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RE: [oletrucks] RE: IFS, but not to open any can or worms again

To: "'A.B.'" <bigfred@unm.edu>
Subject: RE: [oletrucks] RE: IFS, but not to open any can or worms again
From: Whittaker Bill G Civ ASC/SMY <Bill.Whittaker@wpafb.af.mil>
Date: Fri, 15 Sep 2000 12:21:11 -0400
Sorry but I respectfully disagree with almost everything you said.  

Yes the front axle is held in by 8 nuts. A system that was designed and tested 
by the factory to work properly on their trucks and it has proven itself over 
millions of miles of use. Comparing that system to bolting on an adapted 
aftermarket system that may or may not have been designed by knowledgeable 
people is like comparing apples to oranges. They look similar on the surface 
but they're completely different.  So I don't buy your argument on that one.

It is true that modern software tools allow you to pretty much design and 
theoretically test a system while sitting at your desk, but no one has ever 
come up with a substitute for actual on the road testing. If what you say is 
true the factories would never come out with improvements or changes to their 
suspension systems because they would be perfectly designed from day one.  I 
seriously doubt that any auto manufacturer puts a system in a vehicle for sale 
that hasn't been extensively tested on the road. That's why you don't have 
entirely new models every year.  They stick with designs they have millions 
invested in and through testing and experience on the road make small 
improvements each year.  

Designing a suspension system isn't rocket science.  Racers do it every day.  
However the systems they design are for a specific purpose and aren't designed 
from the outset to be able to put up with years of over the road use.  Therein 
lies the problem.  It takes a considerable amount of money and testing to 
design a bolt on suspension system that can handle the stresses of daily use, 
and not every Tom, Dick, and Harry is capable of doing that. Even though their 
sales literature might say otherwise. 

The Pacer conversion is a popular one and most people seem to like it.  
Properly installed it is a safe system, however like I said before, I think any 
bolt on system would be safer if welded in place.  I do understand your reasons 
for bolting it in though. I would just suggest you (or anyone who prefers to 
bolt on an aftermarket IFS or do a conversion like your doing) periodically 
check the tightness of the bolts if for nothing else than the piece of mind it 
will give you.  

Bill Whittaker
'53 3100 Hemi
Built Like A Rock
With Mopar Stock




-----Original Message-----
From: A.B. [mailto:bigfred@unm.edu]
Sent: Friday, September 15, 2000 11:28 AM
To: Whittaker Bill G Civ ASC/SMY
Cc: 'Old Trucks'
Subject: RE: [oletrucks] RE: IFS, but not to open any can or worms again


ooh ooh, can I jump in...
I really think that if a bolt is properly tightened, and maybe some
threadlock is used, that a weld would be more likely to crack (or mayb the
metal near it) then the bolt would be to back out.... After all, isnt' the
original front axel held in by 8 small nuts? I'd be more worried about my
front axel rolling down the road then I would be an after market
suspension.  Either way, I really doubt that designing a front suspension
system is as much rocket science as you would have us believe. I could be
wrong though. It has been said before, modern software tools can allow you
to easily revise designs before you ever cut metal and test out the
system, thereby avoid the *YEARS and MILLIONS of dollars* the factories
spend on developing their front suspensions.  BTW, I really don't buy the
argument about bolts backing out. If so, the rods in motor, and my
cylinder head would have fallen off long ago.  Anyway, the reason I am
jumping in is that I'm planning on putting in a Pacer front
suspension.. Obviously, a front end that was not specifically designed for
my truck, but everyone I know who has done this particular conversion
seems very happy with it. Apparently you can bolt it or weld it in. I'm
gonna bolt it in because it is more reversable if I ever want to build a
show truck or go back to stock.  Anyway, I just wanted to say, that I
really enjoy this discussion, but I don't think designing a proper front
suspension is beyond the means of normal man and should be left to the
superhuman engineers at the factorys.
-alfie


On Fri, 15 Sep 2000, Whittaker Bill G Civ ASC/SMY wrote:

> What you're talking about is a unibody sub-frame that has been designed and 
>developed by a major auto manufacturer who spent millions of dollars along the 
>way to ensure it works as advertised.  The system has been extensively tested 
>and the design was modified as problems surfaced over it's development cycle.  
>That's why factory designed bolt on systems are safe for the vehicles they've 
>been designed for.  
> 
> However this is not necessary the case with aftermarket IFS systems.  
>Virtually none of the small shops that manufacture these kits have the money 
>or capability to completely test a bolt on design.  As an example, when you 
>adapt a IFS like the Mustang II to an old frame, the conditions and stresses 
>the suspension system is subjected to are different with each and every 
>vehicle. It all depends on what modifications have been done to the original 
>frame and how they have effected it's overall condition. Things like boxing 
>and crossmembers that may have been added for transmission, engine, or rear 
>suspension mounting will all add to or subtract from the frame's strength, and 
>they all effect it's rigidity and how and where it flexes.  Mods to the frame, 
>the age of the metal, and its general condition are all factors that change 
>the way the frame reacts under stress.  Flexing and vibration are the two 
>major culprits that loosen bolts, and they don't discriminate as to which bolt!
s !
> they decide to covertly back off for you.   Because each of these 
>installations is subjected a unique environment there is really no way to 
>accurately predict the installation integrity (over time) of any of the 
>aftermarket bolt on IFS systems.  Therefore, in the case of Mustang II and 
>similar kits, it will almost always be safer to weld these systems in place 
>rather than trust your life to 8 small bolts.    
> 
> Bill Whittaker
> '53 3100 Hemi
> Built Like A Rock
> With Mopar Stock
> 
> 
> -----Original Message-----
> From: Brian _ [mailto:pkupman57@hotmail.com]
> Sent: Thursday, September 14, 2000 6:53 PM
> To: ryan_border@hp.com; oletrucks@autox.team.net
> Subject: RE: [oletrucks] RE: IFS, but not to open any can or worms again
> 
> 
> list,
> i work for the ford dealer in town. ive changed several engines in vehicles 
> and most all FWD cars and vans use a bolt on front sub frame. the ford 
> windstar for example, uses 4 bolts to hold the front sub frame, engine, 
> suspension, steering, tranny, everything onto theh body. makes it EZ to 
> change engines tho, as you only undo 4 bolts, brake lines, and steering and 
> shift linkage, and the whole shabang drops out from under the van. so i dont 
> believe that the majority of bolt on front suspensions are unsafe.
> Brian M
> Atwater, CA
> '57 Chevy 3200
> _________________________________________________________________________
> 
> 
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
> 
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959

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