Shock selection for HPDE NASCAR

[ssanto]

I've got a NASCAR road course chassis I'm building into an HPDE track day car. I'm still new to this game so I'm not looking to set any records. I am thinking about what shocks to purchase and I honestly don't know where to start. I honestly don't think I'd get to the point where I'd be trying to adjust them to improve handling performance until I get waaaay down the line. So I would suppose that non-adjustable would be fine. But I still don't know what specs I should be looking for.

Here are the specs for the car:
3200 lbs
Truck arm rear
Double a arm front
450 HP 383
4 speed dog ring transmission

Any advice? What might be a good starting point?

[Chad-1stGen]

Shocks are one of the most critical parts to handling performance. For budget conscious folks I always recommend ridetech single adjustable shocks.

I’d highly recommend talking to JJ at Ultimate Performance for shock advice and purchasing. https://upspeedshop.com/

[anguilla1980]

As someone who is on their 3rd set of shocks since starting their build, I'll throw in some advice. I thought with my first set I wouldn't need adjustables either. I was wrong, way wrong. Right away I wanted to make changes and I was stuck.

You don't have to get super high dollar adjustables, but I would certainly get adjustables.

[nokones]

I would contact someone like Mike Naake at Naake Racing. He know his stuff when it comes to Road Racing and Oval Tracks and Nascar/ASA type chassis and suspensions. He was the Shock Engineer for the Morgan McClure Team when Ernie Irvan was their driver. He helped me to setup my road race Monte Carlo that had a Howe Chassis. I competed in the SCCA Regional Series in a Spec class where the shock rules where that the purchase price could not exceed more than $199 per shock so Mike recommended that I purchase the QA1s at the suggested retail price at that time which was a tad under the rule limit, and he put Penske innards (Valving) in the QA1 shock body. Essentially, the shock performed as a Penske. There was no rule regarding the cost to rebuild the shock.

In anycase, you want to buy a rebuildable shock and if the shock is built/valved for the spring rate and for the type of use you're going to do, you really don't need an adjustable shock. I found it wasn't necessary to change the valving or needed to adjust the shocks, Mike got it right the first time. The only adjustment that I need to do was adjust the front sway bar depending on the conditions (weather & tire, etc.). That will help to keep from spending mega dollars when you really don't need to.

[BMR Sales]

As someone who is on their 3rd set of shocks since starting their build, I'll throw in some advice. I thought with my first set I wouldn't need adjustables either. I was wrong, way wrong. Right away I wanted to make changes and I was stuck.

You don't have to get super high dollar adjustables, but I would certainly get adjustables.

I agree

[ssanto]

I see some with with valves where you can add/release nitrogen. And I see others with knobs you turn to click for adjustment. It seems like the knobs would be what I'd want to have repeatable adjustments.

How do the nitrogen valve ones work?


Thanks!

[dontlifttoshift]

The nitrogen isn't really an adjustment. The gas (nitrogen) is there to apply pressure to the shock oil to keep it from aerating. If the shock oil turns to foam, you no longer have any damping ability.

You can make very minor changes in effective spring rate by changing the pressure of the nitrogen, but it is not huge and not something I consider to be a tuning tool.

Plus one for just buying the ridetech single adjustable shocks that fit the chassis.

[Sleeper68]

I've got a NASCAR road course chassis I'm building into an HPDE track day car. I'm still new to this game so I'm not looking to set any records. I am thinking about what shocks to purchase and I honestly don't know where to start. I honestly don't think I'd get to the point where I'd be trying to adjust them to improve handling performance until I get waaaay down the line. So I would suppose that non-adjustable would be fine. But I still don't know what specs I should be looking for.

Here are the specs for the car:
3200 lbs
Truck arm rear
Double a arm front
450 HP 383
4 speed dog ring transmission

Any advice? What might be a good starting point?

The Varishock's from Chassisworks have worked great for me. I have the non adjustable versions but have driven cars with the 2 way adjustable versions (quick set 2) and they are awesome. The 2 way adjustables come in two versions: "performance handling" and general.

General is for a streetcar with a range that allows for drag racing a such. You would want the "performance handling" versions.

If you can give Chassisworks the corner weights, spring rates,and motion ratios for the car they should be able to get the damping setup in the correct range in hope that you won't run out of adjustment.

Any idea on what the spring rates, motion ratios, and corner weights are for the car? From that info you can calculate ride frequency which is a good way to compare cars.

Ryan