Mk4 VW suspension thoughts

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john vanlandingham
40mm

I realize they are all 40mm inserts, I'm wondering if the housing would fit the Mk4 upright with the brackets removed.
Then again that puts me basically right at a standard Mk4 Bilstein HD again.

John:
I'll bite, just pm me what your prices are like for the basic end of what you offer.

Thanks,
Grant

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Grantmac
Danny:
Your solution would probably meet my needs very well except the stock Sachs struts are know to destroy themselves very quickly even under normal road conditions. If I stick with a stock-type strut then the only taller springs will be the VR6 units that I've already got and they are only 170#. I haven't installed them yet but it's the next thing I will do when I get a day to fiddle.

Interesting to hear that about stock Sachs struts as I have not heard of that before. Got a link so I can have a read? However that said I have seen various imbeciles within the VW community running their cars stupidly low and hammering out their shocks.
The spring design used on the mk4 platform is quite similar to a number of other manufacturers. You also get two sizes of pigtail spring seat for the top. In the past with my bodgeineering exploits I've used both Ford and GM springs on VW struts so that may open up other spring options in both rate and free length.

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john vanlandingham

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danster
Anyway all the recent Fiesta hype and chat seems to have stopped so that's old news, I am jumping back on the Escort mk2 bandwagon now as I assist my mate with his bitchin Kawasaki Green car.

This post is useless wifout pitchers!

Quite right, pics are what fuels the internet, so this was yesterday after carrying out some carb tweaks.

---

Disappointingly not yet a Jackass

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john vanlandingham


This post is useless wifout pitchers!

Quite right, pics are what fuels the internet, so this was yesterday after carrying out some carb tweaks.

[/quote]

AAhhhhh that's sweet. nice car, nice color, a little regionalism wif the flag os StAndrew, and best of all a subliminal hint pointing the way forward for us right there in black and white---on the numberplate:

240...

What do i call Volvo 240?

"The Escort for North America"

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

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Grantmac
I've actually been toying with getting some junkyard STI struts and doing a bracket-ectomy then running threaded sleeves like you've got there.

-Grant

BT, doing that, it was a big pain in the ass.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

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Pete

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Grantmac
I've actually been toying with getting some junkyard STI struts and doing a bracket-ectomy then running threaded sleeves like you've got there.

-Grant

BT, doing that, it was a big pain in the ass.

Roger that!

I'm beginning to accept that perhaps I just need to run some Bilstein HDs for a while then make a move towards something with adjustable perches in the future.

On a slightly different note: has anyone play around with reducing some of the anti-dive in a VW platform? I'm wondering if going with a higher ride-height in the front would have that effect? It seems like it would, but I get a little hazy with geometry.

Thanks
Grant

What you would need to do is to raise the front control arm bushing or lower the rear one. This is what the "anti lift kit" bushings for Subarus do. Anti lift is kind of a misnomer since this actually is PRO-lift, but whoever named it was thinking in terms of what the tires are doing and not what the chassis is doing.

Look at what WRCars do - they have the control arm mounted at a ridiculous angle so that thrust will push the tire into the ground. Then they mount the strut at an even more ridiculous angle to gain back anti-dive so they don't bottom the suspension when they touch the brakes. As a bonus, mounting the strut at an angle allows them to fit 12-13" of travel in the struts without having the strut tops sticking a foot through the hood.

I'm going to be playing with this with Quantum Syncro v2. Although, since the way the control arm mounting to the subframe is somewhat bogus for geometry tweaking, I'm just going to space the rear subframe mount down an inch and then space the trans mount back up a similar amount. On an A1/A2/A3 it would be easy-peasy to space the rear control arm mount down a bit, and on the A2/A3 this could also be incorporated with a less bogus method of attaching it to the car.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.



Edited 1 time(s). Last edit at 12/21/2013 10:49AM by Pete.

That makes total sense. Although the entire car pitches to the rear there is really more force attempting to keep the front wheels in contact with the ground. I wonder if the standard anti-dive geometry is responsible for some of the wheel hop these platforms are known for.

When I picture the car having a lower ride-height in the rear it seems like that should accomplish a similar change in the geometry just not as dramatically. Perhaps the answer is to change a few things to make it happen:
Offset rear bushings.
Lower the rear of the subframe.

When I think about it caster will also effect this geometry but it will effect it differently depending on the angle of the lower control arm. If a car had totally level control arms there would be no effect. With pro-dive geometry adding caster would actually reduce the effect (WRC car), with anti-dive geometry adding caster would reduce the effect.

In both cases it looks like adding caster (or laying the strut over) reduces the effect by making the triangle shorter.

All this makes me remember why I love karts so much. Not because they are simple, but because geometry is such a critical part of the set-up and easy to adjust.

-Grant

With struts, more caster = more brake antidive. Or more exactly, more strut angle to the rear = more brake antidive. The further the strut is from vertical, the more the upright will rotate as the suspension moves up, and the brakes put a big torque on the upright trying to rotate it the other way. It's a small effect until you get into big changes like sticking the bottom of the strut a long ways ahead of the ball joint.

This sort of thing is fun to theorize with and muck about with, but it's not as important as the basics - no sense in completely redesigning the suspension if you're still going to use shit struts.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.



Edited 1 time(s). Last edit at 12/21/2013 02:30PM by Pete.

Clearly the geometry isn't the weakest link, but it's fun to theorize about things. I get great enjoyment from trying to figure out complex systems.

Although the Shine set-up isn't rally-worthy, when I think about the way it adjusts the car's geometry I wonder if there isn't more to it then just controlling the roll center.

Getting some decent struts and bushings into it is definitely the priority, but I was going to make some solid subframe bushings anyways so a little tweek there wouldn't be tough.