Maximum Speed of a Stock 70-71 Cuda/Challenger?

[ShelbyDogg]

Around 1990, I had my fresh 440 in and pulled out the 3:91s and put in some 2:76s to drive to Chicago later that month. I decided to see where the speedo would top out, since I did that with my Dad's new GM cars and they would all just stop pulling at different speeds above 100.   

I hit the highway in the middle of the night then punched it on the open highway. Around 120 it never stopped pulling but I had the floating feeling with the whole car and I decided right then that I didn't want to die that day, then let off. I don't know how fast it would have gone.

[swede-cuda]

my cuda 383-70 4speed with 3.23 all stock from carb to pan.the gps shows 182 km/hour,at that speed the car is steady but the fenders,especially the left shakes a bit.last week i drove stockholm-malmoe its about 350 miles single trip and 130km/hour or 80miles/hour seems to be a great long distance speed,i hope the tach shows wrong cause it said 4500-5000 rpm.no problems during the trip exept a lot of rain,and then almost worse ,just a little rain,just ehnauff that you have to trickle with that wiperswitch all to often.thats the thing i miss the most when using the car as a driver,sort of,an intermittent wiper function.

[1970 RT Challenger 1970]

Does the Go-Wing function the same and keep the rear end down like the GM F-Bodies (67-69 Camaro)?

(Does the Challenger (front spoiler, go-wing, RT Hood, have similar results compared to the front and rear spoilers (D80), Z28 Cowl Induction Hood, on a 67-69 Camaro that went through lots of computer testing?)

[HP2]

I'm sure it provides some benefit at those types of speeds, but the Go Wing was primarily an asthetic addition. The AAR and T/A duck tail spoiler was used in competition and was tested for such, so it is highly effective. But keeping the rear planted isn't always a problem.

The biggest issues with E bodies is the recessed grill area traps a lot of air and provides huge amounts of front end lift. The chin spoilers used on these cars were primarily asthetic additions and not ever used in competition. Like a Go Wing, they may provide some marginal benefit, but that is a secondary concern.  Any competition spoilers used under the front of E bodies tended to be fairly large.

The best reference to E body aerodynamic improvements is seen on the trans am cars, where they regularly qualified in the top of the field.

[brads70]

The best reference to E body aerodynamic improvements is seen on the trans am cars, where they regularly qualified in the top of the field.

  Like in my avitar.

[1970 RT Challenger 1970]

I'm sure it provides some benefit at those types of speeds, but the Go Wing was primarily an asthetic addition. The AAR and T/A duck tail spoiler was used in competition and was tested for such, so it is highly effective. But keeping the rear planted isn't always a problem.

The biggest issues with E bodies is the recessed grill area traps a lot of air and provides huge amounts of front end lift. The chin spoilers used on these cars were primarily asthetic additions and not ever used in competition. Like a Go Wing, they may provide some marginal benefit, but that is a secondary concern.  Any competition spoilers used under the front of E bodies tended to be fairly large.

The best reference to E body aerodynamic improvements is seen on the trans am cars, where they regularly qualified in the top of the field.

So the Superbird and Charger Daytona would be more ideal for high speed?

[brads70]

Yep the Superbird and Charger Daytona were designed for Nascar and 200 MPH.

[Wollfen]

I just read this thread and I do have something more to add that hasn't been touched on, even if you had the best aerodynamics in the world on these cars they still would do the floating feeling thing simply because at these high speeds the power steering pump is pumping so hard it makes the steering hyper sensitive, I do know that in police cars it was an issue in high speed pursuits, so they built in a restrictor valve that would start kicking in at above 80 mph. It went a long way towards dealing with the floating feeling in the cars. These type of pumps were introduced I think in the early eighties.

[sadil340]

My '70 340 Cuda with 14 inch tires (original owner wanted a full size spare) 3:55 gears and a 4-speed topped out at 132. I lowered the front end a bit and it felt pretty stable but I wouldn't have maintained that speed on a curve. Plus you wouldn't want to do that with any traffic around as you've got about 3 seconds worth of braking power with manual drum brakes at that speed! 

Manual steering if that matters...

[BB 70 Challenger]

...if you had the best aerodynamics in the world on these cars they still would do the floating feeling thing simply because at these high speeds the power steering pump is pumping so hard it makes the steering hyper sensitive, I do know that in police cars it was an issue in high speed pursuits, so they built in a restrictor valve that would start kicking in at above 80 mph. It went a long way towards dealing with the floating feeling in the cars...

  Thanks for that power steering pump info, Wollfen.

Assuming that is true, now, so if somebody has driven a not-power-assisted-steering E-body on high speeds, so that should be a better experience, right? Somebody done that? Please comment? Thanks!
  

PS  by the way: Burt Munro is one of the toughest man ever existed on earth !!!

[Chryco Psycho]

my 71  Charger has no power steering & on the track last year I had it up to 145 MPH , I would have gone faster but ran out of straightaway , it did not feel unstable & had a decent wheel alighnment & awesome aero

[heminut]

My first Cuda, a 340 4 speed, was manual steering. I had it up to around 135 MPH one time and the front end got extremely light. It concerned me enough that I never did it again!

[drewcrane]

Well i can give my opinion here since it is an open forum ,

there are alot of factors with this debate,

to many to mention ie, fuel type, tires,suspension,etc,

My intrest is just what did a person use to measure the speed,

as we all know the speedometor  in these cars is not accurate right?

So on my V.P trip i used my dash speedo and a gps unit, and sure enough they were not the same, due to gear ratio,trans gear for the speedo,and tire /wheel size.

at speeds exceding 120 on the dash ,my GPS said 116 mph,

i realized that if a cop saw that on my gps i would be penalized , so i un plugged it,

so after that i planted the tach beyond 6 k, i feel that i went about 120 to 125 .and i felt the front end rise a bit but i have lowered the front as well as a front air spoiler/dam, does make a difference but .............not like a car prepared for this type of test

 for these challengers to go above 130(true 130 plus) mph in stock form aint gonna happen,there is way to much air resistance for the car to actually go that fast .

the only reason i KNOW that is i have a buddie that has a 69 amx (with the similar cavernous grille), just to go above 130 mph(his max speed was 185 certified) he had to tape up every  gap,hole, headlight,side light. etc.including the grille which was flush with duct tape,and the side windows because at 140 the windows were sucked out side the frame by a 1/4 inch, and he had to go in to the pits to fix /and tape all this,

the question i have to ask is with a question,


what did you use to measure this speed? your dash speedo? or a track radar?

I f you think your dash speedo is correct ? think again,am I right on this theory?

[dodj]

My intrest is just what did a person use to measure the speed,

as we all know the speedometor  in these cars is not accurate right?

Previously I stated I had the Challenger up to 135mph. Since then after checking with a gps, and extrapolating the error in the speedo reading @ 80mph, I would say I was probably going closer to 115-120mph. Once I get around to doing the SRT front spoiler mod that drewcrane did to his challenger (still sitting untouched on the workbench), I wonder if it will make any significant difference to the front end feel @ 80-100 mph?

[heminut]

I f you think your dash speedo is correct ? think again,am I right on this theory?

Not if you're a cop and have access to a Speedgun to use in calibrating your speedo! (I now have a pretty decent range of speedo gears lying in my toolbox!)