BrandenZ Posted October 26, 2011 Share Posted October 26, 2011 My current predicament is that I can't get more than 2.5 degrees of positive caster out of the car without rubbing my tire against the fenderwell / front bumper. Before the start of next season, I'd like to be able to dial in between 6-8 degrees of positive caster. However, if at all possible, I'd like to avoid cutting / flaring my stock fenders. Is this even possible? Here's the rundown of my current setup: 245/45/16 tires 16x8 wheels with a +26mm offset MM Z31 hubs (+3/4" further outboard than stock) Sectioned struts with GC coilovers, hypercoil springs, and tokico illumina struts Mikelly adjustable front control arms Mikelly adjustable T/C rods MSA bumpsteer spacers This is how it sits in it's current configuration: I've been looking at these: http://www.k-mac.com/pages/newprods/datsun/datsun.htm But no one can seem to tell me exactly how much caster I can expect out of them. It's almost like I need caster plates, not camber plates! The car is intended for autox, light track, and light street duty. I'm more concerned about what's right from an engineering and handling perspective than comfort. Any and all advice would be greatly appreciated... even if that advice is "just suck it up and cut cut cut if you want track alignment specs!" Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 26, 2011 Share Posted October 26, 2011 You could run the biscuit style camber plates, they adjust both at the same time. I wouldn't use the Kmac plates with the poly bushing, but with the monoball they're probably OK. You could also run a smaller diameter wheel/tire combo. I think it's quite likely that you'll need to cut to get that much caster. Quote Link to comment Share on other sites More sharing options...
johnc Posted October 26, 2011 Share Posted October 26, 2011 Is this even possible? No. Quote Link to comment Share on other sites More sharing options...
BrandenZ Posted October 26, 2011 Author Share Posted October 26, 2011 Thanks for the quick responses! Jon -- From what I can tell, K-Mac only sells the stage3 kit for Z's, which appear to be the sandwich monoball style, but perhaps someone who has experience with the units can confirm. John -- Always appreciate blunt honesty! Is that a "No, but you can get maybe 5 degrees with the K-Mac's", or a flat out it isn't going to make a darn bit of difference? Presuming I go the flare route, which it sounds like isn't optional at this point, is it still to my benefit to have the K-Mac's, or some type of camber plate? From what I've read, it seems like from an engineering perspective, it's better to dial the camber in at the tower than the control arm. Also, going the flare route -- does this mean _all_ 6-8 degrees come from the T/C rod?! I feel like I'd be dangerously close to running that sucker out of threads. Thanks again for the help and clarification! Quote Link to comment Share on other sites More sharing options...
EMWHYR0HEN Posted October 27, 2011 Share Posted October 27, 2011 I'm running +4 degrees with 255/40/17 and I had to cut at least 2 inches from the bottom of the air dam. I had to remove my front corner marker so that the fender flare could move up. Just suck it up and cut cut cut if you want track alignment specs! Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted October 28, 2011 Share Posted October 28, 2011 Why not cut and relocate the strut towers in the engine bay? With a welder handy it can't be that hard to do. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 28, 2011 Share Posted October 28, 2011 Why not cut and relocate the strut towers in the engine bay? With a welder handy it can't be that hard to do. You could do that, but you'd have to fill the hole in the fenderwell. Might be easier to get a 2nd Z, (or the parts) and cut the strut tower down the middle and splice it on to make the strut tower wider. Just be sure to reinforce the plate in the strut tower... Quote Link to comment Share on other sites More sharing options...
260DET Posted October 28, 2011 Share Posted October 28, 2011 Yeh, modify the strut towers so the tops can be located further back towards the firewall. That's what was done with my 280ZX to allow up to 8* of caster, it's a very rewarding mod for handling improvement, particularly turn in. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted October 28, 2011 Share Posted October 28, 2011 Yeh, modify the strut towers so the tops can be located further back towards the firewall. That's what was done with my 280ZX to allow up to 8* of caster, it's a very rewarding mod for handling improvement, particularly turn in. Would you post a few pictures? Quote Link to comment Share on other sites More sharing options...
johnc Posted October 28, 2011 Share Posted October 28, 2011 My "No" was an answer to your caster goal and not having to cut the bodywork giving your wheel and tire combo. I had to cut my old car when running 225/50-15s once I got past +5 caster. Quote Link to comment Share on other sites More sharing options...
BrandenZ Posted October 28, 2011 Author Share Posted October 28, 2011 260DET - I would love to see a few pictures of this as well if possible. Welding isn't a problem if it's necessary. Again, I'm more interested in doing what's "correct" and has the least amount of unintended negative consequences than what's quick, or aesthetically painful. I suppose I'm misunderstanding the camber/caster plates in all of this. I would expect that units like the K-Macs that offer caster adjustment would essentially allow me to 'artificially' relocate my strut tubes closer towards the firewall. To me this would seem to be perfect, as there's a _ton_ of room in the 'backside' of the wheelwell towards the firewall, just practically none on the frontside towards the bumper. Also, by going the route of either redrilling the towers or locating further back towards the firewall, won't this cause the front control arms to essentially be angled as opposed to being perpendicular to the hub? If so, is there a danger of compromising the the control arm(s) or fastening points by doing so? Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted October 28, 2011 Share Posted October 28, 2011 (edited) You could easily calculate how much caster you would gain from the K-macs, knowing how far back the top of the strut can move, and the length of the strut. Guessing at 24" strut, and 1" back, you would gain only 2.5 degrees. And yes, you could bind the stock control arms, you may want to consider units with inboard heim joints if you move the tower mounts back. Edited October 28, 2011 by SleeperZ Quote Link to comment Share on other sites More sharing options...
KAZU Posted November 6, 2011 Share Posted November 6, 2011 Mine. Upper plates are trimmed strut tower bar ends from AE86. A portion of hood ridge reinforcement was temporary removed for complete welding. Don't forget with this modification you also get too much caster trail. I canceled the phenomenon by offsetting the strut bottom mounting toward front. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.