Club TR/ GLTC BMW E90 Part 1: Intro/Weight Reduction

If you didn’t know, we have many project cars. I can think of ten off the top of my head. With life being hectic and us being lazy with media, we have been doing you all an injustice. Starting today, I’ll do my best to write about some of your projects, starting with our Gridlife Club TR / Touring Cup BMW E90.

For the record, I’ve always looked at German cars as a mistake. They are over-engineered for simple tasks at times. This tends to lead to a lower component lifespan. They make their gaskets from paper towels because they always dry up, shrink, and leak. The myth is true about BMWs leaking every fluid they “contain.” I didn’t see any oil spill spots on the ground when I bought this car, but the E90 immediately puked all over it. I always thought BMW owners were a little different as well. Think about it: in what other car circles do you hear the phrase: “They are super reliable when reinforcing the shock towers and changing the rod bearings.” Coming from the Japanese car maker side of things, that sounds asinine. At most, with cars like my S2000, you have to change the timing chain tensioner when they start rattling, or in rare instances, they will jump timing.

With that being said, let’s switch things to a positive note. When a performance-oriented BMW works, they are great. I get those particular owners I talked about earlier now. When you buy a preowned beamer, you get a lot of car for the money (the depreciation of these is real), which balances things out. BMWs are worthwhile outside of complexity, cost of ownership, and depreciation. You have to simply where you can.

What is Club TR and Gridlife Touring Cup?
GLTC, a part of the Gridlife series, features 12-15 minute wheel-to-wheel races with four events per competition weekend. Points are earned based on race finish positions, not lap times. It’s a single-class series known for its high car count, often exceeding 30 cars and sometimes reaching 60. Cars like K-swapped S2000s, Corvettes, M3s, Caymans, and Miatas are common choices. Rules center around a power-to-weight ratio of 12.5:1, adjusting for factors like aero, transmission type, and engine specifications. E90s are relatively rare in the series, with one or two occasionally competing.

Club TR, short for Track Rat, is a budget-friendly time attack class. It limits modifications to the powertrain, allowing everything outside the engine internals to be modified. There are exceptions for reliability upgrades such as an oil pump and baffled oil pans, but to put things condense. The engine must remain sealed from the valve cover to the oil pan. Engine size is capped at 2.5 liters for naturally aspirated/ NA (or a special exception like the BMW, which is allowed to have a 3.0 liter NA engine that is not from a “M” series car) and 1.6 liters for forced induction. Everything outside the head port is a free game, except you can’t add forced induction to a non-forced induction car. You are allowed to run any intake manifold or exhaust manifold you want unless you are running a turbo manifold; then, it must remain OEM. Turbo internals must be OEM, and to that engine too, no secret sauce, Tommy Kaira, only five were made turbos are allowed. There’s no horsepower cap, but making more than 250 wheel horsepower with those restrictions is hard. You are also allowed a few aero mods like a rear wing (up to 701 square inches), a 3-inch splitter, and fender vents are permitted. The spec tire is Falken RT660 (255 widths), with a minimum weight requirement of 2500 or 2550 for swapped cars. It’s a flexible class that lets you customize your car’s performance while keeping costs lower than other classes like Street Modified and Track Modified.

On to the E90, Why?
One of the things that attracted me to the E90 was the N52 engine. The N52 comes in the E90 328i, 328i, and 330i are mostly the same throughout the models, except for the 330i’s intake manifold, which adds an extra valve to adjust the airflow inside, adding power. With modifications like a tune, exhaust, 330i intake manifold, and intake changes, these engines can reach around 220-230 wheel horsepower. I like the N52 because it is highly reliable, which, as you know, isn’t a strong suit of BMWs. The N52’s engine block is magnesium. Magnesium is lighter than aluminum but more prone to corrosion, which is problematic when coolant flows through it.
Consequently, the N52 engine’s inner block’ is aluminum, leading to the use of aluminum bolts and fasteners. BMW often prioritizes over-engineering. The E90 chassis is stiff and abundant, making replacements easy. It has a racing pedigree in events like the World Touring Car Championship and Continental Challenge, resulting in aftermarket performance parts availability. For GLTC, achieving a weight of around 2700 lbs without exotic materials is ideal.

Kick things off with less weight.
With all things equal, the lower your power-to-weight ratio is, the faster your car will be. A lighter car is easy to accelerate. As cliche as that sounds, a vehicle that accelerates quickly can be the difference between winning and losing. Lighter cars are generally more agile and responsive. They can change direction quickly, making it easier to maneuver through corners. Lighter cars require shorter braking distances because there is less momentum to slow down. This improves the car’s ability to decelerate quickly. This also aids in less stress on tires, reducing tire wear. Ask a C6 Corvette owner about their consumable cost. Stopping, turning, and accelerating a 3100lbs car will cost you far more than something like a Lotus Exige, even though they have similar power-to-weight ratios. Even though I listed all these benefits, don’t go outside cutting everything off your damn car. It’s essential to have a light vehicle and keep your chassis as stiff as possible ( for a racing application). That’s why it’s best to replace heavy components with alloys, titanium, carbon, and fiberglass to save some weight. If you are budget-orientated like us, though, FRP is king.

Downsides to having a light car
Blasphemy, I know. There are a few things to having a car that is too light. For one, they are typically more fragile. Lightweight components tend to crack or crash more easily. An example would be a car door made out of FRP/Carbon, which absorbs far less impact than the one made out of steel (like on most passenger cars); the FRP would be less tough. Toughness is the ability to withstand shock loading without fracture in nerd engineering terms. Extreme lightweight vehicles can be more susceptible to instability at high speeds due to reduced downforce. Fun fact: the more your car weighs, the more traction it has. Have you ever wondered why we use lbs when discussing downforce numbers? Essentially, you add that much weight to the car, increasing traction. Lastly, but likely the most important thing, is cost. Building a race car is costly, and lighter components can get expensive quickly. Look up a dry carbon anything, and your eye may shed a tear.

So what Can we do?
Ideally, I want to get the E90 down to 2550lbs. I’ll tell you right now. There is no fucking shit that’s going to happen. Club TR does not allow you to gut a car like the good lord intended completely. I can’t hack away on the chassis because it has to remain in stock with no “fabricated components.”

The doors must also remain stock; I have four, so that’s not ideal. Speaking of four, each of those doors must have OEM glass in them as well, which polycarbonate (Lexan) would have helped cut down some weight. I also have to retain “OEM interior components,” but they can be trimmed or modified to accommodate safety items like seats and rollbars. However, most people in the class remove most things inside when a cage or rollbar is added. I notice that all dashes and door cards are intact, so that I will follow that lead. I am also allowed bolt-on components like a hood and trunk to be made from alternate materials like fiberglass, carbon, aluminum, etc.

So This is what we did.
I am starting with the “free” weight reduction, and that’s ripping out the interior. It’s legal because I wrote my intentions here. You all see it. You are my witnesses. I’ll be reusing a seat and steering wheel I had in my last two track cars. This should save a big chunk compared to the OEM Sport seats and steering wheel. I also removed all the components from the truck. The E9x series has a plastic panel that holds the spare tire/emergency stuff; removing it leaves a nice-sized hole to the ground. I’ll need to cover this hole in the future. I don’t want debris flying in or exhaust fumes coming up. I also shed some weight with the backseats being yeeting to the curb with all the airbags in the car. The previous owner did me a solid with getting rid of the factory resonators and mufflers already. The most significant weight decrease may come from my not being so fluffy. Going on my race car diet, I always forget that if I made myself jockey-size, that’s 50 fewer pounds to cut from the car.

Pump the Brakes
Based on Controller Area Network (CAN) technology, the BMW electrical system offers numerous advantages. It enables high-speed data transfer at 500kb per second, facilitates control of various subsystems, and provides real-time alerts and independent system checks. Aftermarket gauges often use OBD2 ports for critical powertrain data.
Chaining CAN modules is standard, offering backup and simplifying diagnostics, reducing repair downtime. It allows for modular customization, reducing development costs. However, chaining can complicate issue resolution, increase signal susceptibility in harsh environments, and add wiring complexity, requiring careful management.
A detailed examination of schematics and coding is essential to avoid unexpected issues and explore further possibilities. That said, I want to ensure that I don’t eliminate something that will leave the car stranded or acting insane. I don’t want to be on the wrong end of discovering the BMW myths about electronics ruining my day.

Up Next
We’ll cover suspension travel adjustment, spring selection, alignment customization, aero positioning, fine-tuning settings, and more. I want to help you seize the often-overlooked, low-hanging fruit in building a race car. I’m here to assist and prove that your race car can look great while performing well and breaking the ‘Send-It shit boxes’ mold, one reader at a time. We aim to break stereotypes and demonstrate that a high-performing race car stands out from the rest even in the world of the META Corvette (it’s nerd gaming meaning for a generally agreed upon strategy by the community, e.g., a particular chassis dominating the field).

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.