October Trivia Question 2
#32
Contest
Originally Posted by ChrisXoxide
I get a kick out of everyone here posting up answers, corrections, etc etc. I'll be on later to declare the winner. I don't know for sure the answer until I get home. If I were to guess myself I'd say (without a calculator on hand) somehwere around 2700.
Make sure not to actually EDIT your post or it won't count.
Make sure not to actually EDIT your post or it won't count.
#40
Originally Posted by madmatt
HAHA too bad I already guessed it lol.
Originally Posted by Chris from last Contest
Trick question? hahah, no! Why would I intentionally try to trick you?! Putting some ideas in my head though =D
#43
Originally Posted by ChrisXoxide
At 75MPH in 5th gear, on stock 17 inch wheels and tires, a GT with a TR3650 transmission is at what RPM - with 4.10 rear gears? First to guess within 25 RPMs.
Ok, they don't run a 3650 either.
#46
Old hot rodders RULE!
Originally Posted by ChrisXoxide
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.
#48
RPM calc.
Originally Posted by bshiek
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.
Chris, can you provide the details on how you calculated that? -- turn this into a tech thread. Many of us could use the lesson.
#49
Originally Posted by 03BullittClone
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".
#50
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.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!
#51
http://www.tchracing.com/tech/gearca...selectedgear=1
Originally Posted by bshiek
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.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!
#52
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.
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.
#53
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.
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.
#54
Originally Posted by bshiek
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.
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?
#56
Originally Posted by ChrisXoxide
TR3650 is .62 5th gear though?
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.
#57
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...
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...
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