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 18: One of the simplest & most predictable methods to tune handling balance, are rear wheel spacers. If you have enough tire room & a floater rear end with 5/8 studs, a smart strategy is to build the floater rear end 2 narrower (1 per side, as long as you have the room in the rear fenderwell/tub).Then utilize a set of various width wheel spacers for tuning. Our pro wheel spacer kit comes with 1/4", 1/2", 3/4" & 1 billet aluminum spacers.We dont want to get too far away from the front track width.If your front track width is 58. We often make the rear track width 57 without spacers & run 1/2 wheel spacers making the rear track 58 as a baseline, matching the front. From here, you can tune your rear track wider or narrowerfrom 57 to 59 in 1/2 increments.At a track, if we find we need more rear grip, we simply remove or lessen the rear wheel spacers. If we find we need more front grip, we simply add or increase rear wheel spacers. This simple strategy provides you with a quick, easy & predictable track day tuning tool. We dont use this strategy in the front because it negatively affects the scrub radius. It is a never ending cycle. Racing keeps changingso we have to keep learning & improving.327'