IRS deploys a 26 mm stabilizer bar, and in front a 28 mm bar is used. [bold]IRS permitted higher spring rates and a stiffer car, so while the stabilizer bars changed their sizes compared to a solid rear axle '98 Cobra, equivalent roll stiffness was retained.[/bold]
[bold]Important ride and handling benefits are derived from IRS and the modified MacPherson strut front suspension. Steering response and on-center feel are improved over a solid rear axle car including a reduction of the turning circle to 38 feet[/bold] for the Cobra.
[bold]The IRS system also made the rear track wider by 1.2 inches, increased suspension travel, and gave the Cobra better weight distribution. Thanks to IRS, handling is especially refined on uneven or bumpy road surfaces and rear-end lift under hard braking is reduced.[/bold]
Michael Erdody wrote:Guys I'm not "hating" I understand the principles behind IRS but stop and think for a minute - once you add a sway bar essentially your bring the car back towards being a solid trailing beam setup since when one wheel compresses the sway bar transfers the force back to the other wheel causing it to want to compress - obviously not as much as the stock suspension but having a sway bar on IRS is like taking a short step backwards after taking such a leap forward and P.S. I have Tig, Mig, and Oxy/acetylene welded for over ten years and those welds looked like they may have not had enough penetration and I just don't want anything bad to happen to another j-body fan who obviously put a lot of hard work into that - so stop bitchen and re-read what I had ask it was intended to be a polite question
the IRS which serves no purpose in drag racing or autocrossing
Michael Erdody wrote:Event - whats good for the goose is not necessarily good for the gander ie just because PURPOSE built race cars have IRS does not mean that it will work the same on a street driven car - "ignorance" as you stated is ASSuming it would ( p.s. to assume is to make an ASS out of U and ME ) see how that word spells - again I applaud mcmoney for his work I think the idea is cool but think about it if you can get off your high horse of assuming you know everything about suspension design - when he enters a hard turn now the car is naturally going to want to shift its weight to the opposite rear corner of the car causing the front inside tire to want to lift - to avoid this you need to do one of or both of two things put on a VERY stiff rear spring rate and or apply a sway bar - again a sway bar transfers force from one side of the vehicle to the other JUST LIKE THE STOCK TRAILING ARM SETUP that;s why the car does not come factory with a rear sway bar because the trailing arm setup is designed to act as one - the only reason to add another sway bar is to stiffen up the rear anti roll effect more than it is already built in from the factory - which IF YOU READ THE OTHER POSTS "you" already recommended in your "suspension how -to" - if your going to try to insult me get your facts straight - besides I am an ASE certified tech with 4 years of schooling in automotive repair and design I do have a very good idea of what I'm talking about, also on any race track or any parking lot auto cross event you will most likely never see an indifference big enough to see ANY benefit from IRS in a CAVALIER it will naturally have way to much Body flex as there is no solid chassis under our cars - welding in a heavy roll cage may help but only mildly to moderately as this car was not designed as a race car
P.S. J~ thank you for the polite and intelligent counter opinion you offered although I still disagree with you on exactly how a sway bar works you seem to understand what I am saying and as I'm sure we are both not "experts" on the subject I do have a large amount of knowledge on the subject and better yet schooling on the subject and on-hand experience which is where my opinion comes from - I just want people to stop and think about the benefits vs consequences of this conversion vs how much more they would benefit from a good "stock" suspension setup and If money and/or skill permit an LSD - besides more people are likely to cause serious mis-alignment issues and or permanent damage to there cars trying this sort of conversion which is most likely above most avid tuners skill level
also on any race track or any parking lot auto cross event you will most likely never see an indifference big enough to see ANY benefit from IRS in a CAVALIER it will naturally have way to much Body flex as there is no solid chassis under our cars
Chris wrote:After reading only half of this thread, and knowing probably half of what some people know about suspension, i think that you guys have missed one of the greatest things about IRS (although i don't know what type of IRS the alero is, so this might be wrong).
With our axle as the suspension is compressed, the camber is not affected. As the body rolls, and the car becomes angled relative to the ground, this reduces the contact patch, which affects traction (yes, for tires, surface area does affect friction, trust me, i've done a lot of research). In an IRS suspension, (or at least a multi-link IRS), camber is adjusted as the suspension is compressed, keeping the tire "flatter" on the road, enhancing the contact patch, increasing grip. I'd have to say that's worth it alone.
Lenko, John Lenko wrote:Ok... work with me here
Assuming you didn't have to skinny the setup... which I'm not planning on doing (my rear wheels are about 1 inch inside of the fender as it is... I was looking forward to the wider stance this mod would give).... then you don't have to shorten the bars... then you don't have to shorten the trailing arm....