Guldstrand mod ??

**mdprovee** · 03-03-2005

I am no way any type of expert, in fact I don't know S**t. I purchased the DSE uppers and lowers, no coilover, and talked with Kyle too about two weeks ago. He said with his arms, he does not recommend the Guldstrand mod. It would not be needed. Just my 2 cents.

Mike

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**David Pozzi** · 03-03-2005

baz67,
I'm guessing as to what the design thinking is these days, here's what I think is going on.

Most street suspension geometry (Corvette/Viper seems to be focused on high amounts of caster which adds neg camber when the wheel is turned, but leaves less static neg camber. Less static neg camber setting will improve braking, make straight line stability better because there is less camber thrust to deal with, less toe out would be needed to counter the camber thrust. Millikan and Millikan discuss camber thrust and the required toe out required to counter it.

Lower amounts of camber gain and lower roll centers seem to be used, probably all for stability reasons in a straight line. Keeping body roll very low would help prevent some of the camber loss, lower profile tires MAY not need as much neg camber, but I don't know that as a fact.
Just throwing out some (more) speculation for discussion...

I remember reading the C5 Lemans corvettes used stock suspension A arms and spindles, but more camber gain than stock, stock vettes have pretty low neg camber gain but a low CG and I think they don't want the RCH too high on them, maybe for tire wear reasons, maybe stability/driver feel reasons when driving straight line.

**Salt Racer** · 03-03-2005

Originally Posted by David Pozzi

...Corvette/Viper seems to be focused on high amounts of caster which adds neg camber when the wheel is turned, but leaves less static neg camber....Lower amounts of camber gain and lower roll centers seem to be used, probably all for stability reasons in a straight line....

That definetely is the current trend.

**baz67** · 03-03-2005

David I see where you are coming from. When I get all the pivot points measured and can figure where the RC is its migration I will ponder on it more.

Brian

**baz67** · 03-03-2005

Not to add anymore confusion to this, but the DSE location used for thier coilover conversion is not that far off of the Guldstand location. Makes one think if you do not need to do the Guldstand mod with either GW or DSE arm why then are the mounting location moved for the coilover kit? I am not questioning DSEs comments at all. It is just one of those things.

Brian

**MrQuick** · 03-04-2005

That does raise some suspicions B, well I say go ahead and drill it out for the mod, hell if it don't work just put it back to stock position right? I'd rather have it and not need it, then need it and screw up that nice power coating.

**David Pozzi** · 03-04-2005

I can speculate that the normal street guy may do less hard cornering and more straight line driving, perhaps tire wear would be a little higher with the Gmod or DSE mod, they (DSE or GW) may reserve this mod for a more agressive/serious builder and not recomend it for the "average" builder. GW seems to recomend the same thing with his upper arms, - "do the Gmod if you autocross or track your car, otherwise the arms are good enough alone".
That's their words above, not mine. I haven't heard of any complaints from Gmodder's on the net and I've heard from plenty of them.
The Gmod has more camber gain than any stock late model Camaro or Vette.
More guessing! ;)

**68BNUT** · 03-08-2005

So any comparisons with and with out the guldstrand mod using the global west upper a-arms???? or does global west recomend NOT doing the mod??

**67lt4** · 03-08-2005

I set my car up with 550 lb springs, 1 1/8" sway bar, poly bushings and the G strand mod, AGR quick ratio box and short steering arms, KYB shocks. It reduced the body roll but you had to make the car steer into the corner. Fun to drive and less push through the corner. The ride was harsh and the poly squeeked after about two weeks. Not fun to drive. I then added the GW UCAs with Delrun bushings and and set of Koni shocks. This made a huge differance. The car wanted to turn into the corner. Ride was plush. The same sprrings but the wheels went up and down. WOW. The poly will stop deflection but also bind a arm movement. Try to move the a arm with stock ar poly bushings. It will move but takes a lot of force. Then try Delrun bushings. One finger movement. Let the springs and shocks do the work. I also added a set of sub frame connectors to stiffen the chassis. I would recomend Delrun or similar bushings and UCA the increase camber. Koni shocks. You can't believe the differance this will make. G strand mod if you go with GW.

**NovaPwr** · 03-09-2005

OK guys, you got me more confused now than when I joined this site to get better educated on my suspension options. LOL...seriously, I have a set of the QA1 coilovers I am going to use and had been checking out GW's upper and lower arms and Speedtechs also. You guys brought DSE's products to my attention as well. I have read and reread all the threads on using the G-mod and not using the G-mod .......I am a little confused at this point. Lets say I drive the car normally. No autocrossing or roadracing, but I still want the car to have an improved suspension. The QA1's with the Delrin bushed control arms (upper and lower) and the 1 1/8" sway bar should make a world of difference just for everyday driving then I am assuming? Seems everyone has their own opinion on this from what I have read. Thought I read where someone did some testing and was going to post the results but I lost it. I have enjoyed reading all this info the past couple weeks. Thanks guys.
Dave

**68BNUT** · 03-09-2005

Ok well I called global west today and they do not recomend doing the G-mod with there arms, They said if its already been done no biggie but you dont really gain anything with there arms doing the G-mod, GREAT NOW IM REALLY CORNFUSED!!

**baz67** · 03-09-2005

Justin, the GW arms with the Guldstand mod is part of what I am doing. If you have some time I should be able to give better answers in a few months. Unfortunetly work gets in the way on me devoting the time I want to give this.

Brian

**68BNUT** · 03-09-2005

I hear that about work now that ive just been trying to get things apart im like oh man I better get this and I better get that startin to nickel and dime me now

**David Pozzi** · 03-09-2005

Chicane67, has posted here, that GW's owner, -Doug, recomends just the arms for street use, if you autocross or open track the car he recomends dong the Guldstrand mod too.
I haven't heard from ONE person that they were sorry they did the Guldstrand mod.
The extra positive caster (5 deg +) that the arms allow help keep the tire flat when the wheels are turned, it's like neg camber that only kicks in when you turn the wheels, then goes away when you drive straight or brake. The Guldstrand mod is still needed for maximum cornering traction, but the arms help a lot.

**68BNUT** · 03-09-2005

Thanks for that Dave, on your website with the g-mod is there any thing I can take to the allignment shop after I do the g-mod with the stock uca or the gw uca's? so they no what optimum settings would be??

**baz67** · 03-10-2005

Justin, David has two alignment settings while using the Guldstrand mod on his site. I got these from there.

Guldstrand recommends the following specs for a "touring car":

* Caster: 3 - 4 degrees positive (+) PS = more, manual steer less.
* Camber: 1/4 to 1/2 degrees negative (-)
* With upper a-arm relocation Camber: 0 degrees
* Toe-in: 0 - 1/8 inch

Guldstrand recomends for racing:

(assumes "Guldstrand mod" is done)

* Caster 3 to 4 1/8 deg pos
* Camber 1.5 to 2 deg neg
* Toe in 1/8" out to 1/8" in (I would try 1/8" out first) more neg camber = more toe out.

Brian

**68BNUT** · 03-10-2005

cool apreciate that I guess when I was looking through his site I had been staring at the screen for too long

**uraceulose** · 05-12-2009

Did they ever post the results to the tests with the different A-arms and with/ without the mod etc...??

Thanks,

Donnie

**Not puke green 71** · 05-19-2009

Where can i find out more about a Gulstrand mod.
I remember reading about it once, but i cant find it now. Has this been done to a 3rd gen Nova before. I think it would have the same benifits as in a Camero, since they share so many simalaities. Thanks Eric

**68Formula** · 05-19-2009

http://www.popularhotrodding.com/tec...ech/index.html

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Thread: Guldstrand mod ??

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