New-to-240z Posted January 28, 2015 Share Posted January 28, 2015 (edited) Hello everyone! So, I'm in the process of dialing in and taking on the setup of my current configuration. If you've followed any of my posts in the past you'll know the following . . 1973 240Z 8KG Front and 6KG Rear Megan Racing S13 Street coilovers 1" MSA front 240Z anti-roll bar Stock 17mm S13 Rear sway bar Rear S13 full subframe with fully adjustable components (UCA,TC, etc) Toyo R888 Front: 225/50R15 Rear: 235/50R15 I have checked the front LCA position when car is on level ground and they sit almost exactly parallel to the ground at its current ride height, so I do not believe I will need bump steer spacers. My question that I have is that my car seems to have some pretty bad understeer under hard cornering. I have been reading up and with the stiff springs that the Megan CO's have, it might be a better idea to go with a softer front anti-roll bar (maybe back to the stock 240Z bar?) and stiffer rear anti-roll bar. I was going to purchase the 240Z adjustable sway bar end links in conjunction with the stock bar to give me a changeable setting to even further soften the front. I know that I can bring the pressure up on the tires a bit, but the last time I took it to the track it was at 32 and 35 PSI. I would be afraid of upping it any more then 37. Any insights or recommendations? Edited January 28, 2015 by New-to-240z Quote Link to comment Share on other sites More sharing options...
tube80z Posted January 28, 2015 Share Posted January 28, 2015 I'm not sure if this would work but for a no cost fix try swapping springs front to rear. Your setup if definitely front stiff so it doesn't surprise me that it understeers. On a Z you need to control roll at all costs so I don't think I'd do a softer front bar. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted January 28, 2015 Share Posted January 28, 2015 (edited) 3 degrees of negative camber up front will solve your problem. Unless of course you are already there. I autocross and road course with only 26 psi on each end. Drop the front pressure till your tires start to roll a bit, then add a little air til it stops. Ya don't need as much air as folks think. Use shoe polish to figure that out. Zs need camber up front. Go to the FAQs section and look for the suspension alignment settings recommended by johnc. I am not a pro racer by any stretch of the imagination (I actually kinda suck), but other drivers can drive my car fast and they always say nice things about it, even when they have an opportunity to be critical. For me at my level, those suspension alignment setttings that johnc worked out are pretty much "plug and play." My car pushed bad until I added the camber up front. It was like night and day. What is the fastest way to gain camber up front? DP bolt-in camber plates from DP. Just google DP bolt-in camber plates and you should be able to find them easily. Call and talk to the guy there-he will need to know your spring diameter and brand of shock. You are looking at less than $300 and a weekend to install them. After you fix the front you will want to add a little camber in back-the effect of added camber is dramatic. Edited January 28, 2015 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
johnc Posted January 28, 2015 Share Posted January 28, 2015 Does the car understeer on corner entry, mid corner, and corner exit? Does it understeer under power? Does the understeer go away if you lift off the throttle? Does the understeer go away if you unwind the steering? Also, as Keith said, alignment is critical and is the reason you're putting all that stuff on the car. Quote Link to comment Share on other sites More sharing options...
New-to-240z Posted January 28, 2015 Author Share Posted January 28, 2015 (edited) @Tube: Looks like the Megans can be switched front to back and can even switch out up to + - 2 KG in spring rate without affecting the shocks performance. So, I'll be keeping that option in the bucket for my next event. @Rebe: Luckily the Megan coilovers have camber adjustment plates already. So, I'll be looking into marking 0,-1,-2,-3, 3, 2, 1 on the plates for future reference (as long as I don't change ride height, this should work for on track changes correct? I'm guessing I'll need to note the amount of change in toe when adding neg camber to make the adjustment accordingly?) @JohnC: You are one of the most talented/knowledgeable guys on here. Thank you for even jumping in. Will the alignment settings for the front that Rebe talks about work on my car? I would think the rear would need to be different since it is using the S13 subframe. In any case, its is primarily in Mid corner. by understeer under power do you mean in a straight line or while in mid turn with power applied? I will take more time taking notes next event to gain more information. My alignment will be done by a recommended alignment shop that specializes in unique suspensions, and will hopefully make a noticeable change. **JohnC's Alignemnt Post in FAQ** Edited January 28, 2015 by New-to-240z Quote Link to comment Share on other sites More sharing options...
johnc Posted January 29, 2015 Share Posted January 29, 2015 Don't make any changes (other then the tire pressure recommendations) until you get the alignment done. Regarding the rear, the numbers should be similar at static ride height. Toe in and camber is good regardless of the rear suspension setup. Quote Link to comment Share on other sites More sharing options...
gnosez Posted January 29, 2015 Share Posted January 29, 2015 When you get a chance try a set of Toyo RA-1s. Much, much better than those 888s. Makes a real difference in the corners. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted January 29, 2015 Share Posted January 29, 2015 Johnc is usually worshipped for his Adonis-like figure, so don't confuse him. Hybridz Rule Number 1: Dont Feed the Animals. You can make this as complicated as you like, but if you set the alignment where the FAQ recommends and leave it alone, you can work on other things, like your driving. Every ride height and camber change requires a toe adjustment, so it is kind of a pain to mess with it all the time, unless maybe you have a drive-on lift at home. Definitely not fun at trackside. I leave mine set for the year and get it checked annually. Shocks, tire pressure and tire temps will keep you busy enough at the track. Get a co-driver so you can see the course twice as many times on race day. Unless you are super consistent with everything, it will be hard to verify the results of changes in setup over a 1-2 minute course. Quote Link to comment Share on other sites More sharing options...
johnc Posted January 29, 2015 Share Posted January 29, 2015 My pear shaped figure is what causes the worship... Quote Link to comment Share on other sites More sharing options...
New-to-240z Posted January 29, 2015 Author Share Posted January 29, 2015 (edited) @Gnosez: Looked them up and they look nice, but unfortunately they top out at 225 in R15. My rear rims are 10.5" Work CR01 and the 235/50R15 R888's fit perfectly on them. The fronts however are using 225's, so I might look into the Toyo RA-1s for them (but I'm afraid of running different tire types front and rear). @Rebek: I think what I'll be doing is using JohnC's alignment guide for one year. I'll work with the alignment guys and mark 2 different settings. Here's my thought process... Setting 1: Around town (normal camber and toe settings to help keep tire tread wear down.) Setting 2: JohnC settings I'll mark down the John C settings by doing the following. Have them set the camber and toe to normal/safe range. Mark Camber/toe spot location on top plates and rear adj. arms. Then, after setting the the JohnC angles I can count number of TC rod turns to get to correct toe from normal settings. (do same thing for rear) This way I can set my track (johnC) settings at home before the track using the notes, and can return the car to normal after the track day. Since the Toe arm is 6 sided, I could be able to number each side to make the process easier. (same for rear arms except they only have 4 flat sides). Do you think this would be possible or would this, in the end, cause more problems? Edited January 29, 2015 by New-to-240z Quote Link to comment Share on other sites More sharing options...
johnc Posted January 30, 2015 Share Posted January 30, 2015 You should be able to switch back and forth without too much trouble. Once a year have an alignment shop check each setup to make sure your marks (or something else) hasn't moved. Quote Link to comment Share on other sites More sharing options...
clarkspeed Posted January 31, 2015 Share Posted January 31, 2015 My 2 cents. You don't want the front CA's parallel, but at a slight angle down. That will keep the front RC above ground. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted January 31, 2015 Share Posted January 31, 2015 Please PM me with your method for marking the street and track toe settings on the inner tie rods. I would love to copy you, but I couldn't come up with a practical way to mark them. I think you have a great concept. I drive so little that I'm not concerned about wearing out my tires from too much camber-they age out before they wear out. I leave my fronts with -3 camber and I switch my rears from between +1 camber for drag and -3 for all else. It looks like my front tires are falling off to the uneducated. Changing the rear is easy, I just neglect toe-in, since it really isn't adjustable. Quote Link to comment Share on other sites More sharing options...
New-to-240z Posted February 1, 2015 Author Share Posted February 1, 2015 A little off topic, but do you think that this picture shows that I need bump steer spacers? From the looks of the tie rods, I do, but a second opinion is always welcome . . @Rebek: I'll post a walk through once I think about all the steps I'm not the smartest guy, so hopefully someone can poke holes and offer some constructive criticism on my process. Quote Link to comment Share on other sites More sharing options...
johnc Posted February 1, 2015 Share Posted February 1, 2015 FYI... You are not going to get the alignment right the first time. You have to do a few test sessions and take tire temps to find out what's right for you and your car. You will also adjust the alignment between sessions to better suit the track and the conditions. That's normal. I suggest you have a marked setting for the street alignment only. And for toe adjustment, you don't mark anything, you count turns. Quote Link to comment Share on other sites More sharing options...
johnc Posted February 1, 2015 Share Posted February 1, 2015 And your picture above shows the car is to low in front, raise it, add a bumpsteer spacer, or relocate the inner LCA mounting point. Also, you ARB end link bolt is in upside down and trim the tie Rod End cotter pin or you'll scratch the shIt out of your hands. And you've tightened down the end links too much. Don't squish the bushings. Just snug it down. Quote Link to comment Share on other sites More sharing options...
aongch Posted February 1, 2015 Share Posted February 1, 2015 Since you have coilovers, when you do the alignment also do corner balancing. I 'thought' just by estimating based on threaded collar positioning it looked correct, but it was off by a bit! Our cars are light enough, sensitive to balance. My braking and turning was inconsistent, it was definitely fixed. Quote Link to comment Share on other sites More sharing options...
New-to-240z Posted February 4, 2015 Author Share Posted February 4, 2015 (edited) @JohnC: I'll mark adjustment points for the 'standard' driving position and of course number of turns as well. - I'll flip the ARB end bolts and snug them down this time (may have to buy new bushings since they have always been this deformed since install. Amazed no-one has noticed this with all the alignments). - The car is at the perfect ride height for what I am looking for, so I'll purchase the bumpsteer spacers from MSA the next time I'm there and install those and see what difference that makes. Hopefully it will be enough to correct the angle. I've read that people needed to take some material off the BS spacers, is that the case with the MSA ones or is that only Arizona Z? @Aongch: My feeling was to have a standard alignment done and then another using JohnC's. Then, getting everything tested and figured out. Then finally move to corner balancing and getting it dialed in exactly. (this may not be the right order. I may want to corner balance first, but I would think that I would want my exact alignment settings before corner balancing.) Thank you EVERYONE for all the help. Once this is all put back together on the Z, I'll be taking her out to the track and having some fun learning! (On a side note, I've also read that the 8KG front and 6KG rear is too stiff for our cars. I have the ability to grab some Swift springs and was thinking of going 6KG front, and 4 or 5 KG rear. This would allow for a little extra give, but that's just me looking over numbers and other people's setup and company's products [Arizona Z] ). Should I leave the 8kg and 6kg springs in for now or switch to the softer springs since everything is out of the car and not aligned yet?) Edited February 4, 2015 by New-to-240z Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted February 5, 2015 Share Posted February 5, 2015 With just 15" wheels, and bumpsteer spacers, the grease zerks in the outer tie rod ends, and the tie rod ends themselves can rub on the inside of the wheels. Removal of the grease zerks (install a little plug) and a little grinding on the tie rod will fix this. Going to 16s or 17s makes the problem go away. Think about making some blocks (even wood can work) to space the swaybar away from the frame a half inch to keep it from binding on the body. You can just use longer bolts that pass thru the sway bar bracket and the spacer. Quote Link to comment Share on other sites More sharing options...
johnc Posted February 5, 2015 Share Posted February 5, 2015 For your use the 8kg spring doesn't get you anything, 6kg is about as much as I would run on a 240z without chassis reinforcement. Shocks must also have enough rebound control. Nothing sold by Tokico, Monroe, KYB, etc. will work. Quote Link to comment Share on other sites More sharing options...
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