IRS vs SRA for the corner carver/street car...help me pick

Swap the SRA out for an IRS??? remember, just a fun street car

  • DO IT!!! IRS ROCKS!!!

    Votes: 32 56.1%
  • Build the SRA!!!

    Votes: 25 43.9%

  • Total voters
    57

cobrakidz

High mileage R
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Since I owned an 04 Mach and my 03 Cobra at the same time I can say that the IRS handles much better in the mountains and curves. I even had full length sub frame connectors and pan hard bar installed in the Mach.
 

04Mach1Blurr

1st GT500 M122 Eaton Mach
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Since I owned an 04 Mach and my 03 Cobra at the same time I can say that the IRS handles much better in the mountains and curves. I even had full length sub frame connectors and pan hard bar installed in the Mach.

Thanks, That is a great help when compairing the two axles.
 

Jaimie03Cobra

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SRA is superior when setup for autocross, except....when the corner is uneven or bumpy. The SRA will always keep your wheels planted evenly. The IRS is superior for ride quality and handling over uneven surfaces. Just remember that the IRS Ford made was a compromise to fit the Mustang. It was not a purpose built handling setup as say from a BMW. If the tracks you go on are smooth I would go SRA. If you like corner carving also on public roads I would go IRS. You have much thinking to do on the subject and ultimately you have to make the choice. You will get 50 different opinions on a forum and 50 different experiences. :) .

Jaimie
 

CobraRed01

CornerCarvinCravin
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Frankly...I call BS on the Griggs Hill Climb video as a testament to the superiority of an SRA in the Mustang. 1) The hill climb course is perfectly smooth....nothing a properly setup SRA or IRS Mustang couldn't handle. Try that on a rough course and see what happens. 2) The Griggs Mustang in question sports a front SLA suspension which is really what is making the difference on that course.

If you wish to give up superior handling when corner-carving real roads for the occasional autoX or drag event (or regular street drag racing... not advised) go SRA. If you like superior handling daily and life to bash the backroads regularly...stay IRS.
 

slowr w/o blowr

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I went 3 link MM trq arm and panhard bar. Traction is amazing. Holds corners and it feels like its on rails. If you do hit a massive bump in mid corner, like all SRA's it will get out of line. I can deal with that. One minor drawback with the t.a., you will pick up a minor amount of NVH. Its barely noticeable, but, its noticeable. I'm not sure how unmuscleish or luxury like you want your car to be.
 

Jmac72187

Corner Carver
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Frankly...I call BS on the Griggs Hill Climb video as a testament to the superiority of an SRA in the Mustang. 1) The hill climb course is perfectly smooth....nothing a properly setup SRA or IRS Mustang couldn't handle. Try that on a rough course and see what happens. 2) The Griggs Mustang in question sports a front SLA suspension which is really what is making the difference on that course.

If you wish to give up superior handling when corner-carving real roads for the occasional autoX or drag event (or regular street drag racing... not advised) go SRA. If you like superior handling daily and life to bash the backroads regularly...stay IRS.

Do you really want to be pushing your car to the handling edge like that on the street anyway?

Whether it be a build SRA or IRS, I don't think I would want to see its handling edge on the street. That is more dangerous than street racing.
 

CobraRed01

CornerCarvinCravin
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Do you really want to be pushing your car to the handling edge like that on the street anyway?

Whether it be a build SRA or IRS, I don't think I would want to see its handling edge on the street. That is more dangerous than street racing.

Good points for sure...but a few notes. The hill climb referenced was on a closed course as usual I would imagine. You don't need to go fast to realize the benefits of an IRS...even the relatively flawed Mustang variety. The back road bashing I do is really actually pretty tame from a speed perspective. Many places 50 mph is maxed. It's an 80% proposition at best on some pretty roughly paved roads and I never sweep into the opposite lane. I actually enjoy the rough stuff because it's a marvel to me how this IRS equipped Mustang "sticks" (to borrow an Olympic term) in the rough. I've O/T'd and Autox'd a few times where I've tested the edge and despite being a stock IRS I found the actual edge really very predictable and confidence inspiring. :beer:
 

Jmac72187

Corner Carver
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Good points for sure...but a few notes. The hill climb referenced was on a closed course as usual I would imagine. You don't need to go fast to realize the benefits of an IRS...even the relatively flawed Mustang variety. The back road bashing I do is really actually pretty tame from a speed perspective. Many places 50 mph is maxed. It's an 80% proposition at best on some pretty roughly paved roads and I never sweep into the opposite lane. I actually enjoy the rough stuff because it's a marvel to me how this IRS equipped Mustang "sticks" (to borrow an Olympic term) in the rough. I've O/T'd and Autox'd a few times where I've tested the edge and despite being a stock IRS I found the actual edge really very predictable and confidence inspiring. :beer:

I completely understand the hill climb part being legal and on closed roads.

I was just talking about open roads. I love taking on/off ramps but I don't push it to the edge. I save that for the auto cross course.

Think about those crash tests that you see on TV, they are usually pretty slow (~20mph) and those cars don't come out very well.
 

NJ 03Mach1

Hillclimbers do it better
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Do you really want to be pushing your car to the handling edge like that on the street anyway?

Whether it be a build SRA or IRS, I don't think I would want to see its handling edge on the street. That is more dangerous than street racing.

Yes, yes I do. I've done the IRS swap as well, and love every minute of it. See vid link in my sig, while not as fast as the car above, I do hillclimb it.

Good points for sure...but a few notes. The hill climb referenced was on a closed course as usual I would imagine. You don't need to go fast to realize the benefits of an IRS...even the relatively flawed Mustang variety. The back road bashing I do is really actually pretty tame from a speed perspective. Many places 50 mph is maxed. It's an 80% proposition at best on some pretty roughly paved roads and I never sweep into the opposite lane. I actually enjoy the rough stuff because it's a marvel to me how this IRS equipped Mustang "sticks" (to borrow an Olympic term) in the rough. I've O/T'd and Autox'd a few times where I've tested the edge and despite being a stock IRS I found the actual edge really very predictable and confidence inspiring. :beer:

Sticks perfectly doesn't it? Even when bashing isn't tame.. :)

I completely understand the hill climb part being legal and on closed roads.

I was just talking about open roads. I love taking on/off ramps but I don't push it to the edge. I save that for the auto cross course.

Think about those crash tests that you see on TV, they are usually pretty slow (~20mph) and those cars don't come out very well.

I hill climb, and I take the on/off ramps very aggressively whenever given the chance and the IRS doesn't ever let me down. Much more confidence then when I had the SRA in the car. Mine isn't much over stock (yet) but it only gets better with every mod. Tires as well make the difference, don't forget that.


And of course gentlemen (and ladies) don't forget the most important part of this equation. Bruce Griggs has unlimited access to the parts, tuning and the funds to put the best available on that car. More then most of us here will ever have access to.

Not to mention he is a great driver and regardless if it's "smooth" or not, a hillclimb takes balls to do at full speed wide open.

I'm also pretty sure that camera has the "smoothing/balance" effect on it (I dunno what it's called) if you watch the edge of the hood (cowl area) in relation to the road it's a lot rougher a ride then it appears.

Connor, this Spring/Summer we plan on quite a few mild bashing runs. Let me know if you want in.
 

ON D BIT

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Yes, yes I do. I've done the IRS swap as well, and love every minute of it. See vid link in my sig, while not as fast as the car above, I do hillclimb it.
And of course gentlemen (and ladies) don't forget the most important part of this equation. Bruce Griggs has unlimited access to the parts, tuning and the funds to put the best available on that car. More then most of us here will ever have access to.

Not to mention he is a great driver and regardless if it's "smooth" or not, a hillclimb takes balls to do at full speed wide open.

Bruce builds/fabs those parts based on engineering and chasis geometry. The list below are the deficiencies that Griggs suspension corrects in the sn95 chasis.
Front Roll Center - Rear Roll Center - Roll Axis - CG (Center of Gravity) - Understeer - Oversteer - Neutral Steer - Spring Rate - Motion Ratio - Wheel Rate - Roll Bind - Roll Steer - Bumpsteer - Ackerman - Camber - Caster - Toe

Based on these changes the infamous snap oversteer is eliminated. The CG and Roll Axis is corrected so that you can use softer springs and still keep the car flat in the corners. Also they lower the car by changing attachment points not shorter springs. This means that the car is lower but will lose little if any suspension travel!:rockon:

Its easy to drive hard with the Griggs setup. In 2009 both Bruce and his wife won the Virginia city hill climb with the same car. Bruce drove it to win the mens division. His wife drove it to win the womens division!
 

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