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Ascona/ Manta 400/commo Rear Bottom Link Angle.


falk5150
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Dude's,

Gunna have trouble explaing this but....

Just wondering if anyone actually knows whether the bottom links on a 400 etc are flat / level 'or' banked / tilted (lower inner) by 3 degree .ish?

Obviously they tow in from axle to body but i'm fannying around with an old axle with old bushes so it;s making wonder.

Also, if anyone has any 'solid dimensions / spec for 400 body/axle geom', that'd be splendid!

Ta!

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Not got the exact dimensions, but, (and it obviously depends on ride height) they are banked downwards towards the axle by a few degrees (your 3 deg guess prob not far off, could be a touch more).

What I never sussed was the "toe in" angle as you put it. I've seen different angles on different cars, depending on the way the car has been bracketted! (you'd think they would be the same but they appear not to be,depending on who built them!)

back to your question though, certainly the spring pans are designed to sit at a slight angle at their natural rest position

Edited by Retro Power
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Yeah, it's fun aint it! :blink: I see why everyone else just uses a couple of them escort 4 link kits in instead of f** **in round trying to suss the floor profile etc.

Trying to keep it looking factory though so the 'arse-ache' way it is!

I've gone 18 deg bottom, 10 deg top (I think d'asconas started off with parallel top links, but looks like they changed later) an 3 ish deg tilt, but running a t56 so much longer box, so that may change a lil'.. :unsure::) .

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Yep!

on curts 400 replica we used a kind of halfway house, using commodore (same as Victor FE) lower arms, but lengthened, and with a 3/4" rose joint on the front end, fitted straight (no angle) to the original standard lower rear arm mounts, then used shortened escort links as the top links, again fitted straight. I could never work out why vauxhall/opel used the angled rear arms!! I can't think of any benefits since a panhard rod was fitted anyway, and the upper links are so short that they completely ruin the geometry anyway!!

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Yeah, i saw your build up, Splendid job! :thumbup

I think the toe-in bottom / toe-out top is kind of a sash link set up that just makes d'rear axle steer harder into d'bend once the roll kicks in, but can't much benefit on a road car with so little travel an stiff springs.

How did the ascona handle with your set up, Fine i imagine? Did u use an anti-roll bar? I cant remember now Dude. :rolleyes:

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I have been looking through the original build manual for the 400s and that doesn't really help also.

There isn't any info on geometry, just some axle pictures and info on the diff

I'll send you a copy if you want one

400axle.jpg

Edit

Wow look at how far those bottom arms come in!

Some pics of the underneath of my mates 400

400axle.jpg

102_2364.jpg

102_2360.jpg

102_2359.jpg

102_2358.jpg

102_2357.jpg

Edited by Kevin Abbott
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Yeah, they must really contort the bushes!

Ta Kevin, those shots are splendid!

A very helpful dude let have a butchers at his ascona 400, but d'pics i took were on my shit phone! :rolleyes:

You can see the fun i've had with trying to get floor profile right for the leg flange can't you.

Don't suppose you can nick the measurement between the top link certres at the axle end chap?

No wurriz if not. :D

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Yeah, i saw your build up, Splendid job! :thumbup

I think the toe-in bottom / toe-out top is kind of a sash link set up that just makes d'rear axle steer harder into d'bend once the roll kicks in, but can't much benefit on a road car with so little travel an stiff springs.

How did the ascona handle with your set up, Fine i imagine? Did u use an anti-roll bar? I cant remember now Dude. :rolleyes:

Yea I wondered about a bit of rear steer, but (and I couldn't be bothered to put it all in susprog or draw it up in CAD) I don't think it will do, not in any beneficial way.

The cars that the setup was used on before it was robbed for the 400's were hardly renowned as great handling machines!! (the vauxhall victor we have which is on ebay at the mo incidentally, was hardly a great handler!)

The upper links are so short that the diff nose is pitched wildly for very small amounts of suspension travel, and in roll, the whole lot just binds up without the very big, very compliant rubber bushes. I dare say if you fitted polybushes the axle would go solid in roll!

I did do some 2d drawings of the setup on Curt's car before we fitted it, just to check diff nose pitch during travel, and with the much longer upper links that we used it is much reduced (but still very noticeable, just not horrendous as with the commo setup!!)

I guess this is why Opel used the long upper arm setup on a lot of the rally cars!

re. Curts car handling, from what its possible to tell on the road, it handles very well. Rough surfaces during cornering don't upset it AT ALL (which is one of my pet "requisites" for a modified road car) it just grips and goes. It just needs a lot more power now!! A std XE on throttle bodies is nowhere near enough to test the potential of the car! I reckon around 275hp normally aspirated XE would do the trick!

PS no rear roll bar.It has the mounts in place for the rear mounted 400 type bar, but none fitted at the mo as I advised against it. There is a little roll, but don't make the common mistake of thinking that any roll is bad, its only bad if it upsets the tyre contact patch, other than that it doesn't matter a jot! The car has a std manta GTE front bar fitted, and feels spot on. The progressive springs on the rear keep it nice and soft at initial movement, keeping traction, but stiffen up nicely under heavier load, all very progressive though.

Edited by Retro Power
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Sorry Kevin, didn't explain what i meant properly. It's just the distance between the 2 top bracket centres on the axle that i was wondering about.

Again, no wurriz if he cant be arsed, as it is a bit of an arse ache to get with diff / brake pipes in the way.

Cheers for d'photos again dude.

Edited by falk5150
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Yea I wondered about a bit of rear steer, but (and I couldn't be bothered to put it all in susprog or draw it up in CAD) I don't think it will do, not in any beneficial way.

The cars that the setup was used on before it was robbed for the 400's were hardly renowned as great handling machines!! (the vauxhall victor we have which is on ebay at the mo incidentally, was hardly a great handler!)

The upper links are so short that the diff nose is pitched wildly for very small amounts of suspension travel, and in roll, the whole lot just binds up without the very big, very compliant rubber bushes. I dare say if you fitted polybushes the axle would go solid in roll!

I did do some 2d drawings of the setup on Curt's car before we fitted it, just to check diff nose pitch during travel, and with the much longer upper links that we used it is much reduced (but still very noticeable, just not horrendous as with the commo setup!!)

I guess this is why Opel used the long upper arm setup on a lot of the rally cars!

re. Curts car handling, from what its possible to tell on the road, it handles very well. Rough surfaces during cornering don't upset it AT ALL (which is one of my pet "requisites" for a modified road car) it just grips and goes. It just needs a lot more power now!! A std XE on throttle bodies is nowhere near enough to test the potential of the car! I reckon around 275hp normally aspirated XE would do the trick!

PS no rear roll bar.It has the mounts in place for the rear mounted 400 type bar, but none fitted at the mo as I advised against it. There is a little roll, but don't make the common mistake of thinking that any roll is bad, its only bad if it upsets the tyre contact patch, other than that it doesn't matter a jot! The car has a std manta GTE front bar fitted, and feels spot on. The progressive springs on the rear keep it nice and soft at initial movement, keeping traction, but stiffen up nicely under heavier load, all very progressive though.

Yeah, reckon your right, they've gotta be reasonably soft even with a couple of inches travel. Does all seeem to wanna fight against itself.

Cheers dude!

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  • 4 years later...
On 11/08/2012 at 19:26, Kevin Abbott said:

I have been looking through the original build manual for the 400s and that doesn't really help also.

There isn't any info on geometry, just some axle pictures and info on the diff

I'll send you a copy if you want one

400axle.jpg

Edit

Wow look at how far those bottom arms come in!

Some pics of the underneath of my mates 400

400axle.jpg

102_2364.jpg

102_2360.jpg

102_2359.jpg

102_2358.jpg

102_2357.jpg

Any chance you could send me a copy of that 400 build manual please (email to john at rutthenut dot com would be great if poss)

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On 24/11/2016 at 15:19, Kevin Abbott said:

 I could do, but really we should be buying them from the club shop to support the website.:)

Is there any way to see what is in the club shop?

There is a 'regalia' section in the forum but is there a main shop site?

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