Front Suspension for Scratch Build Chassis

[GeeDub]

I have not had much success searching for info on what is the preferred choice(s) for front suspensions when scratch building a chassis.  In particular, pro street/pro stock/pro mod are my primary interest.  I don't see much available on the aftermarket sites that I am familiar with. 

I guess it would be a good idea to start with the front end of the car the chassis is being created for.  However, I know some of the kits have poorly designed front suspensions that are not worth using.  I am looking at several AMT 1:25 NASCAR front suspensions that might be a good choice.

Anyone who has built a chassis for a drag car, I would greatly appreciate your input in this area.

Stay safe & well!

[afx]

Several Pro-Street/Pro-Stock kits have been issued previously.  One example. 

My guess is you are looking to build a tubular Pro-Mod chassis.

[440 Dakota]

here check this site out, lots of tube chassis parts http://futurattraction.com/7.html

[GeeDub]

Sorry if I was not clear in my original post.  Yes, I am planning on building a tubular pro street/stock/mod style frame. 

I am trying to determine what will be the best way to go for the front suspension.  The detailed parts from the above link are just too costly for a complete front suspension.  I am looking at robbing parts from another kit.  I do have some spare AMT & Revell 67 Chevelle Pro Street kits, so robbing the parts from them is an option. 

I was also looking on ebay for suspensions and found quite a few different versions (makes/models of vehicles donating the parts).  In particular, I was wondering if the few 1:25 NASCAR parts would be of good use. 

 

 

[Ace-Garageguy]

51 minutes ago, GeeDub said:

... In particular, I was wondering if the few 1:25 NASCAR parts would be of good use. 

NASCAR front suspensions are generally of the unequal-length-upper-and-lower-control-arm type, required to maintain acceptable camber patterns in turns...something drag racing cars do not have to deal with.

NASCAR vehicles have to contend with high lateral and vertical loadings for an extended period of time (due to high-speed cornering forces), and for multiple intervals per lap.

So in general, NASCAR front suspensions will be much more heavily built than the light lower-control arm-and-strut type suspension shown on the example above.

However, the relative simplicity of the illustrated suspension makes it a natural for scratch-building.

 

 

[GeeDub]

33 minutes ago, Ace-Garageguy said:

NASCAR front suspensions are generally of the unequal-length-upper-and-lower-control-arm type, required to maintain acceptable camber patterns in turns...something drag racing cars do not have to deal with.

Ah, yes indeed.  I forgot about the NASCAR designs to handle high levels of stress for long periods and also making all those left turns.  If the models are designed accordingly, then they should look a bit odd on a drag chassis.  

[GeeDub]

I forgot to ask... Do most tubular chassis use rack & pinion front suspension setups?  I guess that is the term for the type with struts that contain the spindle as well as the shock.

[Casey]

25 minutes ago, GeeDub said:

I forgot to ask... Do most tubular chassis use rack & pinion front suspension setups?  I guess that is the term for the type with struts that contain the spindle as well as the shock.

Yes. Rack and pinion refers to the steering, well, rack and the pinion gear inside. Here's a visual:

 

This of steering system is more compact and easier adapted to custom setups than the older steering box, drag link, etc. type setups, and also lighter.

The triangulated front suspension you mention, with the strut and coil over spring touching a lower control arm and a fixed upper frame member was common among full tube chassis drag, and later Pro Street, vehicles, so it'll be found in most Pro Stock and Pro Street kits from the '80s on up. The AMT '66 Nova Pro Street kit uses the stock Nova front suspension and parallel leaf springs in he rear, which works, but is not adjustable, like a four-link rear suspension is.

You might be best off finding an existing Pro Stock/Street style chassis which matches he wheel base of the body you are working with, then modifying the roll cage to fit the body better, if necessary. That way you can use the front and rear suspension as they are, and adjust other things to properly "fill out" the interior area and engine compartment.

Edited July 13, 2020 by Casey

[GeeDub]

28 minutes ago, Casey said:

You might be best off finding an existing Pro Stock/Street style chassis which matches he wheel base of the body you are working with, then modifying the roll cage to fit the body better, if necessary. That way you can use the front and rear suspension as they are, and adjust other things to properly "fill out" the interior area and engine compartment.

Yes, I have a stack of extra pro street & pro stock kits for this very purpose.  However, I have a few car kits that have longer or shorter wheel bases.  This is why I am planning on scratch building a tubular chassis or two.  

Thanks for the details, Casey!  Much appreciated.

 

[Casey]

You might want to look into the '90s era AMT/Ertl '57 Chevy Bel Air Street Machine kit, too, as it has a back-half style chassis, four link rear suspension with coil over shocks, a mini-tubbed floor pan, and many parts which might be adaptable for your needs:

[Mark]

Most of the pro street kits (except those that are variations of all-out drag cars already issued) have front suspension that is shared with the stock version of the kit.  

Another reason that many drag cars use rack and pinion steering is space utilization.  In most applications it frees up space in the right places for header design.  

[GeeDub]

13 hours ago, Mark said:

Another reason that many drag cars use rack and pinion steering is space utilization.  In most applications it frees up space in the right places for header design.  

Space for headers is a definite and desired benefit. Thanks for the info, Mark.

I have noted that front strut and 4 link rear suspension sets are offered at a few aftermarket parts sites online.  A little pricey but quality makes that less of an issue.  I will look into this further as I get closer to my first scratch build chassis project.

[GeeDub]

15 hours ago, Casey said:

You might want to look into the '90s era AMT/Ertl '57 Chevy Bel Air Street Machine kit, too, as it has a back-half style chassis, four link rear suspension with coil over shocks, a mini-tubbed floor pan, and many parts which might be adaptable for your needs

Thanks for the tip, Casey!

After researching availability and costs on ebay, I believe I will pass on that and probably go with aftermarket strut front and 4 link rear suspension kits.  These should cost about the same as the 57 Bel Air Street Machine, and since I already have all of the styrene items needed to create the chassis & roll cage, would be the more logical choice.  However, I will definitely keep the 57 Street Machine on my list in the event I come up with a future need.

Thanks again.

[Brutalform]

Glenn, maybe look into the Revell 85-2046 Pro Sportsman 55 Chevy? The kit has a nice tubular drag race suspension set up, complete with the rack and pinion steering, large headers, and a bunch of other great parts. Or at the very least, download the instructions from the kit, and maybe that might give you a general idea on how to place all the styrene tubing/rod, whatever you choose to scratch build it with. 

[GeeDub]

9 hours ago, Brutalform said:

Glenn, maybe look into the Revell 85-2046 Pro Sportsman 55 Chevy? The kit has a nice tubular drag race suspension set up, complete with the rack and pinion steering, large headers, and a bunch of other great parts. Or at the very least, download the instructions from the kit, and maybe that might give you a general idea on how to place all the styrene tubing/rod, whatever you choose to scratch build it with. 

Will do, and thanks for the tip, Tom!