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SCCA Super Touring U Build

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Old 06-12-18, 07:25 AM
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Originally Posted by mustanghammer View Post
Yes. Once I really got to hammer the car last year I couldn't help but be impressed by the corner exit grip. No waiting, just gas and go.

This isn't my first go round with this king of rear suspension. I had exactly the same thing in an autox mustang and that is the reason I went with it for this car. With spherical bearings there is zero bind, very easy to adjust and cheap to build.
Cool! I assume you put spherical bearings in all of the links? Did you put the suspension in any 3 link calculator programs?
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Old 06-12-18, 12:52 PM
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Originally Posted by Freeskier7791 View Post
Cool! I assume you put spherical bearings in all of the links? Did you put the suspension in any 3 link calculator programs?
Yes - all Aurora rod ends - 5/8 bore/shank on lower control arms - 1/2 bore/5/8 shank on third link. At the chassis, I had bronze spacers made so that I could use the factory 14mm bolts with the 5/8 bore rod ends.

No, applied monkey see, monkey do logic after studying this suspension design back in the 90s on late model stock cars and GT1 road race cars.

Also considered the triangulated design that SirLaughsAllot is using on his car. Exhaust packaging nixed that option for me, but it appears that SirLaughs has a solution. You will see this suspension design on allot of tube frame GT cars at the track - especially the small bore cars. In fact, I share shop space with a GT Lite Toyota that uses this rear suspension. It was also used on several C Prepared solo cars I used to compete against.
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Old 06-13-18, 06:10 AM
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Originally Posted by mustanghammer View Post
Yes - all Aurora rod ends - 5/8 bore/shank on lower control arms - 1/2 bore/5/8 shank on third link. At the chassis, I had bronze spacers made so that I could use the factory 14mm bolts with the 5/8 bore rod ends.

No, applied monkey see, monkey do logic after studying this suspension design back in the 90s on late model stock cars and GT1 road race cars.

Also considered the triangulated design that SirLaughsAllot is using on his car. Exhaust packaging nixed that option for me, but it appears that SirLaughs has a solution. You will see this suspension design on allot of tube frame GT cars at the track - especially the small bore cars. In fact, I share shop space with a GT Lite Toyota that uses this rear suspension. It was also used on several C Prepared solo cars I used to compete against.
Thanks for all the info! I am familiar with triangulated designs from the offroad world, they work really well. I think I will do the non triangulated version instead though. There is a guy I work with that runs IT7 and just went to a trilink and panhard setup as well, and is very happy with it
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Old 06-13-18, 11:41 AM
  #454  
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Just as a random thought... I'm looking at a different solution for the EProd car build I'm doing, but mostly because Prod doesn't let you move the front pivot of the third link to where it really wants to be. I'm going to try to get that to where I'm working on the unibody this week even if it's just doing 3d scans - should probably do a thread.

The triangulated 4 link setup can work well too obviously (if unconstrained by rules) but I'd really like to see the lower links go to one big spherical instead of two spaced a bit apart... I know it's probably fine, but it just seems like it's going to have to tweak things a little to have the axle roll vs the body.
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Old 06-14-18, 04:41 AM
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Originally Posted by mustanghammer View Post
Yes - all Aurora rod ends - 5/8 bore/shank on lower control arms - 1/2 bore/5/8 shank on third link. At the chassis, I had bronze spacers made so that I could use the factory 14mm bolts with the 5/8 bore rod ends.

No, applied monkey see, monkey do logic after studying this suspension design back in the 90s on late model stock cars and GT1 road race cars.

Also considered the triangulated design that SirLaughsAllot is using on his car. Exhaust packaging nixed that option for me, but it appears that SirLaughs has a solution. You will see this suspension design on allot of tube frame GT cars at the track - especially the small bore cars. In fact, I share shop space with a GT Lite Toyota that uses this rear suspension. It was also used on several C Prepared solo cars I used to compete against.
I'm always down to chat suspension configuration. My exhaust system is simply 4" downpipe to dual 3" to get over/around the Toyota 8" solid axle and it's 6.15" stroke coilovers. Ideally I want to merge dual 3" back into a single 4" outlet at the very end. Fingers crossed on that one.

For those of you who haven't seen this already, my YouTube Channel has a bunch of videos of what we're talking about:


RGHTBrainDesign YouTube
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Old 06-14-18, 11:54 AM
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Originally Posted by Kenku View Post
Just as a random thought... I'm looking at a different solution for the EProd car build I'm doing, but mostly because Prod doesn't let you move the front pivot of the third link to where it really wants to be. I'm going to try to get that to where I'm working on the unibody this week even if it's just doing 3d scans - should probably do a thread.

The triangulated 4 link setup can work well too obviously (if unconstrained by rules) but I'd really like to see the lower links go to one big spherical instead of two spaced a bit apart... I know it's probably fine, but it just seems like it's going to have to tweak things a little to have the axle roll vs the body.
The C Prepared Mustangs I used to compete against used a single mount on the bottom of the rear end housing when they ran a triangulated 3 link. Specifically Frank Stagnaro's 65 Fastback. Currently i believe that car runs a three link like the one I built.

Two other concerns. First is roll center adjustment - you could lower roll center but not raise it unless you also change tire diameter. The second is ground clearance. On the Mustangs this was not a big deal because they ran 27" tall rear tires. E Production cars run a 23-23.5" tall tire. Also, on an autocross mustang ground clearance in the center of the rear axle was not a big deal. On a car that can get driven off the track or over a curb.....this could be a problem.

Regarding three link location that the trans tunnel....reread the Production rules. You get to add clearance for the driveshaft....just saying.
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Old 06-14-18, 06:47 PM
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Sorry, separate thoughts. I wouldn't do a triangulated 4 link in prod, just saying for that design I prefer one triangle to two links firming a virtual triangle. Probably just nitpicking though.

I'm friends with one of the guys on the prod committee who used to run a 1st gen - I'm pretty sure adding "clearance for the driveshaft" enough to get the front pivot where I'd like it is a bridge too far. I'm actually thinking torque arm.
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