Should Same Size Tires Be Used On Front And Rear For Pro Touring Or Autocross?

04-30-2015, 08:56 AM

Been here a long time agone, and made several choices that I felt were better choices for performance, and saved money for not buying wiz-bang parts that don't work as good. Couple affair to bespeak out:

Yes, you can go to a fairly broad tire on the dorsum of a mill 2d gen without chopping things up back there. 305 is enough broad, and at that place's no reason to go larger than that from a performance stand up signal. Drag racing yes, wider is ameliorate, only non and then when etching corners. Keep in mind, the larger the contact patch, the less downwards strength on the contact patch, so it is possible to go besides big. 2d gens are kind of calorie-free in the back as it is. 295-305 is enough. And there are cases where y'all tin go to a 315 without mini-tubbing. Roll the lips, bang the seat belt burl in, slightly shorten and center the rear, and run optimized offsets on the wheels and you're done.

You lot need to run a cycle that has proper clearance for larger calipers, so THAT is the key gene on the wheels. Only way to practice that is to use templates to limit the risk of not plenty clearance. I say limit, because even afterward checking, you may withal have problems. No way is a 17 going to work by the way, it will take to be at least an eighteen. Staggering the sizes is up to you, only personally, I stay the same bore front and rear, to limit any tire size/matching problems.

Personally, I recall the 4-link setups for the rear of a 2d gen is a total waste of coin. With a properly setup and tuned 4-link, the difference in operation is so slight that a good commuter could use the OE leaf arrangement and proceed up or surpass a four-link setup. And so the price is hardly if at all justified.

On rear ends in 2d gens. First, 2nd gen rears are not centered, and are generally start to the passenger side some. Why? Considering the pinion gear rides on the side of the ring gear, and to keep the driveshaft straight, information technology has to be. This makes it tough to clasp tires in at that place, you bank check the fit on the driver side, then the rider side doesn't fit. GM wanted to standardize replacement parts, then axles were the aforementioned length. The all-time way to correct this is a custom width rear that slightly shorter on the passenger side.

Total width. Since disc brakes require additional space for the rotor to mount, it'southward best to shorten the rear to account for that. To account for the rotor, i/ii per side is standard. You may want to become slightly shorter to heart the wheel over the axle begetting, which is the best spot for reducing bearing loads, but that means yous have to know what your bike width and tire size is going to be. Remember, you tin can go too far inboard, because every bit the tire rolls on the wheel around a corner, the tire 'bulge' can contact the foliage spring. And moving the leaf inboard compromises stability. (think 'wide-track'?) Talk to Moser about total width and recommendations in that location.

Strength. Scratch the ten commodities first of all, over time, you lot will destroy it. That leaves the 12, lx, and nine. A 12-commodities will do you fine at your CURRENT power levels, but if you ever bump it up a few notches, information technology will be similar running a x-bolt at your current level. Over time, it will become away. Only, IF you were to do a 12-bolt, spiral going used, get a Moser NEW 12 bolt housing, and take the 'Torino' ends installed, and you tin even accept like a ane/2 degree camber added to ameliorate cornering. 'Torino' ends are called that because Ford apply a large, commodities on flange type bearing on the Torinos with the ix". Those tin be added to the 12 bolt, and that's the hot ticket. S60 and nine". What makes them stronger is the pinion bearing support (for the nearly role). There are slight differences between the 2, but both are almost every bit potent, and it takes big power to tiffin i. Affair when you run either is that for one, no way can yous run a crossover muffler (but that might not be a concern on a truthful performance motorcar). FYI - toll of a 12, S60, and 9 are all roughly within a 100 or so bucks of each other.

Other rear mods: Aside from centering the rear so you can clasp the largest tire on, and the addition of a little pulley, have dissimilar pads for mounting put on. Use the single leaf mount pads with multi-leafage springs, and delete the rubber isolators. That way the locating pivot positively locates the rear, and there is no way it can move around. Big power cars or even cars with slicks can popular the locating pin right out of the prophylactic/poly mountain and push the rider side of the rear forward, which will make contact with the quarter and brand a mess.

Intermission: Never had any luck with Hotchkis springs, e'er as well soft, and inconsistent rates. Simply way to go is Global W, unless you are a interruption guru and tin can source directly from functioning spring manufacturers, and I'm non talking virtually Detroit Bound or places similar that. (They are always way off on rates and consistency). Landrum, Afco, and the like are the places to go, and believe Landrum does the leafs for Global West. The Global Due west leafs with the delalum bushings are the style to get. Tell them what you're doing and they will provide the proper rate for front and back, and blast the opinion commencement fourth dimension. Use their' tubular command arms too, and go to C5 uprights, mainly because of the bearing packs. Those uprights likewise allow for a broad variety of brake options, since they apply C5/C6 components.

Subframe connectors (weld in), at to the lowest degree a 4-point whorl bar, solid frame bushings, and firewall braces are minimum. Chassis needs to non deflect so you tin can tune using shocks. I use the 1/2" lower body mounts too, but take to have that into consideration when squeezing tires in. Practise the Herb Adams anti-squat modernistic.

In that location are 2 approaches to springs and bars, soft springs big bars or stiff springs and minor confined. I use a combo of both and information technology works real well. 200 leafs, 700 springs, i/25 front bar, and still on the contend on the rear bar, will most likely apply a 1". Skip the Guldstrand mod, parts these days take that into business relationship, and it mainly applies to 1st gens.

Transmissions: 6 speeds are a waste unless you run a pocket-sized cake. At one end or the other, that actress gear becomes worthless. Y'all tin go a cryo TKO 600 and that should exist plenty strong, especially if y'all don't run slicks or do lots of drag strip launches.

Anyway, this is a big discipline, there's plenty of 'cooks', so you're going to see a variety of opinions, even among the so-called 'pros' in the industry. I say practise your homework and do it well, and use as much common sense as possible.

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