antmike

Can anyone tell me the top speed of a stock 74 318 duster? Can't find it anywhere

RacerHog

Back in 1980 I had a 1972 Dodge Demon 318 2 barrel carb auto trans w 2.73 rear gear, this thing had about 75,000 mile on it at that time... 112 MPH Wide Open, Out over Desert Hwy 395... That was it!!! and with its tong hanging out..

demetri

How were you measuring speed? Was that based on speedometer? If yes, that may have been 5% faster reading than you were really going.

A 3.23 may have been better for speed for that car. May be counter-intuitive, but it would bring more torque in the 100-110 range.

RacerHog

Thats what the speedo said at the time.... Take it for what its worth....

Skwerly

i've gone 117 in my fury with a 318. i actually have had it all the way to 120, but nobody was there to verify that. would regularly do 110 without too much huffing.

2.72 gears.

pro-tech

I dont understand the question?????.......If you take a stock 426 hemi 440,413 wedge 383,360, 340,318,273,225,173... and the red line is 5,000 rpms or even 5500rpm and they all have the same rear gear ratio and the same gear ratio in the transmisson,, then outcome will be the same????,,,,True...The only difference would be that the bigger cubic inch engines would get to that speed quicker...and be more fun to drive...Bill...Am I right???

moparted

maybe 100 but will take 2 miles to get there

pro-tech

Better check your timing..LOl There are some good running 318s out there he also didnt specify 2 or 4 barrel carb. The old trooper cars ran good but if they ran them in pursuit for more then a few miles the #5 & 7 pistons would melt down and burn a hole through...So with that inside information ( I worked for the chrysler dealership) my friends would out run the cops all the time and get away because they were running big blocks and were modified...It was so funny to me to hear the cops tell the story of the pursuit and all the time i knew who it was they were chasing...Until one day they got him because he wrecked his car when drunk and being chased...Bill

demetri

When you have very low gear ratios (numericaly high, i.e., 3.55 or 4.11) you are correct, the top speed is rpm limited. But with tall gears, top speed is typically drag limited. That means, as the engine revs up on high gear, the aerodynamic drag and rolling resistance prevent you from going any faster, even though you have not reached your rpm limit.

Speedometers is the last indication of how fast you are really going when you compare car to car. That is, each car has different speedometer errors, partly due to manufactring tolerances, partly due to tire differences from stock. 118 on the fury may be 110 mph real, whereas 112 on the Dart may be 105 real. Nobody knows. Best way to eastimate speed is with an electronic tach, tire rolling resistance, and gear ratios. Even this can have errors due to tire expansion, and other factors.

Skwerly

Not really. More power equals more oomph up high to propel the car faster. Go extreme: think about a walkman motor in a Mopar. Same gears and everything as the 440. think it has the same top speed? You’ll not get a factory /6 to reach the same top speed a 426 wedge can; the juice just isn’t there.

pro-tech

Got it ...So what you are saying is you will never red line a 318 in high gear if you are running tall gears because of resistance/drag on the car...It's like the song says its to the floor and there aint no more... I still think it is a bogus question there are to many varibles to give a accurate answer...Exhaust, fuel delivery,gear ratios, ....Its like when kids look at a car and say wow look how fast this car will go because the speedometer goes to 160MPH...Why would you ask a question like that???? You can make it as fast as you want if you've got the money to do it...Just saying

Skwerly

Hmmm, I do see your point the more I think about it. I’d never really thought about it that way. it’s an interesting query... might be a good topic for discussion!

MoparRon

An engine has to have the power to fight the wind. If they all had 4.11 rear ends you might be right. But put a 2.73 rear-end in all of them and the wind will slow down most of them. A stock hemi or 440 might reach top end without being souped up . I know a Ford with a 351 can't do it.

Kuvasz101

5000 revolutions of anything going through a transmission with a ratio output (ex. 5000 in to a transmission and coming out 1000 rpms it's 5 to 1). Same rearend gears at 3.23 revolutions gives the same top speed no matter the driving force. The BIG KEY here is getting that engine with same ratios to actually reach 5000 rpms. That's where the elephant engine has the capability over the 318.

Lostviking

68 Barracuda, 2.76 318 auto. 135MPH, clocked by my buddies Charger RT with a 160MPH speedo. The front end was slowly moving up and down at that speed. Didn't try it again.

Edit: Not a stock motor or exhaust.

Iowan

There is an equation for air resistance x speed but I’m not sure how it works. I do know that it can multiply hp required by two just for a small increase in speed. I’d say a stock 318 couldn’t pull 5000 rpm with a 2 Series gear in even an Abody.

Kuvasz101

I know when they did top speeds in my 2010 Dodge Challenger SRT 6 speed, top speed was attained in 5th gear. 6th gear slowed the rpms down too much and speed went down. The 6th gear was good for gas mileage only.