Announcement

**Fair!** · 09-05-2024, 03:06 PM

Update:

While there was a Fastrack dated November 2023 advising members about Max removing the alternative classing...

That never made it into the official online rules page, at least as of 9/5/2024:

Who knows what tomorrow brings. Very likely: more change.

**Fair!** · 02-10-2025, 02:39 PM

More on this subject - my latest letter to the SCCA TTB, submitted Feb 10, 2025:

I am prepping two new builds at our shop (Vorshlag Motorsports) for Max4 and Max5 class and have some questions about interior prep limits. Unlike many Max builds that are just Tuner cars with a wing clapped on, we want to maximize weight reduction on our builds, but without running outside of the Max prep levels.

Our BMW E30 Max4 build: https://photos.smugmug.com/Racing-Ev...MG_5890-X2.jpg

I have already asked about some engine swap specifics on the BMW E30 above, but I?ve got a question about our Max5 1995 BMW M3 build. Our 1995 BMW M3 is particularly heavy at the moment and we are chasing pounds.

Our M3s weight: https://photos.smugmug.com/Projects/...0012325-X2.jpg

There aren't a lot of "fully prepped" Max cars in the Texas region and only a few at the 2024 SCCA TT Nationals. I tried to scrutinize cars there for commonly done weight loss changes, and I did see a lot of interior mods "under the skin" on Max cars that I want to replicate - if deemed legal.

As this SCCA TT series grows in popularity, more and more builds get bumped into Max. I encourage folks to look at that category if they like to tinker, as it seems most aligned with the Builder Classes in Solo: CAM/XS, Street Mod, and similar classes.

I want our TT Max builds ? which we document thoroughly with forum build threads ? to be a good example for others when it comes to what is legal, what to chase to improve performance, but without gray areas.

Max 1.1 Philosophy - "Max Category is a place for enthusiasts to maximize the street-worthy car of their dreams with minimal limits on engine, suspension and bodywork. Max Category vehicles must have all road-going equipment such as headlights, tail lights, blinkers and windshields/windscreens"

That wording seems to allow a lot of leeway. Aero, suspension, brake, body, and performance modifications are well worded and lined out in the existing Max rule set. But interior modification - outside of the Safety Level 2 and Level 3 loopholes - just don't state very much.

Max rule 1.2.2 Interior - talks about a few interior components "like panels, carpet and seats may be replaced (but not removed)" but says little else.

What about the heater, air conditioner, radio, speakers and the like? We removed the conditioning condenser and auxiliary fan ahead of the radiator from our Max5 car from the following rule:

Max rule 1.6.3 Cooling states, "Cooling systems for engine, transmissions and differentials are unrestricted"

From that I infer that we can remove the engine radiator related bits, but what about the parts under the dash?

https://photos.smugmug.com/Projects/...MG_6090-X2.jpg

Remember, some kit cars are allowed in Max (which I think is a mistake, but that's another topic) and most of those won?t have a heater core, evaporator core, interior HVAC duct work, controls, or things like car radios. What about the factory gauges ? there is nothing spelled out, and ?If modifications are not specifically authorized in these Rules, it is not allowed.? We plan to use digital dash screens on both cars, and removing the factory gauges would make sense.

I am just looking for some clarity before I make changes on our very publicly shared builds that are not what the rules makers intended. Very likely I am missing some this is commonly removed rule for Max. Thanks for any clarity on these unlisted but commonly removed items for Max prepped TT cars.

Thank you,

Terry Fair - SCCA member # 338999

EDIT: I received an indirect answer from a member of the TT Board, which brought some clarity on the bare minimum interior HVAC item basics needed for Max: a heater

So we added an electric based heater with a blower motor, and all is good. No radio, no speakers, no air con. The heater is shown above with ducting going to the defrost vents. It 100% functions as a car interior heater, and is all electric.

We would say that our Max5 1995 BMW M3 has a complete interior and is 100% beyond reproach, and visually includes more items than some other Level 2 Safety prepped Max entries we have seen. It has a full dash with no gaping holes. A full interior ahead of the roll bar, including: recovered A- and B-pillar panels and headliner. An aftermarket set of carpet covers all areas of the floor required. And a functional heater / defroster.

This is the official response from the SCCA, which came weeks later.

**Fair!** · 06-17-2025, 07:10 PM

My latest rant about SCCA TT "Rules I Don't Like" (TM) - my latest letter to the SCCA TTB, submitted June 18, 2025

LEXAN ALLOWANCES - A SIMPLE ASK

Let's talk about Lexan windows in Max category classes. Or if you like, lets just make this part of the Safety Level 3 allowances. Please keep an open mind and look at my reasoning, as I've already tried to get this changed and lost.

After running three seasons in SCCA Max1 and one season in Unlimited, I am ready to make a class change back to Max - which has more entries, and a more realistic set of rules and limits. I am asking the TT Board to not make me do this in the most difficult way possible, for a car that was previously legal but got bumped to U1 from a rules take back.

After half a season in the dumping ground for unwanted TT cars that is called "Unlimited", and running against some truly ridiculous cars (including a local 1400 whp twin turbo Pikes Peak car), I'm am realizing this was a huge mistake. We made some changes to our car after it was forced out of Max, to try to make it more competitive in Unlimited, and most of those have either blown up in my face or made the car a real challenge to load, transport, drive, and work on.

FULL CARBON OK, BUT LEXAN NO WAY!

I will start off with the comparison of basic allowances allowed in Max class: We can swap all body panels to alternate materials, like carbon fiber. These are lighter, much more costly, and more fragile. I am OK with that because this category isn't called "Middling" it is called "Max". This should be "the builders class", like CAM / XS are in SCCA Solo.

We jumped through the somewhat ridiculous hoops to have a "full interior" when the car had Level 2 safety, and even kept much of that after adding Level 3 safety with: door panels, carpet, dash, center console, the works. Adding the cage made a headliner and upper interior plastics impossible to fit, but again - this is Level 3 Safety equipped.

Before going to Level 3 Safety, this 2015 Mustang had a Lexan rear window installed in 2022 in preparation for a future rear wing project. We ordered this back Lexan window from Plastics 4 Performance (a supplier out of the UK) at the cost of $254. It weighed a bit over half what the glass window weighed, but on a 3600 pound car, that 9 pound savings was barely noticed. We installed this to make clearance for wing uprights and easier access to the back of the cabin.

This was when Lexan was legal in Max - it is explicitly allowed in CAM / XS, and Max class allowed alternate class rule prep (including aero differences - which were made Max legal in 2025). We were Max legal for 3 seasons like this.

IS TEMPERED GLASS A SAFETY HAZARD?

Now I am not advocating for FRONT Lexan windows, as a 2-layer, laminated, "safety glass" front windshield is a modern miracle. These are very strong, durable, and absorb energy very well when items get thrown at the front of a car - rocks, tire klag, birds, bugs, etc.

The hardness of the outer layer of glass also makes them work very well with windshield wipers without scratching, which a street car and even many race cars need and use regularly. Nearly impossible to scratch with bugs, wipers, and klag. So we ALWAYS use OEM 2-layer laminated windshields, even on our wildest customer race car builds. They just FUNCTION better than Lexan in front facing windows. Easier to clean also.

What I have an issue with is being stuck with TEMPERED glass in the side and rear windows on what most people would otherwise consider a "race car". Virtually all OEM cars as far back as the 1960s use tempered glass in these non-front facing locations, but it has its drawbacks. This technology was first discovered in the 17th century and patented in 1874.

Tempered glass is characterized by its built in internal stress structure, with outer surfaces in compression and the interior in tension. This structure is what causes it to break into small, blunt fragments rather than dangerous, jagged shards when shattered.

Club Racing and Endurance Racing organizations not only allow for replacing tempered glass with polycarbonate or Lexan plastics, they encourage it. When tempered glass shatters upon impact, and it explodes into thousands of small and hopefully blunt pieces, it goes everywhere - into the car, onto the track, shooting at your eyes, etc. Which is why road race groups don't want it in race cars.

MAKE IT A LEVEL 3 SAFETY ALLOWANCE?

Many of the cars people race in Max are at least Level 2 safety equipped, like our 1995 M3 below. That is what most Level 2 Safety prepped cars looks like - a 4-point roll bar, fixed back racing seats, and 6-point harnesses. But also carpet, door windows, headliner, center console, dash, and other interior requirements we went to a great deal of effort to meet. We pushed the rules to the limit of Level 2 - of course - but we're racers, and its what we do. Not everyone takes the prep as seriously, and that is fine, but many SCCA entrants do take things to the limits - which is why they are the ones that tend to ask for clarifications.

This car could technically be street driven, too, and has roll up windows, a heater, wipers, lights, turn signals - the works. But it gets transported to TT events in a trailer, because it is a 30 year old car and breaks down. And we aren't masochists who drive a prepped car with Max legal aero on the street. A splitter built to the limits of this category is going to be smashed on many public roads in a big hurry.

Going further to Level 3 Safety rules already allows TT cars to gut the doors and remove the side door windows completely (with the right kind of roll cage), as well removal of all of the interior carpets and plastics other than the dash. This Level 3 Safety prep work is legal in Sport, Tuner, and Max as far as I can tell. And that level of safety prep looks curiously like a club or endurance road race car....

Those Level 3 cars are almost never "street cars" in any way, shape, or form. Let's not try to fool ourselves that every Max car also has to be street driven. None of the ones we build are, but they do meet the letter of the rules - even if some rules seem arbitrary and tortured. I get it, its an image thing.

I don't agree with many of the requirements used in the Optima/USCA series, either, but they have to "look" like street cars for their viewers, too. But these "wants" by racing groups need to be clearly spelled out requirements and well written and easy to interpret rules. Any time a rules clarification is asked for by a competitor formally, there was a failure in the rules writing. There should be no grey areas, no ambiguity, no "that's not what we really meant" answers.

When a local endurance team that runs Champ, WRL and other local endurance series (that I co-drive with sometimes) in a 2014 BRZ asked me what SCCA TT class they'd be in, and I told them Unlimited 2, they thought I was nuts. That's when I had to explain that there was just one reason it wasn't Max legal - the Lexan back window.

The same Lexan window they are encouraged to switch to for safety reasons makes them ineligible for SCCA TT Max classes, even when they are already running Level 3 safety - which virtually any road race car meets. If the SCCA wants to attract endurance and club race drivers who run 200TW tires and who meet Safety Level 3 requirements to come run in SCCA TT, don't let a simple Lexan rear and/or side quarter windows run them off. Make it part of Level 3 Safety and this hindrance is gone.

I often get calls at my job or asked in person at the track to help class peoples' NASA TT cars for SCCA TT. I still encourage these folks to look at Max, as usually it is simply a matter of "Hey, just run a 200TW tire and you're there!" - and those series have seen more racers using 200TW tires in the last few years. But they think I'm lying when I admit that a race car with real aero, full cage, gutted interior, and carbon body panels is legal in Max... as long as they don't run a Lexan side or back window.

This limitation makes SCCA classes seem less serious than other groups, and with this one Lexan issue, they aren't wrong. Probably the top half of the NASA grid in our region would go to Unlimited, even if they switched to 200TW tires.

Again, I am not asking the board to allow front Lexan windshields, or to even remove door windows willy nilly, only to think about allowing side / rear windows to be replaced with Lexan or polycarbonate plastics for fully caged, Level 3 safety cars. Because it is such a common modification, and makes the car safer and only negligibly lighter.

LEXAN IS EASIER TO DIY INSTALL & SERVICE

Removal of window glass happens when you are installing a roll cage, and at our shop we pay a windshield supplier to come by and do this for us. Why? Because it is a tricky job to do, and the likelihood of a regular Joe getting a windshield, or side or back glass out intact is very low.

Then the installation requires some expensive adhesives and a DIY install is also practically impossible. We have paid as little as $75 per window and as much as $250 to have an existing window glass removed then paid as much again to have it reinstalled.

A pre-cut Lexan window is very easy to install, and can be done with relatively simple tools like a drill and a rivet nut installer.

After those threaded nut inserts are installed once, they don't have to be installed again. We like to seal these in place with 1" wide x 1/8" thick piece of weatherstrip foam, which is adhered to the window frame. Then the Lexan is lined up and bolted down and stays air and water tight.

Going to a bolt-in Lexan rear or side window makes removal and reinstallation a breeze - just remove the bolts and out comes the windows for welding room or other access and repairs. The typical DIY guy cannot do this at his home garage with modern tempered glass that is bonded in place.

WHY MY CAR WAS PUSHED FROM MAX 1 TO UNLIMITED 1

Do I have a dog in this fight? Of course I do. I ran in Max1 for 3 seasons in my 2015 Mustang, which has a rear wing that is just under 8.0 square feet (the aero limit in Max) and it is attached via swan neck mounts that attach to the chassis in the back seat area.

The wing mounts on our car mimic the S650 Mustang GT3 and GT4 class and street car GTD wing mounting. On our setup it bolts into the car at the back seat bulkhead using 4 factory threaded mounting holes (seat belt and child restraint anchors), plus two additional thru holes we drilled. Really stout, and I'm very happy with our setup.

This wing setup worked extremely well with zero changes in Max1 for us, and to fit the uprights onto the car without butchering the rear sheet metal or carbon fiber trunk, we used a Lexan back window and slid the upright mounts through the back window opening.

We built this whole setup to work with small cutouts at the lateral edges of the rear window - we cannot just go back to the OEM window and "notch the rear glass", as again: tempered glass shatters. I don't want to have to burn dozens of hours rebuilding the whole back half of the car to meet this rule, that was legal for 3 years before the Jan 1, 2025 take-back.

I'm not asking for Lexan window replacements in all Max classed cars or in front window locations, just make it part of the Level 3 Safety allowance - which is not a stretch, considering what Level 3 allows now. It is a safer material than glass when it breaks, it is also more easily removed for access - we can unbolt our and remove our back window in about 5 minutes. It also opens up the SCCA TT series to a number of other entries who would otherwise be Max legal - more customers, more competition.

Many of us are going to push the rules the moment they are written, that just happens. Rules stability is always appreciated, but on the other hand, rule take backs are not. Please work with us to attract more competitors to the SCCA Time Trial series by just adding this one line to the Level 3 Safety allowance:

Sample wording: Level 3 Safety allows Polycarbonate or "Lexan" windows with a minimum of 3mm thickness to be used in side and rear window locations. Front windshields which must remain OEM style laminated safety glass.

Thanks for your time.

Terry Fair - SCCA member #338999

Announcement

SCCA TT: Interior rules different than CAM/XS?

SCCA TT: Interior rules different than CAM/XS?

Comment

Comment

Comment