2564.6675159235665

woot

math powa!

 

How we doin'?

 

2696.6234472782

 

I know Chris saw this thread... are we all wrong? lol

 

Shh...It's a trick question.

 

AH! Maybe the answer is "within 25 RPMS"... Oh man that would rule. Thats my new guess.

 

Now that would be funny. Mean...but funny.

 

I'm changing my guess to "within 25 RPMS"

 

HAHA too bad I already guessed it lol.

 

You said... "maybe" plus you already won once. Your out of the running.

 

Am I really, lol never read that...oh its mine lol.

 

2496.7557592713847

 

Hey, are we talking about a Ford GT? They don't have stock 17 inchers -- they are 18s.

Ok, they don't run a 3650 either.

 

At 75 MPH in 5th gear, your motor is turning at 2,495.4 RPM

BAM. Who wins here? I'm almost sure this is EXACT.

 

Ok... looks like 03BullittClone, I think he was the first to officially post his RPM though, correct? 03BullittClone, PM me man, we will work things out.

 

SLP catted X, come to papa!

 

Congrats, Clone!

Chris, can you provide the details on how you calculated that? -- turn this into a tech thread. Many of us could use the lesson.

 

I applied an old hot rodders rule of thumb, updated for 5-speeds. See Modular Tech Forum, thread "Choosing Gears". However, I would also be interested in the formal calculation, if it can be provided. Speaking for myself, I know the advent of sophisticated computer programs have generally made me "math lazy".

 

theres online calcs that you type all the ratios in and the speed, the only varation would be the tire size, i went out and measured my tires to get the size, i guess it wasent right, congrats man!

 

I used the engine speed calculator from Modular Depot, and I haven't figured out what I missed yet. Somebody please show me the light. Thanks!

http://www.modulardepot.com/engine_speed.xls

Basically,

diameter = section/25.4*aspectratio*2/100+wheel

rpm = gear*transratio*75*336/diameter

For example:

gear = 4.10
transratio = 0.67
speed = 75

Tire diameter:
section = 245
aspectratio = 45
wheel = 17

diameter = 245/25.4*45*2/100+17
rpm = 4.10*0.67*75*336/25.68

I must have missed the diameter too!

 

http://www.tchracing.com/tech/gearca...selectedgear=1

 

Thanks, Chris! I am curious which transmission ratio that calculator uses. Maybe I'll email them about it. Another calculator that is referred to on the tchracing forums is at http://www.f-body.org/gears/. This one shows the RPMs at 2700.

I want to see the actual calculation and tranny ratios so that I can estimate my trap speeds in the future. Plus the logic interests me.

 

Here is another calculator that outputs conflicting numbers...at least when I use 0.67 for a tranny ratio.
http://www.allfordmustangs.com/Detailed/608.shtml

At this point this isn't about the contest, but I do want people to use the right calculations when they're deciding on gears and such. This is my research (dunno if it would be considered tech yet) contribution to this board.

 

TR3650 is .62 5th gear though?

 

thought it was .62? what is the tire size?

 

Here is what I have found for the 3650 from multiple sources:
1st 3.37
2nd 1.99
3rd 1.33
4th 1.00
5th 0.67

But then I found this on Tremec's site (see the link to pdf):
1st 3.38
2nd 2.00
3rd 1.32
4th 1.00
5th 0.67

http://www.ttcautomotive.com/English...nsed_Specs.pdf

I understand that these could be different for different model years in the mustang lineup. Curious stuff... I wish I was home so I could look in my Helm's manual.

 

More findings...

http://www.corral.net/forums/showthr...highlight=3650
To quote DHG-Bullitt-GT on this thread:
"The pre 2002 T3650 have 5th as .67 the 2002 and up have .61 for 5th..."

Also tremec's site shows two different ratios that could have been used:
http://www.ttcautomotive.com/English...ts/TR-3650.asp


Maybe we should have specified which model year mustang to estimate for...

 

I vote Bullit Clone and I both get $50 gift certificates.

 

i vote next time the answer must be within 1 rpm!
signed,
sore loser