This is topic 99+ Cobra...Keep the IRS? in forum Road Racing, Auto X & Drifting at Northern California Ford Owners  .


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Posted by Black94 5.0 (Member # 655) on :
 
I was just wondering if any of the hard core race Cobra's with independent rear suspension actually have good luck with it...

I know of a black Cobra in NASA A.I. that switched to a solid rear...

Which would be better, a modified IRS, or a modifed solid rear using a torque arm and panhard bar, like Griggs or MM?....

Thanx, Rob
 
Posted by Mach0ne351 (Member # 927) on :
 
IRS ownz!

-marek
 
Posted by 99snakerider (Member # 1736) on :
 
Well it all depends on what you wanna do with the car. If you take it to drag strip alot then solid is the way to go. If you auto-x then the IRS is the best, but one thing for sure on the street irs got the best ride really smooth over the bumps and stuff.
 
Posted by Black94 5.0 (Member # 655) on :
 
quote:
Originally posted by 99snakerider:
Well it all depends on what you wanna do with the car. If you take it to drag strip alot then solid is the way to go. If you auto-x then the IRS is the best, but one thing for sure on the street irs got the best ride really smooth over the bumps and stuff.
Obviously I'm not talking about the drag strip [Roll Eyes] Yeah, and I'm sure the IRS's ride quality is better...

I want to know for example If you had bought a 99+ IRS Cobra and wanted to compete with other Mustangs in A.I. or any SCCA or NASA events would you keep the IRS or switch to a solid rear axle???????......

From what I've read you can make a solid rear axle superior to "Fords after thought" IRS....I'm interested to know info from the people who've delt with the IRS and tried to make it work or have made it work.... [patriot]
 
Posted by 1Sicgt (Member # 714) on :
 
Its hard to say which is better. I have raced the cobra, and it feels like it wants to get rearend loose but it sticks constantly. Its a tough choice. If you have it and use it alot, you would get used to its feel. But I race with solid constanly, and I am used to the stiffness.
 
Posted by Bill/APEX Motorsports (Member # 636) on :
 
My preference is a solid axle with torque arm and Panhard bar. That setup is a lot more predictable and confidence-inspiring than the Mustang's IRS, in my experience.
 
Posted by season'd 88 (Member # 169) on :
 


[ November 06, 2006, 02:34 AM: Message edited by: season'd 88 ]
 
Posted by 66 AC COBRA (Member # 904) on :
 
maximum motorsports is in development stages of aftermarket control arms for IRS cobras, that should mix things up a little

i saw them fabing some up the other day in there shop [worship] [worship]
 
Posted by racercosmo (Member # 1864) on :
 
It's probably cheaper to swap a stick axle with a torque-arm, but I'm not completely sold on the idea that the Cobra IRS cannot be made to work.
 
Posted by Black94 5.0 (Member # 655) on :
 
Has anyone seen or felt how heavy the Cobra IRS is to the solid axle?...I couldn't believe how heavy the IRS was when I saw WIKD281's 99 Cobra...Harold/WIKD281 did the switch for drag racing purposes, since the stock 99 IRS had horrible wheel hop/axle wind up...

Jon/1SIC~Is your dad's 03 Cobra IRS stock or did he replace the housing bushings?...
 
Posted by 1Sicgt (Member # 714) on :
 
It has Kenny Brown CSR IRS aluminum Diff Bushings , IRS Rear Steer Kit (49550)
, IRS Forward Torque Brace, Extreme Matrix Subframe System, Rear Shock Tower Brace, and a few other goodies.
 
Posted by cobraracer46 (Member # 1142) on :
 
I have an 87 GT with A griggs touque arm, panhard rod + all the other gr40 bits and a 01 Cobra Vert with the factory IRS. On the street, the IRS rids so much better than the stick axel and with a set of road race tires, it feels better than griggs at race track speeds. If you have a Stock Cobra with IRS, I think it would be foolish to dump it for a touque arm and stick axel set up in my honest opinion.
 
Posted by Black94 5.0 (Member # 655) on :
 
WOW, thats interesting...You have the best of both worlds....So, are you saying that an '87 GR40 Mustang has worse handling than a stock 01 convertable IRS Cobra?!!!!!!! [Confused] ....
 
Posted by TheDavemeister (Member # 2521) on :
 
quote:
Originally posted by cobraracer46:
I have an 87 GT with A griggs touque arm, panhard rod + all the other gr40 bits and a 01 Cobra Vert with the factory IRS. On the street, the IRS rids so much better than the stick axel and with a set of road race tires, it feels better than griggs at race track speeds. If you have a Stock Cobra with IRS, I think it would be foolish to dump it for a touque arm and stick axel set up in my honest opinion.
What about springs and shocks? You can change out the springs and shocks in your Griggs equipped car for better ride quality if that's what you want. How a car "feels" and how it performs are two different things.
 
Posted by mtbaughs (Member # 4052) on :
 
Well thats somewhat of a tough one. I've driven both, a fully prepped griggs solid axle and a fully prepped IRS car meaning griggs K-member, front arms, rear delrin bushings beefier axle brace and coil overs all the way around. The IRS car wins hands down in ride quality but I don't think thats what you are asking. There's two different kinds of Griggs solid axle cars, one that has been set up properly and is well balanced and one that is not. Theres a huge difference in the two. I personally like the solid axle much better for all out handling than the IRS. The car is much more predictable in the turns and there isn't the wheel hop. Now this could be because I've have a lot more experience driving the solid rear than I do the IRS but to me the overall feel of the car is so much better with the solid rear combo.
 
Posted by 9cobrasnake9 (Member # 575) on :
 
i owned a 99 cobra and theres inherint problems with the irs. it was designed to fit in a space irs really would not work properly. Anyone who has taken a 99+ cobra hard through an off camber turn has felt why. The car ends up rolling over its suspension. The tire goes up but does not camber in enough to compensate and you end up with a nasty feeling of your car riding on the sidewall. This is because the control arms are too short for the setup. Ask Griggs, or mm they with both tell you on the track IRS from a 99+ cobra will be punished by a solid axle. I looked into this a lot for my car. just my .02
 
Posted by cobraracer46 (Member # 1142) on :
 
quote:
Originally posted by Black94 5.0:
WOW, thats interesting...You have the best of both worlds....So, are you saying that an '87 GR40 Mustang has worse handling than a stock 01 convertable IRS Cobra?!!!!!!! [Confused] ....
Not really. I have not run both cars back to back on the track to know for sure, but on the street, it's a no brainer, the IRS is the way to go.
 
Posted by racercosmo (Member # 1864) on :
 
A stick axle car is also easier to regain control of when you get loose.
 
Posted by Black94 5.0 (Member # 655) on :
 
quote:
Originally posted by racercosmo:
A stick axle car is also easier to regain control of when you get loose.
Uh, are you sure on that one?...Why do you think that Cosmo?....
 
Posted by FAST67 (Member # 4229) on :
 
hey i read somewhere that i could put an cobra's IRS in my car. Do you think it is wise to do so?
 
Posted by racercosmo (Member # 1864) on :
 
With an IRS, the wheels are free to move about as they wish. Obviously the stick axle keeps both wheels at the same constant angle, so they are not fighting eachother. When you get into a tank-slapper, you don't have to settle each side of the car before you add throttle to control the rear end.
I love the Z06, but I've gotten into some scary shit that would have been solved by simply squeezing on the pedal with a torque-arm and stick axle Mustang.
That being said, I wouldn't give up the Corvette on that issue alone.
 
Posted by kpl (Member # 1879) on :
 
I remember reading about Rob's (V8VENOM) experience with his AI car switching from the IRS to the Griggs WC setup on corner-carvers and recall the following. You can go and search there to find the threads. Now the IRS was mostly stock except springs, dampers, delrin bushings on the lower control arms, and FR500 brace. After switching he compared his Thunderhill times and was only a hair quicker. He admitted he needed some more seat time to adjust his driving style, and some time to fine tune the car. It seemed to me like a lot of money for a very little gain. Unfortunately he dropped out of the AI series and we never got to see how much his times improved after adjusting to the new suspension and setting up the car better, if that was possible. Since then there are a few more things available for the IRS so it would be interesting to see another comparison.
 
Posted by racercosmo (Member # 1864) on :
 
Steve Libby also switched to a stick axle TA/watts Linkage on his 99 Cobra. He liked it a lot better, and he was a bunch faster. The disclamier is that he switched from an aftermarket IRS configuration, the much maligned IPS/Contex POS designed by Corey "Reactive Kinematics" Shaw.
 
Posted by cobraracer46 (Member # 1142) on :
 
Last week, I heard that Maximum Motorsports is in the prosses of making tubular Cobra IRS control arms. It would certinly be interesting to see an MM IRS Cobra duke it out with Griggs torque arm equiped Cobra.
 
Posted by 66 AC COBRA (Member # 904) on :
 
quote:
Originally posted by 66 AC COBRA:
maximum motorsports is in development stages of aftermarket control arms for IRS cobras, that should mix things up a little

i saw them fabing some up the other day in there shop [worship] [worship]
reffering to cobraracers post 1 above this
yes i posted that almost 2 weeks ago about 10 post previous of urs in the same thread [Big Grin]
 
Posted by 66 AC COBRA (Member # 904) on :
 
how about this

even though MM is coming out with a new control arm for the IRS cars

there dedeicated race car that has well over 2 years of work done to it and still not finished, having the ebst of everything they own to go race in the some series, is using a torque arm, not an IRS swap into a fox

MM want to win to promote there product, and they are using a there torque arm over there own brand new IRS control arm
 
Posted by Black94 5.0 (Member # 655) on :
 
quote:
Originally posted by racercosmo:
With an IRS, the wheels are free to move about as they wish. Obviously the stick axle keeps both wheels at the same constant angle, so they are not fighting eachother. When you get into a tank-slapper, you don't have to settle each side of the car before you add throttle to control the rear end.
I love the Z06, but I've gotten into some scary shit that would have been solved by simply squeezing on the pedal with a torque-arm and stick axle Mustang.
That being said, I wouldn't give up the Corvette on that issue alone.
With that said, a "stick axle keeps both wheels at the same constant angle", but what if it's not the correct angle?...Then both wheels are wrong, where as IRS will be less affected...That is one reason other cars have IRS...I could understand what you mean with the Cobra IRS, but I think you were general talking about IRS since you included the ZO6 in your post...

[ March 15, 2004, 11:06 PM: Message edited by: Black94 5.0 ]
 
Posted by racercosmo (Member # 1864) on :
 
Black945.0, I was just stating why a stick axle is easier to recover from extreme sidewaysiness (Copyright on that word).
 
Posted by phildog (Member # 1214) on :
 
Just a heads up, if anyone with an IRS Cobra wants to sell the whole set up and switch to a solid rear, I am a cash buyer for your stock IRS Cobra setup. I have one ready for my SVO and I have two other friends who want to swap them in as well. Me personally, I think an IRS in a FOX would be bitchin, that's why I'm doing it. To each their own...

[ March 16, 2004, 10:23 PM: Message edited by: phildog ]
 




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