Baseline Setup: Spec3

“What’s this?” you are probably saying to yourself. If so, you have been paying attention to Speed News. This kind of story is the beginning of something new. As part of its mission to help NASA members learn more about the sport we all enjoy so much, become faster drivers and better mechanics, Speed News’ latest series is called “Baseline Setup.”

This new suspension tech series is designed to help drivers in various series, classes or chassis to find a good starting point for setting up their cars for HPDE, Time Trial and racing. “Baseline Setup” was conceived to provide a good starting point for drivers within a given series or class. A good baseline setup allows you to go to the track with something decent, and then have something you can tweak throughout the weekend, or perhaps not at all.

In theory, a good baseline setup helps keep you from having to make major chassis changes at the track. It lets you focus on driving rather than on the car. The hope is that even drivers in a different class with the same chassis could sometimes stand to benefit from the information assembled herein.

As much fun as it is to come up with new editorial ideas, producing them is another thing altogether. The execution requires a lot of work, and our writers are only experts in a niche or two. As such, this series would be impossible to without the generosity of drivers of a given class sharing their expertise and actually offering up their “speed secrets” to anyone who cares to read it, including their competitors.

As you might have gathered from the opening photo, we are starting this new series with Spec3, a class that is arguably one of the two most affordable racing classes in all of NASA. Donor cars are affordable and reasonably plentiful, the fields are growing and the racing is genuinely good. NASA Northeast Spec3 series leader Taylor Johnson, of course, went above and beyond, and offered even more information than we sought.

“Anyone with an E36 with big power and big aero should promptly ignore all of my setup information. Spec3s like slip angle and need to be driven partially sideways to get the most speed out of them,” Johnson said. “The springs are softer than just about anything you’ll find on an ST or GTS car and as such and the cars require you to “set” them before asking the car to make a change in direction. E36s need a big front anti roll bar to cancel out the camber gain from compression of the suspension, but too much front bar will cross back over into understeer territory. The fast Spec3 people seem to run a stiff rear ARB as well to get the car to rotate since we don’t put down as much power as the M3s and don’t have aero.”

The following fields are the information we requested from each respondent. To get more detail, we also asked some follow-up questions, which were devised to add context and nuance.

Front Settings

Ride Height Measured @

Toe (in/mm/degrees per side):

Camber:              XX degrees

Caster:                XX degrees

Anti-roll bar:

Shock adjustments (if any):

 

Rear Settings

Ride height Measured @

Toe (in/mm/degrees per side):

Camber:              XX degrees

Caster:                XX degrees

Anti-roll bar:

Shock adjustments (if any):

Rake:

Cross Weight:

For the first installment of this new series, we offer our thanks and appreciation to Spec3 racers Taylor Johnson, Charles Ford and Andreas Schmidt, who willingly shared their expertise. Here’s hoping for the same kind of eager participation from other NASA drivers throughout this series.

Name: Taylor Johnson

Region: NASA Northeast, NASA Mid-Atlantic

Class: Spec3

Car: 1995 BMW 325i

Years Racing: 4

Front Settings
Ride Height Measured at:	NA. Spec3 are not ride height adjustable.
Toe (in/mm/degrees):	I set toe with degrees at .1 degree toe out each side, .2 total toe out
Camber:	E36s like as much camber as you can. 3.5-4 degrees
Caster:	as much as possible (ends up being 6-7 degrees with Spec3 suspension)
Anti-roll bar:	For the new H&R Anti Roll Bar, the softest setting
Shock Setting (if any):	3/5 soft front

 

Rear Settings
Ride Height Measured at:	NA.
Toe (in/mm/degrees):	0 to 0.1 degrees in. Currently 0.1 in
Camber:	As much as possible (Spec3 uses stock camber arms). 2-2.5 degrees
Caster:	NA
Anti-roll bar:	Full stiff for most tracks. Maybe medium for tracks where rear traction is at a premium, like VIR or Pitt Race.
Shock Setting (if any):	3/5 stiff rear I currently run 3/5 soft front and 3/5 stiff rear to keep it stable under braking and curb oversteer on corner exit, but I’m constantly changing these depending on other changes like rear toe. Depending on how much under steer mid turn and corner exit I’m getting next event, I may stiffen the front again.
Rake:	NA
Cross Weight:	I’ve never corner-balanced my bar. We can only set cross weight by adding or removing the stock spring pads, which I’ve never bothered to do. I certainly should, though!

Q: How do you like a car to handle?

A: E36s naturally understeer when stock. It’s fairly difficult to make them too “loose,” especially at our power level, but I prefer it on the looser side of “neutral.” Being able to rotate the car under braking is important, and not understeering when you get back on the throttle (or having) the car attempt to lift the front inside wheel is critical. You can’t take it too far though, because spinning a rear tire on corner-exit is completely unacceptable in a spec racing class. You’ll get left in the dust on the subsequent straight. 

Q: Do your preferred settings achieve that?

A: I think so. I believe a majority of the tuning is in the rear anti-roll bar setting. Readers will be shocked to see that we run the rear bar stiff, when a lot of GTS cars probably have the rear ARB completely disconnected or as soft as possible.

Q: What tires do you use, and what is the effect of your preferred settings on tire wear?  

A: Toyo RR is required for Spec3. In theory, the tire wear for this setup is fairly equal if you rotate tires properly. This is my first season running toe-in on the rear, so I’ll report back if my rear tire wear changes. Usually the inside of the rear wears first and the outside of the fronts, so rotating them diagonally gets you equal wear. 

Q: What alignment settings have you tried that you didn’t like? 

A: I haven’t strayed too far from the tried-and-true E36 alignment specs that I use. I have run more toe out-in the front and didn’t mind. I have run 0 toe in the rear as well, combined with a softer rear bar and it was fine.

Q: What didn’t you like about it? 

A: It’s difficult to make an E36 unpleasant to drive, so I haven’t disliked any of my alignments in the past. The focus for this year has been improved turn-in and better corner exit. I believe running toe-in for the rear has allowed me to make my rear ARB stiffer for that rotation I wanted under braking and the additional toe-in has made it more stable midcorner and on corner exit. 

Q: What is the maximum amount of negative camber you can achieve, front and rear? 

A: 4.5 up front and 2.5 rear.

Q: When you have to make adjustments at the track, what do you usually change first? 

A: I don’t. I’m racing Spec3 because I don’t like to “fiddle” with the car. Just drive. If I’m feeling particularly enterprising, I may change the rear ARB from stiff to medium depending on how much rotation and on-power grip I want, or I may slightly stiffen or soften the front rebound on the shocks if I need to maximize front traction on throttle (soften) or during trail braking (stiffen).

Q: Do you have baseline setups specific to particular tracks? Why or why not? 

A: I don’t. I’m racing Spec3 because I don’t like to “fiddle” with the car. Just drive.

Q: What advice would you give someone trying to get the most from his or her setup on a car like yours?

A: For a Spec3, start with a neutral setup and season to taste. I see too many people start with a stiff rear anti roll bar and they spin the car. It takes a good bit of car control to run the car loose enough to rotate under braking and have the right slip angle on corner exit and it takes time to get that car control. 

Name: Charles Ford

Region: NASA Mid-Atlantic

Class: Spec3

Car: 1992 BMW 325is

Years Racing: 9

Front Settings
Ride Height Measured at:	Fender lip, 24 1/8” LF and 23 ¾” RF (no driver)
Toe (in/mm/degrees):	LF = 0 toe, RF = anywhere from 0″ toe to 3/16″ toe out
Camber:	Between 3.5 and 4.5 degrees
Caster:	Max allowed with Vorshlag camber/caster plates
Anti-roll bar:	Full stiff
Shock Setting (if any):	Full stiff, back off 1/4 turn

 

Rear Settings
Ride Height Measured at:	Fender lip, 23 7/8” LR and 23 ¼” RR (no driver)
Toe (in/mm/degrees):	0 toe
Camber:	Max, should land ~ 2.5-3.0 degrees
Caster:	NA
Anti-roll bar:	Dependent on track/weather, see below
Shock Setting (if any):	Full stiff, back off 1/4 turn
Rake:	Set due to spec suspension. You can adjust with spring pads in the rear if needed. I do not run any spring pads (front or rear).
Cross Weight:	49.9 %

Q: How do you like a car to handle? 

 A: There has been a lot of work put into the Spec3 suspension package over the years, and the springs/shocks/sway bars/tire package was chosen to deliver a predictable base rather than a setup for all-out lap time. The result is a chassis that drivers can feel comfortable pushing to the very edge of both the driver’s and car’s capabilities. On the spectrum between a full stock suspension to something you would find on a Super Unlimited car, the package equates to something similar to an aggressive street setup.

That being said, I have found myself using the suspension additions allowed in the rules to stiffen up the chassis as much as I can. There is still quite a bit of roll and weight transfer with the spec springs and anti-roll bars, which can easily overload the Toyos. Since we do not have any aero bits to help with downforce and grip, one of my main goals is to reduce the body roll as much as possible.

The rebound on the Koni shocks is adjustable, but again, with them being a street-sport shock I find that they perform best when they are as close to full stiff as possible. The anti-roll bars work great with the front and rear set to full stiff, but some might find car rotation a little more difficult in slower turns with this setup. If that’s the case, you can set the rear anti-roll bar to medium or soft to help with rotation.

Q: Do your preferred settings achieve that?

 A: Yes, to a degree. I’ve become quite accustomed to the characteristics of the Spec3 chassis and feel that, on my best days, I’m able to push to car to its capabilities.

Q: What tires do you use, and what is the effect of your preferred settings on tire wear? 

 A: Our current dry-weather tire is the Toyo RR, which has always been known for great tire wear and consistency. Grip on the straights and corner exit (to a degree) isn’t a factor in our cars, so maximizing entry and midcorner grip is paramount. My suggestion is to run as much camber that your wallet can stomach. You will see some increased inner tire wear with running any front toe-out and/or max camber, but that is where you will find the lap time. If you see too much inner wear for your liking, back off on the camber a bit. Also, get an infrared digital thermometer and measure temperature across the tire after your sessions. If you see more than a 30-40 degree delta between the outside and inside of the tire then you are running too much toe or camber. Keeping notes, tracking settings and tire temps/pressures will help you immensely in dialing in your tires over a season and help you find that missing lap time.

Q: What alignment settings have you tried that you didn’t like? 

 A: Anything that increases body roll.

Q: What didn’t you like about it? 

 A: The Swift springs we run are on the softer side, and the Toyos can easily be overloaded by too much weight transfer in the corners.

Q: What is the maximum amount of negative camber you can achieve, front and rear? 

 A: The Vorshlag camber/caster plates we use in the front have 6 lines on the top of the plate to help you set camber. Due to our strut towers, it is difficult to get all the way to the 6th line for max camber. Mine are typically set around the 5 to 5 1/2 mark, which should put your negative camber somewhere around the 3.5 – 4.5 degree range. Dial it back if you see excessive heat on the inside of the tire compared to the outside. Maxing out negative camber in the rear should get you somewhere in the 2.5 – 3 degree range. I rarely ever touch or change the camber settings on the car.

Q: When you have to make adjustments at the track, what do you usually change first and why? 

 A: Tire pressures and rear anti-roll bar. Soften the bar if you are looking for more rotation, stiffen if you need more stability in high-speed bends. If you do stiffen the rear bar, just be careful because when the rear steps out, it will step out a lot quicker than when the rear bar is set to full soft.

Q: Do you have baseline setups specific to particular tracks? Why or why not?

 A: I have found that driving the car to 10/10ths is easier with greater confidence in the chassis versus adjustments made to the car. That is not to say that we don’t make adjustments, but more often than not, the setup on the car remains the same from track to track. For folks starting out, my suggestion would be to use the settings above for 1-2 years and get familiar with the chassis before making changes. You will find more lap time in confidence than making changes to the car.

Q: What advice would you give someone trying to get the most from his or her setup on a car like yours?

 A: Tires, tires, tires. Your hot pressures after a session or race should be in the 35-38 psi range. You should be taking pressures before and after every session, keeping track of them, and making adjustments for subsequent sessions. An easy thing to do is to adjust the tires to your desired pressures right after you come off track (air out or air in). This is a good way to know your tires will be in the ballpark of your desired pressure when they come back up to temp. Record the pressures before you go out on track. You might be surprised what the starting pressure is for each tire, and most of the time the pressures are not the same for all four tires.

Name: Andy Schmidt

Region: NASA Southeast

Class: Spec3

Car: 1994 BMW 325is

Years Racing: 3

Front Settings
Ride Height Measured at:	NA
Toe (in/mm/degrees):	-0.04 degrees out per side
Camber:	-4.0 degrees
Caster:	5.7 degree (maxed)
Anti-roll bar:	28mm H&R on full soft, or 26mm Eibach on full stiff
Shock Setting (if any):	Rebound full stiff minus 3/4 turn to soft

 

Rear Settings
Ride Height Measured at:	NA
Toe (in/mm/degrees):	.06 degrees toe in per side
Camber:	2.2 degrees (maxed)
Caster:	NA
Anti-roll bar:	24mm Eibach on full stiff with H&R front bar or on full soft with Eibach front bar
Shock Setting (if any):	Rebound to 3/5 stiff
Rake:	NA
Cross Weight:	~50% (yes, a Spec3 without coilovers can still be reasonably corner balanced)

Q: How do you like a car to handle?

 A: I prefer mild understeer. 

Q: Do your preferred settings achieve that?

A: Mostly. The nature of the car can lead to some oversteer at turn-in for high speed turns, but Spec3 cars are mild mannered.

Q: What tires do you use, and what is the effect of your preferred settings on tire wear?

 A: Toyo RR in 235/40/17 is the spec tire. We get excellent and even tire wear that allow us to run 20-plus heat cycles on a tire.

Q: What alignment settings have you tried that you didn’t like?

 A: I’ve tried 0 toe in the rear and felt like it was too much oversteer. Anything above 0.12 degree toe in is also too much understeer.

Q: What didn’t you like about it?

 A: See above.

Q: What is the maximum amount of negative camber you can achieve, front and rear?

 A: -4.3 degree and -2.2 degree

Q: When you have to make adjustments at the track, what do you usually change first and why?

 A: Our spec cars have limited adjustments we can make. Usually adjustments to the sway bar are the first thing I would consider to address handling balance. I may adjust rebound, especially if either end is too stiff and causes pack down.

Q: Do you have baseline setups specific to particular tracks? Why or why not?

 A: For most tracks I would use the above alignment. For a track like PittRace, I may soften the rear bar or add a bit of toe in for the rears because the nature of that track lends to oversteer. A track like Summit Point can benefit with a bit more rotation in the car. But generally speaking, I stick to my base alignment because the adjustments on this car are limited.

Q: What advice would you give someone trying to get the most from his or her setup on a car like yours?

 A: Do the research on what adjustments do on your car first. Then go out and experiment, but be methodical about it. But once you find that base setup you like, just drive the car. Spec3 cars aren’t complicated to set up, which is why we have such great parity between the cars. The difference between the best and worst set up car is less than a second.