Suspension Anxiety...

[68-GTO]

I just got my ’68 GTO, now my imagination takes over. I plan on doing everything to the suspension to be able to autocross/track the car. I’m not ready for the coil conversions or the fancy frame mods, so I plan on doing a suspension overhaul with one or more of these brands, Global West, Hotchkis, and SC&C.

I’ve been reading about these brands to see what they have to offer, but so far I’m not sure which one is the right one.

One difference I notice between GW and Hotchkis, is that GW uses tubular U/L control arms and Hotchkis uses boxed style arms, are tubular arms better than boxed arms, or can you really tell the difference?

Another difference I noticed between them is their bushings. GW has a Del-a-lum bushing that really sounds like a performance plus for street/handling cars. Hotchkis uses greasable polyurethane bushings, just like a lot of other suspension brands. GW says even with the greasable bushings, the polyurethane creates rear suspension bind for street and handling cars. Is this true, does anyone experience any binding problems from poly bushings?

Besides these differences they both offer pretty comparable parts, Hotchkis has thicker sway bars for the front and also has lower sport springs.

One other thing both companies have are tubular A-arms, Hotchkis is still designing their lower A-arms and should be out this coming January. I first heard of GW for there A-arms and there are a number of people running them. Are both brands A-arms pretty evenly ranked in performance? Just the other day I was reading the (’72 Chevelle GW susp) thread and saw that SC&C makes A-arms that are a lot less expensive and out perform the GW A-arms, I saw what Derek69SS posted,

Originally Posted by Derek69SS

OK, assuming you want a mild street setup:

My suggestion for the front: Stage II package from SC&C http://www.scandc.com/suspensions.htm - This will do more for you than the GW setup by a long-shot. You have the option to keep your stock brakes and 15" wheels, your geometry is improved, It's cheaper, and you reduce bump-steer and keep your turning radius. It will drop your car about 3/4" in front. Something like a Hotchkis spring and a 1-1/8" sway bar will work well if you want to keep the smooth ride, and don't intend to autocross the car.

In the rear, keep your stock upper arms and put new rubber bushings in them. Lowers, you could use the factory F-41 style boxed arms and 7/8" F-41 sway-bar. Again, just use rubber bushings. Don't use any poly-urethane/poly-graphite or delrin bushings in the rear. The binding will make the car ride like crap, and handle mediocre at best.

now if you want to autocross it... I've got some different suggestions

The SC&C A-arms sound like a better alternative than the GW and Hotchkis.

So if someone could please assist me and steer me in the right direction for my suspensions sake, and lay my suspension anxiety to rest , every comment is well appreciated. I'd also like to hear your autocrossing suggestions Derek69SS.

Thanks, Brian.

[sinned]

Originally Posted by 68-GTO

Another difference I noticed between them is their bushings. GW has a Del-a-lum bushing that really sounds like a performance plus for street/handling cars. Hotchkis uses greasable polyurethane bushings, just like a lot of other suspension brands. GW says even with the greasable bushings, the polyurethane creates rear suspension bind for street and handling cars. Is this true, does anyone experience any binding problems from poly bushings?

OMG, you need poly bushing 101 for the rear arms for sure. BTW, while doing your reading, anything negative said for running poly bushings in the rear arms goes triple for running Del-a-Lum or Teflon bushings. Check the following links (I'd copy/paste it for you but it's about 30 pages worth or so).
post #1
post #2
post #3
post #4
post #5
post #6/my personal favorite

[Derek69SS]

Front: Poly bushings are good, delrin bushings are better

Tubular lower A-arms - they all keep the exact same geometry, and most weigh about the same as stock arms, so you're not shedding much, if any unsprung weight. The only advantage tubular arms will get you is added strength, and they look cool. You can box your lowers for far less to make up for any strength concerns.

Tubular upper A-arms - There are a lot of options for these, from the $49 circle-track arms that are built very light to the beefy $569 GW arms with delrin bushings. They all do 1 thing - they are shorter to allow for a taller spindle. I prefer the SPC adjustable arms from SC&C for $269. I plan to use them to get the car aligned, then lock in the lengths and use shims to make an easy to reproduce "track" alignment setting.

Spindles - read this http://www.chevelles.com/forums/showthread.php?t=107745 I think I covered all the popular spindle swaps. The best options available out there are the stock spindle with tall ball-joints from SC&C, the tall drop spindle from Fatman, and the AFX spindle from ATS... I think the tall ball joints are the only ones currently available though.

Rear: Poly is bad, Delrin is WORSE. Rubber is good, and spherical rod-ends are better.

If you want a cushy ride, stick with rubber uppers in your stock upper arms

If you're more concerned about handling, go with something like Wolfe Racecraft arms with spherical ends, and their spherical bearing for the housing.

[68-GTO]

thanks Dennis68 for those links, lots of info. that i needed.

also thanks Derek69SS.


what are both of you running for bushings in your rear arms?

[68-GTO]

Derek, i noticed you posted about getting the Wolf Racing double adj. arms in all 4 spots with all solid spherical bearings...

i was wondering did you finally get that setup, if so, how do you like it?

thanks for that link, i'm considering that same set up.

[sinned]

Wolfe race Craft housing pivots, Edlebrock upper links (bushed rod ends), my own design lowers (sphericals all 4 locations).

[Derek69SS]

Originally Posted by 68-GTO

Derek, i noticed you posted about getting the Wolf Racing double adj. arms in all 4 spots with all solid spherical bearings...

i was wondering did you finally get that setup, if so, how do you like it?

No, I do not have them yet... my current setup is a perfect example of what not to do - poly upper bushings, and teflon lower bushings. The ride is horrible I can't speak for the ride of the solid bearings, but it can't be any worse than what I've got now. **note to self - do more research before blindly buying products based on what the ads claim**

Denny, you mention the bushed rod ends (Johnny Joints), how well do they wear compared to a solid rod end? Better, worse, same? Does anyone make a lower arm with those on both ends? That seems like a good alternative to having a fully solid setup, as long as they hold up to a lot of use.

[sinned]

The bushed ends will last virtually forever, Teflon products have VERY long wear lives.

Look into Currie arms, I'm not sure if they offer lowers or not. You could be real brave and build your own by purchasing some Jonny Joints and threaded tubing, I think Vince is working on building some links.

Vince???

[68-GTO]

Dennis i can tell why post 6 is your favorite. You posted alot of information that was well needed. Everyone could learn from that thread.

Are the UMI UCA's the ones you would recommend over any other double adj. UCA's?

What would you recommend for the axel end of the UCA, what are some other alternatives, i now know poly is the devil, and you posted this on the chevelle forum...

Note:something I forgot to mention early on in the thread is that not only does the poly induce bind as a result of it's inability to allow "twist" in the arms but as the axle rolls the arms NEED to change length. Obviously a solid link cannot change length so the bushings give allows for some movement, this is why the bearings in all positions do not work.

I would guess that with the johnny joints in the front of the edle brook (inside joke) and rubber bushings at the axle there at least be some compromise.

So is rubber on the axel end the only other option?

Also, for the LCA's, i was looking at the Wolfe Race Craft LCA's, they look similar to yours in the picture. Are spherical rods (jonny joints?) on all corners the best thing to do when it comes to LCA's?

Thanks for the info/help to steer me in the right direction, i would have felt like a douche bag for not doing such thourogh reseach and ending up with poly bushings.

-Brian

[68-GTO]

Woops, forgot to ask for a comparison between Wolfe Race Craft LCA's and UMI's LCA's...

i was first interested in the WRC's, probably just because they were the first spherical LCA's i saw, you know how that goes. But now it depends on which ones are better.

And if there are more companies with spherical rod LCA's let me know, also which of them you'd recommend.

thanks, Brian.