what uca to use with gstrand mod

[double d]

hey guys i am new here but love this site already . i was reading something about a company that was going to compare stock uca ,gw and dse with gstrand mod . i have a 69 camaro stripped down and cant decide how to build front end mostly because i dont know crap about suspensions. any help would be appreciated dave d

[Denvervet]

Do a search and you'll get info ad nauseum on here. I chose the SPC adjustable arms due to their "adjustability" and look a little diff then all the other aftermarket uca's . Savitzke Classic and Custom carries them and others. You can call them and Marcus will talk your ear off explaining the entire suspension geometry issues. Great guy
http://www.scandc.com/contact.htm

[ProdigyCustoms]

I am not a big fan of multi piece arms on true street cars. I like a solid welded arm. We sell and install DSE, Hotchkis and Speedtach arms. They are all awesome pieces and do the same thing. The Speedtech is the best deal at $500 a pair. The others are about $100 more and are great too.

[Vegas69]

If you go DSE they have their own gulstrand mod template.

[1968Maro]

Let me start out by saying that I am no expert, and what I am about to write will be considered committing blasphemy on this site. However, I have been working to get smarter and make my own decisions about what the best thing to do is. I have read a bunch of the suspension forums at this site and they will help you a tremendous amount, but at the end of the day there are conflicting ideas about the best front suspension, the only way to decide is to get smart and try to make up your own mind.

The Gulstrand mod changes the pick-up points (where your UCA's attach to your front clip) which increases the "aggressiveness" of your camber curve in your front suspension geometry.

Camber curve will help to increase the tire patch that stays in contact with the ground through a curve. You can only seriously affect camber curve by changing the mounting points for the suspension on your car.

Now, that being said a couple of things to point out. I have talked with guys at Hotchkis, & DSE. They all assure me that you will gain a little bit (a half a degree or two) of camber curve by swapping your control arms because of their shape and they way they meet the spindle. It sounds to me like they are blowing smoke up my *** to sell a product, but they are also alot smarter than me. New control arms are able to affect castor signicantly because of improved shape, but not camber.

I have also heard that the other way of changing your Camber curve is with taller spindles, but I havent even tried to go down that road yet.

So long story short, I was all set to go through the headache of doing the Guildstrand mod when I talked to some guys both on this site and at lateral-g as well as some people at DSE, and they all told me the same thing. Unless you plan on auto crossing and diving into the cones at 60 miles an hour, you as a weekend cruiser will never notice a Guldstrand modification.

My car will be a cruiser, but I want it to handle and feel like a new BMW. I want that feeling of confidence that when I dive into a turn on the exit ramp that my 60’s muscle car can do it without doing a 180. If that’s all your after then the Guldstrand modification might be a lot of work that you will never notice.

Final thought, the Guldstrand modification does improve camber, and thus improves the performance of your car. Now if you are used to racing cars, and you can leap out of a car after the qualification run wearing your nomex suit and declare that you are detecting 1 degree of wobble in your right front ball joint. Then yes you will need and want to do the Guldstrand modification.

Here are a bunch of great resources. That helped me, Pozzi, steve please feel free to shoot holes in my comments.

http://www.pozziracing.com/first_gen_suspension.htm#Handling%20discussion
http://www.camaros.net/forums/showthread.php?t=151501&highlight=lower+control+ar ms&page=2
http://www.chevyhiperformance.com/tech/chassis/suspension_steering/0909chp_muscle_car_suspension_basics/stock_subframe_parts.html
http://www.chevyhiperformance.com/tech/chassis/suspension_steering/0512ch_1968_chevy_camaro_suspension_steering_upgra de/index.html
http://www.guldstrand.com/gtheory.asp

[Mkelcy]

1968Maro - I'm not going to jump down your throat, but I think your post does yourself and this site a disservice.

This is Pro-Touring.com, not Camaros.Net. Folks who come here are looking for advice on how to make their cars handle, not what finish was on the UCA bushing retention bolt. The Guldstrand mod, tall ball joints or tall spindles - as you note - improve the camber curve for first generation F bodies. Improving the camber curve has the important effect of maintaining a larger tire contact patch when the front end is loaded in a turn. Maintaining a larger tire contact patch in turn both improves the speed you can carry through the turn and saves the tires. Take a look here at the tires on a '68 Camaro that ran at Streets of Willow, with no camber correction:



Here's the same car from a distance:



Now look at two cars with camber correction:


and the car above without:



Notice how the top of the front tires on the cars with camber correction are tucked much farther into the wheel well than on the car without camber correction? That translates into speed and safety.

I agree with your observation that control arms alone don't do much for camber correction.

[Vegas69]

Perfect example Mike. The gulstrand mod is not alot of work. It's simply drilling new holes in your control arm mounts. I would want to trim down the existing bracket on a stock sub to make it cleaner but I'm pretty anal about that stuff.

[Mkelcy]

Perfect example Mike. The gulstrand mod is not alot of work. It's simply drilling new holes in your control arm mounts. I would want to trim down the existing bracket on a stock sub to make it cleaner but I'm pretty anal about that stuff.

If you really want a clean look, cut off the UCA mounts, trim them as needed for the Guldstrand mounting points and reweld them to the subframe. I'd recommend building a jig first.

[dhutton]

Great post Mike.

Thanks,
Don

[Vegas69]

Yep..that's exactly what I was thinking. I've seen photos of exactly that. Maybe it's on Pozzi's site.

[Mkelcy]

Yep..that's exactly what I was thinking. I've seen photos of exactly that. Maybe it's on Pozzi's site.

The DSE coilover kit comes with a jig that reflects their version of the Guldstrand mod. If you're planing on doing the cut and reweld method, you might try finding someone who's got the DSE jig left over.

[double d]

mkelcy thats what i am talking about i stripped down the car so i could make it handle as best as possible . i want to push this car as hard as possible on the street and maybe the track knowing that i did as much as i could before assembly . i will be running a 427 sm blk 5 spd and a 9in that are currently in my 68 ss/rs . one other thing where can i find a template for the gstrand. thanks for the input guys dave d in R.I.

[Twentyover]

A component that is not frequently comented on is the impact of body roll. Usually discussions like this revolve around negative camber gain in bump due to suspension compression in turning. Equally important is the transverse movement of the upper and lower inboard pivots as the body sets in roll. On the outboard corner, the lower inboard pivot will be pulled toward the center of the car as the body leans, and the upper inboard pivot will be pushed away from body center, resulting in +camber gain, even if there were to be no suspension compression (an impossible theoretical condition, but the concept of it reinforces the +camber gain in roll idea)

Gulstrand helps on two fronts- first, the increase angle of the upper control arm improves -camber gain in bump, and second, the distance reduction between the upper and lower pivots produces a reduced + camber gain resulting from body roll.




This is an example of how a decent 60's street suspension works when asked to provide big grip. Stock pivot locations. Tires are 195-55/14 V700 on 6" rims, Treadwear 50. 500 lb/in springs (about 130 lb/in wheel rate) and a 7/8" front bar. I would cord the tire about 1 " in from the outboard sidewall in 3 weekends, about 125-150 miles. Inside of the tire would show MAYBE 1/2 wear. Clearly the entire tire was not getting used. but we never got a good pyro on the tire to get a temp distribution. I could have increased static negative camber, but then i would be giving up distance in braking.

To reduce the amount of positive camber the outboard tire gives, I've got a taller spindle assm (this car uses a trunion based kingpin and a swivel axle.). The taller 'spindle' assm will gain me in 2 places- I've moved the swivel up the kingpin, and stretched the kingpin 1.25" between trunions. While the car has not run w/ this configuration yet, i hope next summer to run it as a LP car at Waterford.


1968Maro, I believe you overestimate the performance of our stock '60's suspension systems with good tires, and underestimate the impact of seemingly minor tweeks. I'll point you to Sprint Cup racing, where minor adjustments of the same suspension can put a guy 1/2 sec a lap faster. Tweeks that appear on the surface to be minor can, and do, have significant impact.

No bashing, just a different perspective.

[Mkelcy]

mkelcy thats what i am talking about i stripped down the car so i could make it handle as best as possible . i want to push this car as hard as possible on the street and maybe the track knowing that i did as much as i could before assembly . i will be running a 427 sm blk 5 spd and a 9in that are currently in my 68 ss/rs . one other thing where can i find a template for the gstrand. thanks for the input guys dave d in R.I.

Unless budget is of extreme concern, before going to the Guldstrand mod, I'd go either of two ways - the SC&C SPC arms with tall ball joints or the SC&C SPC arms with the ATS (now Speed Tech, I think) tall spindles. In the photo of the three red cars above, the car in front has the Guldstrand mod and the second car has the ATS tall spindles (we don't speak of the third "car").

I understand that the camber correction is better with either the tall ball joints or the tall spindle than with the Guldstrand mod (but I don't have either the knowledge or ability to put any of the three through a suspension analyzer), but more importantly, tall ball joints or tall spindles are both reversible and upgradeable when the next great thing comes along. Once you do the Guldstrand mod, you're pretty much stuck with it and a stock height spindle.

[double d]

OK GREG with that said and a lot of other things i have been reading it seems to me the first thing i will do is the gstrand mod and try to figure out uca and if i should use coilovers or spring shock setup do you know if this mod will allow for a bigger rim ??? thanks dave d

[double d]

oh boy now i am really confused money is not the issue wasting it is. i like the idea of changing something that is not permanent and if what you said is right mike will a tall spindle or ball joint allow for bigger rims ? dave d

[Mkelcy]

oh boy now i am really confused money is not the issue wasting it is. i like the idea of changing something that is not permanent and if what you said is right mike will a tall spindle or ball joint allow for bigger rims ? dave d

For a stock subframe I'd skip the coilovers and go with the AFCO 9.5" tall springs and their spring adjuster - http://www.afabcorp.com/AFCO_Dynatec...ct_coil-access

Just cut a helix to match the subframe spring recess and you're good to go. Setting ride height isn't as "easy" as with some coil overs, but how often are you going to reset front ride height (and realign the front end)?

Both the tall spindle and the tall ball joint allow (require, in the case of the tall spindle, I'm not sure about the tall ball joint) larger front rims.

There are, by the way, a number of "tall" spindles out there. I'd avoid those with the 2" or so built in drop, they can lead to severe tie rod to wheel interference issues. The ATS tall spindle has (IIRC) 0.75" drop built in.

[double d]

ok mike that sounds like i will be on the right track !!! you also mentioned sc&c spc arms are those just upper arms or uca and lca and is there different spring rates that i should consider if i went with the afco thanks dave d

[Twentyover]

OK GREG with that said and a lot of other things i have been reading it seems to me the first thing i will do is the gstrand mod and try to figure out uca and if i should use coilovers or spring shock setup do you know if this mod will allow for a bigger rim ??? thanks dave d

I'm don't want to argue for Gulstarnd vs. tall ball joint vs tall spindle, I'm arguing for considering minor (in the case of tall BJ or spindle, reversable, in the case of Gulstrand CHEAP) changes to optimize the huge grip advantage from modern tires.

Agree w/ Mkelcy on coilovers, IMO the only place a coilover is required is a formula or sports racing car (this is my opinion only- others are entitled to theirs. Mine is correct, of course ) where quiick spring rate changes and ride height adjustments are required. Again, my opinion, coilovers have been oversold because the "race cars use them." Some do, some don't. I like the adjustable cans Mkelcy is recommending for cars that are primarily street.

I'm not aware of any mod precluding a bigger rim, although some drop spindles do mandate the use of certain offsets to clear tie rod ends

[double d]

thanks greg ihave some time to digest all of this seeing that 8 months of winter are almost here in the northeast