Wheel size & backspace necessary with AlterKtion ?

[CudaSRT8]

I currently have "mock-up" parts on my car and have clearance issues.   

I have stock, Granada discs and late model Mustang GT wheels (17x8) bolted up and the wheels hit the upper control arm when turning inward.   

Final parts will be either SSBC or Baer brakes.  (leaning toward SSBC because Baer seems to have an "attitude").   Anyway, I don't want to push toward the widest wheels/tires possible, I'd be happy with 17x7's with 225-50s.   What backspace should I order to tuck the wheels/tires in as much as possible without the wheels hitting the upper control arms? 

Bill, are you listening?  Do you by chance have the "known" wheel mount surface dimensions when using the SSBC rotors or Baer rotors with your system?   Seems like this would make it easier to choose wheel backspace and offsets...   

[rjsjea]

On my AlterK w/ Wilwood's 5.75" BS on an 18x8 rim is what Bill recommended.  I am gonna push a 8.5" or 9" up front hopefully w/ about 6" + BS.

I had a poor experience w/ SSBC and Wilwoods have been way better.......my .02

[CudaSRT8]

Rob,
Bad experience of SSBC huh?    Please do tell.   I was leaning toward SSBC or Baer because they have dirt seals for road use whereas (I've read and been told) the Wilwoods have been more for racing, and don't have seals.   Also wanted to have SSBC do some "personalized" lettering on the calipers...

[rjsjea]

I dont like to  bash on the forum, this was about 5yrs ago........PM sent

your box is full





-Rob

[Bill_Reilly]

With Wilwoods on an a-body, I always subtract 2.25" from the advertised width and that works great for a backspace number. Brakes are all different though, and it will depend on the brand. The iron rotors you have now are 1/4" narrower than the wilwoods, and I have no idea what the SSBC and Baer stuff is.

I can't fathom that a 17 is hitting the upper on an a-body if the car is roughly aligned - I've always seen lots of room in there. Also, as far as I've experienced in the shop here, the 17" mustang rims will not fit on the rotor you have because the center register is too big on the granada rotors. I've never used GT wheels though either, only the bullets.

On the same topic, I'm about to recieve a new brake kit from Wilwood - it's the 12.19" 4-piston kit that's 3/4" narrower than the current brake kits they make. It'll be nice to suck the wheels in that much more, although they'll still have to be 17 or bigger.

By the way, Wilwoods biggest market is dirt track cars. Seals aren't really a concern unless you drive in the snow.

[CudaSRT8]

Thanks for the reply Bill.   Woke me up a little as to alignment.   I pretty much just through the suspension together and am thinking that maybe the upper control arm ends may not be screwed in far enough.   Should the be pretty much all the way in?   

The wheels I'm mocking up with are the 17x8 Mustang wheels that look like an American Torque Thrust.   They look like the wheels I've seen on your Dart at one time (that's why I bought them).   These were brand new "take-offs" I got from a dealer, with tires (for super cheap, couldn't pass them up).  Pretty sure they're the same as Bullit wheels.   I was looking for cheap, temporary rotors and you recommended the Granadas.  These wheels fit on them just fine.

I'm going to go look at how far the a-arm ends are screwed in and I'll get back to you...

[CudaSRT8]

The ends are screwed in pretty much all the way.   One is sticking out about a quarter in (threads).   How critical is this for clearance.   Should they all be scewed in all the way?

[Bill_Reilly]

It doesn't matter. All that matters is that camber,caster, toe are set roughly correct and that the steering is centered. Roughly correct with an angle finder is close enough for clearance checking, you don't have to have it professionally done to check the rim clearances. If the wheels are too far out of adjustment, they can hit in all sorts of places that would normally have plenty of room.

This is the best picture I have of that wheel installed - with the angles set fairly close, there's a good half-inch of clearance at the closest point with the wheels turned. So even with the granada rotors 1/4" in, there should still be 1/4"-3/8" clearance.

[CudaSRT8]

Thanks Bill.   The problem must be in my lack of setting any caster/camber.   I had just thrown it all on so I'd have a "roller" while mocking up the engine/tranny.   At that time, I was checking things like oil pan and header to pavement clearances.   Sounds like there should be no problem when I make my final selection of brakes and wheels.   I'm probably going to go with a 7" wheel in front, so that should help too...

[abodyjoe]

On the same topic, I'm about to recieve a new brake kit from Wilwood - it's the 12.19" 4-piston kit that's 3/4" narrower than the current brake kits they make. It'll be nice to suck the wheels in that much more, although they'll still have to be 17 or bigger.

thanks bill..  you may have just cost me more money...

[Bill_Reilly]

Yep, I installed this brake kit yesterday - works great, and it does in fact pull the wheels in 3/4" per side. I also know that 15 X 4.5 wheels will work with it if an 1/8" wheel spacer is used. So even with 15-wheeled strip cars, it will still get the wheels inboard over 1/2".