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 Post subject: Guldstrand Mod - The hard way
PostPosted: Sun Aug 15, 2010 2:06 pm 

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I did the Guldstrand modification to get better geometry in the front suspension. I decided to do it the "other" way i.e. cutting the A-arm mounts in the lower part and welding them back again. The reason for this is that it will look like the original and still be as strong as possible.

I started with a sandblasting job on the frame to get it down to bare metal, it had a few layers of paint, among them a layer of bright red. It was popular in the eighties with a lot of color on the underside. Mine was red and all loose items painted in blue.

When the frame was clean I started making a jig locating the controlarms mounting bolt holes. The jig was fixed to the frame in the engine stands bolt holes.






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The jig gave me the location of the control arms boltholeso that I could put the mounts back in the right place when they had been lowered.



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So first I did brackets to bolt the standard holes to the jig and weld it together. The jig is bolted to the frame where the engine mounts are bolted.



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The brackets for the holes must be large enough so that there is room for the new holes. I placed the template on the jig and drilled the new holes. And after that the brackets were cut off the frame. I used an electrical grinder with a cutter wheel.



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The jig was then bolted back to the frame and the mounts where grinded for fit until the new holes lined up without any large gaps for the new welds.



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The mount is then welded to the frame, I used a MIG-welder for this and kept the jig bolted until all reachable welds where done.


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The welding is almost done, the jig is gone and it looks good!



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Just a mockup to see how the upper A-arm looks with in the new location.




This modification of the front geometry greatly improves the handling of your firstgen Camaro. One of the benefits is increased Caster angle with a few degrees. This had to be taken in to consideration when I later changed the upper control arms. When driving on track it had a tendency to understeer, it could maybe have been cured with a more agressive camber setting but I didn't want to play with a street setup and a track setup. I just want to drive and enjoy.

On the market for upper control arms we have maybe 20 or more manufactureres that supply them, each of them has different characteristics built in, one of them is caster gain. So if you do the Guldstrand mod you have to choose one with the least built in caster gain. Tyler Beauregard who formerly had ATS gave me advice on several control arms and he had meassured the caster gain on several of them. I did choose the Speed Tech arms who had the least amount of caster gain. Even though I ended up with 8 degrees of caster which is about 2 degrees to much. You will aim for 6 degrees. 8 aint bad but you can run in to clearance problems with the tires hitting the inner fenders on full turn.

Now with all these changes that included Hotchkis front springs the car is a dream to drive, it behaves really good and has a neutral balance, you can easily get it to oversteer but it is controllable with the throttle. That is fun!
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 Post subject: Re: Guldstrand Mod - The hard way
PostPosted: Sat Aug 21, 2010 6:49 am 
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Joined: Fri Jan 08, 2010 9:29 pm
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First Name: Andrew
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You did a great job and thank you for the write up with photos. You should consider renting out that jig. If I was Guldstrand modifying a frame I would be willing to buy it from you and receive a partial refund upon return to you.


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 Post subject: Re: Guldstrand Mod - The hard way
PostPosted: Sat Aug 21, 2010 9:35 am 
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Joined: Sun Dec 13, 2009 3:19 pm
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How far back and down did you move the holes? If you just went the distance that template goes it seems alot of work for a little gain. I think Pozzi says you can go 7/8 back if ya cut em off and still fit in the fenderwell opening; This is on my to do list near the top.

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If I drive my Camaro in 2012 , will the world come to an end?


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 Post subject: Re: Guldstrand Mod - The hard way
PostPosted: Sun Aug 22, 2010 2:00 am 
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Joined: Fri Jan 08, 2010 1:10 am
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First Name: Jan
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For me it was just a matter of estetics, I wanted it to have the factory look. The holes are moved by the Guldstrand template so there is no geometrical change. I just thought that moving the holes and cut the stand to clear the controlarm didn't look good.

Jan

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 Post subject: Re: Guldstrand Mod - The hard way
PostPosted: Sun Aug 22, 2010 8:31 am 
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Thanks Jam. I'm planning on doing mine the "hard Way" also. I realized after I posted that certain aftermarket arms can add the extra caster that would be gained by moving the holes farther back.

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If I drive my Camaro in 2012 , will the world come to an end?


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 Post subject: Re: Guldstrand Mod - The hard way
PostPosted: Sun Aug 22, 2010 10:37 am 
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Very nice work Jan :thumbsup:

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