[Cave Man]

Can anyone direct me to literature/website/anything that can teach me about how the suspension system of a 72 nova works and what can be done to improve it (across varying applications)? I do have the fisher body manual as well as the 72 repair/maintenance manual, so I have an idea of the part names and how they are assembled/disassembled? If there isn't anything that specific, perhaps something reasonably close.

I have 0 (zero) knowledge of suspension. I'm also looking for something that will discuss the basic engineering of a suspension system (front and rear) as well as provide info on what does what as far as handling/geometry, etc. Something that discusses the pros/cons of varying systems (coil overs vs ??; leaf vs ???; tubular control arms; tire width and handling; sway bars and size; lowering the vehicle, discuss springs and what rating I need, etc. Something that can help me decide what kind of improvements/suspension I want for my intended use. Something that discusses each aspect of a suspension system and how it contributes to the overall handling of the vehicle.

As always, I greatly appreciate any advice you have for me!

 

[Nova Thug]

GM's A,F, X & B body platforms of the 60's, 70's, and 80's all shared fairly similar front end suspension and geometry layouts. GM's basic formula of the time was to engineer their suspensions to understeer thinking that this would make their cars safer. You state that you want to improve the suspension on your 72. In what ways would you like to make improvements?

 

[Cave Man]

Thanks for replying Nova Thug!

To answer your question as simply as possible, I'm trying to improve the cornering characteristics without sacrificing general ride quality in as cost effective manner as possible. I'm sure everyone says this but I want to be able to get into the corners a little bit on the back roads but not have a terribly uncomfortable ride on the highway. My intended use is cruising (no drag racing).

However, I don't want just an answer to my problem. I love learning things and I want to understand what does what and what changes what. For example, I've been doing some research and it appears that ride comfort and handling have an inverse relationship. The more comfortable the ride, the less hard you will be able to corner (all things equal). Also, I found that a slight negative camber angle increase corning ability (I didn't even know what camber angle was and assume this and other wheel angles is what people are referring to when they say "geometry"). I found discussion on other angles (can't remember their names) too. I also saw info about how sway bar/roll bars can increase/decrease oversteer and understeer (depending on size, and where it's located).

Ultimately, I'm trying to find reputable sources that can explain all this stuff (in general and as it pertains to a 72 Nova if possible) so that I can learn and create my own suspension characteristics that fit my driving style.

 

[Pragmatist]

Suspension design and improvement is not a short subject but the basics can be understood and easily improved upon fairly quickly. The gen III nova is the first suspension where you can see the engineers are actually taking a look at how to improve things. Ride was their primary concern so sway bars front and rear can make a dramatic difference. Lowering can certainly help but ride will diminish depending on how low you go. Disc brakes are always a good addition and you don’t have to break the bank on huge discs. Another benefit is through bushing replacement. New rubber will provide the smoothest, quietest ride but urethane properly installed will not only improve your ride but will outlast rubber. Just a few thoughts surely others can chime in…..

 

[Cave Man]

Suspension design and improvement is not a short subject but the basics can be understood and easily improved upon fairly quickly. The gen III nova is the first suspension where you can see the engineers are actually taking a look at how to improve things. Ride was their primary concern so sway bars front and rear can make a dramatic difference. Lowering can certainly help but ride will diminish depending on how low you go. Disc brakes are always a good addition and you don’t have to break the bank on huge discs. Another benefit is through bushing replacement. New rubber will provide the smoothest, quietest ride but urethane properly installed will not only improve your ride but will outlast rubber. Just a few thoughts surely others can chime in…..

Thanks Pragmatist. I've been watching some YouTube videos on suspension (by Engineering Explained and others) and I agree that suspension design/improv. is not a short subject! But is sure is interesting to me for sure.

I currently have discs up front, drums out back. I had all body bushings replaced (urethane baby!) about 1 year ago. I also had the front end rebuilt for a lack of a better term. So, I'm hoping to do discs all around, and keep the control arms and just add coil overs and lower the car. But as I've learned if you lower your car you can end up changing geometry and lower/change other angles (which I can't remember) which can have negative effects. Same thing with sway bar it appears if I go too big up front I could cause oversteering, so you've got to put one out back, etc.... So, I'm just trying to learn as much as I can before I do this.

 

[Nova Thug]

Improving the tires contact with the pavement is best thing you can do to improve the cars ability to negotiate corners. The are several ways to achieve this. What you want to do is make the chassis as stable as possible to minimize chassis flex. By doing this the suspension can the do its intended job. New body mounts is a step in the right direction the next step would be subframe connectors. This ties the front subframe to the back unibody structure. Once the chassis(which is the foundation of a car) is stiffened up the changes that you make to the suspension will be more focused on doing their job.

One can go out an buy all kinds of suspension goodies that claim to do one thing or another but to truely evaluate what any of those goodies might be able to do will be be better served when the chassis(foundation) stabilized. You really can't go wrong if you start with this step..

The next step would be to improve the camber and caster characteristics of the front suspension. This can be achieved in a several different ways. The Guldstrand modification is basically a relocation of the upper control arm mount to effect the negative camber gain for cornering.. Today, this can be achieved with bolt on parts that will create the same basic effects but this modification is the origin from which most of thosr parts come from. Understanding why this is important will save you in the long run from buying things that do nothing to improve handling characteristics but look really cool..

https://www.camaros.net/forums/16-b...o-guldstrand-mod-hard-way.html#/topics/198421

http://news.classicindustries.com/productspotlight/what-is-the-guldstrand-mod/

There are many different strategies for setting up a car to corner and there is no one right way to get the job done. A lot of it depends on the driving style of the driver and how he/she likes to have the car set up. Heavy spring rate and light sway bar or lighter spring rate and heavy sway bar. These are decisions that can be addressed once the chassis is prepared..

 

[Cave Man]

Improving the tires contact with the pavement is best thing you can do to improve the cars ability to negotiate corners. The are several ways to achieve this. What you want to do is make the chassis as stable as possible to minimize chassis flex. By doing this the suspension can the do its intended job. New body mounts is a step in the right direction the next step would be subframe connectors. This ties the front subframe to the back unibody structure. Once the chassis(which is the foundation of a car) is stiffened up the changes that you make to the suspension will be more focused on doing their job.

One can go out an buy all kinds of suspension goodies that claim to do one thing or another but to truely evaluate what any of those goodies might be able to do will be be better served when the chassis(foundation) stabilized. You really can't go wrong if you start with this step..

The next step would be to improve the camber and caster characteristics of the front suspension. This can be achieved in a several different ways. The Guldstrand modification is basically a relocation of the upper control arm mount to effect the negative camber gain for cornering.. Today, this can be achieved with bolt on parts that will create the same basic effects but this modification is the origin from which most of thosr parts come from. Understanding why this is important will save you in the long run from buying things that do nothing to improve handling characteristics but look really cool..

https://www.camaros.net/forums/16-b...o-guldstrand-mod-hard-way.html#/topics/198421

http://news.classicindustries.com/productspotlight/what-is-the-guldstrand-mod/

There are many different strategies for setting up a car to corner and there is no one right way to get the job done. A lot of it depends on the driving style of the driver and how he/she likes to have the car set up. Heavy spring rate and light sway bar or lighter spring rate and heavy sway bar. These are decisions that can be addressed once the chassis is prepared..

Thanks again NovaThug!!!!! Yes, bolt on frame connectors are first on my list. There are many expensive ones out there ($250 +); however, Summit/Jegs has their own brand for @ $140. Any reason I shouldn't get the less expensive Summit brand?

When lowering the car in the front, the minimal research I've found suggests that using lowering springs isn't a good idea because it will change geometry (I presume they were assuming all else unchanged???). So, if I get adjustable coil overs (which seems to be the more recommend way to best lower your car) won't that change the geometry too? Perhaps this is why you suggested Guldstrand modification? More research and learning for me to do (starting with the links you posted)!!!!

thanks again

 

[Nova Thug]

Any subframe connector is better then no subframe connector.. It is true that some are more expensive and some are rediculously so.. Look at the house brands and compare them to some more expensive ones.. Look at how they are attaching to the car. I would also look at Competition Engeneering, Global West, and Hotchkis subframe connectors. Just to compare..

With regard to lowering, understanding what happens as your suspension articulates will make the point for you as to why it changes the geometry. Basically, the way GM set up these front suspensions going back to the 60's was to set the upper control arm cross shaft higher then the ball joint. As the suspension compresses the control arm travel upwards and as they travel upwards the top of the spindle connected to the upper ball joint begins to go into positive camber. This is caused by the initial static ride height having standard alingment settings has to follow the two arcs that the short upper and long lower control arms. With the upper ball joint at stock ride height sitting lower then it's cross shaft as it articulates up it also pushes the ball joint out.. Is a straight line going over bumps in the road this doesn't cause much trouble. When you try to go around a corner at speed the body of the car begins to roll to the outside of the turn. When this happens the front suspension on the outside wheel compresses and now the outside front wheel is taking the weight transfer on to a wheel that is in a camberd out attitude riding on the out side edge of the tire.. This is not good for cornering. What is required is negative camber on the out side wheel.. As the body roll over to the outside of the turn the front wheel travel up and in towards the engine and then to tire has a more squared up relationship to the road.. A heavy sway bar can minimize the body roll but it can't correct the bad factory suspension geometry nor can adjustable coil over shocks.

The Guldstrand modification addresses the poor factory geometry which improves the negative camber gain aspect of the front suspension..

If you try to lower the static ride height with the stock geometry the tops of the front wheels will be at the beginning stage of going into positive camber.. This will have to be addressed if cornering is imprtant to you. Tall spindles, offset cross shafts, camber correcting upper control arms, or the Guldstrand modification are all strategies to address this problem..

 

[Cave Man]

Any subframe connector is better then no subframe connector.. It is true that some are more expensive and some are rediculously so.. Look at the house brands and compare them to some more expensive ones.. Look at how they are attaching to the car. I would also look at Competition Engeneering, Global West, and Hotchkis subframe connectors. Just to compare..

With regard to lowering, understanding what happens as your suspension articulates will make the point for you as to why it changes the geometry. Basically, the way GM set up these front suspensions going back to the 60's was to set the upper control arm cross shaft higher then the ball joint. As the suspension compresses the control arm travel upwards and as they travel upwards the top of the spindle connected to the upper ball joint begins to go into positive camber. This is caused by the initial static ride height having standard alingment settings has to follow the two arcs that the short upper and long lower control arms. With the upper ball joint at stock ride height sitting lower then it's cross shaft as it articulates up it also pushes the ball joint out.. Is a straight line going over bumps in the road this doesn't cause much trouble. When you try to go around a corner at speed the body of the car begins to roll to the outside of the turn. When this happens the front suspension on the outside wheel compresses and now the outside front wheel is taking the weight transfer on to a wheel that is in a camberd out attitude riding on the out side edge of the tire.. This is not good for cornering. What is required is negative camber on the out side wheel.. As the body roll over to the outside of the turn the front wheel travel up and in towards the engine and then to tire has a more squared up relationship to the road.. A heavy sway bar can minimize the body roll but it can't correct the bad factory suspension geometry nor can adjustable coil over shocks.

The Guldstrand modification addresses the poor factory geometry which improves the negative camber gain aspect of the front suspension..

If you try to lower the static ride height with the stock geometry the tops of the front wheels will be at the beginning stage of going into positive camber.. This will have to be addressed if cornering is imprtant to you. Tall spindles, offset cross shafts, camber correcting upper control arms, or the Guldstrand modification are all strategies to address this problem..

Thanks Nova Thug! I have found some YouTube engineering channels that have discussed this/shown it and am beginning to understand the basic theory (in general). You insight into the Nova specifically helps as well.

Based on my research thus far, I have been very impressed with Hotchkis. I've had a couple of conversations with Rob there already and believe Hotchkis suspension (starting with the TVS system and adding the Hotchkis/Fox shocks) is the direction I'm heading in. This TVS system lowers the Nova @ 2" from stock height. This should be plenty for me. Rob did discuss the TVS kits impact on camber angle. If I understood correctly, the lowering springs actually increases my ability to get negative camber (he recommend alignment between -0.10 to -0.50 max). He said I should be ok; however, to properly correct the front end geometry he recommended their upper/lower control arms which will also address the caster angle. This is all new to me so I may have misunderstood him.

With regard to subframe connectors, I will look into that. I have looked at a few, including Hotchkis. From the ratings on Jegs/Summit, etc. it seems that everyone, regardless of cost, requires some widening of holes, etc. The more expensive ones do look thinner from a profile standpoint which would help ground clearance, but I don't think I need to be worried to much there. Summit's frame connectors are @ $130; Hotchkis is $400. That's more than 3x the price. Are the connection points on the Hotchkis connector that much better? Also, I was going to bolt on the Summit connectors and then put a couple welds here and there for good measure (grinding off paint/powder coat/rust/etc. first).

Lot's more research to do for me.

 

[Nova Thug]

Hotchkis is pretty high ticket stuff. I would not have a problem with the Summit connectors at $130. The look very similar to the Competition Engineering connectors. The Hotchkis connectors have some contours in them that might be to clear the floor I'm not sure though. The installation sheets look the same for the Summit and the Competition Engineering connectors.