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Originally posted by 91foxbody:
It seems strange that the solid axle would be a better choice. Consider the fact that the solid axle will make the rearend bounce when just one wheel makes contact with a raised surface. The IRS would allow for that wheel to bounce without affecting the other wheel. What do you think?

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Originally posted by Mach0ne351:
but dont forget, if one side of teh solid axle goes byebye, the whole rearaxle assembly needs to be replaced, unlike the IRS when only a halfshaft needs to be swapped out, which is only 30min or so to do...if that.

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Originally posted by Mach0ne351:
the 07 cobra was supposed to have the IRS "option", but ford is too cheap to put money into engineering a quality IRS....no wonder the mustang does competite in the 24hr LeMans like all the other high performance vehicles

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Ford probably figured they did not need to do a IRS after the Ford Mustang Equipped teams in Grand Am Racing, in their 1st year with the car, beat the other teams with Porsche's, BMWs, Nissan, Cadillac, etc. Ford Mustangs have won 4 out of 8 races, finished in the TOP 2- 6 out of 8 races, and they also recieved a 3rd and 5th place finish. I would hardly say they do not compete well against other high performance vehicles. I would say that is pretty damn good in my eyes

Dodge's current IRS system on their Magnum/ 300M/ Charger is pretty good and is actually a prior generation E Class Mercedes Suspension.. that is why the new Chrysler/ Dodge suspension is so good. The basic difference between the MB unit and the Dodge/ Chrysler unit is one is aluminum(MB) & the other is stamped steal.

The real reason why Steeda, MM, Griggs, etc dont run the IRS is beause Ford's IRS is inferior to the more developed solid axle setup on the Mustang. In American Iron you are allowed to use IRS or solid-axle in the series. If the Ford IRS was that good I guarantee most of the teams in the series would be running IRS. Also, in AI West, 26 out of 32 teams are running with a solid axle based Mustang. There is only "1" IRS based Mustang and he is not even in the top 20! The solid axle in the Ford Mustang is an excellent setup when setup properly.. that is why almost all the teams in American Iron are running Mustangs when they have their choice of Camaros, GTOs, OR even Vette's if they comply with the rules.

Also, it would be REAL hard to bend the solid axle unit.

BTW, if anyone is interested... we are offering IRS to Solid Axle Swaps for 99+ Cobras. Imagine a 2003 Kenne Belled Cobra with a Full Griggs OR Maximum Motorsports setup... sik!

Mike Mak
Apex Motorsports
ApexMotorsports.com
2555 Lafayette Blvd. Suite #122
Santa Clara, CA 95054
Phone: 408/588-0075 Fax: 408/588-0089

Griggs Racing, Maximum Motorsports, Evolution Motosports, SCT, Racelogic, H&R, Ford racing, Kenne Bell, MAC, Bassani, Vortech, Powerdyne, AMSoil, Koni, Hawk, AFR, Tokico, Baer Racing, Magnaflow, Flowmaster

[ August 22, 2005, 09:48 PM: Message edited by: Apexmotorsports ]

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Originally posted by Mach0ne351:
really? hows so? i know the "axles" themselves can be replaced if bent, but it the whole assembly is bent, the whole thing needs to be swapped. the axles yes can be swapped like halfshafts...no problem

marek

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Originally posted by 1Sicgt:
Well Lets clear up alot of garb and bs. The ford IRS has many downfalls, alot that surpass even the downsides of the stock solid rearend. The major problem the IRS has is that it DOES NOT GAIN NEGATIVE CAMBER UNDER COMPRESSION. Lets understand what this does. Under side G-load, the wheel travels up into the wheel well, but not gaining negative camber, actually creating more positive, creating a push in the rearend of the car. Thus, NEVER allowing full power to be transfered to the ground exiting corners. Period. And NO AFTERMARKET PARTS, or CURRENT IRS FOR FORD FIXES SUCH PROBLEM. So even adding all you want, it won't matter. Next, the rear cover is prone to failure. The casting they used is really cheap, and has failed numerous times for many people. Plus the stock IRS is known for its wheel hop.

Now VS. the stock solid.

The solid has 3 main down falls too. But not nearlly as severe. The uca bind in the pivot bushings. Crappy design being angled. They should have done it as a straight four link, moved the springs to the rear farther. 2nd, weak sway bar, which really is not a true sway bar but in its design, its a torque link. A sway bar needs to pivot from the frame or a solid point to give a true function. The Swaybar here bolts between the lca's only. But right above it is the REAR END that is bolted to the same LCA's. This does NOT allow the Rear Sway bar to pivot or twist as it should. Instead, under hard transfer, whith no pivot location, all the stress is transfered to the weakist link which is the flat of the swaybar, where many of us have seen them brake. 3rd, the cheap stamped LCA's are easy to bend under hard G-loads.

Now the solid has a bit of negative camber in it from the factory, approx -1.2' this stays constant under corner loads, allowing more power to be applied exiting corners, thus giving the solid its first advantage. Another advantage is the wieght of the two systems. The IRS in all its mighty, weights alot more. Ruffly 200# more. See where I am going with this???? If you need more info, feel free to bug me.

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Dont forget you told me that solid has more of a feel than irs

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who

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Originally posted by Mach0ne351:
excellent post John...but i think the Solid axle diff cover is weaker then the IRS one..the IRS atleast uses a good piece of aluminum to cover that darn pos lol instead a tiny little piece of sheet metal as all GT and MAch1's have....but overal, the LA will be cheaper, lighter, and be plently of handling power, with some added parts (roughly $1000-$1200) worth in parts....even the LA gets wheel hop. i drive my wifes 01GT, and it has wheel hop as well, but not as bad as the stock IRS unit did in mine...

yes, the solid axle MIGHT put some more power down coming out of a turn, but without the proper mods to the solid axle, the IRS unit will put more power down DURING and IN the turn. when a solid axle unit is put under cornering situations, one side goes down, and one side goes up. with an IRS unit, their both down, and independant. so, that's why many people say "coming out of the turn, the solid axle puts down the power." that's because it was made for going straight.

if i was to do a LA swap, i would do it right the first time, and put a 9" rearend, and add MM torque arm, panhard bar, LCAs, UCAs, and add Hans Subframes while im at it....then 3.73/4.10 gears.

the one thing i love about working on a car with an IRS is, exhaust work (mid pipe and back) is CAKE compared to the solid axle. getting exhaust over the axles (or off the car), can be a bitch with jack stands...on a IRS equipped car, it's 15min of work...on and off....

there are advantages to both, as well as disadvantages...ill stick with the IRS, as everyone probably already knows

marek

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Ok, first thing is the IRS has an aluminum cover yes, but just becuase its thick and its aluminum doesn't make it good. It is actually a really waek sand casted cover. The mold is made out of a sand base, then the molten aluminum is poured in, which by the way is not the best grade, they use a 2000 grade aluminum, which is a cheap commercial grade of aluminum with a higher copper content. The higher content of copper is supposed to keep temps down disapating heat better, but the main problem is in the casting. The form used, commonly gets a pits in the metal. Not visible to the working surface, but once you cut into it, you see air pockets. Hence why alot of failures have been happeing. If done correctly they should have used a 7000 series tooling aluminum for the stregnth it has. Down side to it, it doesn't disapte heat as well becuase it is a more dence* material.

Now you proved my point with out knowing it Marek. Problem is, the IRS' lack of negative camber gain effects it through the WHOLE turn from start to end. The design of the ford IRS was based upon street driving, and street feel. A street car is supposed to make tire noise before breaking loose in a corner. If the car was to gain correctly like we need it to for the track, It would not get tire squeal from the positve camber it is gaining, and then just snap loose without warning. Unlike us, who know how to determine the breaking points of our cars, the avg. Joe, wouldn't realise he is loosing control unless he hears it first. This is one reason ford didn't do the IRS design correctly.

With IRS you actually have more body roll. straight up its the design of the suspension.

Imagine you are looking at the rear of the car. On a stick car, as the right rear compresses, it transfers the load upward on the right rear tire, actually lifting the left rear upward too. This can be very bad if this happens too fast. This is where the solid rear feels light, and on the edge of spining. (Good driver would be able to know this feeling and compensate) Now with the IRS same thing being, the car body has to transfer its weight onto the right rear as it compresses. The left rear will lower and keep forward drive initally, but since the right rear is now leaning on the positive side the tire is actually scrubbing speed, which will do one of two things. If the transfer is too fast, it will feel like the car is sticking then violently break loose. Or, it will instantly give the front end a push, making the car not want to turn, thus loosing more speed.

Remember slow in fast out. Its hard to be fast out it the car is pushing. The Looseness of a solid, is (stock vs. stock) Closer to wear you would want to be. Fast cars drive on that edge of in control and out of control. Its hard to be there if you have a built in push.

Hell, just for shits a giggles, we are planning on doing the SVTOA event in buttonwillow in end of Oct. early Nov., lets swap cars for a few laps, no bias, and see what lap times fall. I will put down my solid, lower hp car will get faster times. You game??

[ August 24, 2005, 12:04 AM: Message edited by: 1Sicgt ]

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14 Focus TS ST3 full Stg3, ready for bigger Turbo
2003 Cobra Track Car

posted                             

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Originally posted by Mach0ne351:
wow. i just learned a lot. and yes..fords design of the current IRS is junk compared to what it SHOULD be they made it work for a Liveaxle chassis.....that's what the main downfall is, along with other things. but you know what, i dont have ANY issues, and ill stand by the IRS all the way. the thing is...all liveaxle racers NEED to put $$$ into it, to make it work better then the stock IRS system. i wont be out at the SVTOA event bro lol...im planning on thunderhill next

$50 says ill own you in AutoX ive got the belt to prove my worth...with the IRS at that hehe

marek

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ahhhh cones suck. I like to go fast with my corners thank you very much. Which T-hill event??

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14 Focus TS ST3 full Stg3, ready for bigger Turbo
2003 Cobra Track Car

posted                             

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Originally posted by LuvMy04GT:
can i be a spectator to this event?

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Sure. Maybe you could get your ride out there and try some laps one day too!

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14 Focus TS ST3 full Stg3, ready for bigger Turbo
2003 Cobra Track Car

posted                             

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Originally posted by Mach0ne351:
$50 says ill own you in AutoX ive got the belt to prove my worth...with the IRS at that hehe

marek

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I would love to see this event....Cones or open track! Preferably open-track

BTW, let me got get my old BONE STOCK Miata and I'll take you up on your $50 bet in AutoX I love Mustangs BUT they cannot hang with Miatas in AutoX.



Mike Mak
Apex Motorsports
ApexMotorsports.com
2555 Lafayette Blvd. Suite #122
Santa Clara, CA 95054
Phone: 408/588-0075 Fax: 408/588-0089

Griggs Racing, Maximum Motorsports, Evolution Motosports, SCT, Racelogic, H&R, Ford racing, Kenne Bell, MAC, Bassani, Vortech, Powerdyne, AMSoil, Koni, Hawk, AFR, Tokico, Baer Racing, Magnaflow, Flowmaster

posted                                

quote:

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Originally posted by Apexmotorsports:

quote:

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Originally posted by Mach0ne351:
$50 says ill own you in AutoX ive got the belt to prove my worth...with the IRS at that hehe

marek

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I would love to see this event....Cones or open track! Preferably open-track

BTW, let me got get my old BONE STOCK Miata and I'll take you up on your $50 bet in AutoX I love Mustangs BUT they cannot hang with Miatas in AutoX.



Mike Mak
Apex Motorsports
ApexMotorsports.com
2555 Lafayette Blvd. Suite #122
Santa Clara, CA 95054
Phone: 408/588-0075 Fax: 408/588-0089

Griggs Racing, Maximum Motorsports, Evolution Motosports, SCT, Racelogic, H&R, Ford racing, Kenne Bell, MAC, Bassani, Vortech, Powerdyne, AMSoil, Koni, Hawk, AFR, Tokico, Baer Racing, Magnaflow, Flowmaster

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funny..i beat out 1/2 of the maitas running in nasa/x that season and i was 1 sec. behind a s/c miata in a class above mine good friend of mine... imo, miatas are probably one of the best autox rides out there.

john john john...haha do you have a problem of quick reaction racing?? hehehe.....

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2001 SVT Cobra
SCT Tuned by APEX Motorsports @ 317rwhp/304rwtq
www.32valve.com

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Originally posted by 03SHKER:
I want to be there for this too.

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