ZF Design

I can’t recommend Zach at ZF Design highly enough. If you own a Subaru and care about performance, reliability, and doing things the right way, this is the place to go. ZF Design is widely known for their expertise in Subaru transmissions, but they’ve expanded into engine blocks, accessories, and performance parts as well, and the level of knowledge behind the work is second to none. Zach is easily one of the most knowledgeable people I’ve ever met when it comes to Subaru performance. He doesn’t just replace parts, he understands the engineering behind them and takes the time to ensure everything is done correctly. What really stands out is the attention to detail. Every build is approached with precision and care, and the shop itself reflects that mindset. The facility is state of the a

I can’t believe I never wrote this review! I’ve driven almost 20,000 miles on this build now, so I guess you can trust it when I say I’m happy with it so far. ZF Design is THE transmission shop. If you want your car to have a tranny built by the same shop Flatirons Tuning trusts to build their Pikes Peak Hill Climb STI transmission, then you’re in the right place. Needless to say, their work speaks for itself. Absolutely top quality work from quote to delivery. This shops knows their transmissions. Zach set me up with Type RA 1-4 gears, we kept oe5th for cruising. carbon fibre coated 1&2 synchros and several other really nice bits. It’s a fun box and I couldn’t be more grateful for Zach’s excellent customer service even years later when I call for advice. Don’t bother shopping for othe

They have a new customer for life. I’ll try my best to explain my experience. I recently bought a WRX that I was told only had a small oil leak and a brand-new transmission. No problem, right? Well, long story short, after driving about 10 miles, the clutch started chattering. Not the end of the world, but definitely frustrating. My son and I pulled the transmission, and the clutch looked like a 16-year-old learning to drive had smoked it. I’m honestly shocked I didn’t notice during the quick test drive around the block. My son told me about ZF Design. About five years ago, he bought a clutch kit from them. There was an issue with the throwout bearing in his kit compared to what he needed. The owner personally drove to our house to swap it out. That kind of customer service is almost un

Great customer service, Zach is probably the most knowledgeable Subaru expert in Colorado… I did get talked into a sequential, so just be careful with saying “I want to go fast” in there.

Had my 02 2.5RS transmission rebuilt but ZF. I took their advice and put in a carbon syncro on 1st and 2nd gear. Also did a slightly longer 5th for better highway cruising. Wow. What a change it made for the vehicle. They showed me everything that was inside my transmission and explained what was wrong and why. Cannot recommend them enough.