Keeping a long story short, it looks like I'm going to have to ballast up around 150lbs to meet min weight for class. I've admittedly spent so much time reading how to lose weight on my car the last few years, that I haven't spent much time focusing on how to add weight back into it for this circumstance. I'm looking for some photo inspiration on setups that have worked well for anyone here. Bonus internet points for those who have setups that are completely and easily removable (as I do still street my car). Any helpful links to where you got materials would be great as well.

 

Does your class have rules about where the ballast can be added and how much?

I remember seeing one autocross Miata that had a super beefy, heavily-overbuilt, 80+ pound "rear subframe brace" in order to get creative with ballast limitations.

In my M3 I have ballast bolted to the mounts that used to hold the passenger seat.

--Ian

 

There are a few SM builders that make weight boxes that bolt into the passenger seat mounting.

https://mazdaracers.com/store/produc...allast-system/

 

The class I'm referring to is ClubTR in Gridlife. As of today, there are no rules as to where it can be added.. Given the infancy of the class, its pretty open for creativity.

I've already got a pretty heavy steel frame seat (Sparco Sprint) on the passenger side. I'd prefer not removing it as doing so is a giant PITA. My initial thought was to have plates bolted through the floor on the passenger footwell as close to the seat as I could physically mount them, but I'm definitely open to options and better ideas on that...hence the thread.

 

I’ve seen folks bolt plates to the spare tire mount. Helps with weight balance in a track-stripped car to get more weight on the back end, as well as on the right side. Have also seen people do plates further back like in the trunk well to further dial in the F-R balance. 150lbs is a lot to add in one spot though.

As for materials, lotta guys I know will take old lead wheel balance weights and melt them into ingots with a hole or two drilled through them for bolts with big fender washers to hold em in place

 

What are your corner weights, start there. In front of the passenger seat might sound easy, but might not be a great place to put it. Start looking at any thing that might be heavier and gain performance. Bigger intercooler, frame rail braces for curb protection, 3” sch40 exhaust?? 150 lbs is a **** ton. We bolt giant plates to our e46 floors and they’re 37 each. Drilled and tapped one for a smaller 18lb plate. So 92 total. Feels crazy bolting them in for t3. 150 sounds insane for a Miata. What the hell have you removed.

 

I think you might wanna reread the rules a little closer pal; the way I read it, any car that doesn’t have a higher-displacement engine swap doesn’t have a minimum weight requirement listed.

There are only weight requirements listed for common engine swaps that gain displacement.

 

He's got a K24, which sounds like it follows this rule: "Vehicles with swapped engines that are larger displacement than originally equipped by factory must meet a minimum weight of 2550lbs lbs with driver."

 

ah yes that is valuable info I lacked lol. Signatures done show up on the mobile site.

 

this is what I used. Simple and cleanish solution. Other cars run weights bolted to the passenger floor, though I don’t see how you would get to 150 lbs using that method. At least not in a single location.

 

Either something super dense or probably going to have to add weight in a few areas. Over the right rear is a good place to balance out driver weight. I'd borrow some scales and start placing weights in places to see what helps the balance the motor. ClubTR has cars with pro setups behind them, so just throwing some weights is going to leave a lot on the table.

 

Here are my corner weights. This is taken with a ~1/2 tank of fuel as I recall. Top image is with me in the car and the bottom image is without me in the car.


150lbs is insane, well aware, hence the thread...

• In the corner balance chart above, that was using a 3lb Li battery. I did end up having issues with that battery, so I swapped back to a typical lead/acid optima yellowtop, which is 28lbs total (+25lbs heavier)
• I should just see if I can run with a 150lb passenger
• I like where your head is at with adding heavier mechanical components, I don't really want to change anything mechanical as I want the weight to be easily removable for the days that I don't need to run any ballast (HPDE's, etc). I'm using a naturally aspirated K24, so there aren't a ton of cost effective opportunities to change much there given how simple the setup is IMO.
• I need to re-scale the car with the new cooling system now that I've redone it. My luck, the new system is probably lighter and making this ballast issue worse haha.

Given the above battery comment, I may be looking at closer to 100-120lbs of ballast required, but you get the idea. Its not a small number.

I take some level of pride in the fact I've gotten the car this light without giving up a lot of creature comforts or making the car look like a gutted out track rat. Every wire, nut, bolt, and component has been touched in some sense throughout the car with the mindset of trimming weight without making the car "too racecar" and awful to drive on the street like I have admittedly done on previous cars. In short, the gram strategy was put into effect. I trimmed 8lbs of wire from the OE chassis harness as one example...

That said, I've got frame rail braces, barge board alumalite aero (functionally debatable, looks cool, but easy minor weight down low regardless), and sparco sprint seat assemblies (belts, seats, brackets) which are just over 30lbs each (relatively heavy for the fixed back seat world). The interior would by labeled by most people as "complete". I still have full OEM HVAC (without AC), still have a radio, still have a pile of suede wrapped body/door panels and carpet, still have an OE hardtop (soft top removed), still have power windows, full exterior road legal lighting and windshield wipers. My build thread details through all of this if you really wanna know the details, but I guess where I'm getting at is, I put some solid mental effort into keeping a decent amount of weight in the car already. I could relatively easily pull another 150lbs out from where I'm at now with minimal effort, but adding another 100+lbs back is where I'm looking for some inspiration.

 

Are you planning to be competitive and run a full season of ClubTR?
If yes, then this doesn't matter. You will want to setup/test the car exactly as how you run it in competition.
If no, you're just looking to add some "competition" to what's otherwise an HPDE, then just start adding lead/steel plate to the floors/trunk and run at maximum fuel load. It's not worth spending lots of $$$ when your not trying to be at the pointy end of the field.
Or to phrase this differently: Are you willing/able to spend the money and time to build a competitive car and need to find every edge possible, or do you just want to be able to compete, regardless of if you're consistently 7th place?

 

The short and sweet of this is, yes. Plan to run enough of the season to qualify for a season win, which ends up being 5 events.

That said, the ClubTR field (with exception of some few civic guys) all really struggle to hit min weight. Many of the S2K/BRZ crowd guys are in the 2700-ish realm. I'm currently positioned in a relatively unique scenario where my car is non-purposely already positioned at the tippy edge of the rulebook as long as I get it to min weight. Placing lead around the car in various zones may end up being the play, and for all intensive purposes, that may be far more competitive than most would think. As reference, there are no other kmiata's that have ran in this class to my knowledge.

 

I did the easy button and got ESR's passenger seat ballast setup:
https://mazdaracers.com/store/produc...allast-system/

I got a buddy to cut some 37lbs steel plates with his plasma cutter. I have 259lbs of plates and I think the seat bracket is 20lbs and the single plate from ESR is 15lbs so a total of 289lbs from the ballast itself.

Seems like you don't wanna deal with removing your passenger seat soooo maybe these could help? How much ballast are you looking to get, what's your min weight in Club TR for this coming season?

Bigass battery, our cars are always light in the corner anyways.
Fire suppression system in the front part of the trunk.
Cool Suit and big cooler in the passenger floor board
Spare tire put in or some type of heavy *** something in it's spot with a couple of other fasteners.
Full tank of gas.


Also, in regards to Kmiata being at the pointy end of Club TR. While at first it seems pretty logical, you'll want to peak at GLTC this season...... several Kmiatas have dropped back a ways after the move from Hoosiers to street tires. The short and skinny is the longitudinal grip of the shorter street tires is much less, thus short-tires are losing out multiple tenths on a regular basis. Almost all under braking as well. So much so that there's chatter on shorter tires getting a break for the 2023 season. Perhaps that will carry over to Club TR as well?!