When a C5 Corvette takes the win in Grid Life Touring Cup, folks notice.. and when it does it two seasons in a row everybody starts to pay attention. That was the case with Matan Rosenburg taking the 2025 Grid Life Touring Cup. Taking is a bit of an understatement. Matan delivered one of the most consistent and competitive seasons in GLTC history, racking up 12 wins and 28 podiums, making it a season for the record books.
We caught up with Matan Rosenburg to ask him some specific questions about his C5 Corvette platform.
Editors note: The car has gone through several liveries so while the aesthetic may change, these are all photos of the same C5 Corvette.
Q: What’s the current setup of your C5 — engine, aero, suspension, brakes, tires, weight, and power output?
A: We've got a 525 ls3 with 4 stage Dailey drysump, Tilton clutch, 6060 transmission, c7 4.11 differential, brembo 380mm 6piston front brakes 345mm 4 piston rear brakes, BMW MK60 abs, weighing in at ~3750lbs after a race. We're runniung 305/19 Falken 660+ tires on 19x12.5” spec wheels. For aero we've got a custom undertray/front airdam along with an afterdark speed rear spoiler, Penske 2 way remote coilovers, and after darkspeed front and rear bumpsteer correction kit/camber bolts.
Q: How did the build evolve over time? Any major revisions or lessons along the way?
A: This car started its life as a race car years ago when it was raced in the one lap of America by Danny Popp. My dad purchased the car 15+ years ago as a relatively stock corvette with a cage in it. Over the years he built the engine, upgrade the brakes, drivetrain and suspension. He used it over the years to scratch the track day itch. Three years ago the exhaust broke and melted the leaf spring on the car and I fixed the car and started to prepare it for GLTC. Over the past few years I’ve rebuilt the car multiple times upgrading ECUs, the drivetrain a few times, replacing the engine, cooling, suspension, roll cage... almost everything completely!
Q: What’s your favorite modification and why?
A: We bolted in a c7 automatic 8l90 and had a fast shifting 8 speed shifter with paddle shifters. We had to remove it due to some issues with class rulkes, but I look forward to developing it further and we're looking into reinstalling it.
Q: Any budget-friendly mod you’d recommend to someone just starting out?
A: Drive your car! Make sure the tires aren’t too old and the brake pads have life and enjoy it! Build your car as your build your driving ability.
Q: What part of your build surprises people the most when they learn it’s still stock, or that you DIY’d?
A: I think the automatic was a cool project when it was in the car.
Q: What made you choose a C5 over other platforms?
A: I previously drove a Miata which is a well developed platform but not nearly as high of a performance ability. The C5 was doing well in the series and with my dads car sitting broken... it worked very well for my situation.
Q: What do you think people underestimate about the C5 platform?
A: How universal it is. You can build these and win in them in almost every single series they are allowed in.
Q: What has been the most challenging part of making the C5 competitive?
A: Keeping up with the constant rules being made to bring them inline with the class and continuing to make it better even after you think you’ve extracted everything from the car.
Q: Any C5 specific quirks or recurring issues that have tested your patience?
A: C5 diffs are a bit weak so swapping to the c7 was a big upgrade.
Q: What class are you currently running in, and what’s your best result so far?
A: I have ran the car in Gridlife GLTC for the past 3 years. I have over 20 wins and I won the championship in both 2024 and 2025.
Q: How do you approach optimizing your car for your specific class rules?
A: Gear ratio, power band, suspension tuning, maximum aero with the least amount of penalty in the rules.
Q: What’s been your most memorable moment or battle on track?
A: Multiclass pass for the win on the last lap at Laguna Seca this year.
Q: What’s a track or event that really showed you what your car was capable of?
A: Road America or Road Atlanta this year.
Q: How do you approach data gathering and analysis? What sort of tools do you use?
A: I have an AIM PDM that runs the entire car and logs ECU, lap, and a bunch of other data. I use it to check car vitals and lap analysis.
Q: How do you balance mechanical grip versus aero grip in your setup?
A: Based on the class both our mechanical grip and aero is limited by sizing. I run the maximum size tire for the class and the largest spoiler without taking a penalty. I run very soft springs and shocks to get the most out of the 200tw tires.
Q: What’s your general tuning philosophy — do you tune to suit the car, or to suit your driving style?
A: I set the car up to the track and make it fast but also try to make it easy to drive it consistently fast.
Q: What kind of tire and suspension setup are you running, and how does it affect your confidence behind the wheel?
A: 305 Falken 660+, Penske 2 way remote coil overs with Eibach springs. I’m able to do a lot of tuning with that setup. Sprint rate, shock pressure, adjustable sway bars, tire pressure, camber, toe.
Q: What does a “perfect lap” in your C5 feel like?
A: A lap you can spend as much time near the limit of grip without exceeding it which typically loses time.
Q: For someone new to tracking a C5, what’s the first thing they should address or upgrade?
A: Again, their driving! Then as they find the weak points there is plenty of info on what to replace those parts with.
Q: What’s one common mistake you see people make when setting up a C5 for competition?
A: Overly stiff springs for the tire.
Q: What’s a piece of advice you wish someone had given you before your first event?
A: Work on social media if you plan to race a lot!
Q: What’s next for your build or your racing goals?
A: I would like to move to a more professional series but I am weighing my options.
Q: Any big upgrades or changes on the horizon?
A: I plan to put my automatic back in and continue to have fun developing it.
If budget were no object, what would your “ultimate C5” look like?
A: Haha not sure. Maybe a C5R?
