maddoc Posted December 22, 2009 Share Posted December 22, 2009 LCA offset bushing does push the wheels forward and should give you more feedback from the road.Have you ever ride a sport bike with the forks straight up compare to a cruiser with the forks at angle,same effect,I will be installing Perrin's LCA soon. only sport bikes . How much does the offset bushing push the wheel forward? Has anyone measured? I'm concerned because I'm already pushing the limit of tire @ 235/40/18 and plan to pick up some bridgestone that are going to be beefier... I already rub on the fender liner at full lock. Just trying to make a sound decision Link to comment Share on other sites More sharing options...
Rimfaxe Posted December 22, 2009 Share Posted December 22, 2009 The offset LCA bushings should change the caster by about half a degree. They do move the position of the front tires forward a little- I've never measured the actual distance (I think it would be hard to measure anyway). Here are my before and after numbers in terms of degrees caster. Before LCA offset installation (with stock suspension): LF: 6.05* RF: 5.94* After installing LCA offset bushings, Bilstein HD and STI Pink spring install (Alignment Date 8/15/09) LF: 6.56* (range 5.17 - 6.67) RF: 6.75* (range 5.17 - 6.67) Link to comment Share on other sites More sharing options...
maddoc Posted December 23, 2009 Share Posted December 23, 2009 The offset LCA bushings should change the caster by about half a degree. They do move the position of the front tires forward a little- I've never measured the actual distance (I think it would be hard to measure anyway). Here are my before and after numbers in terms of degrees caster. Before LCA offset installation (with stock suspension): LF: 6.05* RF: 5.94* After installing LCA offset bushings, Bilstein HD and STI Pink spring install (Alignment Date 8/15/09) LF: 6.56* (range 5.17 - 6.67) RF: 6.75* (range 5.17 - 6.67) Those just look like a bunch of #s to me...what does that relate to in words Link to comment Share on other sites More sharing options...
Rimfaxe Posted December 23, 2009 Share Posted December 23, 2009 Those just look like a bunch of #s to me...what does that relate to in words As mentioned in this thread, the offset bushings increase the caster measurement in your alignment- this is not typically adjustable. These numbers are printed on your data sheet when you get a front end alignment. Caster is measured in degrees. It is basically the tilting of the uppermost point of the steering axis either forward or backward (when viewed from the side of the vehicle). A backward tilt is positive (+) and a forward tilt is negative (-). Caster influences directional control of the steering but does not affect the tire wear and is usually not adjustable on this vehicle. Caster is affected by the vehicle height, so in my case, when I lowered the car by installing the Bilstein HD struts and STI Pink springs and offset LCA bushings, my caster values increased as indicated above. The additional caster is similar to the chopper/sport bike analogy already mentioned. With too little positive caster, steering may be touchy at high speed and wheel returnability may be diminished when coming out of a turn. While greater caster angles serve to improve straight-line stability, they also cause an increase in steering effort. For example, BMWs typically have 7+ degrees caster. That is why they tend to have a very 'planted' feel at highway speeds and tend to be somewhat self centering. If one wheel has more positive caster than the other, that wheel will pull toward the center of the vehicle. This condition will cause the vehicle to pull or lead to the side with the least amount of positive caster. I've already mentioned the stock specs above. A half degree to one degree of additional caster will provide a pretty big difference in the feel. Now with all that said... The poly bushings will provide a firmer response but also additional NVH (Noise, Vibration, Harshness) over the stock LCA bushings. If you're concerned about your tire fitment and additional NVH, then replace the LCA bushings with stock. If you're more concerned with your tire fitment and want a little better feel of the road and don't mind some additional NVH, then go with the non offset poly bushings. They will not significantly change your caster values. If you want a more 'planted' feel particularly at highway speeds and that 'self centering feel that increased caster provides.... and don't mind a little additional NVH and are not concerned about possible oversized tire fitment issues, then go with the poly offset bushings. If you track your car and want no give and maximum feedback from your LCA bushings, then go with the Perrin bushings. These are not a good choice for a daily driver, especially on rough road surfaces. From what you have said, if you want to keep the oversized tires and a the car is a daily driver, you may want the non offset - either stock for a softer ride or poly for a bit more feedback and NVH. Hope that helps. jd Link to comment Share on other sites More sharing options...
SBT Posted December 23, 2009 Share Posted December 23, 2009 ^ Nicely summarized. Well-exampled and to the point. - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
D_J Posted December 23, 2009 Share Posted December 23, 2009 +1 makes me feel like I made the right decision with the AVO non-offset's. The Perrins looked good too but I need something with less NVH and better for daily driving. Also got the AVO poly steering bushings. Link to comment Share on other sites More sharing options...
SBT Posted December 23, 2009 Share Posted December 23, 2009 I went with the AVO offset LCAs and I've been very happy with how the car drives, handles and feels (mostly). If you drive on a lot of really rough pavement surfaces, you'll probably want to go with something other than the poly bushes as the NVH (feeling part) definitely gets through to the interior. OTOH - the way the car handles and plants itself definitely compensates you if you can tolerate the NVH part. - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
bluesuby Posted December 24, 2009 Share Posted December 24, 2009 +1 makes me feel like I made the right decision with the AVO non-offset's. The Perrins looked good too but I need something with less NVH and better for daily driving. Also got the AVO poly steering bushings. Thanks for the recommendations. Initially I was considering the Perrins, but my car is a daily driver, so I think the AVOs will give me an improvement over stock but aren't hard-core track material. Link to comment Share on other sites More sharing options...
maddoc Posted December 24, 2009 Share Posted December 24, 2009 If you drive on a lot of really rough pavement surfaces, you'll probably want to go with something other than the poly bushes as the NVH (feeling part) definitely gets through to the interior. OTOH - the way the car handles and plants itself definitely compensates you if you can tolerate the NVH part. Well I drive through DC on weekends, and Baltimore on a daily basis...neither of the roads in the city are "nice".... hmm. Maybe I'll be looking into the Group Ns or Spec Bs. Link to comment Share on other sites More sharing options...
SBT Posted December 24, 2009 Share Posted December 24, 2009 I just drove 3200 miles cross-country through some of the best and worst roads imaginable, and, now that I'm living in the South Carolina low country, I find the roads here to be a solid mixture of both. That said, for daily driving the AVO offset LCAs are exactly what I want both for the planted, on-center feel, and for the toss-ability factor. Can't be beat in my view. - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
SBT Posted December 24, 2009 Share Posted December 24, 2009 Well I drive through DC on weekends, and Baltimore on a daily basis...neither of the roads in the city are "nice".... hmm. Maybe I'll be looking into the Group Ns or Spec Bs. Let me clarify a bit. If you drive on "washboard" roads, like you find on rural Southwest U.S. roads - where the desert sun bakes the roads intolerably and then vehicle traffic "rubs" the tarmac into "ridges" - you would not be happy with any type of poly bushing, offset or not and the NVH will drive you crazy. For the preponderance of U.S. roads and highways, where the surface is reasonably "smooth" you'll not even notice the NVH. The other thing is that pothole-ridden areas will tear your SpecB or LGT LCA bushes faster than you can say "fark". That will lead to really crappy handling and a high replacement rate for the stockers, so getting poly bushes is the way to go IMHO. - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
D_J Posted December 31, 2009 Share Posted December 31, 2009 I went with the AVO offset LCAs and I've been very happy with how the car drives, handles and feels (mostly). If you drive on a lot of really rough pavement surfaces, you'll probably want to go with something other than the poly bushes as the NVH (feeling part) definitely gets through to the interior. OTOH - the way the car handles and plants itself definitely compensates you if you can tolerate the NVH part. Just got these installed and you're right. It definitely feels more planted now and handles more consistent. I hardly notice any NVH differences at all. Link to comment Share on other sites More sharing options...
SBT Posted December 31, 2009 Share Posted December 31, 2009 Glad it worked for you. It's a substantial difference (for the good) IME. - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
uberwagon Posted January 1, 2010 Share Posted January 1, 2010 I have the Perrins...... car feels super solid........I do feel every crack/seam/blemish/bump/tiny hole/pebble in the road Not for everyone.... Link to comment Share on other sites More sharing options...
bace Posted January 4, 2010 Share Posted January 4, 2010 just wondering what size wheels and tires people have with the offset LCAs and if lowered or not. I read itsme went with standard cause of his 19s and lowered. Im planning on getting lowered with coilovers and getting 18x8.5 wheels with 245/35-18 tires. I would like to go with offset LCA for better handling and planted feel at high speeds since I spend most of my driving on highways and the steering currently feels effy. Link to comment Share on other sites More sharing options...
SBT Posted January 4, 2010 Share Posted January 4, 2010 Volk 18x8 GT-Vs with 225/40 MPS ASes, dropped ~1.25" all the way around on Bilstein and Swift Springs. Installed a WL roll-center kit to fix the lowered "bump-steer" issues and to get my front camber back under control. No rub issues at all, but 19s would likely be a problem - Pro amore Dei et patriam et populum - Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.