Now that I’ve prepped the GT for track duty, I figure it needs a race series to compete in. Where do economy cars go when they want to race against vehicles of equally mediocre performance? I don’t know. So I made up my own time trial series with some unusual rules. Hello world, whether you asked for it or not, I give you SPEC-20.

Use the link provided above for the most up-to-date rules. The text below may be out of date.


SPEC-20 is a not-so-serious(1) time trial racing series for low powered racecars(2). SPEC-20 is unusual in that events are asynchronous(3) and delta-based(4).

  1. We are somewhat serious about racing, but not so much about rules.
  2. All cars are racecars. Also, racecar is a palindrome.
  3. Drivers may record their laps at any point during the season.
  4. Drivers earn points by beating specific lap times.


1.0 Vehicle Rules

1.1 AWP. All SPEC-20 cars must have an Adjusted Weight to Power (AWP) ratio of 20:1 or higher. Weight is defined as factory curb weight. Power is defined as factory brake horsepower. Base Weight to Power ratio (BWP) is simply Weight divided by Power. AWP adds or subtracts values from this figure. See Rule 1.8 for alternative classing systems.

1.2 Weight Modfifications. OEM components may not be removed or exchanged except as noted here.

Adjustment Item
-0.0 Remove spare tire, tools, floor mats
-0.25 Replace front seat (each)
-0.25 Replace lead acid battery with lightweight unit
-0.5 Remove front seat
-0.5 Remove rear seats (all)
+0.1 Wide angle central mirror
+0.25 Stereo with trunk kicker
+0.5 Roll bar

1.3 Power Modifications. Bolt-on modifications to the engine are generally allowed, and result in negative adjustments to AWP. No internal modifications are allowed. All engines must be naturally aspirated and run on standard pump gas.

Adjustment Item
-0.5 Non-OEM cold air intake
-0.5 Non-OEM exhaust
-0.5 Non-OEM header
-1.0 Modified ECU

1.4 Tires. All tires must have a UTQG rating of 200 or higher. See the table below for positive adjustments to AWP. No, not all tires in the same treadwear category have the same performance. Cope.

Adjustment Treadwear (UTQG)
+0.0 200
+1.0 220-280
+2.0 300
+3.0 320-380
+4.0 400+

1.5 Exterior. Non-OEM aerodynamic modifications result in negative adjustments to AWP (some things like vortex generators have no actual value, but paying points for them may make some owners feel better about having them). OEM hood and trunk may be replaced with lightweight components, but no other exchanges are allowed.

Adjustment Item
-0.5 Non-OEM spoiler
-1.0 Non-OEM wing
-0.5 Non-OEM air dam
-1.0 Non-OEM splitter
-0.1 Non-OEM vortex generators
-0.1 Non-OEM hood vents
-0.15 Non-OEM side skirts
-0.25 Non-OEM diffuser
-0.25 Non-OEM hood
-0.25 Non-OEM trunk

1.6 Free upgrades.

1.6.1 Brakes. The entire braking system may be freely upgraded (you won’t be going faster by going slower).

1.6.2 Suspension. Struts, springs, sway bars, and alignment are unrestricted. Stanced/slammed cars are welcomed (every competition needs losers).

1.6.3 Wheels. Wheel size and wheel spacers are unrestricted. Overstretched tires are appreciated (again, losers needed).

1.6.4 Interior. Steering wheel, shifter, pedals, and hand brake may be replaced (ideally with faux carbon fiber).

1.7 FTR. All vehicles are granted +0.5 AWP adjustment under the FTR exemption (Fuck The Rules).

1.8 Alternative Classing.

1.8.1 Real Measurements. As an alternative to rules 1.1-1.3, you may use actual power and weight with an adjustment of -3.0 AWP. Weight is defined as actual car weight with fuel and driver. Power is defined by wheel horsepower. Weight measurements may be taken by any method where there is a visible readout. Power measurements may be taken with a chassis dyno or phone apps that estimate power from acceleration. Weight and power measumements must be captured in photos or video and be featured in the walk-around video).

1.8.2 Sundae Cup. Any vehicle meeting the standards for GridLife Sundae Cup is also legal in SPEC-20.

2.0 Competition Rules

2.1 Events. SPEC-20 events are seasonal, asynchronous, track-dependent, and delta-based.

2.1.1 Seasons. There are 3 seasons, each lasting 4 months: S1 (January – April), S2 (May – August), and S3 (September – December).

2.1.2 Asynchronous. During each season, SPEC-20 drivers may attend any number of track days in order to record their fastest laps. Drivers need not attend the same tracks on the same days.

2.1.3 Track-dependent. Each track counts as its own event. If there are multiple configurations for a track, each configuration may be counted separately.

2.1.4 Delta-based. Drivers gain points by beating delta times. At the end of the season, each driver compares their fastest lap to the track delta table to earn SPEC-20 Points. The SPEC-20 rules committee may update delta times during the first month of any season.

2.2 Championships. There are Seasonal and Annual Champions as well as Track Aces.

2.2.1 Season. At the end of each season, the driver who has accumlated the most points during the season is declared the SPEC-20 Champion for that season (e.g. SPEC-20 2020-S1 Champion). Each driver may submit a maximum of 4 events per season.

2.2.2 Annual. At the end of each year, the driver with the most points is declared the SPEC-20 Champion (e.g. SPEC-20 2020 Champion). Each driver may submit a maximum of 10 events per year.

2.2.3 Ace. The fastest driver at each track is declared the Ace of that track (e.g. SPEC-20 Laguna Seca Ace) until someone posts a faster lap time, at which time the faster driver becomes the Ace.

2.3 Timing. Lap times must be recorded with a GPS-based timer with a live display of lap time. Approved devices include dedicated lap timers such as AiM Solo and phone-based timers such as Harry’s Lap Timer. AMB-260X transponders are not allowed (because fuck them, their fucking subscription model, and their fucking monopoly).

2.4 Video. Laps must be recorded on video with both the driver and live lap time in view. A camera mount anchored to the driver’s seat head rest works well. In addition to lap videos, a driver must also record a walk-around video at each event.

2.5 Protests. Anyone taking this series seriously enough to warrant protesting or filing a protest should go find a more serious racing series.

Delta Tables

A few examples are shown below. For a complete list, follow the link at the top.

BW13 – Buttonwillow #13

Points Delta
10 2:18
9 2:19
8 2:20
7 2:21
6 2:22
5 2:23
4 2:24
3 2:25
2 2:26
1 2:27

LS – Laguna Seca

Points Delta
10 1:55
9 1:56
8 1:57
7 1:58
6 1:59
5 2:00
4 2:01
3 2:02
2 2:03
1 2:04

ORP – Oregon Raceway Park

Points Delta
10 2:15
9 2:16
8 2:17
7 2:18
6 2:19
5 2:20
4 2:21
3 2:22
2 2:23
1 2:24

PIR – Portland International Raceway

Points Delta
10 1:39
9 1:40
8 1:41
7 1:42
6 1:43
5 1:44
4 1:45
3 1:46
2 1:47
1 1:48

RMP – The Ridge Motorsports Park

Points Delta
10 2:13
9 2:14
8 2:15
7 2:16
6 2:17
5 2:18
4 2:19
3 2:20
2 2:21
1 2:22

TH5 – Thunderhill Raceway Park 5 mile

Points Delta
10 3:40
9 3:41
8 3:42
7 3:43
6 3:44
5 3:45
4 3:46
3 3:47
2 3:48
1 3:49

TH3 – Thunderhill Raceway Park East

Points Delta
10 2:20
9 2:21
8 2:22
7 2:23
6 2:24
5 2:25
4 2:26
3 2:27
2 2:28
1 2:29

TH2 – Thunderhill Raceway Park West

Points Delta
10 1:35
9 1:36
8 1:37
7 1:38
6 1:39
5 1:40
4 1:41
3 1:42
2 1:43
1 1:44

11 thoughts on “SPEC-20

  1. 1969 BMW 1600; 2200lbs.(measured, wet) 72whp(measured), so ~90bhp? –> 24.4 BWP.

    Adjustments: engine swap to 2.0L (previous owner, ugh, i’m out), ok, or, carrying on…
    -0.5 air dam (hella functional at 50mph…), -0.25 front seat (haven’t found cheap solution safe for roll bar), 0.0 roll bar/rearseat!, +0.5 FTR…

    and just did a track day –> 2.22 #13cw. doh! no points…. but easily a couple more seconds if i stop buggering a couple of corners…


    1. FYI, vehicle weight (if you don’t have Ian’s big scale) can be had at a place that sells pavers. some scales are certified for the DMV, just ask. generally they’ll let you do it for free. +/-20lbs, but still….

      also, iphone dyno apps. dyno’d my car last year during lunch at a place about a mile away for $100 (spent the rest of the day at work reeking of burning oil…. needs a rebuild), and then got an iphone app and tried it on the way home. same curve and peaks within 1-2%. i can only imagine the power was so low the time from 2000 rpm to redline was SO LONG the app has LOTS of data points to smooth / integrate. and the speeds were so slow there’s essentially aero involved. and certainly no grip effects. when i get a rebuild i’m going to do it again and see what happens…


      1. Kyle, which app? I imagine that some are better than others for sure.

        Alternately, Ian, that makes me wonder if it make more sense to define classing in 0-60 or 60-100 times. Not only would those be easier to get to, it seems like that’s really the whole point since it covers all kinds of aero/power/etc issues. Just a random thought.


      2. Oh, that is much simpler. Good idea. I think a good way of measuring performance in a time trial setting would be to examine the acceleration on the straights. Something like 40-90 mph depending on the track.


    2. At 24.4 BWP motor swaps should be legal. Your car is certainly in the SPEC-20 performance expectation. I need to modify rules a bit to accommodate. Maybe 2:12 is too low for the 10 point Buttonwillow delta time. Maybe I should set the base values to 107% or something.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s