I was looking at the 200mph speedometer today and I was wondering... what is the theoretical top speed this car can go?

I did find a website that lets you enter the gear ratios and tire size to get an approximation:

Top Speed Calculator

By this, it says the max is 194mph, in 4th gear. This seems about right, since I've done some searching on the forum and someone claimed a 186mph top speed run. However, I don't think this takes into account the drag coefficient and theoretical maximum speed based on a reasonable horsepower range. I'd like to calculate the top speed stock (350hp) and with intake/pulley/tune (prob about 390-400hp).

I tried working out the math using a few formulas I found online, but I'm not getting anything close to about what it should be.

Anybody else want to try working out the formulas? Do a search on google for "calculating top speed of an automobile".

EDIT: This is assuming you remove the top speed limiter at 158mph.

 

Having taken mine up to 160 after the tune in 1 mile, yes 1 mile from a standing start...I feel they are gear bound to the mid 170's myself....I would have needed some more running room to have made 170....the wind was definitely making the little roadster work...but, it was very stable at that speed....wish we had an old air force runway we could borrow for a few trips....lol

 

I posted a PDF showing speed vs RPM for the SRT6 in in this thread: https://www.crossfireforum.org/forum...tml#post433896

For stock size tires, the SRT6 is gear limited to 188MPH.

As for calculating Horsepower required to maintain a speed, I've used this one:

Calculate HP For Speed

For the calculations: (Found in this thread)

Coefficient of Drag: 0.370
Frontal Area: 20.56 sq. ft

With a car weight of 3400 lbs and a speed of 188 MPH, the calculator I linked to gives a required horsepower of 367 HP.

 

This is EXACTLY what I was looking for. Thanks!

For those interested:

Top speed (drag limited) for stock SRT6 (about 349hp): ~ 185mph
Top speed (drag limited) for modded SRT6 (about 390hp): ~192-193mph

This is for the COUPE at stock tire sizes, stock weight. Roadster will be less due to higher drag coefficient.

So, our speedometers scale perfectly, assuming you bump the governor back up to 200mph to match the cluster (which I plan on doing when I get my tune).

Thanks again Thumper.

 

our srt6 was power limited at 168 having only a nw cai. we held that speed for around 15-20 seconds before we found it wouldnt go any faster. On a closed track of course.

 

I hit 169.384 MPH from the standing mile with Factory PS2's, rims and gearing - modded only with the 185mm pulley, SL55 intake and tune. But that was before what I know now.

I still had a some RPM's left on the gauge at the mile marker - just no more track...

My goal is 185+ MPH next time.....

 

"I hit 169.384 MPH from the standing mile with Factory PS2's, rims and gearing - modded only with the 185mm pulley, SL55 intake and tune. [U]But that was before what I know now."[/U]

BrianBrave, what do you know now that you didn't know then?? Care to share?

Cheers,
KrzyFast

 

I personally have hit 172 on the highway with about 400-500 rpm left. I have slightly taller tires, so a bit over 172. I think 180's is all we got.

 

You're nuts. Imagine the speeding fine if you got caught. Or the **** rape u could have gotten in jail.

 

You feel more alive when you're living on the edge! There are insanely long stretches of highway in the southwest with NOBODY on them, I wish I had the guts to take it up over 135 but I didn't want to get pulled over because I *just* got the car and it didn't have insurance or registration on it.

 

I have had a lot of cars to top end over the years, and I can tell ya, I will be the first to congrats anyone hitting 180....because there wasn't 180 in the roadster, maybe the coupe will fare better...

 

dont forget the crap factor.... that is where you take your foot out of the gas so you dont crap you pants!

 

true Mike...the wind was getting really bad, and you could tell she started to struggle to climb...it was still climbing when I let off, but no where near the pace it was climbing to 140...so, the butt factor figures she might make it to 180, but you would need a few more miles...

 

As some of you have known for some time I have run 173mph and She had plenty left...
I would bet my left nut she do 188-192
Mike

 

Hey Doc, theres NO WAY I would need more miles as you said, I hit 173 from a cruising speed of 60 in less than a mile!
I've never tried it from a dead stop.
mike

 

I have seen 160-162 several times in my Roadster and it didn't seem like it was having any stress or trouble getting there , felt like it had more ***** than I did ,,,,

 

I've never met a police officer nuts enough to try and keep up at 170 honestly your biggest risk assuming you know how to pull off the highway and weave through traffic is messing up not the police. The slightest mistake at those speeds and you'll be dead half a second later. It doesn't matter if you're on 2 wheels or 4 you don't survive 170 mph accident on the highway. And the police follow at around 110-120 so they don't kill someone else on the highway.

 

Speed of the police is @ 670 MILLION MPH ( radio waves ), you can't outrun that.

 

Old thread gentleman. I have since built a coupe and seen the 170+ mark. Need a quiet long stretch of road. No crossroads. I found a few while in Illinois. Little roaster is or was capable, but I just cruise in it now. No racing for it anymore.

 

8 year old thread revival...impressive