Now just the fact that there is 2 different size sway bars proves the parts book is wrong.
Nope, doesn't prove anything, except Pontiac didn't acknowledge there is a difference and/or you are seeing a variance in supplier parts (1/32" could be with the variance.. now it was 1/8" or more... then yeah, that is significant).
quote
Originally posted by sardonyx247:
But as the RPO codes go, is there a RPO code for fastback taillights vs notchback taillights, fastback decklid grills vs notchback decklid grills, fastback decklids vs notchback decklids, fastback decklid locks vs notchback decklid locks? You see where I am going with this. No, it was part of the package. So that elminates the RPO code theory too.
When you buy a fastback taillight, it has a part number that is different than a notchback taillight. When you want a specific spring, it has a part number. Same for anything used on any package, as you call it. Each unique part has a part number. How would Pontiac even inventory these parts or determine which part when were, if it wasn't assigned a part number? Especially, when you claim that they may have had both parts at the same time, on the line.
You are jumping to conclusions based on ONE piece of data, based on 30 cars, from one area of the country. It is an interesting set of data you have, but to jump to your conclusion... well, the rest of the data doesn't support that theory.
This are obviuosly 2 sway bars, something has to be different when the cars were made. I based my data on alot more than 30, that is all we have left to double check. The notchback was the only common factor I found, it could be tire size as for the reason why, but still the notchback was a common factor.
Now why doesn't every one measure your bar and add real info, jackispyder your excluded as you don't have one to measure. make this data 500 cars from across the world.
So please if your going to post start with the measument of your bar, type, year, engine. Then what ever theorys you have.
There may be some method to the madness. As built, there may have actually been a difference, by design. Didn't all fastbacks have staggered tire sizes from the factory? 205/60 15s in the front and 215/60 15s in the rear? Didn't all notchbacks have a maximum of 14" wheels with the same tires front and rear? The bars may have been sized to accommodate the difference in tire sizes and/or widths. That difference may have been communicated to the assembly line workers by a paper tag or a colored chalk mark, or maybe a paint mark. Any of which would have probably become dust in the years since the cars were built.
The part number in the 22P may just be a service parts replacement. (That's what the books were designed for, after all. Right?) As mentioned, there are tons of different springs available as RPOs. They are all replaced by a small handful of service part numbers.
Obviously, this post does not take anything "88" into consideration, since they are all different from previous years.
[This message has been edited by Raydar (edited 10-18-2014).]
Still new to PFF so I dont want to get into any kind of bad place but what is the big deal about arguing over a post? The guy stated that there was a 1/32 difference. Im not sure if you guys know or not but that is less than a millimeter. What .8 mm in diameter really help or change the handling in any car? Some of you guys are arguing like little girls over .8 mm! Thats close to the thickness of your finger nail! Come on guys, we all are grown men. The guy just simply stated some info that he found but just coudnt remember the exact detail. Hell i can barely remember what day it is sometimes.
Agreed. Bickering in no way helps. I thought it was at least an interesting anomaly that the bars may be different as well. I can't see anyone actually noticing the difference unless maybe you are driving a race car- Just too many other suspension design issues to worry about than this one. Can't we just stick to the basics here? Don't slam anyone for making an observation. if you don't agree that if fine but it does not take 25+ posts from the same person saying the same thing....
If someone has an opinion great, let's hear it. I personally would like to hear from others who can measure their bars an let us know what you find. If we can get a few others to respond then there certainly will be no reason to bicker over this anymore.
sardonyx247, I think you might be on to something, but the method you are presenting your information won't pass muster with the members who work in math/science/technical fields. We are trained that you can't make conclusions w/o supporting evidence. Even then, your data and method are subjected to high levels of scrutiny by peers to see if they come to the same conclusion, only then is your conclusion deemed accurate (until proven otherwise).
Most of the skepticism comes from 3 areas: 1. No one has seen the data set you used, all we have is your word. We don't know the precise measurements to see how they vary even within the same group, we don't know the tool at which you used to measure, we don't now how many of each year/model were sampled, and we don't even know how many total cars are in the sample. 2. The sample size is too small, sure it supports a localized trend, but can't be unilaterally applied to the whole fastback production run at this stage. 3. How did GM control this? Anyone who works in manufacturing knows that with people involved you must have a robust control plan to ensure the right parts are used when/where they are needed. This is normally done with some type of part # that is unique to the individual part. As the part changes, this part # is supposed to change to (this is part of the reason GM is in such hot water over the ignition switch recall - they changed the design mid production and kept the same part #, which is a huge no-no). If GM did use a different bar on the Fastback cars, how did they do it when all documentation shows that there was only 1 part number?
I have two "theories" at this point (neither can be proven at this point) for #3: ***When GM expanded to the Fastback line, they brought in a 2nd vendor for the sway bars and gave them the same specs that included a +/- spec for thickness. This new vendor then supplied a bar that was at the other end of the specification as the original vendor, but still was in spec. Since there were so many different/unique parts for the Fastback, GM decided to isolate its assembly process from the Notchie and could have even had its own stock room for the some of the parts. If GM targeted all sway bars from Vendor B to go to the stock room for the Fastback, or the Fastback assembly area, then they could have had some level of control to put these dimensionally smaller bars on only one type of car.
***GM had two Vendors for the sway bars and wanted to be able to tell which vendor supplied each set of bars, so they had them put a difference color paint mark on the bars to differentiate them internally. Then knowing that the paint mark would not last, chose a specific model (fastbacks) to use them on so if any issues came up after use, they would know which vendor to go back to.
sardonyx247, if you want to pursue a greater understanding of this inconsistency I would suggest the following:
1. Redo your measurements with precision (0.XX") and pair each measurement with year and model and specify the tool used to measure (digital calipers, dial calipers, tape measure, etc). 2. Start a new thread identifying the inconsistency you are seeing in your sample group. Acknowledge that your data set is too small for any wide spread conclusions, but that it does show a trend that needs to be better understood with more data samples. 3. Ask others to contribute measurements from their sway bars and add it to the thread. 4. The goal of the measurements is to get a range of precision measurements to better determine if the differences in bar thickness is just normal process variation, if there were actually two vendors which produces the bars at slightly different thicknesses, or if there were indeed 2 separate bars (to confirm this you would have to test/measure their torsional rate) 5. If the larger data set still points to a specific bar being used on only the Fastback Fieros, then how did it happen. Are the parts books wrong and there were 2 part #s, or did GM have some other means to keep the bars isolated to he proper application (like a different color paint or chalk mark and/or assembling the Fastbacks in their own isolated area)...
Then sit back, let the data flow in and see if the data supports your theory. If you take this approach, you have shared your work, identified something strange, have not made any unsupported conclusions, and asked for others to help research your observation further... most would support this initiative and their would not be much negativity.
The part number in the 22P may just be a service parts replacement. (That's what the books were designed for, after all. Right?) As mentioned, there are tons of different springs available as RPOs. They are all replaced by a small handful of service part numbers.
While true about the 22P, it is used to install factory replacement parts and when you look at the spring section, I think, all of the RPOs and spring rates are there, from what I remember. I don't have the paper copy in front of me right now and it looks like the online version only has the green pages which has the diagrams (not the white ones, which may have the detailed info).
I'm just throwing this out... What I would really like to know is there a way someone could measure the flex resistance (don't know what else to call it). Given that there might be a difference in the metal used in the two different sized sway bars, I am wondering if there is a difference? Or, was it that maybe two different vendors used different metal compounds, and one had to be thicker than the other to give the same flex resistance but was still within GM's diameter tolerances?
any idea's?
------------------ "Because in a split second, It's gone"
Ayrton Senna
[This message has been edited by Ponnari (edited 10-20-2014).]
