Driver Posted November 16, 2007 Share Posted November 16, 2007 This is a new and fascinating term for me. From what I understand, you shim your steering rack mounts, moving it further away from the K member (then get an alignment). Will this effectively modify your steering ratio, i.e. fewer steering wheel turns for more turn in? The theory being, as the angle of the tie rod changes, so does the amount of wheel movement for a given shaft movement. Not by a huge amount, but every bit counts. Is this correct? Has anyone done this? Sounds like a good semi-free mod. Quote Link to comment Share on other sites More sharing options...
FlyingDog Posted November 17, 2007 Share Posted November 17, 2007 It would only change bump steer. Quote Link to comment Share on other sites More sharing options...
Renntag Posted November 17, 2007 Share Posted November 17, 2007 Also keep in mind that another mod for mustangs is to remove 1/4-1/2" of material from the BACK of the rack to move it rearward also to benefit removal of bump steer effect. Quote Link to comment Share on other sites More sharing options...
Driver Posted November 17, 2007 Author Share Posted November 17, 2007 Also keep in mind that another mod for mustangs is to remove 1/4-1/2" of material from the BACK of the rack to move it rearward also to benefit removal of bump steer effect.That is something I hadn't considered. Quote Link to comment Share on other sites More sharing options...
Bruce L. Posted November 17, 2007 Share Posted November 17, 2007 don't know if you are a racer or not, but remember it is only "free" if allowed in the series' rules. cheers, bruce Quote Link to comment Share on other sites More sharing options...
Driver Posted November 17, 2007 Author Share Posted November 17, 2007 That's actually where I first saw reference to shimming the steering rack; TT rules. Quote Link to comment Share on other sites More sharing options...
Projectfc3s Posted January 14, 2008 Share Posted January 14, 2008 This is a new and fascinating term for me. From what I understand, you shim your steering rack mounts, moving it further away from the K member (then get an alignment).Will this effectively modify your steering ratio, i.e. fewer steering wheel turns for more turn in? The theory being, as the angle of the tie rod changes, so does the amount of wheel movement for a given shaft movement. Not by a huge amount, but every bit counts. Is this correct? Has anyone done this? Sounds like a good semi-free mod. Yes you are correct, this will change your ratio as well as your total steering angle. I had originally done this on my 87 rx7 with some washers on my manual rack. I then purchased a ps rack and there are already shims made that bolt in front of the inner tie rod (adds about 1 inch), this is something that is done frequently in the drifting world. Quote Link to comment Share on other sites More sharing options...
Renntag Posted January 14, 2008 Share Posted January 14, 2008 don't know if you are a racer or not, but remember it is only "free" if allowed in the series' rules. I am a racer, but there are many posters in this thread, all from different disciplines. In TT and PT, numerous mods are allowed and everything is based on points. Then there are the HPDE drivers just looking to make their rides more refined. Quote Link to comment Share on other sites More sharing options...
Driver Posted January 18, 2008 Author Share Posted January 18, 2008 (edited) Holy thread resurection, Batman! I one of the fellas that Rentag is talking about, kinda by accident...but it also illustrates Legworks point also. When I got the car, I gutted it and caged it. I was eager to get going, and I was also.... my god I was 21, I can't beleive I've had this thing that long. Anyways, the cage wont pass tech inspection for door-to-door racing. So, this will just be a "as bloody fast as I can make it" kinda project. I kinda like that, feels like ghetto Can Am. If I were to build a racer, I'd start with a new shell anyways. This could still see TT. Edited January 18, 2008 by Guest Quote Link to comment Share on other sites More sharing options...
Frank Corkran Posted January 18, 2008 Share Posted January 18, 2008 Also keep in mind that another mod for mustangs is to remove 1/4-1/2" of material from the BACK of the rack to move it rearward also to benefit removal of bump steer effect. I'm pretty sure the purpose of moving the rack rearward on a Mustang is for improved ackerman. Moving the rack up/down effects bumpsteer. On my car the rack is lowered for sump clearance, then bumpsteer is corrected by spacing the rod ends down. A lot. Quote Link to comment Share on other sites More sharing options...
Renntag Posted January 19, 2008 Share Posted January 19, 2008 I'm pretty sure the purpose of moving the rack rearward on a Mustang is for improved ackerman. ... I think you are correct, but for some reason I remember reading/hearing that this also had a positive effect on bump steer. Quote Link to comment Share on other sites More sharing options...
IGZOSTD Posted January 21, 2008 Share Posted January 21, 2008 Being a TTer , I think its stupid we have to pay points for bump correction , I have had just about All years of Mustangs , the 65 through 73 came with bumpsteer from Ford . My daughters Fox's and her sn95 seem to suffer a little from this also. My 06 has it also , For me its not worth the points , I never notice it ontrack , only on the hwy. If I were Iron racing it or just HPDE I would surely fix this problem. Quote Link to comment Share on other sites More sharing options...
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