redraif

To be honest weight savings is nice...concidering this car weighs a ton somehow! But I'm more trying to do this to free up space for the turbo we are planing! So I want strength and space...weight is the low man in the totum pole!

RTFC

"you'd be surprised"

Well hey, surprise me then. Don't just talk about something, do it. If you are going to make a statement then you should back it with picutres and proof. I do this around here.

You claim to do such great work on alot of priceless cars, lets see some action? I do the stuff and I post pictures and results.

redraif

Well since I WAS concidering one I would love to have the details if you don't mind! All this helps my case when I have my talk with them about what they are going to do to make things right!

redraif

Is that PAs?

redraif

Now I don't have red wheels or a red windshield get it right!

wow according to your drawing I have so much downforce the backend is squated to the ground

MrDude_1

yup... i think everyone who thought out why to get a Kmember came to the same conclusion.
weight has NOTHING to do with it... its about the space the tubular Kmember clears up..

that one is PAs

ive had both PAs and Profabs..... to be honest, both have HUGE room for improvement, in both the companies and products....

the only one out i havent tried is Hawks.... i havent really looked into it, but looking at one installed on a car at his shop, it looked nicer... *shrug*


in anycase, im caught... i cant run stock A-arms on a tubular Kmember. and i cant run the stock Kmember, spohns bar making the V arm a A arm is nice, but its right in the way... and coil overs dont allow enough room for my wide front tires....

so im screwed one way or another.. if it breaks, eh, better chance of me living thru it then if any of the 100s of aftermarket parts on my bike break..... no matter what, its a compromise...

redraif

Conntacted PA yesterday...

got the:

"Ok... well we will need to see the broken unit then we can determine what went wrong and go from there. We we would prefer you send back both sides, but at least the broken unit. Sned them to us with your contact info and we will let you know what we find out..."

That was it! Not even an offer to send a ups p/u label... Well I'm going to call them back about that when we get the thing off! I got the Tow bill and they are going to get a bill for the labor for removing the broken unit and replacing with stock!

Also there is a custom tubular chasis place near where I work. He is nationally known. I figure I will give him a call and see if I can get an impartial inspection from an expert before the unit leaves my hands. I don't want something to conviently to happen to the a-arm, or them to make some wild claim that I can't verify since I don't have the unit!

So we cleaned up the garage (Fiero junkyard day on Monday...think whole rear section & full interior all over the place) to make room for the teardown. So tonight we are digging in. Going to run tape and dig camera of the damage! Figure you can never be too careful with your evidence!

Sad thing is I cleaned the a-arms on Fri (for gathering) and saw and felt no cracks. Yes this means laying under car wiping and washing (i'm that ****). Then again Sat I wiped them down. Still nothing. Then Sunday...boom!

redraif

If spohn just had a whole front suspension piece I would go with it. Just sucks they don't just have a complete kit so to speak... I would get the steel strut towers...k member and a-arms

I'm actually thinking alot of my decision will boil down to what PA does about it...what the chassis guy here finds. I may just get replacements from PA & their kmember. Set it up with my springs and then when spohn gets the steel strut towers for a coilover set up then run a coil over set up. Let the spring pockets work for strength only. I'm going to be doing a rim upgrade at some point anyway... the coilover will give me the additional addjustment I need.

Kenwood

iTrader: (1)

MAN I WISH people would research this because I see this misinformation all over the place here... YOU CAN RUN A TUBE K_MEMBER WITH STOCK ARMS>>> just not a POFS PA or profab one...

I have an AJE K-member with STOCK arms... works perfectly...is advertised to work with stock arms...and my car is rolling proof that it can be done.. For the record an AJE one is a LOT beefier than a PA or profab...it makes the one pictured look like a twig... Also the AJE stock spring pearches bolt between the kmember and unit body frame rail>>>the plate uses the frame rail to support the spring>>>versus that skinny weld on the PA unit... Yes the AJE one is more money...but there is a reason for it....Also the AJE comes with new mounting hardware so its trulyy a bolt in deal..

Karps TA

iTrader: (2)

AJEnuthugger

MrDude_1

AJE also doesnt clear my stuff... so unless i want to redesign everything to go around it (and then be in the way of other things, like the spark plugs) i have to run a PA or Profab unit... *shrug*
money isnt the problem as much as space is.. theres only so much room underhood.



btw, go add that to the Kmember FAQ

Kenwood

iTrader: (1)

Not being a nuthugger but every tube k-member post says you CANT RUN STOCK ARMS>>> Im saying YES YOU CAN... Feel free to come look at my scary rare setup>>>tube k-member with stock arms... or just pick up a jegs catalog...read under k-member>>> will work with stock or aftermarket a-arms...


But Yes I am pro AJE... After looking at Guidos Pro fab one and my AJE....Ill stay and be called an AJE nutswinger..

Kenwood

iTrader: (1)

There is a K-Member FAQ??? LOL>> I added this on a couple of ddifferent posts but it always goes on deaf ears>>> what wont the AJE one clear....???? just curious... but Guido designed his turbo headders and stuff around his PA unit... It cleared all mine perfectly... Only thing that is different is the motor mounts>>>which I dont use...and the tubing diameter is much larger on aje so maybe oil pan clearance??

MrDude_1

yea, i got pissed this morning reading thru the same repetitive crap looking to see alternative ideas to mounting my brake line to the Kmember....


i had it here in the suspension/chassis forum, but the mods here move every FAQ to the "FAQ" board... without leaving a cross-ref link to this forum.... so expect the same people to never see there's a K-member FAQ and ask here anyway..... that should make it fun when you search for info..



(im feeling a bit sarcastic today... heh)

Guido

FWIW, the stock a-arms also bolt to the PA Racing one. I ran mine like that for a year before I upgraded to the tubular a-arms.

I hope I dont have a similar failure like raif did. But then again, I dont have a 400 pound spring bearing down on a chinsy looking spring pocket either. Ive just got a strut to the spindle and a 175# coil over that. LOL Much less stress Id like to think. But then again who knows. I may see about adding some braces to my arms just to strengthen any weak areas.

Hey dude, what are you putting in your car that yourhaving trouble clearancing for?? You could always go with a motor plate like I am.

MrDude_1

didnt you get the memo? shhh. lol

think 3rdgen LS1 phamspeed

Guido

No i was busy making cover sheets for my TPS reports. LOL

interesting.

redraif

Well upon looking at the piece off the car I was wrong initailly with my break point guestimation....
The actual break point intersected the spring pocket at the rear on the further most rear leg of the a-arm (pass side). Looks like it started to crack at the rear courner weld point and then the crack moved towards the bottom and then the piece let go. Upon inspection of the front most leg of the same a-arm Joe and I detected a crack in the powdercoating. Usually for the powdercoat to crack the metal is cracked/stressed beneath it. The crack is in the same point we believe the crack started on the other leg (the rear most weld point of the spring pocket). Also noticed on the front leg of the a-arm...the weld where the tubing meets up to the a-arm mounting point (to the chassis) there are some cracks in the powdercoat at that weld point.

Also noticed that overall the legs of the a-arm b/w the chassis mount and the spring pocket seemed to have a slight bend in the tubing. Not sure if this is intentional or something that was occuring.

The drivers side has not been removed just yet! Tonight.

Did not notice any contact points with the body!

Will have pics up soon. Not sure the digital cam took very good ones. Will look at them tonight on the computer and post! I videoed and plan to shot with the 35mm as well!

HorseflyDF

I dont understand why people put this tubing
on there cars in the first place. Just for driving in
the street? What is this some kind of joke.

I can understand SFCs because the body flex
on these cars is ridiculous.

Seems to me upgraded shocks and springs is enough.

The great thing about these cars is
you can bolt in a 300 hp engine or more if you want.
Thats enough power for the street to be king of the road.
: )

If you want to go weight reduction just start ripping
out stuff that wont put your suspension and life in danger.
Plus its expensive.
I would rather save my money and get a 500 hp monster.

redraif

Profab and PA are essentially the same. Same design... profab split off from PA! I would be even scareder of their stuff!

Joe & I were discussing the AJE unit...
Will it work with Spohns A-arms?
Any pics or a link to it?
What does it cost?
The most important question....does it use split tubing? or solid?
Do they sell a-arms?

87CIZ

iTrader: (8)

if you've read the history on profab and pa. Profab is run by the guy that designed them and built them. PA is the other guy that helped. He kept the design but he doesn't build them. He has them sent out to be built. Unlike profab that does all his stuff in house. Instead of shipping it out to someone making minimum wage.

redraif

Well above it was mentioned by Dean that the stock a-arms do have some flexing that the tubular ones do not. All the little flexing adds up accross the board to make the car not hadle to its peak. If the blasted tubular ones would just get built beefy enough for real use that none of this would be a prob. Build the light weght ones for drag racing and let the streeters...like us have something substantial. Weight savings is less important then strength in my book!

redraif

Well after seeing the breaks and the stress points in mine I think it is a design flaw not a fabrication flaw!

HorseflyDF

Thats the point probably in the original
design that some components would flex especially
if you consider that the original stock stamp piece has been
on cars over 20 years old without breaking.

I am really considering SFCs, but I had this question
will it eventually crack the unibody? especially where
I live the roads for the most part suck.
The 4th gen SFCs design looks much more supportive
than the any of the 3rd gens.

If your into racing like autocross I guess its worth it,
if its proven to be successful.
For the street I dont think its worth it.

After driving smaller cars that handle much better

I would say 240sx amd a 300zx can out handle these
cars stock for stock, without getting into a arms etc...

AM91Camaro_RS

why would SFCs crack the unibody? they are supports to help strengthen the body and chassis.

HorseflyDF

Modifying something that
was designed to flex.
Now your connectors are welded
parallel to the side rails
Theres no support or triangle for the
middle of the unibody.
The unibody will still try to flex along the rails which
will create stress along the entire rail.
Thats how they could crack the unibody,
I would imagine this has been taken into account already.

Guido

Add a roll cage to be sure. :P

HorseflyDF

I would like to start from scatch with a nascar
tube chassis..
yeah 2500 pound 600 hp car that can handle pretty
good.

redraif

Well I was intending this car for autocrossing...though not with arms that are that weak! Hense me wondering what route I should go!

Guido

I have NEVER heard of someone having chassis trouble from adding subframe connectors. Actually, they help prevent roof cracking around the b-pillar/roof intersection @ the window.

My car never felt better after SFC. Thats the single best chassis mod I ever did. Ive added cage, torque arm, etc since but none had as big of an impact handling wise as SFC's. I cant believe they hurt anything.

MrDude_1

heh, sometimes when people have their head in the clouds, the lack of air gets to their brain....
dont worry about it. lol

james_85Z28

ummmm nascar cars are almost 2 tons.....light they are not.....

MrDude_1

nor are their chassis well suited for street duty.
you would have to move every suspension mounting point if you wanted it to handle at all and still have ground clearance

DuronClocker

iTrader: (1)

He also thinks a 300HP motor would allow you to be king of the street Take what he says with a handful of salt.

Kenwood

iTrader: (1)

The tubing appears solid>>>It was powdercoated when I got it BUT I see no seams on any of it.... Spohns arms???I dunno>>>If spohns arms work with a stock k-member then I suppose yes>>

Cost I dont remember...Jegs sells them...so does AJE.. dont have the links handy though...same for pics...jegs catalog has a picture of it>>>the aje website only shows a pic of the 4thgen version.. Mine had Turbo headders and a crossover tube in the way>>>I remember taking pics when I bought it and first installed it...Ill look for them... and post if possible..

Yes they sell a-arms...they sell rack and pinion steering, with without motor mounts, coil over kits, steering shafts, etc etc.. in moply or mild steel ..

any more detail than this you would have to ask Anthony Jones of AJE..

soulbounder

AJE's website has been updated to show the 82-92 Fbody K-member but it doesn't appear that they offer it with spring perches.

redraif

FIERO! 2800Lbs stock and rear engined...just drop in a 383! thats whats in the future for Joe and I!

redraif

Ok back to serious matters! We got the other side off tonight. Guess what I found...stress cracks at both of the rear spring pockets...right where the other side broke. Also the rear most one was worse. So this side was ready to let loose as well!

I would say serious design flaw. I mean why would you weld something to the side of a tube that was going to have that much pressure on it! Why would you not set it up so the pocket legs go on top of the tube...thus having the weight on the tub and not on a small section of weld!?

I'm thinking I would not ever trust these again to run springs in! Maybe with a coil over kit!? They are going to be looking at a refund and then some compensation in my opinion. Enough to pay me to get sphons a-arms pay for my expenses with the towing and uninstall/reinstall/uninstall/reinstall... then I will be getting in the AJE K member... looked at a jegs cat and that is much beefier!

Dean: I cut .5 coil off the Eibach prokit springs...what would my spring rate be? I know its stiffer! And what rate should I get to have it ride the same in a coil over conversion?

83 Crossfire TA

iTrader: (2)

The caddie engines, like the old 4.x, northstars… are better swaps, they bolt right up to the tranny without any adaptor plates… we’re also doing a blown 3800 swap in one. Good luck in keeping a fully trimmed v8 fiero light. For that matter, the trannys are the limitation, not really much of a point in building cubes for one since a smaller displacement built to wind up will be much more forgiving to the tranny.

I’ve always thought that either a ford 302 based engine (about 200lbs lighter and slightly smaller then a SBC) or a Buick/Rover aluminum block V8 would be a killer swap in one.



Of course, Dean believes that I don’t have a clue but it sounds like you’re finding exactly what I was expecting. It’s good that you caught it before it _really_ caused a problem.

Going to coil overs would make this much less of an issue, since you wouldn’t be putting the spring pressure in the middle of a length of relatively small tube at all. Of course, coil overs aren’t really a great solution for anything besides making that assembly lighter. In general, I would recommend against them for handling or street use.

Moving the pocket mount to the top of the tube will not help any more then moving it to the bottom, the weld should actually be stronger then the steel that it’s connecting together, it will just make for a heavier piece. Any plate, unless totally oversized should be attached so that it’s tangent to the tube rather then radial. Another thing that would help design wise is anything that distributes that attachment point over a larger area and especially that extends that area down the side tube towards the bushings. Something with some shape to it is better then something flat/straight.

You could always play it totally safe and go back to the stockers.

the spring rate is inversely proportionate to the overall length of the wire that makes the coil spring. If you could give an accurate measurement of the spring wire diameter, the coil diameter and the # of free coils, it could be calculated fairly accurately. It could also be measured with a scale, anything that can apply enough force to significantly compress the spring and a ruler.

Educated guess… judging from the construction of the stock springs, eibach’s advertised rates (depending on where you get the numbers they’re either 697lb/in or 710lb/in), taking half a coil off of them will add about 70lb/in to the spring rate.

There’s a lot of variables with coilovers, but generally you’ll be talking about ½-2/3 the spring rate, but I would just ask the manufacturer for a recommendation of where to start.

RTFC

Shannon, basically if you take a coil spring that has lets say 8 complete coil loops (regardless of spring height, just count spring loops). The top and bottom coils are "dead" coils because they are what contact the outer mount surfaces, thus you would have 6 "free" coils that make up the rate. Lets say your rate is 700lbs@ 1inch compression. Take and cut off .5 coil of the 6 free coils and you are of course left with 5.5 free coils or 11/12th of the active rate section. Divide the 700 by 12 and you equall 58.3. Now in essence (NOTE:this is not an exact science! just a primitive way to estimate) since you are shortening the coil frequency, it does not decrease the 58.3 (or 1/12 of 700) in would in fact increase about that much with each .5 coil cut or decrease that much with each .5 coil added ( this progressively increases though, but close enough for .5 coil add or subtract from the original sping rate.

Fuzzy math

Remeber also that aggressive rate struts will up the compression rate as well.

RTFC

ps- My current project car is 1200 lbs and 200hp- can you say rocketship?

'67 Austin Mini Cooper S with an Acura V-tec motor and transaxle.
That same 1800cc motor puches the 2800lb Acura to a 14.5 sec 1/4- again, the Mini is 1200lbs And it will have a top speed of 135mph proven by GoMini's in Georgia.

Guido

Here is a picture of wood's k-member. I had it hidden away in a forgotten directory. LOL

Kat

iTrader: (4)

Now ya know why Steve built his the way that he did. Also the MAJOR flaw IMO with the PA's a-arms is the bushing. Like I said before, there is no give at all in it. So you get what happened to you. A stress break. All that pressure has to go somewhere. Thats the reason why I'll run poly in the front a-arms for a street car.

Kat

MrDude_1

did my Kmember swap today ( Profab SBC Kmember to PA racing LS1 kmember...)


took some pics to compare, but i left the camera cable at work, so they'll wait till monday... PA updated a couple SMALL things compared to the profab, but its still ehhhh.....

i also stripped the powdercoating off the A arms.... they're painted satin black right now, so theres less covering any fractures or anything... i'll keep a close eye on them for now.


i noticed my a arms are two diffrent designs too.... i have pics, i'll post them monday......





kat, if its only the bushing design thats the prob, why dont we just press some poly bushings in the a arms??

Kat

iTrader: (4)

PA's design is wayyyy to small to do anything like that. 1/8th inch isnt much give IMO.

Kat

redraif

Ahhh why go thru the effort on a swap and not go all the way! Caddie motors are expensive! Good when fresh, but expensive to up keep. If you can find a fresh donor I'm all for it, but good luck. They are crazy $ to rebuild!

PLus V-8 Archie has the v-8 swap done to a science! Can't go wrong. Here is the v-6 girl saying I won't go v-6 in the fiero! Just if you are going to do it go for the gold! Though a TTA or GN would be another fav choice! (more unique and mucho potential)

Quote:

Of course, Dean believes that I don’t have a clue but it sounds like you’re finding exactly what I was expecting. It’s good that you caught it before it _really_ caused a problem.

Agreed! the one side happened and thanks to my car doing what it always does...(getting supersticious now) break in a way that is at a safe place or "not as bad as it could have been" Man I have too many of those. Not complaining. Glad it happened how it did!

From this event I have learned...no to PA for me! No new ones...just give $ back and pay for tow, shipping, and labor!

Quote:

Going to coil overs would make this much less of an issue, since you wouldn’t be putting the spring pressure in the middle of a length of relatively small tube at all. Of course, coil overs aren’t really a great solution for anything besides making that assembly lighter. In general, I would recommend against them for handling or street use.

Done! Coilover kit, with new a-arms & k member bought today! Road race set up! (more reinforcement bars) AJE makes the whole kit...show special (super chevy) so i got it. Powdercoated transparent red to! Man their stuff is much beefier! Feel much better about running it then chancing PA again!

The coil over idea made me nervous, but it will help fix alot of issues I'm having... like the ride height issue with it being a 6 and no real lowering springs out there! New POSSIBLE wheel combo would benefit from better height adjust. Plus I could convert to a better spring for drag racing...maybe help that line spin a bit! Though the spohn torque arm would be the best solution! (soon)

Quote:

Moving the pocket mount to the top of the tube will not help any more then moving it to the bottom, the weld should actually be stronger then the steel that it’s connecting together, it will just make for a heavier piece. Any plate, unless totally oversized should be attached so that it’s tangent to the tube rather then radial. Another thing that would help design wise is anything that distributes that attachment point over a larger area and especially that extends that area down the side tube towards the bushings. Something with some shape to it is better then something flat/straight.

OH! Didn't think about it that way! Heavier...I don't care! Safer!

Quote:

You could always play it totally safe and go back to the stockers.

lol...NO!

Quote:

the spring rate is inversely proportionate to the overall length of the wire that makes the coil spring. If you could give an accurate measurement of the spring wire diameter, the coil diameter and the # of free coils, it could be calculated fairly accurately. It could also be measured with a scale, anything that can apply enough force to significantly compress the spring and a ruler.

Educated guess… judging from the construction of the stock springs, eibach’s advertised rates (depending on where you get the numbers they’re either 697lb/in or 710lb/in), taking half a coil off of them will add about 70lb/in to the spring rate.

There’s a lot of variables with coilovers, but generally you’ll be talking about ½-2/3 the spring rate, but I would just ask the manufacturer for a recommendation of where to start.

Thanks for the idea! Gets me a feel for what I should tell the manufaturer. They said AJE would pick out something appropriate...just wanted to give his some rough figures to try to match with the ride I like!

redraif

Whew! nice!

redraif

Nice! Mines on the way! I'm a convert too!

redraif

Yes we asked for polyurathane on the new a-arms.... wanted to run sphons, but I got an offer I could not refuse on the whole swap! Could not beat it if I bought stuff in pieces!

Kenwood

iTrader: (1)

Cool>>welcome to the AJE nutswinger club...LOL. So I take it you got his arms and stuff as well??