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Front Suspension Swap question


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have you considered using a helper spring with a coilover setup? it allows two different spring rates. the softer one would compress before the harder one takes action.

 

usually for stability almost like adjustable shocks they use on paris dakar, only without the gas/oil and about as much as 10% of the technology involved. :-P

 

Careless, You completely missed what Terry was mentioning...

 

A strut needs 6 inches to operate... 1 inch for topping out, 4 inches of stroke travel, and one inch of sag. A "helper" spring in a coilover application isn't gonna matter if the suspension is lowered beyond those limits and the strut or shock piston isn't usable, because the car is already lowered beyond that 6 inches of strut piston.

 

Also, Do a search on coil overs for the Zcar, and then go over to Sylvia.net to compare the two... I think you'll find that once you understand the whole concept of how the strut needs to function fully in that whole 6 inch range, you'll understand better why Terry is talking about running a shorter strut body strut like the 8610 (Which I just installed in mine last week) and a shortened outter strut housing. Until you understand those two issues, I'd not touch a thing or make a decision to buy anything. Not grasping this issue fully could cost you some serious bucks...:shock:

 

Mike

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In your pics, the gold anodised rods, are they aluminum? If they are, I can tell you from first hand experience that they will bend and then fail. Just a heads up... There's a tremendous amount of load being applied to both the control arm and the TC rod. The TC Rod will fail first though...

 

And while you're at it, I'd consider opening up the strut tower opening more to get full adjustment of that camber plate, like this:

PICT0015.jpg

 

It looks as though you may need to come back closer to upright a little, and you don't have much ability to do that with it the way it currently is...

 

Mike

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Also, Do a search on coil overs for the Zcar

 

Mike

 

ive been doing so since terry replied to the post on the other page, months ago infact.

 

I've reassessed what I've been told about suspension and shocktravel, and I know what i wrote doesn't lend a hand to any of the problems, so disregard or delete that if you like.

 

I just started getting heavy into my Z build, so I'll be able to provide more accurate information (or information that is correct, for that matter) once I start to get into that portion of the build.

 

I hadn't had a chance to play around with teh zee, becuase it didnt run, didnt disengage the clutch, and didn't have floors. so excuse my "noob" ness :oops:

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My 280ZX project car has had a S14 front and rear suspension transplant, which of course gives it five stud hubs and power steering. The S14 front is better than the S30 setup not surprisingly, for a start the steering rack is behind the Xmember.

 

The shorter Tein struts I was going to use had camber adjustment where the strut bolts to the hub assembly. The pic below shows a trial fit with the Teins, the wheels are 17x8".

 

mypic79.JPG

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I am doing the swap you are talking about right now. I used the whole hub, brake and arm assembly from an s13 (with r33 discs and callipers) with a racing logic coilover. I had to redrill the strut towers to accept the camber tops, swap the left to the right and vice versa because the s13 has a rear mounted steering rack and have made adjustable s13 lca's and adjustable s13 caster rods both are on car adjustable and use rod ends. It will bolt straight up to the original lca's and caster rods. So to answer your question it is possible and is not a very difficult swap.

 

Wow! That looks really easy to do. For some reason, just looking at how the S13 suspension is setup, it just doesn't look very strong. 3 bolts trying to hold a strut straight at 1.5' of extension supporting 500+lbs just bugs me.

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What I should have added was that it would be difficult and expensive to fit a S14 front to a S30. Rear located steering rack will from memory foul a L engine's sump, front located tension rods will require significant chassis structural work, probably other things as well.

 

Can't see the point in fitting a S14 rear either, unless it is part of a complete performance upgrade including chassis stiffening, the stock S30 rear is very good for the age of the S30's design.

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What I should have added was that it would be difficult and expensive to fit a S14 front to a S30. Rear located steering rack will from memory foul a L engine's sump, front located tension rods will require significant chassis structural work, probably other things as well.

 

Can't see the point in fitting a S14 rear either, unless it is part of a complete performance upgrade including chassis stiffening, the stock S30 rear is very good for the age of the S30's design.

 

can you check your pm, or your email, i've sent you one recently. perhaps we can talk in more detail, through IM or something

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What I should have added was that it would be difficult and expensive to fit a S14 front to a S30. Rear located steering rack will from memory foul a L engine's sump, front located tension rods will require significant chassis structural work, probably other things as well.

 

Can't see the point in fitting a S14 rear either, unless it is part of a complete performance upgrade including chassis stiffening, the stock S30 rear is very good for the age of the S30's design.

 

would an RB30 with a large snail, and rusty floors and virtually no frame rails be enough of a reason to go the extra mile? That's my reason.

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Nothing is impossible, but there will be quite a few unusual challenges with the S14 front swap. The advantages of the S30 set-up is the weight of the TC rods and its reinforcement is behind the axle. If the frame rails are "gone", the you'll need some really stout framing way out in front of the axle. The floor and rail issues you've mentioned will still need attention regardless which direction you go, but we (Hybridz) thrive on unusual solutions to unusual problems.

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I always liked the fact that the S-30 TC rods are mounted behind the front crossmember, near the firewall and the doubled frame rails... and it keeps their weight rearward as well...

 

If I were going to convert to the S-14 suspension... It would be to convert to rear steer... Which is one reason the TC rods face forward on the S-14... and the steering knuckles bend INWARD...

Think about the fact that the high offset wheels and brake disks on the S-14 need the inward bends on the steering arms for clearance... If you convert to front steer you will never get the steering geometry correct without hitting the disks...

 

 

The whole conversion to S-14 would be to use it as it was designed... otherwise you might as well custom fab the entire suspension... Many more improvements could be made using off the shelf racing components...

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..........................

 

 

The whole conversion to S-14 would be to use it as it was designed... otherwise you might as well custom fab the entire suspension... Many more improvements could be made using off the shelf racing components...

 

Thats the thing exactly, say no more.

 

As far as the capacity of the S30 rear end itself to handle power goes, using available aftermarket parts including rod ended wishbones and beefing up the diff mounting arrangement, what, 4-500WHP??? Basically whatever a R200LSD will handle???

 

EDIT: But with 4/500WHP no problem using a S13/14 rear end, should work OK with an upgraded S30 front.

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Nothing is impossible, but there will be quite a few unusual challenges with the S14 front swap. The advantages of the S30 set-up is the weight of the TC rods and its reinforcement is behind the axle. If the frame rails are "gone", the you'll need some really stout framing way out in front of the axle. The floor and rail issues you've mentioned will still need attention regardless which direction you go, but we (Hybridz) thrive on unusual solutions to unusual problems.

 

so wouldnt replacing the front subframe with thick square tubing be stout enough to relocate the TC rod to the front and not have them collapse? I would also x-brace the rad too, incase.

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My 280ZX project car has had a S14 front and rear suspension transplant, which of course gives it five stud hubs and power steering. The S14 front is better than the S30 setup not surprisingly, for a start the steering rack is behind the Xmember.

 

The shorter Tein struts I was going to use had camber adjustment where the strut bolts to the hub assembly. The pic below shows a trial fit with the Teins, the wheels are 17x8".

 

mypic79.JPG

 

I have those same wheels on my wife's BMW 328is! :2thumbs:

 

Mike

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so wouldnt replacing the front subframe with thick square tubing be stout enough to relocate the TC rod to the front and not have them collapse? I would also x-brace the rad too, incase.

 

Correct. I'm looking at this project from a different viewpoint than you. My point of view is reduced weight, and especially anything excessively forward or rearward of the axles (e.g. reduce polar moment, or at least don't increase it). Most everybody on this site (myself included) provide opinions based upon their point of view, which is why I hesitate so often in adding any comments at all on other's projects unless the owner's goal it is perfectly aligned with what I see for the car. Regardless, I am always facinated when new ideas come to fruition, and if any site exists that illustrates "out of the box" thinking, it's this site, and this group. Keep us informed of your project, and please photodocument it.

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In your pics, the gold anodised rods, are they aluminum? If they are, I can tell you from first hand experience that they will bend and then fail. Just a heads up... There's a tremendous amount of load being applied to both the control arm and the TC rod. The TC Rod will fail first though...

 

And while you're at it, I'd consider opening up the strut tower opening more to get full adjustment of that camber plate, like this:

 

 

Yes they are aluminium, I had a choice between them and steel ones but was assured by the race shop (they deal with stock car racing) that they would be strong enough. Would the steel ones be strong enough or would you recommend something else, chromoly has been suggested to me but it is rather expensive, do you know of a source for 5/8 threaded or threadable rod (I have L/H and R/H taps) that would be strong enough.

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Nascar folks use those tubes on tie rods, so they don't see an over-abundance of stress, which is OK I guess (although I'd still not use them). We bent a pair at the MSA Show back in 2001 just autocrossing, and only in one day's use. So I'd absolutely not use them for either TC rods or control arms. I'd buy the steel units or cromoly units if you can find them, but I'd no way use them on a street or track car.

 

The upside is they look great, which was why we had them on our demo parts we were showing at MSA that year. It was our first year at the show and we learned a lot of what worked, what didn't, and who the competition was or in this case at the time, wasn't!

 

http://www.colemanracing.com had the solid steel units. The swagged units aren't strong enough in my opinion, so stick with the solid steel units and order them in the lengths you need, and since you're so far away, I'd order double everything to have spair sets. They were about $10.00 each USC.

Mike

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AZC sells aluminum 5/8" TC rods and has for quite a while. I used 3/4" aluminum rods for 6 years or so without any issues and put 40K miles on them, autoxed and track days on everything from sticky street tires all the way up to slicks. 74_5.0_Z had an incident with a swedged rod where the rod hit the frame and bent, but that was due to his tube frame design, and not necessarily a weakness in the rod.

 

Just food for thought.

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