4.10 peeps in here, pronto!

[Spreadman]

I'm installing the gears (4.10's) tomorrow, and won't have my chip until Tuesday. So here's what I need ya to do if you can. I need RPM's for the following speeds:

40mph
50mph
60mph
80mph

I know there are several calculators out there, but I don't trust them. I want real world numbers.

If a couple of you could do this for me I'd be GREATLY appreciative!!! I might even spring for some custom titles.

 

[COramprat]

Auto or 5 speed...

 

[Spreadman]

5-sp.

BTW, Bill the Cat owns all cartoon cats.

 

[COramprat]

My experience in my 96...in 5th...before my speedo gear...was the speedo was off by 20%. So when I was reading 100mph I was actually only doing 80. I had my wife pace me in my Expedition. So basically if you take your MPH and subtract 20% you should get what you are looking for, or at least very close. If my math is correct:
40=48
50=60
60=72
80=96

Even with the white speedo gear I was still off by 10% so I finally broke down and bought the speedcal.

And yes...Bill rules...ack

 

[Spreadman]

Hmmmmm. With the t-45 right?

All measurements would be in 5th.

 

[RIP 112]

I have a 4R70W, but the ratios between it and the 5spd aren't too far apart.

40mph-1800rpm
60mph-2100rpm
80mph-3000rpm
100mph-3400rpm

weird thing is, alot of people say that a stock mustang with bolt-ons doesn't have enough power to reach the governed speed- 147mph, the funny thing is I reached 145mph and the car still didn't govern. Whoever says that a mustang w/ 4:10's cant reach 150, or 147, is full of it, because I DID IT!

 

[COramprat]

Hmmmmm. With the t-45 right?

All measurements would be in 5th.

Yes...T45 but the errors in speedo are in all tranny gears. The different rear end gears only effect RPM's thus the 4.10 to 1 gear ratio has a different RPM than that of 3.27's. The speedo is off by the same percentage no matter if you are in 1st, 2nd, 3rd etc....I misunderstood your original post. I was thinking speedo error and not rpm's. See below..

See here

Note: Pics of speedo are Speedcal corrected but it gives you an idea of the RPM's at each speed.

 

[BlackenedSVT]

I have a 4R70W....

I've been seeing this a lot lately...
What is a 4R70W type or trans? Never heard of it...

 

[COramprat]

I've been seeing this a lot lately...
What is a 4R70W type or trans? Never heard of it...

THat's fancy talk for auto....

 

[GTsleeper]

I have a 4R70W, but the ratios between it and the 5spd aren't too far apart.

40mph-1800rpm
60mph-2100rpm
80mph-3000rpm
100mph-3400rpm

weird thing is, alot of people say that a stock mustang with bolt-ons doesn't have enough power to reach the governed speed- 147mph, the funny thing is I reached 145mph and the car still didn't govern. Whoever says that a mustang w/ 4:10's cant reach 150, or 147, is full of it, because I DID IT!

Gotta agree totally with you on that one. I hit my ride at 138 and still had a few more mph to go. My r's are a little hire but I believe its due to that 85mm MAF that I have on. Trying to find my stock one so I can put it back on.

 

[jimfitzgerald]

With 4.10's your speedometer will indicate 25 percent higher than with 3.27's. So, if you're going 60 mph, you will indicate 75 mph, etc.

 

[GTsleeper]

With 4.10's your speedometer will indicate 25 percent higher than with 3.27's. So, if you're going 60 mph, you will indicate 75 mph, etc.

Not to be a smart ass but its called a speed cal, or SCT with a dyno tune. If your vehicle reads 15mph more than what its indicating I would hate to see the tickets you have. I checked mine with a 60mph roll on the highway, it was dead on.

 

[COramprat]

Not to be a smart ass but its called a speed cal, or SCT with a dyno tune. If your vehicle reads 15mph more than what its indicating I would hate to see the tickets you have. I checked mine with a 60mph roll on the highway, it was dead on.

Yes, you are a smart ass....

The question was what speed vs. RPM's BEFORE he had his chip installed since he was getting the gears today and would not have the chip until Tuesday. We all understand (see Jim's over 6000 posts and my nothing-to-sneeze at 1600 and note we have been around awhile) that the speedo can be corrected with a chip, flash, or speedcal but thanks for your input.

 

[GTsleeper]

O.K. I feel like an ass guess I gotten his post all wrong. I was even going to add its only 15-20mph off without the speed cal or tune. OOps! Besides w/those mods and 1/4 #'s should of know thats what he meant.

 

[StngStr]

Just use the calculator. They are more accurate than these morons getting in their cars and telling you what their speedo says. The calculators actually do the math with the correct formulas. Some guy just checking his speedo isn't as accurate. We all know that the speedo's are off more the faster you go.

http://www.tchracing.com/tech/gearc...givenval=5500&givenvaltype=RPM&selectedgear=5

 

[Jackie Chan]

Just use the calculator. They are more accurate than these morons getting in their cars and telling you what their speedo says. The calculators actually do the math with the correct formulas. Some guy just checking his speedo isn't as accurate. We all know that the speedo's are off more the faster you go.

http://www.tchracing.com/tech/gearc...givenval=5500&givenvaltype=RPM&selectedgear=5

haha, are you calling jimfitz a moron? he will put you over his knee when you actually make it out to a race next year

 

[jimfitzgerald]

haha, are you calling jimfitz a moron? he will put you over his knee when you actually make it out to a race next year

Now I remember why I moved to ModularDepot. I should know better than to post on StangNet. (No offense to Mike Raburn)

 

[COramprat]

Now I remember why I moved to ModularDepot. I should know better than to post on StangNet. (No offense to Mike Raburn)

I'm here less and less...and over at the Depot more and more.

Just use the calculator. They are more accurate than these morons getting in their cars and telling you what their speedo says. The calculators actually do the math with the correct formulas. Some guy just checking his speedo isn't as accurate. We all know that the speedo's are off more the faster you go.

http://www.tchracing.com/tech/gearc...&selectedgear=5

Thank you for your input. Your vast knowledge has enlightened us all we are better citizens because of it. I will do my best not to be a moron in the future and be sure I check with you on each and all issues concerning the Ford Mustang. You seem to be the omnipotent purveyor of wisdom when it comes to our cars. THANK YOU, THANK YOU, THANK YOU

 

[Jackie Chan]

Now I remember why I moved to ModularDepot. I should know better than to post on StangNet. (No offense to Mike Raburn)

he's not calling you names Jim, he was just commenting on how people just post info wrecklessly. I use to go by the 25% over thing for a few months myself.

 

[COramprat]

he's not calling you names Jim, he was just commenting on how people just post info wrecklessly. I use to go by the 25% over thing for a few months myself.

So it was directed at me I guess...

Oh well...I guess I'll go jump off a cliff. I'm no longer a viable part of the human race. Woe is me.