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Shawn B said:
This is definitely the place for structural bracing, got a whole section on it. As you can tell, pretty much anything having to do with the suspension gets included.

Feel free to PM me or post again on exactly what you would like to see included. I am grateful to anyone that contributes "reasonable knowledge and practice" to this thread.

Since I have no knowledge and am oftentimes unreasonable, I sure can't contribute much myself. :D
Stiffness is very important in suspension tuning.
 
Discussion starter · #123 · (Edited)
choaderboy2 said:
Stiffness is very important in suspension tuning.
I know. You already indirectly told me so, and I quoted you. You probably missed it amongst all the other times I quoted you.;)
Mike Kojima said:
In any high-performance car, it is impossible to make the chassis too stiff. The stiffer the chassis, the higher its natural frequency, making the energy imparted to it by bumps less likely to excite the body's structure. A stiffer chassis enables the use of stiffer springs and shocks without hurting the ride. This is because a stiff, non-flexing chassis transfers more force into the suspension where it can be dissipated by the springs and shocks instead of transferring the force to the occupants. A stiff chassis is also more responsive to roll rate tuning for balancing understeer and oversteer. This is one of the reasons why automotive engineers are continually investigating ways to stiffen chassis without adding weight.
Right at the top of the "Braces" section.

A flaccid chassis sucks.

Is this damn thread getting too big? "Gone With The Wind" Suspension Thread? :melonscratcher:

Nah.......
 
Just when I thought I'd read everything about braces, I walked smack into this...

http://sr20forum.com/showthread.php?t=146257&highlight=progress

Post 16 and 17 refer to a NISMO LCAB, although it sounds like it hangs real low - another good item for the Suspension Manifesto as well.

Shawn, if you do update with this info - you may want to grab the pic from that thread as well, that post isn't too old - but on a related note, I got there from reading about the IKEA brace, and those pics are long gone.
 
Discussion starter · #125 · (Edited)
jrmnet said:
Just when I thought I'd read everything about braces, I walked smack into this...

http://sr20forum.com/showthread.php?t=146257&highlight=progress

Post 16 and 17 refer to a NISMO LCAB, although it sounds like it hangs real low - another good item for the Suspension Manifesto as well.

Shawn, if you do update with this info - you may want to grab the pic from that thread as well, that post isn't too old - but on a related note, I got there from reading about the IKEA brace, and those pics are long gone.
Well, hell yes I'm gonna add it. :)

Love...Suspension Manifesto. *chuckle*

I already grabbed the picture, good advice. I'll upload and insert this information later this weekend. I am working over the next few days.

Uh...once again, you rock. I literally want everything about our suspensions crammed into this thread. One source, as many answers as humanly possible. Thank you once again for your help.
mpg9999 said:
Sorry for the late reply, I completely forgot about replying to this. Anyways, yes, you should not run a harness without a roll bar. The reasoning is if the car rolls and your strapped in, your body can not move out of the way if the roof caves in. With the stock three point seat belts you can. So basically the only harness bar you should be using is one thats on a roll bar.
Late coming back to this. :tongue:

Can you (or somebody smart like you...Mike K, Racing Forum Members with experience, etc....) please elaborate? So all these "harness bars" are flat-out unsafe without a proper roll bar/cage? I see them being used on the forum quite a bit for street use.

No cage/roll bar = no harness bar?

No harness bar = no 5 pt seat belts?

No 5 pt seat belts on the street?

:confused:

Please discuss at length on this topic gentlemen.

I know the stuff about no cage or rollbar on a DD. Unpadded even worse. Use roll bars/cages only with a helmet. etc..etc... I have a whole section on it with quotes from various magazines. You can read what I have already included in the thread. I would love to put down some definitive answers on this stuff. The safety of our forum members is paramount.

Please remember I know next to nothing. LOL.
 
Discussion starter · #129 ·
kioh said:
Does Progress still make coilovers for the B13? What if I wanted a set, what are my chances of finding one?
Yes, they are available. Call them, their number is in their web-site.
 
Discussion starter · #133 · (Edited)
don't know if this has been added but might help out..

http://www.nissanperformancemag.com/september04/b14susp/

under: Bump Stops and Rear Mounting Plates

about the mod to the Koni bump stops.
Thanks Wayne, excellent information, I appreciate it.

I will incorporate this shortly in the appropriate spot in the thread...........DONE, incorporated in three different spots. Plus you forced me to create a whole new category. Thanks for your help. The last person to create a category was...Knuckles, I think.

Gotta update the Tein spring information as well......DONE.

Ask Steve to edit/combine the CSK section with his recent CSK questions thread.....

Add in Mike K's thread on fixing suspension geometry from the Road Racing section....

This damn thread will never be done. :( .....:squint: .....;)
 
IV. Bushings

(Applications: B13, B14, B15)



Very informative thread on rear suspension bind on the B13, which includes links to other threads on the same issue:
http://www.sr20forum.com/showthread.php?t=134794
I took Steve's sage advice and I did search around the Forum.



Another very good thread with Steve dropping knowledge on the issue of suspension bind:
http://www.sr20forum.com/showthread.php?t=168950

If you are not going to the track, perhaps you utilize the car as a daily driver and occasional autocross, this is something to carefully consider:

This stuff about suspension bind is baloney. Sure there is some bind but if you take the damper out and stroke the suspension though its range of normal motion by hand you can see that the bind is minimal, like it adds perhaps 5 lbs to the wheel rate, perhaps as much as 10 and there is no way you are going to feel that in a sedan!

What will happen is that the suspension will tend to move towards toe out under trail braking which exagerates trailing throttle oversteer. If you have dirven a car with stiff suspension, sticky tires and stock bushings you will know what I mean, its a vauge feeling.

If you drive a car with stock bushings and a full ES set there is a big difference.

Socres of guys who actualy race these cars or drive on the track with full ES sets are not wrong.

Your suspension is not going to lock up sending you into wild oversteer. In fact it will be the opposite as less delfection will lead into to more toe in under roll. In fact the latest thing I do on race B13's is to incline the strut rearwards to reduce this tendency.
 
Discussion starter · #135 · (Edited)
This stuff about suspension bind is balogna. Sure there is some bind but if you take the damper out and stroke the suspension though its range of normal motion by hand you can see that the bind is minimal, like it adds perhaps 5 lbs to the wheel rate, perhaps as much as 10 and there is no way you are going to feel that in a sedan!

What will happen is that the suspension will tend to move towards toe out under trail braking which exagerates trailing throttle oversteer. If you have dirven a car with stiff suspension, sticky tires and stock bushings you will know what I mean, its a vauge feeling.

If you drive a car with stock bushings and a full ES set there is a big difference.

Socres of guys who actualy race these cars or drive on the track with full ES sets are not wrong.

Your suspension is not going to lock up sending you into wild oversteer. In fact it will be the opposite as less delfection will lead into to more toe in under roll. In fact the latest thing I do on race B13's is to incline the strut rearwards to reduce this tendency.
I understand your point and I sincerely appreciate you looking so closely at this thread. I want the information in this thread to be as accurate as possible and you happen to be one of my most quoted experts. :)

Slartitbartfast said:
Trailing arm is indeed the culprit. You must leave rubber on one end to allow the arm to move fore/aft as hub moves up/down.
It appears that Steve, Slartitbartfast, and Johnand all state the the rear trailing arm is in fact a problem. It must be repeatedly lubricated or it will bind.

Do the guys on the racetracks frequently lube the bushing? Zirk fittings and grease?

Or do they install the ES bushings in the rear and just leave them alone, with no issues?

Do you think that ES bushings (including the trailing arm) are A-OK for a daily driver, and someone who is not going to take the time to lubricate the ES bushings?

I am not mechanically knowledgeable nor experienced enough to argue either way. I could not even tell you which suspension part is the trailing arm. Again, I just want accurate information for the masses.

I PM'd Steve requesting that he discuss this issue further with you.

Gracias!

PS. Remember the Oscar Meyer song - B-O-L-O....G-N-A. ;)
 
I understand your point and I sincerely appreciate you looking so closely at this thread. I want the information in this thread to be as accurate as possible and you happen to be one of my most quoted experts. :)



It appears that Steve, Slartitbartfast, and Johnand all state the the rear trailing arm is in fact a problem. It must be repeatedly lubricated or it will bind.

Do the guys on the racetracks frequently lube the bushing? Zirk fittings and grease?

Or do they install the ES bushings in the rear and just leave them alone, with no issues?

Do you think that ES bushings (including the trailing arm) are A-OK for a daily driver, and someone who is not going to take the time to lubricate the ES bushings?

I am not mechanically knowledgeable nor experienced enough to argue either way. I could not even tell you which suspension part is the trailing arm. Again, I just want accurate information for the masses.

I PM'd Steve requesting that he discuss this issue further with you.

Gracias!

PS. Remember the Oscar Meyer song - B-O-L-O....G-N-A. ;)
Theorticaly what they are saying is sound and correct but practicaly its not that big of an issue. If I was designing a suspension from scratch its not how I would have done it but for most of us, we are stuck with what we got by the rules or by money one is willing to spend. Note that none of these guys actualy race or do much track driving, testing or development.

If somone thinks this is wrong, they can see what I am talking about by taking off the spring and cycling the suspension through the range of normal motion as constrained by the damper, then remove the damper and move the suspension through the same range, from normal ride height to close to bottomed out as defiend by touching the bumpstop. Sure you can feel some bind but its easily overcome by hand pressure. Note that there is also bind from the stock rubber as well. The bind does not become severe until the suspension is cycled past the point it can move as limited by the damper!

The small amount that this bind adds to the wheel rate is unfeelable in this sort of car. You can feel the difference in the toe change cause by compliance here.

Now certain car like Hondas have bushings in their rear trailing arm that cannot be replaced with urethane without bind issues but the amount of bind that we get our suspension is very small in relation to this.

As far as maintanance, I normaly wrap the bushings pivots with a couple of layers of teflon tape then apply silicon grease. This stays smooth, quiet and sticshion free for a very long time. In fact I havent ever had to service a bushing after this trick.

I got this idea from a fellow list member, what a great idea! I wish I had thought of it.
 
If somone thinks this is wrong, they can see what I am talking about by taking off the spring and cycling the suspension through the range of normal motion as constrained by the damper, then remove the damper and move the suspension through the same range, from normal ride height to close to bottomed out as defiend by touching the bumpstop.
I did the same thing. Thats how I came to the opinion. Maybe it's a east coast/west coast thing. In a place that gets rain regularly ES bushings suck. Especially if you can replace some of the worst offenders with spherical bearings and totally eliminate the binding and friction.
 
I did the same thing. Thats how I came to the opinion. Maybe it's a east coast/west coast thing. In a place that gets rain regularly ES bushings suck. Especially if you can replace some of the worst offenders with spherical bearings and totally eliminate the binding and friction.
Try the teflon tape thing, it makes a big difference.

Like I said, there is bind but it turns a 600 in/lb spring to a 610 in/lb spring or so.
 
Try the teflon tape thing, it makes a big difference.

Like I said, there is bind but it turns a 600 in/lb spring to a 610 in/lb spring or so.
My other issue with ES bushings is that they don't move smoothly. They tend to grab, let go, grab. Very inconsistent. I guess if they are smooth they should be ok. I have found that even on my simple Front LCA (on my 240 that I sold) I needed to not tq down the bolt very much to insure this did not happen. I had to locktite it in place otherwise it would back out. Too tight = bind, too loose = sloopy arm with toe change. Get it right and it was ok. I installed grease fittings so I can relube it easily.
 
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