Originally Posted by Wookie420
That is apparently the issue. See the quote below from Schroth's website. The OEM restraints pass because the shoulder belts don't run down into the rear of the car.
Shoulder Belt Routing (applies to all restraint types)
· Shoulder belts must run from the shoulders horizontally or down, at no more than a 20° angle.
· In cases where the shoulder belts must be routed down to the chassis floor, support by a roll cage bar or harness guide at the appropriate height is essential to establish the horizontal shoulder strap routing off the shoulder/HANS®. Most racing seats are not designed and tested to carry shoulder belt crash loads from downward installation. Severe injury or death could result. A 45° downward shoulder belt installation is possible with seats that SCHROTH has positively tested to take a load measured during a 50 kph [31 mph] and 28 G impact with a 75 kg (175 lb) dummy. Refer to the list of SCHROTH approved racing seats in section “About Seats”. WARNING: 45° downward shoulder belt installation is not recommended with HANS®.
That's odd because Schroth markets the quick fit pro as HANS compatible.
Schroth has two lines of harnesses. One are standard 2"/3" harnesses designed to be used with a harness bar and bolted to the chassis. The other line, the tuning line, are designed to be integrated with the OEM restraint system.
Make sure that you are taking those quotes and applying them to the right product.