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Help! What suspension modifications should I do?


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#21 ZDreamin72

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Posted 30 April 2008 - 08:21 PM

now i know that this is probably goina be a biased argument...but which of the companies is best for parts...each part mentioned in which i wanna look at in stage four is asociated with two or three companies that make their style. Can anyone give me some pros or cons associated with each companies piece, if you would buy again from the same people if you did it all over again, which is the best bang for buck, etc. Companies associated with the product in question are all welcome to give me their eplanations as to why they did what and didnt do this that and the other.
'72 240z, F54, L28, 0.030 Overbored, Flattop Pistons, Mild Race Cam w/ 480 Lift, Internally Oiled Cam, Early:icon12: E88 Head, E88 Intake, Dual Roundtop SUs, 4-Speed Trans, Front Air Dam w/ No Air Ducts, MSA 6-2-Stock Exhaust, ZX Alloy Rims. :icon4:Under Construction.:icon4:

#22 col

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Posted 30 April 2008 - 08:44 PM

KMack has camber tops that also adjust caster. They have what looks like rings with offset holes so when twisted you can get just camber, or by moving the pivot back or forward as well you also adjust caster.
Has anyone used these?
I know you were joking about having the camber tops slotted back to front ,but these do both.
I would think they would be good in the rear.
Do you think adding some caster in the rear would be good?

#23 JMortensen

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Posted 30 April 2008 - 10:32 PM

In screwing around with the rear suspension I've found that the most important thing you can do is to make sure that the strut is perpendicular to the control arm and the strut top. Any movement of the top or bottom forward or back puts a bending load in the strut. Realistically the control arm will bend before the strut does, but this process still puts stress on the arm and also the side force on the strut can't be good for stiction.

Here's a related thread with a solution that nobody has finished yet:
http://forums.hybrid...ad.php?t=129154

Jon Mortensen, owner/operator www.petdoorstore.com


#24 kamikaZeS30

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Posted 27 October 2010 - 10:19 AM

I'm an idiot that can't seem to find the old strut thread.

When you say sectioning the strut tube housing, do you mean cutting off the stock spring perch to allow for installation of coilovers w/ adjustable collars? Is there a magic length it should be when finished?

P.O. of my Z already had installed some coil overs with Tokico HPs. I'm not sure what brand they are, they're not weld-in, but they're pretty stiff, I think they're 200 or 225 lbs/in. rate.

I'm asking because I'm trying to figure out my suspension set-up while I'm doing the V8 swap (it's going on 6 months now, but very close to being finished). The ride-height seems "high" not like 4-wheeling or anything, but it looks close to stock. I'm also running a tire diameter of 24.9" (225/50ZR16) so that would obviously have something to do with it.

I recently purchased but have not installed yet, polyurethane front & rear LCA bushings. I have already replaced the steering rack, and differential mount bushings when I mounted the V8 (steering coupler is in the mail). I also have a set of RCAs (the ones from MSA for "15 inch and larger wheels").

I guess my question is, how does one verify whether or not one is near or at stock ride-height, I mean, I've got bumpsteer like I'm lowered, but apparently that is inherent to the Z suspension? I would like to a go little bit lower with the car (maybe another .5", as it is I need to roll my rear fenders a tad). I figure that if I needed camber adjustment I could drill out maybe an additional 1/4" in the shock tower bolt holes for adjustability.

Any advice would be appreciated, and if this is the wrong thread, I apologize.

edit: I forgot to mention I have the Bad Dog rails and a triangulated STB in front and rear.

Edited by kamikaZeS30, 27 October 2010 - 10:36 AM.

Present: 1/1971 240z - 383 stroker (6.3L) forged rotating assembly, alloy heads (190cc/64cc), cross-wind dual-plane, 242 @.050" .466" gross, roller rockers, electronic ignition w/ MSD 6AL, block-hugger shorties, dual 2 1/4", Edelbrock Performer #1406, '87 Camaro T-5, R200 3.54, 300ZXT CV axles, 4x4 Toyota 4-pots, maxima/280zx set-up in rear, coil-overs w/ tokico HPs, XXR 002 16x8 yokohama S. Drive 225/50ZR16.

Past: 1/1971 240z - L28 stroker (3.1L), Triple Webers, 280z 5-spd, R200 4.11

#25 JMortensen

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Posted 27 October 2010 - 11:15 AM

Here is the strut thread:
http://forums.hybrid...ground-control/

Sectioning the strut means cutting some of the height out of the middle of the strut tube and then welding it back together.

Here's Coffey's thread on ride height and alignment settings: http://forums.hybrid...nment-settings/

Jon Mortensen, owner/operator www.petdoorstore.com


#26 zredbaron

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Posted 20 March 2011 - 07:56 PM

Google isn't turning up any satisfactory results for the "z select" brand of LCAs and TC rods... anyone have a link? I'd like to check out their designs...

(Am I just being retarded?)

Mark Haag
3.1L '71 240Z for autocross (XP). 2009 repaint, 2011 fabrication, 2011 race motor (RIP).

"Oh my god, how do you steer this thing???  It's like a tractor with that manual steering!!" --AS national competitor (Z06 type)


#27 240zzzap

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Posted 21 March 2011 - 01:22 AM

Google isn't turning up any satisfactory results for the "z select" brand of LCAs and TC rods... anyone have a link? I'd like to check out their designs...

(Am I just being retarded?)


since the zselect.com domain name is up for sale, try this Z-select :)
but the e-mail address azcarbum@msn.com shown there led me to hybridZ-member azcarbum whose profile led me to http://www.zccjdm.com/, which in turn led me to the suspension and steering section, which doesn't show the 'Zselect' parts, which does confuse me a bit :)

Edited by 240zzzap, 21 March 2011 - 01:52 AM.


#28 zredbaron

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Posted 21 March 2011 - 04:14 AM

since the zselect.com domain name is up for sale, try this Z-select :)
but the e-mail address azcarbum@msn.com shown there led me to hybridZ-member azcarbum whose profile led me to http://www.zccjdm.com/, which in turn led me to the suspension and steering section, which doesn't show the 'Zselect' parts, which does confuse me a bit :)


Agreed, but at least it lead to me ordering the Z-select alternator bracket! Success, assuming I hear back from that email address! Haha, confusing indeed...

Thanks.

Mark Haag
3.1L '71 240Z for autocross (XP). 2009 repaint, 2011 fabrication, 2011 race motor (RIP).

"Oh my god, how do you steer this thing???  It's like a tractor with that manual steering!!" --AS national competitor (Z06 type)


#29 deja

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Posted 21 March 2011 - 07:02 AM

Agreed, but at least it lead to me ordering the Z-select alternator bracket! Success, assuming I hear back from that email address! Haha, confusing indeed...

Thanks.


I recently bought some stuff from Brian, he will respond to your email at that address. Great guy to do business with.
'77 280Z - Newly built LT1 4 bolt main, LT4 hot cam kit. 4L60E/Transgo shift kit. 300ZX LSD, Wolf Creek CV axles. MM 5 lug front hubs with Silvermine Stage 4 front brakes - MM 5 lug billet rear stub axles and disc brakes. Molded side skirts and ZG flares. 2905 lbs with a full tank.

#30 zredbaron

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Posted 21 March 2011 - 03:39 PM

I recently bought some stuff from Brian, he will respond to your email at that address. Great guy to do business with.


He did, thanks!

Also, in case anyone had the same question I did regarding relocation of the front LCA pivot point, according to johnc: 'I move the hole up 3/4" and out 1/4".'


Front suspension swaps aren't as popular as of yet, but many GT2 Z racers have fabricated their own SLA (short and long arm) front suspensions.


Cool! I did a quick search, but I don't think I'm typing in the right key words...

I did find this page, though:
http://forums.hybrid...pension__st__20

Cool pics, but mostly just experiments. I'd like to see / read about what the GT2 guys are *actually* running on the track!

Mark Haag
3.1L '71 240Z for autocross (XP). 2009 repaint, 2011 fabrication, 2011 race motor (RIP).

"Oh my god, how do you steer this thing???  It's like a tractor with that manual steering!!" --AS national competitor (Z06 type)


#31 JMortensen

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Posted 21 March 2011 - 03:43 PM

The one I recall had the strut tube cut and capped with a stud sticking out of it, and the UCA attached to that. I'm sure I've seen others, but that was the one that stuck with me. Not very impressive fabrication, but if it works, that's the important part.

FWIW, on my car I actually measured the bumpsteer and it tuned out at about 1/2" up.

EDIT--agree about Brian. Have bought parts twice from him, very good to do business with.

Edited by JMortensen, 21 March 2011 - 03:44 PM.

Jon Mortensen, owner/operator www.petdoorstore.com


#32 zredbaron

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Posted 21 March 2011 - 03:56 PM

FWIW, on my car I actually measured the bumpsteer and it tuned out at about 1/2" up.


You'll have to forgive me, Jon, I'm one of the many HybridZ guys that doesn't know anything until I've actually upgraded it! (I'm trying to upgrade / learn about low-friction LCAs, etc. at the moment)

...are you saying that bumpsteer *begins* after the strut moves up 1/2" above where the strut sits at rest when the car is on its own weight?

Mark Haag
3.1L '71 240Z for autocross (XP). 2009 repaint, 2011 fabrication, 2011 race motor (RIP).

"Oh my god, how do you steer this thing???  It's like a tractor with that manual steering!!" --AS national competitor (Z06 type)


#33 JMortensen

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Posted 21 March 2011 - 04:03 PM

Read the bumpsteer FAQ post for a primer on bumpsteer.

When you correct for it, you can either move the outer tie rod down, or the LCA pivot up. JTR has a spec, and various other sites and people have their spec, but I basically see them all as just guessing. In order to really figure it out you have to measure. I slotted the front crossmember and then moved the LCA up until the bumpsteer went away on the gauge. That point was when the LCA pivot had moved up 1/2". With that modification the car went from doing a sharp jerk on one particular bump at the track to being smooth as silk afterwards, and no more sawing at the wheel in long sweepers on the track. It was a very noticeable difference when I was driving at the limit. So while some say 3/4" up and 1/4" out, and others say 13/16" or whatever up, the best way IMO is to measure it and minimize it.

Jon Mortensen, owner/operator www.petdoorstore.com


#34 zredbaron

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Posted 21 March 2011 - 04:20 PM

Great tips! I'll definitely read up. Thanks Jon! :)

Mark Haag
3.1L '71 240Z for autocross (XP). 2009 repaint, 2011 fabrication, 2011 race motor (RIP).

"Oh my god, how do you steer this thing???  It's like a tractor with that manual steering!!" --AS national competitor (Z06 type)


#35 zredbaron

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Posted 21 March 2011 - 05:07 PM

Here's the bumpsteer FAQ in case anyone else's search button hates them as much as mine does...?

Mark Haag
3.1L '71 240Z for autocross (XP). 2009 repaint, 2011 fabrication, 2011 race motor (RIP).

"Oh my god, how do you steer this thing???  It's like a tractor with that manual steering!!" --AS national competitor (Z06 type)





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