Suspension Upgrade for the Mountains

[JP_AstroMan]

So I would really like my '72 Monte, that has wide tires all around and soon to have gobs of 460ci power, to handle as well as it looks. I live in some pretty extreme mountainous (nicely paved) roads. It would be AWESOME to drive this car powering through corners. Has anyone upgraded to a sporty suspension? I'd like to lower the center of gravity by an inch or two as well. 

[Rob Peters]

You do live in a very beautiful area and yes some of the areas can be a bit mounitanous.  

rob

 

[cny first gen 71]

4 hours ago, JP_AstroMan said:

So I would really like my '72 Monte, that has wide tires all around and soon to have gobs of 460ci power, to handle as well as it looks. I live in some pretty extreme mountainous (nicely paved) roads. It would be AWESOME to drive this car powering through corners. Has anyone upgraded to a sporty suspension? I'd like to lower the center of gravity by an inch or two as well. 

If you come up to eastern meet in Carlisle talk to Dan Rutland he redid his suspension and did a very nice job on it and he enjoys talking about it. He did a lot of research on it and very knowledgeable about it.

[Dans '70 Z20]

Nice looking MONTE!!

I love the way mine handles.  Before SC&C had troubles .... Marc helped me set up my suspension.  He wrote the book on "How to make your muscle car handle"  He is very knowledgeable.

Poly bushings everywhere except Rear upper control arms, and johnny joints on lower arms.

SPC upper/lower front control arms, Hotchkis 1" lowering coils (added spacers to get height where I wanted), Hotchkis frame stiffeners, Currectrac dbl adj uppers, billet lower rear arms, Hellwig swaybars (frame mounted rear), double adjustable Vari-shocks front & back.  Also utilized a steering box out of a 87 Monte SS.  Looks identical to original with progressive ratio (3 turns lock to lock).  Just need to use a hybrid connection to mount lines. 

ANy questions or pics needed let me know

Dan

[JP_AstroMan]

Awesome, thanks! Looks like I can just pick up this book and be all set.

[Blackhawk]

A good starting point would be tubular upper control arms, but make sure that they're made to increase positive camber. Most if not all of the $200 control arms will not do this and have no benefits over stock. From there you could go with tall spindles or upper and lower tall ball joints. The tall upper will help with the camber curve and the lower will drop the car as well as reducing bump steer by raising the tie rod boss on the spindle in relation to the frame.

Replace the bushings in the front lower control arms, you can use rubber or polyurethane and either should work just fine. Most tubular lower control arms do not have geometry upgrades, but some do add caster and help center the wheel (adding caster in the upper may pull the wheel back in the wheel well). The biggest upgrade with some lowers is that they add a mount and allow added travel for coilovers.

Sway bars can be tough, as too much isn't a great thing. I would keep whatever you're currently running and see how that feels. If you feel understeer, upgrade the rear sway bar. If you feel oversteer, upgrade the front sway bar. The front sway bar bolts are making about two threads into the frame and frequently pull out, so if you change it I would recommend riv-nuts or a threaded plate placed into the frame. For the rear you can go with a sway bar that attached to the control arms or you can get one that attaches to the frame instead.

For the rears, you can run aftermarket lowers or it looks like you already have boxed lowers. Replace any bushings if necessary, and use spherical joints on the rear end for the upper arms. You can use poly or rubber for the rest, and you probably won't feel a difference either way. Adjustable upper control arms are nice for adjusting your pinion angle, but keep in mind that the stock pinion isn't necessarily parallel and equal with the transmission; From the cars that I've looked at the pinion is about 1* down (or 1* up if looking at the angle from front to back). Introduce too much of a change and your rear springs will start arching from the mounts rotating.

If you're looking at coilovers in the rear, I recommend tying the shock mounts together. They weren't made to hold the car up, and it's easy to see when somebody raised the rear from pumping up air shocks. UMI has a rear shock tower brace, as does Global West but I think they only sell it in a coilover kit.

Upgrade your steering box using either an aftermarket unit or from a Jeep Grand Cherokee. You will need to use adapters to fit the JGC box to your stock lines and the aftermarket units may be the same. I'm not sure if the power steering pumps are interchangeable with later models, but the pump and can for my 2004 LS engine looks similar.

When getting an alignment, don't get the stock alignment. A good starting point is as much positive caster as possible, -.25 to -1.25 degrees camber, and 0" to .125" toe.

 

With everything together and tested, this guide should help you really dial the car in for performing. https://www.ridetech.com/tech/suspension-tuning-guide-high-performance-vehicles/

[Bad Wolf racing]

QA1 makes some awesome complete suspension packages. I installed their "Stage 2" kit on mine with three position coil overs and it handles very nice. I haven't dropped it to the lowest position yet but I know in the middle it's low and handles great.

 

They use tubular control arms, Heavy sway bars, and all the mounting hardware to convert to coil overs. Hardest part was taking off 50 year old components LOL.

 

[JP_AstroMan]

Awesome! Sounds perfect.