BorgWarner Cartridge S300SX-E EFR 61.44mm (8380)

Great product shipped out fast easy install.

Brian R. was extremely helpful and spent a good amount of time answering my questions about switching to coilovers. He was a wealth of knowledge and made the purchasing and installation process very easy.

He is so genuine, he helped me out on which parts I should get for my wife’s ‘16 Veloster Turbo. Parts came super fast and was packaged beautifully

Havn't installed yet so I cannot speak to the parts, as they get some run time I will review. Brian at FI was amesome though all through the process. Had questions prior to ordering and he went above and beyond in providing me with answers. After I ordered the parts he called a few days later appologizing for not reaching out sooner, which is crazy cool since country was dealing with hurricane devestation. I didnt expect to recieve parts for a while however they all showed up in about a week. I will def do buisiness with them again and recommend them to anyone in the future.

I bought Silvers Neomax coilovers with aero spring rates (14k/12k) for my track car. The quality of them is great. Install was straight forward and they are easy to adjust and tune as needed. Real happy with them so far and I think they're the best value out there in coilovers. Great price without a sacrifice in quality or performance. Also Brian at FI PERFORMANCE has been great in responding to all of my questions. Has been a great experience so far.

Quality part.

Brian answered every time I called and answered all the questions

Excellent coilovers
The best customer service from Brian
Highly recommended
Car looks great and. Handles amazing

Works great it stiffens up the rear end and no more wheel hop best diff brace out of all I have used in the past, money well spent.

Installed the After Dark hooks on my C5: the rear hook was very easy, and if you only need one hook, it's a quick and easy install. Front is more work: you're going to want a step drill or right angle adapter, since clearance between the bumper and A/C condenser is tight. Drilling into the bumper is not trivial: it's hard, use cutting fluid and make sure your drill bits are sharp. Once it's drilled and the rivnuts are installed, it's easy from there. It's a good design, well made, and at a reasonable price.

The product was originally marked for 2005 and up gx470. I managed to fit it into my 2003 by flipping one of the front hanger mounts. Sound is throaty and deep a bit loud at first. But the sound has mellowed out after a few hundred miles. Hardest part was removing old exhaust had to use Sawzall. Make sure to buy the 2.5 donut gasket ahead of time. The system is high clearance. Its tucked between the frames no chance of hang ups.

It’s the best mod I’ve done. Should have been the first thing I did.

Brian was extremely kind and helpful to make sure I was getting set up with the correct products. The Brey Krause harness bar is extremely high quality. Don’t cheap out on safety stuff this is definitely the harness bar you want in your c5. The combination of great service from Brian and the quick arrival I highly recommend FI Performance and will definitely be using them in the future!

Five stars for the parts and service. Ride quality is better than expected for a coilover setup. And Brian was super helpful in getting the correct setup for my truck

Fits perfectly and does exactly what it needs to do. No complaints.