Mustang SVO RallyCross/Stage Rally

I would either swap the hubs or prepare to buy a whole pile of expensive custom spec rally 15s from Braid or a similar manufacturer.  Those Maxsports will be OK at first but they're not tough like real rally tires... which, as you've discovered, are almost exclusively available in 15" and smaller.

EDIT:  Messing around on wheel-size.com shows some Dodge/Chrysler minivans with appropriately dimensioned 15x6.5" wheels, maybe try those?  Also seeing early Explorer, Wrangler, Cherokee for 15x7" but a lower offset, which may or may not work depending on how much room your wheel wells have.

In reply to ¯\_(ツ)_/¯ :

Yeah, I looked at the Minivan wheels and even though the centerbore is big enough, it isn't deep enough for the SVO hubs. Explorer and Jeep wheels have a nice centerbore, but the backspacing is far enough out that I would need fender flares (maybe not a bad idea?)

New Edge Mustangs have a 6 spoke 15x7" wheel with backspacing that would get pretty close and they pop up pretty cheap since they are from the V6 models that I might try to get a set and try them out. Then there is always these from SN95:

Looks like they would taco leaving service

If the minivan wheels are cheap and tough enough, and the only problem is the depth of the centerbore, I'd be inclined to bust out the hole saw- if the bore is already most of the way there it should keep things centered enough.

As Chris said, the MaxSport are a rallycross tire, not a stage rally tire, so I would avoid.

There was an Evo that won Rallycross Nationals in 2015 on those three spoke wheels, so they may be tougher than you think.

If you're willing to machine a bit of material out of the wheel bore, the early 90's Dodge Stealths had 15x6.5 with a 37mm offset and 67.1 bore.  The same era of Mazda MX6 are the same story.

With hub centric rings, you add a few options from Chrysler.  The '88-90 Chrysler Voyager/LeBaron had these gems (15x6, 71.5mm bore).  The '87-90 Dodge Dakota has a similar spec.

In reply to ¯\_(ツ)_/¯ :

I did that with the Liberty wheels and it was surprisingly easy.

The hardest part about the van wheels is trying to find them. You'd think with the millions of vans they made it would be easier, but I think most of the 15" are steel, or the vans were optioned to aluminum when they were new. I can find one or two of these, but never a full set:

In reply to FooBag :

Those are pretty good! Looks like I need a trip to the junkyard next weekend, hopefully there are still some of these that haven't gone to the crusher yet. K cars didn't hold up well to Minnesota winters

car-part.com shows some cheap options on the K-car wheels fairly close to you!

In reply to FooBag :

Nice! I haven't used Car-Part.com, crazy to think all the cataloging it must take to control all those part numbers. It's also funny to see most wheels come in sets of 3, I guess there is always one that is the victim of the damage that caused the car to go to the junkyark in the first place . Fairbault and New Ulm are still a few hours from me and I am on a travel restriction, since my wife is due any day now. I might try a yard about 20 minutes from me that I know keeps alot of older cars around, see what I can find. I also found a few craigslist wheels that are cheap and might be worth checking out.

So I did my first rallycross in the mustang today. I scored some used 15x7 wheels with decent winter tires from an '02 mustang that fit pretty well. Also made a skid plate and did a quick string alignment. 

I didn't take any pictures at the track, since I was pretty busy, but overall car ran real good

I was going to take it easy and ignore times, just use it to shakedown the car and get a feel for it in dirt, but that only lasted one round. The next round I pushed alot harder. The trouble was, my times didn't drop very much and I was way off the pace of the leaders. There was a little knock on the rear suspension after putting in the poly bushinged rear control arms, but I knew the stories of mustangs and poly bushings having binding issues, so I brushed it off unit the second run of the second round when the knocking turned into a pounding and the rear of the car was all over the place. I was hoping the noise was the muffler bumping the frame, since I put the exhuast a little too close to the frame last time I hung it. But after end of the second round I crawled under the car and found this

Both of the upper control arm bushings were WASTED. At this point the springs were doing a better job of centering the axle than the control arms. What a bunch of junk. 

So after driving it an hour home down the interstate with deathwobble everytime I let off the gas, I'm left with a dilema of doing what maximum motorsports recommends and running stock rubbers or running some sort of a rod end on the frame side. 

The other issue I had was the track was tight and I ended up mostly in high 2nd gear, with alot of turns too fast to drop into 1st. The problem is, bost doesn't really come on until after 3k RPM, so I either had to rev the piss out of it in 1st or bog through 2nd until boost came on. I have a suspicion my catalytic converter is plugged up, so I might chop up the exhaust to try to free up some power, but I think I will probably need to be more drastic to get any real power down low. 

So I learned alot, found out my car is slower than I hoped and I am rusty as hell, but hopefully some control arms and power bumps will help make up for my current lack of talent

FooBag said:

As Chris said, the MaxSport are a rallycross tire, not a stage rally tire, so I would avoid.

There was an Evo that won Rallycross Nationals in 2015 on those three spoke wheels, so they may be tougher than you think.

If you're willing to machine a bit of material out of the wheel bore, the early 90's Dodge Stealths had 15x6.5 with a 37mm offset and 67.1 bore.  The same era of Mazda MX6 are the same story.

With hub centric rings, you add a few options from Chrysler.  The '88-90 Chrysler Voyager/LeBaron had these gems (15x6, 71.5mm bore).  The '87-90 Dodge Dakota has a similar spec.

I had a Voyager with that trim kit (those wheels and that rocker trim). Still looks great :)

I only mention that because I had that minivan when I was 16, and it did things a minivan should never do, drove over more than one curb directly, and never bent a wheel (while breaking other stuff).

Also, 71.5mm hub bore to 70mm....I woudn't even bother a hubcentric rings, honestly. built-up rust on hubs can account for almos that much lol. 

Side note 1. I woudln't worry about not being fast at a rallycross. I've been rallycrossing for nearly a decade and never seen a Mustang be fast at it ;) Slow rallycross doensn't mean slow stage rally (and vice versa). I'm very fast at rallycross, and not all that fast at rally. I wouldn't sweat it.

Side note 2: What's your currently rally timeline? Man, you should just come to STPR (5 weeks away)....we're gonna have a nice turnout of older RWD cars (e30s, RX7s, Porshe 944s, and others). STPR will also reward your power. 

Also, WTF with those bushings? Even if binding, it's surprising to see them totally ground up like that vice simply splitting. Wow. 

On my car (e30) I've actually reverted from using poly back to using OEM rubber bushings (including on my trailing arms). In rally, sometimes you want more "give" than poly can provide. 

I really only use poly/solid bushings on things that don't move, like engine mounts and subframe mounts. I've gone almost totally back to rubber on bushings that rotate or need radial flex. 

 

Also, 71.5mm hub bore to 70mm....I woudn't even bother a hubcentric rings, honestly. built-up rust on hubs can account for almos that much lol. 

Side note 1. I woudln't worry about not being fast at a rallycross. I've been rallycrossing for nearly a decade and never seen a Mustang be fast at it ;) Slow rallycross doensn't mean slow stage rally (and vice versa). I'm very fast at rallycross, and not all that fast at rally. I wouldn't sweat it.

Side note 2: What's your currently rally timeline? Man, you should just come to STPR (5 weeks away)....we're gonna have a nice turnout of older RWD cars (e30s, RX7s, Porshe 944s, and others). STPR will also reward your power. 

Haha, no problem building up rust here

Yeah, it's hard to not get competitive. It's good to get a feel for tossing the car around, but not real practice for a stage I guess 

I was originally going to try to run Ojibwe, since it is pretty close to where I live, but  I still need more wheels, order tires and get the car sorted out a little better. So I think LSPR or Nemadji Regional is more reasonable. STPR sounds like a riot and it sounds like I would be in good company, (I probably owe you running crew since I pretty much used your build thread as a guide to my build), but 16hr drive out the race in 5 weeks would be tough to do, especially since I now have a 3wk old son!

irish44j said:

Also, WTF with those bushings? Even if binding, it's surprising to see them totally ground up like that vice simply splitting. Wow. 

On my car (e30) I've actually reverted from using poly back to using OEM rubber bushings (including on my trailing arms). In rally, sometimes you want more "give" than poly can provide. 

I really only use poly/solid bushings on things that don't move, like engine mounts and subframe mounts. I've gone almost totally back to rubber on bushings that rotate or need radial flex. 

I don't know, they were a whitebox special and the lowers seem like decent quality, but the uppers feel like the bushing was made out of crayon, it crumbled as I took it apart. 

I think you are right about going with rubber, I take predictability/reliability over precision with possible catastrophic failure 

olso3904 said:

The other issue I had was the track was tight and I ended up mostly in high 2nd gear, with alot of turns too fast to drop into 1st. The problem is, bost doesn't really come on until after 3k RPM, so I either had to rev the piss out of it in 1st or bog through 2nd until boost came on. I have a suspicion my catalytic converter is plugged up, so I might chop up the exhaust to try to free up some power, but I think I will probably need to be more drastic to get any real power down low. 

So I learned alot, found out my car is slower than I hoped and I am rusty as hell, but hopefully some control arms and power bumps will help make up for my current lack of talent

I have similar problems with our e30 (325i w/a 3.73 diff) rallyx car. It doesnt really come alive till 3-3.5k so I struggle with bogging coming out of slowish turns, especially when the course is grippy and tight so I can't keep it sideways through the turn. 

I would definitely do some more rallyx's before making any major engine changes. (Also check and see if cat removal is legal with NASA/ARA). Just focus on learning the car and being consistent for a while. 

olso3904 said:

The other issue I had was the track was tight and I ended up mostly in high 2nd gear, with alot of turns too fast to drop into 1st. The problem is, bost doesn't really come on until after 3k RPM, so I either had to rev the piss out of it in 1st or bog through 2nd until boost came on.

I feel your pain- the XR4Ti has the same issue at rallycrosses, despite the 4.3 rear end.  A fun solution is, a little less than a second before you'd normally get back on the gas, to floor it and kick the clutch- this gets the rpms up and, assuming you held the clutch in for long enough, by the time the rear tires start to hook up you'll be building boost.  It feels extremely violent so make sure all of your bushings, mounts, and clutch parts are in good shape.

Thomas, stage rally cars must have a cat if the car was sold with one. So are you at least you need one of the $30 little tiny summit racing ones like I do.

Are those upper links supposed to locate the axle side to side?

Didn't realize cats could be so cheap, for $30 it's worth a try.

Nesegleh said:

Are those upper links supposed to locate the axle side to side?

Didn't realize cats could be so cheap, for $30 it's worth a try.

It also roughly holds the pinion angle as the suspension cycles, but because the arms are so short, they get misaligned easily, so soft rubber was needed to allow for extreme angles and an extra set of shocks were needed to keep the soft rubber from allowing axle wrap ... bandaid engineering

Yeah, it is suprising how cheap cats are, although they are actually "pre-cats". I dropped down my cat and it doesn't look burnt out, but having it out lets the turbo spool alot quicker and the car is still pretty quiet. So, tonight I am going to chop up my exhaust and get rid of some extra bends and swap the muffler for the cat that I have and see if I can pickup some lowend power and still have a cat. If it doesn't go well, I will probably throw it all away and start over with 2.5 or 3" exhaust. 

In reply to olso3904 :

Hopefully switching to rubber works. Maybe long term consider doing a parallel 4 link?

In reply to Nesegleh

Aparently the key is to make the lowers as solid as possible, with rod ends and just replace the cheap rubber ones when they wear out. There are panhard kits and torque arm kits that work great on a track, but limit travel for rally.

There is always IRS

I rallycrossed a Fox body with the Steeda 5-link and honestly don't think it was much better than stock stuff in decent shape.

When you want something better, I'd just do a big long 4-link with beefy circle track stuff.  The IRS pictured probably isn't much of an improvement for rally use, and has a lot more parts which can fail.

Muffler for Cat swap was sucessful, I also got rid of some nasty kinks and bend left over from when it has dual exhaust. It does boost a little earlier, but even better, it sounds great

I pulled the stock exhaust down and made a custom concrete/dry erase template to use a s a guide to cobble together a a new exhaust

I like that idea of tracing the old exhaust out on the concrete! 

In reply to ¯\_(ツ)_/¯ :

You mean back halfing the car? That's tempting since 4-link components are relatively cheap and bulletproof, but connecting that to a fox bodies floppy structure sounds like some serious engineering.

I put factory rubber uppers in and the car feels a million times better. Even before the bushings shelled out, they must have had some serious play, since I had an off throttle steering pull, that I thought was bump steer, but turns out was the axle changing directions.

For now, I am going to stick with the rubbers and see how long they last. For how cheap and easy they are to replace, they would need to cause a serious issue before I am going to invest much money into redoing the rear suspension. I still have a lot of shakedown work left to do on the car and a trick rear suspension, just isn't a priority.... yet. I also still have a factory 7.5" rear end that I am waiting to pop before finding an 8.8 to replace it with

Been awhile since I have posted, but I have mostly been doing pretty boring stuff to the car. I did however register for the Nemadji Trail Rally in 3 weeks, so I will finally get the car on a stage.

I had been struggling with getting the car to sit even and high enough in the front.  It has slightly higher spring rate Mustang GT springs, cut down slightly to fit the SVO's slightly different control arm height difference, but they were a little too low and the driver's side was about 1/2" lower than the passenger. I thought about doing a coilover conversion, but I have yet to reinforce the strut tower, so I instead welded in some dirt track style adjustable coil seats.

Adjusting them sucks and requires a spring compressor, but now that I have it level and the height I want, I doubt I will adjust it, unless I decide to change the spring rate. I might end up going to coilovers, but I would probably go to SN95 spindles/brakes/hubs and do a cage tie in to the strut at the same time.

Other stuff I have done is mostly around making the heat/defrost work, making the dash easier to remove, mounting the tire/jack/first aid etc, adjusting the harness and making a light bar. Should be OK for Nemadji, but I think I may need another

I settled my wheel issue, by getting lucky and scoring some edge body mustang V6 wheels. The offset is slightly farther out, but the scrub radius is still pretty good and the center bore is correct without any hacking. I was on the fence about whether to use rally tires or winter tires for the rally. Hard to know if we will have much snow by then, but with the weather so far, I know it will be cold. With the rally only being 4 stages and my goal of just finishing and getting the hang of it, I figured new snow tires are a safe bet.

Still need to wire up the LED lights, buy some fuel jugs and fire extinguishers and test drive the new setup of springs/wheels/tires and restrictor. 3 weeks to go!