used the tools and found quite a few small issues , made adjustments then later to the shop for
Final quality confirmation check on the alignment bench.
If anyone is interested in another take on Alignment and stability let me know and I will post up a link and I’m
Sure some might find some answers
Stay safe
Jim


Title: Re: Rear toe
Post by: Glauco on September 11, 2020, 08:01:47 am
Hey hope everyone is ok in your end of the earth.
Doing some post reading and always like this topic of
Stability and alignment.
This topic is in my opinion one that is never really understood and to many
Just end up copying something some one else said to do .
Step 1 is really understanding what the measurements mean and
Step 2 is putting your chassis through its complete range of motion
And watching what changes and how it effects alignment specs,
Once you do this you will be very suprised what you thought was good really
May be the cause of your stability issue ect.
I’m lucky that I have access to great equipment But before I drove the car to the shop
I made some home alignment tools to do some checking at home to see if in fact my alignment
Has drastically changed and was the cause of my top end wandering.
I used the tools and found quite a few small issues , made adjustments then later to the shop for
Final quality confirmation check on the alignment bench.
If anyone is interested in another take on Alignment and stability let me know and I will post up a link and I’m
Sure some might find some answers
Stay safe
Jim

I would like some more info on the tools you made if possible.

Thank you ,
Glauco


Title: Re: Rear toe
Post by: j-dub on September 11, 2020, 15:59:52 pm
I agree that we would like to learn what works, best practices and how to achieve them. It has gotten easier over the years to make a really quick street car however safe and predictable handling becomes even more important.


Title: Re: Rear toe
Post by: jim martin on September 11, 2020, 19:38:34 pm
I think this will get you directly to that section
 http://airspeedparts.com/forums/index.php?topic=914.msg163576#msg163576 (http://airspeedparts.com/forums/index.php?topic=914.msg163576#msg163576)


Title: Re: Rear toe
Post by: jim martin on September 13, 2020, 03:44:04 am
The width of the lower arm is 26” same as tire .
For those that asked.
Readings vs at hone and work same  FYI for those that asked