Motor Trend Mag. SRT8 Challenger vs. GT500

[SlowSVT]

Russ:

That is a VERY good question and I'm not sure I can give you an accurate answer?

BUT...... the R pulled just over a g in testing and the GT500 did not pull a g so I would have to give the cornering nod to the 2000 R. That is cornering only. A specific radius turn driven at the limit by the same driver and in the same track conditions. The GT500 is more nose heavy and it's carrying around more than 300 additional pounds compared to the R. The chassis and suspension, no matter how much it's improved, just can't make up the weight discrepancy. Plus you have the IRS/SRA issue as well. (The R had harder durometer bushings in the IRS making it not as compromised as a Term as delivered from the factory)

You didn't ask THIS question but I will give you an answer to it anyway. Big HP tracks like Road America, Watkins Glen, VIR or Road Atlanta the GT500 wins in a heads up competition. Shorter tracks like Gingerman, Waterford Hills, Grattan, MAM, Auto-Bahn, Barber and the like, the nod goes to the R. This is comparing two factory stock vehicles on street tires and street pads with same driver and track conditions.

That's about the best I can answer! :thumbsup::coolman::beer:

Bruce

The "cornering only" question is what I was after.

In a nut shell, What I think you are saying is: A box stock SN95 based 2000 Cobra R will out turn a box stock GT500.

I know I am breaking this down to very simplistic terms but I just want to keep it simple. I have heard people praising the phenomenal handling capabilities of the Cobra R but no one who has driven a GT500 or who owned one dare to compare it to an "R".

I also realize the Cobra R is nothing more the a race car masquerading as a street car but it is an SN95 based platform with the Terminator being the next one down the performance rung. Which means either the S197 is not as advanced as some would like think or the SN95 is not as bad as those same people would like to believe. Chassis stiffness isn't everything and the S197 does make a few compromises to the SN95 in other areas.

I would image on a twisty Technical road the GT500 would be at a disadvantage to the Cobra R and possibly a Terminator with a set of IRS bushings.

To be honest in the larger scheme of thing it doesn't make much difference. If anyone is driving any of these cars to it's capability on public roads they should be pulled over immediately and have a bullet inserted in their head.

 

[ac427cobra]

Bruce

The "cornering only" question is what I was after.

In a nut shell, What I think you are saying is: A box stock SN95 based 2000 Cobra R will out turn a box stock GT500.

I know I am breaking this down to very simplistic terms but I just want to keep it simple. I have heard people praising the phenomenal handling capabilities of the Cobra R but no one who has driven a GT500 or who owned one dare to compare it to an "R".

I also realize the Cobra R is nothing more the a race car masquerading as a street car but it is an SN95 based platform with the Terminator being the next one down the performance rung. Which means either the S197 is not as advanced as some would like think or the SN95 is not as bad as those same people would like to believe. Chassis stiffness isn't everything and the S197 does make a few compromises to the SN95 in other areas.

I would image on a twisty Technical road the GT500 would be at a disadvantage to the Cobra R and possibly a Terminator with a set of IRS bushings.

To be honest in the larger scheme of thing it doesn't make much difference. If anyone is driving any of these cars to it's capability on public roads they should be pulled over immediately and have a bullet inserted in their head.

Yes, in very simplistic terms, the cornering of the R is better than the GT500. The SVT engineers did several things to accomplish this. The spring and shock/strut package was a contributing factor. As were the firmer IRS bushings. (higher durometer rubber) The R also had specially modified IRS upper control arms which allowed more rear camber which also added to the better cornering ability of the car. And the 100 tread wear BFG KD's also added to the benefit. All of these things compensated for shortcomings of the chassis and allowed the car to break a g in skid pad tests.

The Terminator was less of a race car and more of a street car. That is why the IRS is so compromised on those cars. Also, the spring and shock package does not offer outstanding handling. It rides nice on the street though.

Once you introduce chassis flex to a loaded chassis you no longer have directional control over the tires and therefore lose efficiency in cornering ability and handling.

FWIW

:thumbsup::coolman::beer:

 

[gritz45]

What I'm saying is the S-197 chassis and suspension system is a VAST improvement over the tired SN-95 and continuously re-engineered suspension which evolved on the platform for over 25 years.

In "factory delivered condition" the SRA > IRS. Once you start modding then the tables get turned. A stick axle can be improved but will always take a back seat to an improved IRS.



Chassis rigidity is critical to accurate handling.



And IRS would add 100# or more to this car. Even though the weight would be added to the light end of the chassis, I would not be in favor of it. The additional weight would be the straw that broke the camel's back. This car doesn't need any additional weight even if it was for the upgrade of an IRS.

FWIW

:thumbsup::coolman::beer:

This is an interesting discussion, and I have a unique perspective, in that I own a 99 GT Vert, the 08 GT500 Vert, and a 06 300C SRT-8. Comparing the chassis on the two Mustangs, as has been pointed out, is no comparison. The chassis & platform refinement, and therefore ultimate capability of the GT500, is
fantastic. I have welded SFC's, tower braces, springs, 18" wheels, adj dampers, etc.. on the 99, and it handles great. It also shakes, rattles, creaks when pushed hard, and has nowhere near the grip of the 500, which has the FRPP handling pack. But back to the weight issue. The thing that baffles me is the weight of the 300, listed at 4140, and the weight of the GT500. When I back the 500 into the garage next to the SRT-8, you feel like you are next to a limousine, a much larger car, and it is. It has four doors,the interior is huge, the trunk is huge, it has IRS and a 6.1 liter engine, and a kicker sub in the trunk. Yet it only weighs 100lbs more than the 500 vert, and maybe 200-250 more than the coupe. Based on the weight of the Challenger and description of the car, it is the same old SRT-8 with different sheet metal.

How come the GT500 and Challenger are so heavy?

By the way, my SRT-8 makes 412RWHP, and while it is a great and fast everyday driver, it will not run with the GT500.

 

[ac427cobra]

How come the GT500 and Challenger are so heavy?

You can thank our Nanny State for most of that weight! Crash standards, ABS, air bags, side air bags, crumple zones, more metal and components = more weight. Pretty simple actually.

:-D

Not to mention sound systems with amplifiers, 15 speakers, subwoofers, 24 cd changers, Nav systems, 26 way power seats etc. etc.

 

[SlowSVT]

Yes, in very simplistic terms, the cornering of the R is better than the GT500. The SVT engineers did several things to accomplish this. The spring and shock/strut package was a contributing factor. As were the firmer IRS bushings. (higher durometer rubber) The R also had specially modified IRS upper control arms which allowed more rear camber which also added to the better cornering ability of the car. And the 100 tread wear BFG KD's also added to the benefit. All of these things compensated for shortcomings of the chassis and allowed the car to break a g in skid pad tests.

The Terminator was less of a race car and more of a street car. That is why the IRS is so compromised on those cars. Also, the spring and shock package does not offer outstanding handling. It rides nice on the street though.

Once you introduce chassis flex to a loaded chassis you no longer have directional control over the tires and therefore lose efficiency in cornering ability and handling.

FWIW

:thumbsup::coolman::beer:

While I agree the Terminator handling cannot be described as "fantastic", niether can the GT500. Road & Track were actually quite impressed with the handling of the Terminator stating it was the best handling Mushang made with exception of the 2000 R which they described as in the Corvette Class. The Terminator will hold a .9 G steady state corner which is about where the GT500 is. It likely transitioning from one corner to the next may favor the Terminator over the GT500 with it's shorter wheelbase and slightly reduced mass. Either way both cars are probably a pretty close match with respect to handling

Chassis flex is never a good thing but I imagine the flexi Mustang chassis biggest problem is torsional flex between the cross member and the rear sub-frame. It may have a little negative impact on the handling but not to the point where one would loose "directional control". Overtime the GT500 chassis will fatiqueand loosen up too especially with 500 ft lbs. of torque and 3900 lbs. of mass constantly being applied to the chassis. Give it time. It will loosen up like all cars do.

 

[ac427cobra]

While I agree the Terminator handling cannot be described as "fantastic", niether can the GT500. Road & Track were actually quite impressed with the handling of the Terminator stating it was the best handling Mushang made with exception of the 2000 R which they described as in the Corvette Class. The Terminator will hold a .9 G steady state corner which is about where the GT500 is. It likely transitioning from one corner to the next may favor the Terminator over the GT500 with it's shorter wheelbase and slightly reduced mass. Either way both cars are probably a pretty close match with respect to handling

Chassis flex is never a good thing but I imagine the flexi Mustang chassis biggest problem is torsional flex between the cross member and the rear sub-frame. It may have a little negative impact on the handling but not to the point where one would loose "directional control". Overtime the GT500 chassis will fatiqueand loosen up too especially with 500 ft lbs. of torque and 3900 lbs. of mass constantly being applied to the chassis. Give it time. It will loosen up like all cars do.

Russ:

I think you and I should agree to disagree! :beer: You, nor anyone else, will ever convince me that an SN-95 is equal to an S-197. Aint no way, aint no how.

I doubt I will be one of the first ones to start noticing my chassis in the GT500 loosening up. Although I do drive it pretty hard on track, I've only put 3,000 miles on the car in almost two years. I never drop the hammer and pull a hole shot. Most of my throttle application is applied pretty smoothly. I mean seriously, where in the hell can you use 509 RWHP on the damn street! :cryying:

My 'other' SN-95 car will be getting close to completion in a few months. That's one of the only rigid SN-95's in existence! Stay tuned for further details!

:thumbsup::coolman::beer:

 

[SlowSVT]

Russ:

I think you and I should agree to disagree! :beer: You, nor anyone else, will ever convince me that an SN-95 is equal to an S-197. Aint no way, aint no how.

Not trying to convince anyone of anything. Just the differences are not black and white, more like shades of gray.

I doubt I will be one of the first ones to start noticing my chassis in the GT500 loosening up. Although I do drive it pretty hard on track, I've only put 3,000 miles on the car in almost two years. I never drop the hammer and pull a hole shot. Most of my throttle application is applied pretty smoothly. I mean seriously, where in the hell can you use 509 RWHP on the damn street! :cryying:

Lots of guys are easily making 500, 600 and even 700 hp on the street with both cars. Whether they can use it or not is another question. I do know adding gears, drag slicks and 5000 rpm launches will play havoc with the chassis structure. One thing to consider with the use of coilovers is that it makes the chassis carry the weight of the engine and transmission (that's about 900 lbs more weight the sheet metal will have to carry up front). The stock SN95 suspension bypasses this stress by placing it directly on the cross memeber and then through the A-arm. Coilovers are a much better set-up. When I realized where the loads were being placed in the SN95 by adding coilovers compelled me to beef up my shock towers and fendor aprons as you saw in the photo I sent you.

My 'other' SN-95 car will be getting close to completion in a few months. That's one of the only rigid SN-95's in existence! Stay tuned for further details!

Can't wait to see it. We can compare notes when I'm finished with mine. I can't stand rattley shakey car chassis :cuss: Makes for vague responding car everytime you turn the wheel though I admit I'm eliminating the fifth spring on the chassis. I got way more money into my chassis then in the drivetrain. And when I'm done you won't see any of it :-D

 

[ON D BIT]

:dw:

Can you explain what the definition of "the proper geometry" on the IRS equipped Mustangs actually means?

Let's put it another way: If you were road racing a 99-04 Cobra would you swap out the IRS for a straight axle?

op:

proper geometry is a huge endeavor simply because the engineering and geometry will be different for your different goals. just look at nascar where the teams will have different suspension setups for the vast array of tracks that they run at.

however i do believe that the engineering put into the 78 fairmont was not geared towards corner carving. did ford ever change the attachment points on this chasis at any time during the production cycle of the sn-95 mustang?

sn-95 chasis as explained by griggs racing...
Roll Center - Both front and rear suspensions have a Roll Center. This is an imaginary point around which the body of the car will rotate in a turn. The attachment points of the suspension components determine the Roll Center.
Roll Axis - A line between the front & rear Roll Centers.
CG (Center of Gravity) - The center point of the vehicle's mass.
Understeer - When the front tires lose traction first.
Oversteer - When the rear tires lose traction first.
Neutral Steer - The ideal balance when the front & rear tires gradually give up traction at an equal rate.
Spring Rate - Expressed in pounds per inch, it is the force necessary to compress the spring, i.e. a 200 lb spring requires 200 lbs to compress it 1", 400 lbs to compress it 2", etc.
Motion Ratio - Specifically we usually refer to the relationship between the motion of the wheel and the motion of the spring; i.e. If the spring is half the distance from the control arm pivot as the wheel is, the motion ratio relative to the wheel is .5 to 1.
Wheel Rate - The combined effect of spring rate, motion ratio, friction and/or binding of other suspension components measured at the wheel
Roll Bind - Any binding of suspension components that occurs as the body of the car leans over in a turn
Roll Steer - Generally refers to a steering effect on the rear axle as the car leans over in a corner. Caused by the rear control arms pivoting around their forward mounting point, drawing the axle forward as the arm moves up or down.
Bumpsteer - Toe change as the suspension moves up & down
Ackerman - AKA "Toe out in turns". When turning the inside tire must turn more than the outer tire because it is turning on a smaller radius
Camber - Expressed in degrees, it is how much the tire leans in or out
Caster - The forward inclination of the spindle or strut - like the forks on a bicycle
Toe - The difference in the distance between the leading and trailing edge of the tires


Too much flex through the floor of the unibody.
Rear upper control arms whose function is to locate the axle housing laterally as well as control it's rotation (they don't do either very well). They give the car a very high rear roll center, and bind as the car leans into a corner. The binding causes a sudden increase in the wheel rate that results in the Mustang's characteristic "snap" oversteer.
With the TorqueArm & Panhard bar relieving the upper control arms of their duty, we've eliminated the bind-induced snap-oversteer and lowered the rear roll center. At this time we also install the subframe connectors, significantly reducing the flex through the unibody.


a. The current front suspension geometry yields only about 2 degrees of caster, which was fine for the skinny whitewall tires that were used on the '78 Fairmont, but is inadequate for today's low profile high performance tires.
b. The front suspension also has a very low roll center (it can actually be below the ground if the car is lowered too much), which combined with the high rear roll center gives you a very steeply inclined roll axis.
c. The angle at which the front A-arms are mounted promotes brake dive.
d. Bumpsteer-The stock suspension has too much bumpsteer.
e. Ackerman-The steering rack is not positioned correctly, and does not provide enough toe out while turning, causing the outer edge of the outside tire to drag through the turn.
In front the K-member relocates the A-arm pickup points, increasing caster for better high speed stability, decreasing brake dive, raising the front roll center, and relocating the steering rack to correct Ackerman. Bumpsteer is addressed at this time with the installation of our bumpsteer kit.


Of course the car will still need a good set of springs & shocks, but with the corrected geometry the relationship between the CG and the roll axis is significantly improved, which means we can use much softer springs and still keep the car flat in a corner.

 

[ON D BIT]

Bruce

The "cornering only" question is what I was after.

In a nut shell, What I think you are saying is: A box stock SN95 based 2000 Cobra R will out turn a box stock GT500.

why the 00r vs the gt500? why not the gt500 vs the 03 svt and the 00r vs the gt500kr?


i have not driven/ridden in the irs mustang so i cant compare. i was dually impressed with the live axle swap 01 svt that i had a chance to ride in. about a 160 degree highway offramp at 95 + with no tire squeel was very surreal. add that to the feeling of a softer ride than my stock 03 mach 1 i was impressed.

does any other mustang suspension change the attachment points like griggs? i like the fact that with griggs one can lower the car without losing any suspension travel.

 

[SlowSVT]

ON D BIT

What point are trying to make here and what does a Ford Fairmont even remotely have to do with this conversation?

I would avoid cutting and pasting info off the web. On a topic like this, chances are if you didn't write it, you probably don't understand it. Suspension dynamics is such an involved science neither you nor I and probably just about everyone else on this site can only scratch the surface. If you think you can do a better job designing a suspension then the engineers at Ford I would be very interested using your own words what you have to say. If you moved a pivot point on the suspension system just an 1/8" you wouldn't have a clue what the impact on the handling characteristics would be.......most likely it would be bad.


:nonono:

 

[SlowSVT]

why the 00r vs the gt500? why not the gt500 vs the 03 svt and the 00r vs the gt500kr?


i have not driven/ridden in the irs mustang so i cant compare. i was dually impressed with the live axle swap 01 svt that i had a chance to ride in. about a 160 degree highway offramp at 95 + with no tire squeel was very surreal. add that to the feeling of a softer ride than my stock 03 mach 1 i was impressed.

does any other mustang suspension change the attachment points like griggs? i like the fact that with griggs one can lower the car without losing any suspension travel.

I am trying very hard to show a level of restraint here but your making it very difficult.

 

[ON D BIT]

I am trying very hard to show a level of restraint here but your making it very difficult.

what part? live vs irs or that the gt500kr can corner as the 00r does?

am i wrong? teach me.

 

[ON D BIT]

ON D BIT

What point are trying to make here and what does a Ford Fairmont even remotely have to do with this conversation?

I would avoid cutting and pasting info off the web. On a topic like this, chances are if you didn't write it, you probably don't understand it. Suspension dynamics is such an involved science neither you nor I and probably just about everyone else on this site can only scratch the surface. If you think you can do a better job designing a suspension then the engineers at Ford I would be very interested using your own words what you have to say. If you moved a pivot point on the suspension system just an 1/8" you wouldn't have a clue what the impact on the handling characteristics would be.......most likely it would be bad.

ford fairmont has everything to do with this conversation since it is the same chasis that your 00r(you brought this into context) is built on. how are the attachment points different on the 00r than on the 78 fairmont?

everything else, you are correct. ford also did not design or engineer the mustang to go round corners(you know what i mean). they built it to be a semi fun, very safe car with decent power.

want to compare a ford built live vs irs? your best bet would be the 03 mach vs the 01 svt. want to compare chasis and the irs? 03 svt and the gt500 or gt500kr vs the 00r. either way it makes no sense to compare a specialized track vehicle to a mass transportation vehicle.


edit: what makes the said information less valid or less true since i do not have an engineering degree?

 

[mullens]

This is an interesting discussion, and I have a unique perspective, in that I own a 99 GT Vert, the 08 GT500 Vert, and a 06 300C SRT-8. Comparing the chassis on the two Mustangs, as has been pointed out, is no comparison. The chassis & platform refinement, and therefore ultimate capability of the GT500, is
fantastic. I have welded SFC's, tower braces, springs, 18" wheels, adj dampers, etc.. on the 99, and it handles great. It also shakes, rattles, creaks when pushed hard, and has nowhere near the grip of the 500, which has the FRPP handling pack. But back to the weight issue. The thing that baffles me is the weight of the 300, listed at 4140, and the weight of the GT500. When I back the 500 into the garage next to the SRT-8, you feel like you are next to a limousine, a much larger car, and it is. It has four doors,the interior is huge, the trunk is huge, it has IRS and a 6.1 liter engine, and a kicker sub in the trunk. Yet it only weighs 100lbs more than the 500 vert, and maybe 200-250 more than the coupe. Based on the weight of the Challenger and description of the car, it is the same old SRT-8 with different sheet metal.

How come the GT500 and Challenger are so heavy?

By the way, my SRT-8 makes 412RWHP, and while it is a great and fast everyday driver, it will not run with the GT500.

That is a strong running SRT8 my friend. Avg RWHP is in the 370 range. What kind of mods are you running? You are correct, my SRT8 Charger was a big, fast, comfortable cruiser, but no comparison to the GT500 as far as acceleration. From what I've read I don't see the Challenger as being much different.

 

[SlowSVT]

ford fairmont has everything to do with this conversation since it is the same chasis that your 00r(you brought this into context) is built on. how are the attachment points different on the 00r than on the 78 fairmont?

everything else, you are correct. ford also did not design or engineer the mustang to go round corners(you know what i mean). they built it to be a semi fun, very safe car with decent power.

want to compare a ford built live vs irs? your best bet would be the 03 mach vs the 01 svt. want to compare chasis and the irs? 03 svt and the gt500 or gt500kr vs the 00r. either way it makes no sense to compare a specialized track vehicle to a mass transportation vehicle.


edit: what makes the said information less valid or less true since i do not have an engineering degree?

ON D BIT

your our rainman

 

[sn0man1]

We should praise this article. GO CHALLENGER GO MOPAR It will help sell challengers, and leave gt500's on dealer lots longer and longer. I hope I don't have to spell it out.

 

[500 SNKE]

We should praise this article. GO CHALLENGER GO MOPAR It will help sell challengers, and leave gt500's on dealer lots longer and longer. I hope I don't have to spell it out.

;-)

 

[MedVader]

I am trying very hard to show a level of restraint here but your making it very difficult.

No bud. he's right.

If you want to compare what each chassis has to offer and see if the S197 really does beat the SN95 into the dirt, then compare 2 factory offerings that represent the pinnicle of suspension engineering on each platform.

That would be '00R vs GT500KR.

From what I've read, the GT500KR will hand the '00R its *ss on any track you choose.

 

[CPViolation]

Motor Trend in 1980 awarded the Chervorlet Citation as "car of the year"

That says it all right there.

While I'm not a big fan of the GT500 retro styling I would take it over either the Camaro :xpl: or Challenger. Anything over 4000 lbs. is automatically disqualified. There is a lot to like about the GT500 over the two boat anchors :nonono:

a 116" wheelbase on the Challenger is laughable

2008 Cadillac CTS
2007 Toyota Camry
2006 Honda Civic
2005 Chrysler 300C
2004 Toyota Prius
2003 Infiniti G35
2002 Ford Thunderbird
2001 Chrysler PT Cruiser
2000 Lincoln LS
1999 Chrysler 300M
1998 Chevrolet Corvette
1997 Chevrolet Malibu
1996 Dodge Caravan
1995 Chrysler Cirrus
1994 Ford Mustang
1993 Ford Probe GT
1992 Cadillac Seville Touring Sedan
1991 Chevrolet Caprice Classic LTZ
1990 Lincoln Town Car
1989 Ford Thunderbird SC
1988 Pontiac Grand Prix
1987 Ford Thunderbird Turbo Coupe
1986 Ford Taurus LX
1985 Volkswagen GTI (eligible due to it being built in VW's now-defunct Pennsylvania plant)
1984 Chevrolet Corvette
1983 AMC / Renault Alliance
1982 Chevrolet Camaro Z28
1981 Chrysler K Cars, Dodge Aries / Plymouth Reliant
1980 Chevrolet Citation
1979 Buick Riviera S
1978 Chrysler, Dodge Omni / Plymouth Horizon
1977 Chevrolet Caprice
1976 Chrysler, Dodge Aspen / Plymouth Volare
1975 Chevrolet Monza 2+2
1974 Ford Mustang II
1973 Chevrolet Monte Carlo
1972 Citroën SM (An imported vehicle that was selected overall "Car of the Year")
1971 Chevrolet Vega
1970 Ford Torino
1969 Plymouth Road Runner
1968 Pontiac GTO
1967 Mercury Cougar
1966 Oldsmobile Toronado
1965 Pontiac Motor Division
1964 Ford Motor Company (Not for the Mustang)
1963 American MotorsRambler
1962 Buick Special
1961 Pontiac Tempest
1960 Chevrolet Corvair
1959 Pontiac Motor Division
1958 Ford Thunderbird
1957 Chrysler Corporation
1956 Ford Motor Company
1955 Chevrolet Motor Division
1954 No award
1953 No award
1952 Cadillac Motor Division
1951 Chrysler Corporation
1950 No award
1949 Cadillac Motor Division

Don't forget the Pinto, oops I men Mustang II
Jeff

 

[SlowSVT]

No bud. he's right.

If you want to compare what each chassis has to offer and see if the S197 really does beat the SN95 into the dirt, then compare 2 factory offerings that represent the pinnicle of suspension engineering on each platform.

That would be '00R vs GT500KR.

From what I've read, the GT500KR will hand the '00R its *ss on any track you choose.

Great, more cheerleaders. The guys I was having the discussion with has a lot more depth of knowledge on this subject then you who is basing your comments by what you've "read". Me dragging the 00 R into the subject was kinda push'N it but it was done for reason which seems to have escaped you. And now your dragging KR into the subject :rollseyes

Bruce handles himself quite well and is a person can engage in an intelligent conversation with and learn something in the process.

You miss the point entirely. Move on.