b'TECH TIP PAGETech Tip 17: All suspension springs are not created equal. The spring steel material & theprocesses utilized in manufacturing the spring, play a big role in the PERFORMANCE of the spring. For decades all production car & race springsleaf & coilwere made with 2000 series steelbasically crapthat responded slow, sagged & lost rate with time & use.Hyperco came out coil springs made with 4000 series steel for Indy Cars back in the 80s. The 4000 series steel is simply a superior steel to the 2000 series. Much more expensive, but it sags less, loses rate less & responds faster than 2000. Today, AFCO, Eibach & others spring manufactures make coil springs from 4000 series steel.Japanese firm Swift makes springs with 5000 series steel that are better than the all the 4000 series steel springs. Again, a little more money, but better. But the very best springs are made from 9000 series spring steel from Renton & Draco. Amazingly quick response. No sag. Zero. No rate loss. Ever. Renton makes NASCAR springs. No coil-overs. Draco has a full line.In on track tests with data loggers & shock travel sensorscomparing 4000 series springs to Draco 9000 series springswith the exact same rateshave proven to make the suspension respond quicker, create more grip & run faster lap times. Funny thing is, were only talking a little bit more money. Draco coil-over springs are about $40 more than Hyperco, Eibach, AFCO, etc. The more you knowthe faster you can go.Tech Tip 22:A. Why not install a Rack & Pinion? We can achieve as much Ackerman as we want/need with a rackif were designing the frame from scratch. But we cannot place the rack where it really needs to be if were working with the factory subframe. Frankly, all the add-on rack kits weve seen have horrible geometry in Most applications.B. No Racer worth his salt runs a steering box with centerlink (aka drag link) linkagewithout squaring it all up. Just like correcting the geometry of the OEM suspension, if we want a good handling, proper & consistent steering race carwe have to square up the steering box & linkage. How?See pages 386-393 for a full tutorial.C. Our AXT-Star Centerlink is a game changer for steering box race cars. Slotted centerlinks to relocate the inner tie rod pivot point up or down are not new. Been around for years. But the ability to move the inner the inner tie rod pivot point inwards or outwards is brand new! Relocating the inner tie rod pivot point up or down simply provides us with more or less bump steer. Relocating the inner tie rod pivot point in or out (which changes the tie rod length needed) redefines the bump steer curve characteristics.If the bump steer shows toe-IN in lift & toes OUT initially in dive . but then toes back IN with further dive = the mounting points of inner tie rods is too narrow. If the bump steer shows toe-OUT in lift & toes IN initially in dive . but then toes back OUT with further dive = the mounting points of inner tie rods is too wide.The AXT-Star Centerlink can be setup for the optimum bump steer curve with ANY strategyfor suspension you choosehigh travel, low travel, different camber gains, etc.403'