Hey guys, I recently got a set of soft 8's off craigslist that are 17x9 in the rear and barely clear the leaf springs. Im talking like...1mm. Ill have to get a spacer and im curious what the common rule of thumb is about clearance from the tire to leaf? Id like to use as small a spacer as possible because i plan on lowering the car soon. Also, which type of spacer is safest? The kind that will need extended lugs or the bolt on ones that have a separate set of pressed bolts? Thanks in advance
Yes, the tires are whats close to hitting the leafs. The tires are 275/40. As of now the car sits high enough the fender doesnt come into play. Once i lower the car ill most likely have to roll the fender lip
1/2" -3/4" at most. I havent taken an exact measurement yet but id say thats very close guess. Maybe a full inch but thats be getting paper thin close
Ideally, clearance should be based on the tires aspect ratio/sidewall height. IOW, you need more running clearance using tall balloon shaped 75 series tires than a very square sidewall 40 series tire would require. Running the tire 1/4" off the leaf spring is pretty common for the big tire guys but you need to factor in that the leaf springs geometry/clearance changes under extreme lateral loading/unloading. If you have softer rubber bushings that allow the leafs to twist and layover a bit more?.. then 3/8" clearance might be safer to compensate for some clearance losses during the extremes. I myself don't really prefer the look of shorter tires on the backs of these cars(50's would look better, IMO) but the sub-26" tires you've chosen will allow extra leeway for lowering. You'll want to measure clearance for rear wheel tubs(especially on the inside) during heavy suspension compression. A bit tougher to stuff a square tire further up into round'ish topped wheel tub.. if you catch my drift. Another thing to ponder here. Just like stiffer bushings help minimal leaf/tire clearance requirements.. they can also help shoulder to wheel tub clearance/reduce tire scrub as well. Conversely, bigger/stickier tires will cause more stress/torque/twist/movement in suspensions too. Stiffer leaf spring rates will also allow running tighter tire shoulder/wheel tub clearances because you're basically limiting suspension movement away from those potential contact points. Trust me here, many get them setup to where they may not normally rub on anything but if you've ever been forced to correct an old leaf spring rear suspension that's getting out of shape on you?.. touching a sidewall during the experience can cause some extra unwanted variables. Like some kind of dyslexic mixed up ABS system happening back there when you least want it. Ask any of the older air shock crowd and they will tell you that rubbing tires during an airshock/line failure at higher speeds will quickly make you second guess your driving skills. I've even seen crashes come as a result of overloaded air shocks failing and have also heard of some people losing their lives too. "Plan for the worst and hope for the best".. is pretty good advice for revamping tire and suspension designs far away from what the factory ever intended. More suspension clearance and safety margin is always better than less when you really need it most. Safety comes first.. then add as much cool factor as possible with left over clearances.
Hey Rogue: Keep in mind the suspension will move when you hit a ' dip' in the road sometimes enough to inflict damage to the tire itself. Ruined a good pair of Street/Strip Slicks that way . You might try having a friend or two move your car Up and Down while 'sitting' to check this out . Just my take on that . Thought I'd pass that on . Cometized (Chip)
