Cojohnso1
Well-Known Member
So we ran the two street only cars. (Two years ago.) That on paper are very close. But performed much differently.
'69 GTX 440: a little higher (purple grind) perf cam than stock. Dual plane low rise eddy performer intake. 750 Holley stock exhaust. Approx 410 HP.
'03 Mustang Cobra Supercharged 4.6l. Stock. Approx 400 HP.
GTX A833 4-speed. 1st gear 2.66. Final gear 1.0 Dana rear 3.54:1. Rear tire height 28" on 15" rim.
Cobra 6 speed TI. 1st gear 2.66. Final gear 0.63:1 rear tire height 25.6" on 17" rim. Rear gear 3.55:1.
Both cars very similar dry weight at 3650 lbs.
Race was on a 4 mi closed highway section. (That I'm pretty sure not legal. But better than public access.) A 5-10 MPH 1st gear punch.
Cobra jumped out to and maintained 3 car length lead to 1/4mi end. GTX caught at about 3/4 mi. Cobra then had enough. GTX still pulling a little bit. Estimate speed 140 MPH.
The taller tires of GTX showed as expected. Especially thru the gears. I thought .63 gear would allow Cobra to hold better at top end. My friend driving said car was done. And a little spooky vibration beginning. So shut down first.
So in closing? The newer Cobra was quicker. But 440 was able to real it in. Driving both I suspected this would be the case. The 440 just takes more time to get into its optminal power band. But when it did? It was spitting mad chasing down the Cobra. The car is unlike my first '69 GTX of VERY simular build that I had many years ago. A bit slower thru the gears. But a MUCH better highway commando. Remarkably stable at high speed.

'69 GTX 440: a little higher (purple grind) perf cam than stock. Dual plane low rise eddy performer intake. 750 Holley stock exhaust. Approx 410 HP.
'03 Mustang Cobra Supercharged 4.6l. Stock. Approx 400 HP.
GTX A833 4-speed. 1st gear 2.66. Final gear 1.0 Dana rear 3.54:1. Rear tire height 28" on 15" rim.
Cobra 6 speed TI. 1st gear 2.66. Final gear 0.63:1 rear tire height 25.6" on 17" rim. Rear gear 3.55:1.
Both cars very similar dry weight at 3650 lbs.
Race was on a 4 mi closed highway section. (That I'm pretty sure not legal. But better than public access.) A 5-10 MPH 1st gear punch.
Cobra jumped out to and maintained 3 car length lead to 1/4mi end. GTX caught at about 3/4 mi. Cobra then had enough. GTX still pulling a little bit. Estimate speed 140 MPH.
The taller tires of GTX showed as expected. Especially thru the gears. I thought .63 gear would allow Cobra to hold better at top end. My friend driving said car was done. And a little spooky vibration beginning. So shut down first.
So in closing? The newer Cobra was quicker. But 440 was able to real it in. Driving both I suspected this would be the case. The 440 just takes more time to get into its optminal power band. But when it did? It was spitting mad chasing down the Cobra. The car is unlike my first '69 GTX of VERY simular build that I had many years ago. A bit slower thru the gears. But a MUCH better highway commando. Remarkably stable at high speed.

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