Merkur rear beam and sta solutions

After brs things were bent. After ESPR things were bent even more. I need to figure out a solution that allows me to not have to nurse the car through stages. I think my beam is ok and that the sta is all that is bent but I'm not 100% sure. The rear wheels have the classic 4 degrees negative camber which is commonly a bent sta but I'm not 100% sure on that. The wheel is coming uncomfortably close to rubbing the coil over though. There are web pages that describe the different cosworth setups like this one:

http://passionford.com/forum/general-car-related-discussion/213595-now-where-to-modify-rear-beams.html

Seeing how the TSS square beam no longer seems like its being repeated, what is a sensible option at this point?

Is a square beam THAT much better? Should I just fab some indestructible STA with rose jointed adjustable ends and call it a day? I know of a few people in my position or about to be in my position so any input would be appreciated.

I can weigh in on the square beam. It's not much of an upgrade, if any. The two XRs that I have worked on both needed the square beams removed and modified so the camber and toe could be even remotely "normal". One was a car that had never been rallied and had straight trailing arms, the other is New Dave Clarks XR that had been rallied for a while, but the STAs are reinforced a fair bit.... and mostly straight.

We'll probably be looking at reinforcing a stock beam, using rose joints, and possibly trying to go to a 6deg beam.

Solid axle swap!
Somewhere in that pile of parts was a rear beam reinforcement kit that TSS made, designed by Sean.
I'd stock pile beams and arms if I were rallying those still.
Reinforce lightly, don't worry about adjustable settings. Maybe slot and weld to set a new static position. Be conscientious about shell life with reinforced components. I'd strengthen subframe and diff mounts if I had hugely strengthened arms and beam.

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Grant Hughes

What did ford do with the Sierra rally cars?

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Gravity Fed
What did ford do with the Sierra rally cars?

http://rs500owners.com/index.php?/topic/522-some-uprated-rear-beams-i-have-for-sale/

The 3 upgrade options are pictured in the link. The Sierra and group a escort had the magnesium sta and the wrc escort got the cradle I think.

A 6 degree beam with modified sta seams like it could be done.....I will try and measure things out. Anyone have a good source for the rose joints?

Also, the tss custom tubular sta ended up cracking right? Was it the cromolly welds that cracked or are there higher forces happening than expexted?

I had wondered about just building an entirely new arm assembly since everything important on the end just bolts on. Something like this but with an extra leg to the center...
https://www.appletreeauto.com/D.O.M-TRAILING-ARM-STK-X-1-PR-TASX1/

I've also wondered about changing geometry and if you are actually making it better for gravel. Most of the "knowledge" out there is questionable. I wonder what "degree" the magnesium rear stuff is.
I wanted to do a WRC style setup in the rear of mine, but it's important to note that was for an AWD car not RWD so again, geometry requirements could be quite different. What is the ideal toe and camber curves over full sweep for a RWD car? Maybe a little wanker to worry about it, but I also have seen a friend redesign suspension and result in a worse handling car.
What upright would be good in rear if you did IRS? Focus front? Mustang something? Subaru with the bolt in bearing carriers?

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Grant Hughes

I think the magnesium arms and the beam that they go into are a 9deg setup (stock is 15-18 according to the internets), which was as far as they could move the points according to the rules (50mm?). Less rear camber gain would be amazing on an XR.

If you look at the car setups for the gravel rallies, they are setup with rear toe in and with positive camber at ride height... Straight from the Sierra prep manual. It's exactly what we found with Daves car through trial and error, and looking at the tire wear pattern.

Probably close to wanking as I don't see anyone realistically stepping up to figure out an Escort WRC style rear suspension, but from what I saw Ford did the same sort of strut rear end on the Escort 1700T Group B car, and while it never went anywhere due to the AWD stuff taking over, I have to believe Ford had some idea about designing a RWD rally car.

The wrc cradle seems to be the superior design but also requires new bearing holder, figuring out the caliper position, new coil overs, and all the setup. I found some forum pages where guys over the pond had set them up but way over board for where I want to go.

This link has some pretty detailed pictures of a 6 degree beam and what is being done:

http://www.escortrscosworth.com/forum/showthread.php?t=31856

I'm leaning this direction. I think it is within my ability. Where to get those rod end nut sleeve things is another story though. Does anyone know what you call that?

Seems to be a number of us with the same Sierra details!!!

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Yes, it's a Ranger.
Xr4Ti, it is rwd and was made in Germany.

I probably have fifty hours of internet searching for an off the shelf adjuster like that.
1250 gbp isn't bad.
The problem with a six degree beam in my opinion is you now have a big hanging inner mount in the beam that looks even easier to bend.

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Grant Hughes

6 Deg Beam

I was going to see if this company or the guys that made the Ahmed beam would do a deal to get a few over here.

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Yes, it's a Ranger.
Xr4Ti, it is rwd and was made in Germany.



Edited 1 time(s). Last edit at 11/05/2016 11:04AM by MattP.

You guys are really searching hard for a way to spend a LOT of money.
Seems nobody has a very good grip on the WHY of the square beam or the modded oxen yoke POS, or basic principles of cost/benefit analysis..

jeesus.

And this is the reason something good is so hard to do.

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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.

Quote
john vanlandingham
You guys are really searching hard for a way to spend a LOT of money.
Seems nobody has a very good grip on the WHY of the square beam or the modded oxen yoke POS, or basic principles of cost/benefit analysis..

jeesus.

And this is the reason something good is so hard to do.

And I was hoping you were just going to tell us. Haha. The sierra square beams LOOK like they are a smaller degree than the stock 18 degrees. Some guy measured the difference in toe and camber between the stock and 6 degree (on the escort?). He even did some handling analysis but I'm not smart enough to know if it is better or not. Here:

http://passionford.com/forum/general-car-related-discussion/410165-6-degree-beam-info-needed-3.html

Besides the hemi ends and some steel what cost is there? Isn't it just figuring out the position and then a little welding?

FYI to anyone curious, some guy over on merkur club in ca bought a 6 degree beam but hasn't put it on. I wonder if he would share what he paid just for reference.

Ok all you guys, especially Grant and Culbertson who must obviously know what's coming...

Watch this and then, bearing in mind all those 3 Doors were all driving on modded, steel beams (double skinned all over) and modded arms (Strengthened standard arms) at the most and many of the cars were Group N so stock geometry..








When Grant and Culbertson can drive better and faster than all those guys in the video,
THEN they maybe have the expertise and experience to critique what is so wrong with the standard Xratty/Sierra geometry on their own thread, and how its holding them back...

When here, in their drive to be experts, they missed the main point the OP Mark was asking about which is STRENGTH.
NOT if the camber and toe is a fucking degree point 4 at full compression you geniuses,
who the fuck cares?: the spring pushes it back instantly,
NOT if the wheels go a half a fucking degree POS when in the air.
Who the fuck cares?--wheels are in the air!
They'll be back on the ground and the car will be back at average midstroke position and that's good enough for the guys in the vid,

it OUGHT to be good enough for anybody here, especially a couple of guys who have exactly how many RALLIES driving between the 2 of them?--in what cars?

YOU boys can go spend your money on a fucking 6 degree beam,
Its clearly that which is holding you 2 back from the top 3 results OA..isn't it?
Just what are you going to do when it bends first time you tap something?

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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.