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Science experiment - can the IRS from the S550 be transplanted into a 13/14 GT500?
- Thread starter PhoenixM3
- Start date
IRS (on a car) works best in areas that have little or no bumps or potholes like a race track. The fact is IRS is better from 1" movement up and down which is good for race tracks, after that it is NO better and above 2" up or down is worse. The shorter the auto-center of each side makes it even more pronounced. If the ride is better that is because of spring rates and shock specs. Like I said, IRS is the .05% performance gain on a road course that will beat a SRA. On the street it is no better and cost more for the end user. On a road course that takes 120 seconds to get around identical cars except the rear axle the IRS will be 1 second quicker.
BTW: I haven't heard Ford bragging about the track times with the new mustang like they did the 11-14s.
An IRS does not buck and kick on rough road and expansion joints like an SRA does.
Entering a long sweeping on-ramp with an expansion joint can be a hair raising experience in our cars.....unless you are going very slow.
Entering a long sweeping on-ramp with an expansion joint can be a hair raising experience in our cars.....unless you are going very slow.
:smmon:
You would best be served to resist posting on this topic, all it's doing is revealing your ignorance on this subject.
Whats wrong with you people, these are supposed to be American muscle cars. I like em sloppy and loud not refined and numb.
I just moved back living many years in Germany and owned various BMW M cars. I have spent many 100's of Euro lapping the Nürburgring. When I moved back in June of this year I purchased the Shelby and it was like a breathe of fresh air. Felt like I was undoing the button of my pants after Thanksgiving dinner, ahhhhh.
The SPORT MODE rocks! I turned it on before leaving the lot and havent turned it off since. Its harsh and it requires me to pay attention and drive the car not worry about pandora on my radio. I dont think I have turned the radio on once, the sound and drive is intoxicating to this day.
Get out there and drive that SRA sideways through 4 gears :rockon:
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This was true back in the 60's and even early 2000's but here is the thing....for $60k+ you better not be getting a sloppy and unrefined car that rides like ass. This was fine in 04 when guys where getting brand new cobras for $28k after discounts, but a 100% price increase in just 10 years better mean this "American Muscle" isn't sloppy. People now a days want it all...a muscle car that handles and stops with all the creature comforts. The price tags of the newer mustang speaks to that.
What are you talking about, "price tag of the newer mustang speaks to that" ...
2014 Mustang GT MSRP starting 31,200
2015 Mustang GT MSRP starting 32,100
That is a modest price increase and still a fairly cheap new car.
There are tons of refined cars you speak of out there from Jaguar to BMW to Audi to name just a few for 60-70k.
I bought the Shelby for exactly what you say it shouldnt be, and anyone who is truly buying a Shelby did as well.
Fact is, someone who "wants it all" doesnt buy a 13-14 Shelby, just doesnt.
This new GT may be nice for many but it or any future rendition of a Mustang will never be what the 13-14 GT500 is, iconic in automotive history because of its rawness. You fail to understand that because you fault it for what is best about it.
Finally, it completed the Nürburgring in under 7:40, what do you say about that?
http://fastestlaps.com/tracks/nordschleife.html
Numbers speak volumes and this Beast shows it can hang on a turn, incredible the refined "want it all" cars that were owned.
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Maybe, but I bought a bad bad MFing engine strapped to an stick that vibrates in my hand while I sit in Recaros and look out a glass roof 
The sub par rear suspension is tolerable as I prefer to drag race.
IRS in my '04 Cobra did drive smoother, but I still think the rear suspension would have been best with IRS as an option for those that care, just as a drag pack option would have been nice. In the end, happy with what SVT gave us.
Still surprised the aftermarket hasn't engineered a IRS for the s197, but I doubt it would show cost effective gains at the track and few would pay big$$$ for a better ride quality.
-J
The sub par rear suspension is tolerable as I prefer to drag race.
IRS in my '04 Cobra did drive smoother, but I still think the rear suspension would have been best with IRS as an option for those that care, just as a drag pack option would have been nice. In the end, happy with what SVT gave us.
Still surprised the aftermarket hasn't engineered a IRS for the s197, but I doubt it would show cost effective gains at the track and few would pay big$$$ for a better ride quality.
-J
Delvek, maybe was for the other responders, we must have been typing together, I agree with you.
-J
-J
Yea, I just scratch my head with people like DOM418 and the rest of them. They ignore facts, perhaps they have never owned a 13-14 GT500. Its the most intoxicating car I have owned.
Look, 98% of all these blowhards wouldnt know a road course if they were driving on one. So, lets just say in a fantasy world they are going to put there IRS Mustang GT on one, the GT500 completed the Nürburgring 3 seconds faster then the new 2014 M4? The new GT wont even come REMOTELY close.
How much faster around the most demanding road course is it supposed to be for $60something thousand?
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A torque arm and Watt's link make track use more than acceptable, the bucking and kicking on crap streets and highways is where the IRS would make the huge improvement.
^ this
Totally agree with this - not just for track, but for street too. I drove euro and jap cars for over 20 years and all of them had IRS with my most recent drive being an M3. I didn't know what I was getting into with SRA but the 2013 Shelby was a great proposition and immensely unique in this part of the world. In addition to this, I wanted "bullet proof". The M3 cost me a fortune to maintain the SMG box and multiple rebuilds of the rear suspension from track day abuse.
I do have to say that I realized pretty quickly that the SRA was challenged with the pot holes and general road conditions in a way I was not used to and so had to find a mod to fix. Lowered and BMR'd, I was able to dial out most of the hop but it was still there. I read everything I could find on IRS vs SRA and suspension upgrades and eventually came to the conclusion that I needed a watts link to solve this. Otherwise, the pros and cons really did not favour either.
I have since installed Filip's Cortex racing watts link & torque arm and it has transformed the car. I have driven over 3000kms since and there really is no compromise in this suspension set up versus IRS on track or on bumpy, pot hole ridden, roads. On track I was able to achieve over 1g in corners - uncompetitive driving and road tyres (Pirelli's) measured on a racelogic box. On road the wheel hop is completely dialled out. Tests done on Mustangs with Watts have seen up to 1.3g lateral - that's way more than an R8 or Lambo LP570-4.
Added to this, my wife's confidence in the car went up immeasurably once the watts link was on - and that must count for something
The half shafts are not fairing well at the drag strip!
I'll tell you what put an IRS in your 600hp+ car and beat me at the drag strip. If you want to race at a road course I'll go ahead and forfeit that race to you because like 99% of people on even on this site I have never raced at one!
I don't want it all (in other words I'm not a woman). Having it all means compromise on everything! Go buy yourself a dress if you want it all!
:smmon::smmon:
If you talk to most guys who are drag race enthusiasts it becomes very apparent they're thinking regarding suspension dynamics doesn't extend much beyond what's needed to minimize 1/4 mile and 60' times. For that role a straight axle has it's advantages. The problem is a well sorted drag car makes for a crappy street car or even an occasional track car. Nothing wrong with a car that's built to go fast in a straight line but not very good for everything else which is where the car will most likely put 99% of it's miles on the odometer.
An IRS will do a lot more then provide a "nice ride". That is just an indicator the suspension is doing a better job allowing the wheel to be more compliant with irregular road surfaces and not transferring it to the chassis. They are tailored to articulate the rear wheel maximizing grip as the chassis rolls, pitches and yaws something an SRA can't do since both the wheels are married to one another. There is a lot more going on with regard to suspension geometry then most drag racers realize. I always say to people who dismiss the advantages of an IRS is to go post their views in the Cobra R section where a most of the those guys actually track their cars and see what there reaction is. No one in their right mind swaps out an IRS for a straight axle if they are trying to improve handling. Would you?
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That is my issue, I've had two M3s but they didn't have explosive torque like the Shelby does. I want more predictability and less steer from the rear under heavy throttle. If I wanted that, I'd buy a forklift.....
Truth!
BTW, I'm still laughing at the post where Mobeydick claims that there's a fault with the IRS because the salesman didn't know how it was supposed to improve handling. It's obvious you've never worked at a dealership. Salesmen are salesmen, not engineers. Hell half of them couldn't tell you what engine is in the car you're test driving unless it's printed on the side of the car. Was at a Toyota dealer this spring test driving a 4 Runner for the wife and the salesman was happy to tell me that the one we were driving had the V8 in it, even though they don't offer a V8 in that vehicle in any form.
Hell the other day I had to clarify the engine size of my car to the parts counter guy at the local Ford dealer after telling him my car was a 2009 Shelby GT500, so yes that means it has the 5.4 V8 and not the 4.6 V8.
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