Discussion on rear suspension, input and thoughts

[cbr repsol]

Ok well here we go.
I had a 03 mach 1 with a solid and I've owned a 04 with a irs. I loved both cars but the cobra with the irs in Stock form just felt so so much better than the mach 1.
This leads me your thoughts about my 97 cobra. I plan on turbo or supercharging the car later down the road when I build the motor . I'm still on the fence about the trans to. But I want to road course my 97 (willow springs) I don't need to win any competitions or anything. But I wanna do thing right and not spend more money switching things later. I also would like to drag race the car in the 1/4 just to say I did it . Should I stick with the solid or just go straight to the irs and never look back?
Power wise is most likely be 20 psi all the way to 30 pounds . Depending on if getting e85 is a pain. I know I couldn't really road course the car on that much hp so I would be running 2 or 3 different tunes depending on power adder of my choice to lower the boost down when I do go to willow springs. Just wanna put that out there so your first thoughts are you can't do that with that much power . In the sum of things I guess I'm trying to build a car I can pretty much do it all in even a occasion driving it to work.

Your thoughts appreciated

 

[2DXTRM]

If you decide on keeping with the SRA, have a look at Maximum Motorsports, Griggs Racing and Cortex for their torque arms and panhard bar kits (or Watts Link).

If you do IRS, FullTiltBoogie bushing kit is a must.

 

[98 Saleen Cobra]

I've been looking at letting my front and rear griggs setup go this year.. I have some other stuff in the works. When are you looking to purchase, and what's your budget?

 

[cobralvr01]

Being someone who has a 1997 Cobra with a built IRS with the FTBR delrin rebuild kit, I have to say, go the IRS route and NEVER LOOK BACK! I hit i89 north of Phoenix with a group of guys when I had a live axle and I could barely keep up with lowered s197's on the turns. I mean it took everything I had to keep up with them. But once I threw the IRS in, I immediately felt how easy the front of the car goes into the turns and how planted it feels. The turning response was night and day. I did the same route with the same guys and I was able to keep up with one of the new s550 ecoboosts. If you're looking at road coursing your '97 Cobra, it's IRS or bust. A lot of people suggest the griggs, but what they don't consider is there are other factors into play with aggressive handling that the IRS provides. The biggest improvement is, since we have the lighter, aluminum tesksid block, the IRS adds more weight to the back improving your weight distribution ie, why the turning felt more responsive. Plus, the ride quality, in my opinion, is much more comfortable and you get that wicked IRS exhaust.

 

[cbr repsol]

I'm in no hurry at the moment working on dialing the engine in currently so I can at least drive the car.
I've seen irs complete on ebay for 900 to 1200.
So I'm most likely going to go that route.
Any other opinions welcomed

 

[98 Saleen Cobra]

Being someone who has a 1997 Cobra with a built IRS with the FTBR delrin rebuild kit, I have to say, go the IRS route and NEVER LOOK BACK! I hit i89 north of Phoenix with a group of guys when I had a live axle and I could barely keep up with lowered s197's on the turns. I mean it took everything I had to keep up with them. But once I threw the IRS in, I immediately felt how easy the front of the car goes into the turns and how planted it feels. The turning response was night and day. I did the same route with the same guys and I was able to keep up with one of the new s550 ecoboosts. If you're looking at road coursing your '97 Cobra, it's IRS or bust. A lot of people suggest the griggs, but what they don't consider is there are other factors into play with aggressive handling that the IRS provides. The biggest improvement is, since we have the lighter, aluminum tesksid block, the IRS adds more weight to the back improving your weight distribution ie, why the turning felt more responsive. Plus, the ride quality, in my opinion, is much more comfortable and you get that wicked IRS exhaust.

Have you ever gone corner to corner with a Griggs setup lol? I've driven both. Fully built IRS, and my car.. Around the same track and around the same loop on hwy1 in CA.. Same tires.. Side by side, I'd run a Griggs setup over the IRS hands down. What most people forget is the IRS was designed around body of the Mustang. There is still a lot to be desired in the IRS setup around a road coarse.. Look at all The AI and AIX guys.. They aren't running the IRS for a reason.. They all run SRA with a tq arm and watts link.. Just sayin'..

But again if you're not looking to be the fastest do what you please. But you're going to buy a IRS for 1200, the pro level half shafts (to hold 800+rwhp), then the FTBR IRS setup, then install etc etc..

 

[cbr repsol]

How much do you want for your setup when you upgrade to what your doing?
98 saleen cobra?

 

[cobralvr01]

Not a Griggs set up, but one of the guys in the s197's had a Watt's link and panhard bar. He almost ran off the road trying to keep up with me. OP, as 98 Saleen Cobra said, it's up to you in the end. My suggestion is the IRS route, FTBR kit, and diff brace...call it a day. But this has been a long debate between SRA and IRS guys for years. Final notes, though. There's a reason Ford, after 50+ years, finally switched to an IRS setup with the s550's and that's because they were wanting to balance the Mustang's brute power with plush, corner carving capabilities. Look at all of the car models that have established road cross racing pedigrees. A large majority will have an IRS setup. Another big advantage is seen when you're racing on uneven or poor road conditions ie. canyon roads. If it's a completely flat and well-maintained track, then I can see where the SRA would start closing the advantage gap. But that's what the IRS is designed to do over the SRA. It eliminates the driver and passenger rear wheels from effecting each other allowing optimum tire/pavement contact. Without this, you get the occasional corner + bump issue where it feels like the car wants to steer you or the rear kicks out a bit. Once I switched to an IRS, all of that was immediately gone. I don't have expereince with Griggs and I'm not questioning the quality of the product, but from a mechanics standpoint, I just don't see how an SRA, in real world road courses, can provide better cornering or grip than an SRA.

 

[98 Saleen Cobra]

Not a Griggs set up, but one of the guys in the s197's had a Watt's link and panhard bar. He almost ran off the road trying to keep up with me. OP, as 98 Saleen Cobra said, it's up to you in the end. My suggestion is the IRS route, FTBR kit, and diff brace...call it a day. But this has been a long debate between SRA and IRS guys for years. Final notes, though. There's a reason Ford, after 50+ years, finally switched to an IRS setup with the s550's and that's because they were wanting to balance the Mustang's brute power with plush, corner carving capabilities. Look at all of the car models that have established road cross racing pedigrees. A large majority will have an IRS setup. Another big advantage is seen when you're racing on uneven or poor road conditions ie. canyon roads. If it's a completely flat and well-maintained track, then I can see where the SRA would start closing the advantage gap. But that's what the IRS is designed to do over the SRA. It eliminates the driver and passenger rear wheels from effecting each other allowing optimum tire/pavement contact. Without this, you get the occasional corner + bump issue where it feels like the car wants to steer you or the rear kicks out a bit. Once I switched to an IRS, all of that was immediately gone. I don't have expereince with Griggs and I'm not questioning the quality of the product, but from a mechanics standpoint, I just don't see how an SRA, in real world road courses, can provide better cornering or grip than an SRA.

The guy had a watts link and a panhard bar? or do you mean torque arm? lol. Can't have both a watts and a panhard.. Also comparing your buddy and you isn't the same real world experience you're likely a better driver than your friend. Just sayin'. I could put my friend in my car and me in his cobra and I'd destroy him in his cobra simply because I can out drive him.

 

[98 Saleen Cobra]

How much do you want for your setup when you upgrade to what your doing?
98 saleen cobra?

I'm not entirely sure yet. It would be later this summer that I get rid of it, before my next deployment. I would be looking to get rid of my watts link, tq arm, rear coilovers, and maybe my rear LCA's if you wanted them. I'm still not entirely sure if I'm going to part with it, but this car is going in a different direction, and I plan on building a dedicated track car. No longer doing a car that can do a little of both. But a badass big motor N/A road racing car. Depending on what I can find I might even keep the Griggs stuff and throw it on the next project. But I would entertain selling it. I'd have to come up with a price when the time came.

 

[cbr repsol]

No worries.
Thanks for the input.
I'm still on the fence on what I want to do.

 

[cobralvr01]

One thing to note as well if you're looking to go FI in the future and planning on doing road courses...if you don't already have it, add on a 31 spline conversion to your '97 Cobra. That'll add quite a bit to the final rear end you're using.

 

[98 Saleen Cobra]

^^ that is true. Like how he mentioned this discussion has been beaten to death between the IRS and SRA guys lol.. the IRS in the end is a little more expensive to do.. The SRA will be lighter in the end.

Here's the main thing.. Unless you're truly road racing you won't out drive either setup..

 

[cobralvr01]

Here's the main thing.. Unless you're truly road racing you won't out drive either setup..

Pretty much. I think it'll always boil down to the individual. Whenever these threads pop up, they always end up back and forth like this. lol

 

[cbr repsol]

Thanks for all the input guys.
Only problem is I'm still not sure which route I should go with? I guess a little time will tell.