IER P13b Endurance Prototype: is this $4.95 stack worth it for Gaming?
If your Assetto Corsa garage is stuck in a weird gap between GT cars and full LMP1 hypercars, you know the frustration. You want a prototype that feels fast and technical without requiring a 3,000-horsepower engine or a budget that doesn’t exist. That’s exactly the hole the IER P13b Endurance Prototype fills. It’s a P2-class machine built for Pro-Am racing, packing a 2.8L TT V6 with just under 500 horsepower into a 900kg chassis. For the price of a coffee, you get a car that slots perfectly into multiclass events, offering LMP1-like downforce and cornering grip without the terrifying power delivery. It’s a specific, well-rounded tool for sim racers who want endurance credibility without the complexity of a full Le Mans Hypercar.
Quick answer
| Best for | Assetto Corsa players who want a realistic P2 prototype for Pro-Am multiclass racing. |
| Skip if | You don’t have Custom Shaders Patch (CSP) installed or you’re looking for a pure LMP1 hypercar experience. |
| Price | $4.95 |
| Format | 140 MB digital download (requires CSP v0.2.3+) |
| One-line take | A realistic, accessible P2 prototype that bridges the gap between GT and LMP1 for multiclass fun. |
What you’re actually buying
At $4.95, the IER P13b Endurance Prototype isn’t just a car file; it’s a complete simulation package designed to work with modern Assetto Corsa tech. The core of the deal is the vehicle model itself, built around 2013 LMP2 regulations but with some LMP1 styling embellishments. This means you’re getting a car that looks competitive on the grid but drives with the nuanced, manageable characteristics of a Pro-Am machine. You’re not buying a hypercar that punishes every minor input; you’re buying a 490+ HP, 900kg prototype that exceeds 190mph and holds 3g+ in cornering acceleration.
The technical depth here is what justifies the purchase for serious sim racers. The car is specifically designed to utilize the “Output real steering forces to wheel” setting in Custom Shaders Patch (CSP). This isn’t just a cosmetic feature; it allows for accurate modeling of power steering, which makes the driving experience feel significantly more connected and realistic than stock cars. The listing includes liveries by ANCORD Design Co. and audio work by mikekrybus.com, ensuring the visual and auditory presentation matches the high-quality physics. You’re getting a 140 MB download that integrates seamlessly into Content Manager, ready to slot into your existing endurance events. (IER P13b Endurance Prototype)
This is a “ready-to-race” product. The seller, IER Simulations, has a history of building cars that leverage the latest CSP technology to push what’s possible in Assetto Corsa. The P13b is part of that lineage, offering a “vital take” on prototype racing that feels current and responsive. If you’ve been running GT3s or LMP1s and felt the middle ground was empty, this car provides the specific texture you’ve been missing: enough downforce to be fast in corners, enough power to keep up on straights, and enough mass to feel stable under braking. (IER P13b Endurance Prototype)
Why it’s on our radar
This car is interesting because it targets a very specific niche in the sim racing community: the Pro-Am endurance racer. Most content for Assetto Corsa tends to skew toward either very accessible GT cars or extremely complex, high-power LMP1 machines. The IER P13b sits comfortably in the middle, offering the technical challenge of a prototype without the intimidation factor of a 700-horsepower hypercar. It’s a car you can learn, master, and then use to test your endurance skills against AI or other players in multiclass races.
The fact that it’s built for the latest CSP versions means it’s not a relic. It’s a modern implementation of an older regulation, which gives it a unique character. You’re getting a car that feels like it belongs in a 2013 Le Mans race, but with the software fidelity of today’s sim tech. For the low price point, it’s an easy “yes” if you’re already invested in the Assetto Corsa ecosystem and CSP. It’s a small addition to your garage that can significantly expand the types of events you want to enter. (IER P13b Endurance Prototype)
Buyers have noted the quality of the physics, with one Gumroad review calling it “simply the best prototype physics available for assetto corsa today, I recommend this content 1000%.” Another Gumroad review added, “Excellent work by the IER team, as always. The P13b is fantastic.” These comments highlight the consistency of the IER Simulations brand and the specific appeal of the car’s handling model.
What actually matters
Before you hit the buy button, there are a few specific things to check to ensure this car will work in your setup. (IER P13b Endurance Prototype)
- CSP Version Check: The car requires Custom Shaders Patch v0.2.3 or v0.2.4p1 (or higher). If you’re running an older version of CSP or using a different shader mod, the car may not function correctly, particularly regarding the steering force feedback. (IER P13b Endurance Prototype)
- Steering Setup: The listing specifically suggests using the “Output real steering forces to wheel” setting in the FFB Tweaks tab of CSP. This is crucial for getting the intended driving feel. If you’re used to stock FFB, you’ll need to adjust your expectations and settings to match this car’s design. (IER P13b Endurance Prototype)
- Tire and Brake Management: The seller recommends using tire blankets for your first drive and warming your brakes on the outlap. This is a sign that the car has realistic thermal models. If you’re not used to managing tire temps and brake fade in Assetto Corsa, this car will teach you quickly. (IER P13b Endurance Prototype)
- Multiclass Fit: Consider where this car fits in your existing garage. It’s designed to slot between GT and LMP1. If your events are strictly GT3 vs GT3, this car won’t be relevant. But if you run mixed endurance races, it’s a perfect addition. (IER P13b Endurance Prototype)
Mid-check
If you’re ready to add a realistic P2 prototype to your Assetto Corsa garage, See current options.
FAQ
Do I need Custom Shaders Patch to use the IER P13b? Yes, the IER P13b Endurance Prototype requires Custom Shaders Patch v0.2.3 or higher. It is specifically designed to work with CSP’s advanced steering force features, so running it without CSP will result in a suboptimal experience.
Is this car suitable for beginners in Assetto Corsa? It’s best suited for intermediate to advanced sim racers. The car has realistic tire and brake thermal models, and the power steering setup requires specific CSP settings. If you’re just starting out, you might find the learning curve steep. However, if you’re comfortable with GT cars, this is a natural step up. (IER P13b Endurance Prototype)
How does the IER P13b compare to LMP1 cars? The P13b is a P2-class car with 490+ HP, whereas LMP1 cars typically have much more power. The P13b has similar downforce levels to its LMP1 sibling, which gives it excellent cornering ability, but it’s limited by an off-the-shelf tire compound and lower power. It’s designed for Pro-Am racing, so it’s more accessible and less punishing than a full hypercar.
Bottom line
The IER P13b Endurance Prototype is a sharp, specific tool for Assetto Corsa players who want to dive into Pro-Am endurance racing without jumping straight into the LMP1 deep end. At $4.95, it’s an affordable way to add a realistic, high-downforce prototype to your garage, complete with modern CSP integration and high-quality visuals and audio. If you’re looking for a car that bridges the gap between GT and LMP1, this is a strong option.