hp loss with 4.10 gears - Mustang Evolution

Go Back   Mustang Evolution > 1979-2015 Mustang GT || Tech and Talk > 2011-2014 Mustang GT



Reply
 
Thread Tools Search this Thread
Please support our sponsors and let them know you heard about them here!
Old 08-22-2012, 10:16 AM   #1
Registered Member
Regular
 
Join Date: Jul 2012
Region: Florida
Posts: 441
hp loss with 4.10 gears

Just curious what do you lose for hp numbers on the dyno with 4.10 gears rather than 3.55 or 3.31? I know you dont actually lose it but just wondering if there was an estimate in hp loss?
__________________
Boss IM, with Araid cai, bama 93 race tune, GT500 cat back, jba off-road x-pipe & longtubes, mgw shifter,4.10 gears, Aluminum Flywheel & driveshaft, Adjustable Panhard Rod, BMR adj. uca & lca, BMR relo. brackets, BMR Springs with 1.5" drop, BMR adj. swaybar, BMR tubular K member 1/2 drop motor mounts & BMR tubular A arms, steeda alu. rad. support, aluminum water pump pully, 85mm BBK TB, Rear seat delete. Boss oil cooler, Battery in trunk. AC delete, Evap delete
brianw64 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 08-22-2012, 10:31 AM   #2
The Blue Dragon
Regular
Supporter
 
GrabberBlue5.0's Avatar
 
Join Date: Feb 2012
Location: Louisville
Region: Kentucky
Posts: 5,661
Yea, like you said you don't actually lose power but the way the tq is multiplied and converted and all that crap by the gears will how lower hp numbers with shorter gears.

Borii is pretty good with this stuff, hopefully he'll chime in
__________________
New quick exhaust video

AUGUST 2012 MOTM!!!!
GrabberBlue5.0 is offline   Reply With Quote
Old 08-22-2012, 10:37 AM   #3
Registered Member
Regular
 
Join Date: Jul 2012
Region: Florida
Posts: 441
Re: hp loss with 4.10 gears

im sure its been discussed a million times, i am just curious, 4.10's are really fun but would like to know what im losing on the dyno, even if its just a rough estimate
__________________
Boss IM, with Araid cai, bama 93 race tune, GT500 cat back, jba off-road x-pipe & longtubes, mgw shifter,4.10 gears, Aluminum Flywheel & driveshaft, Adjustable Panhard Rod, BMR adj. uca & lca, BMR relo. brackets, BMR Springs with 1.5" drop, BMR adj. swaybar, BMR tubular K member 1/2 drop motor mounts & BMR tubular A arms, steeda alu. rad. support, aluminum water pump pully, 85mm BBK TB, Rear seat delete. Boss oil cooler, Battery in trunk. AC delete, Evap delete
brianw64 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 08-22-2012, 10:49 AM   #4
Registered Member
Regular
 
Napoleon85's Avatar
 
Join Date: Aug 2011
Region: Ohio
Posts: 3,045
Re: hp loss with 4.10 gears

Why does it matter/do you care if the dyno reads slightly lower? If the 4.10s suit your goals and needs, then install them. A dyno is nothing more than a tuning tool to measure immediate changes on the same car/day/dyno and make adjustments. What it reads at any given point outside of that context is a relatively useless number.
__________________
Official Exhaust Thread Troller
Napoleon85 is offline   Reply With Quote
Old 08-22-2012, 10:56 AM   #5
The Blue Dragon
Regular
Supporter
 
GrabberBlue5.0's Avatar
 
Join Date: Feb 2012
Location: Louisville
Region: Kentucky
Posts: 5,661
I think he's already got 4.10's and is curious what the dyno would read with other gears.

I do agree though, it doesn't really matter if you're having fun with it but it doesn't hurt to know for the sake of knowledge either
__________________
New quick exhaust video

AUGUST 2012 MOTM!!!!
GrabberBlue5.0 is offline   Reply With Quote
Old 08-22-2012, 11:14 AM   #6
Registered Member
Regular
 
Join Date: Jul 2012
Region: Florida
Posts: 441
Re: hp loss with 4.10 gears

its all good guys?? im only asking...i could really care less what the dyno tells me, i just wanted an estimate in what i lose with 4.10 gears? and i just read that it could be 20 hp on the dyno and if i lose 20 hp on the dyno then yeah i would like to know that...and as for how my car feels? well i love it...im only asking a question here and thats what i thought these forums were for?

---------- Post added at 12:14 PM ---------- Previous post was at 12:11 PM ----------

430 rwhp sounds alot better in my head rather than 407 after all the mods and money, but numbers mean diddly if you cant drive it.
__________________
Boss IM, with Araid cai, bama 93 race tune, GT500 cat back, jba off-road x-pipe & longtubes, mgw shifter,4.10 gears, Aluminum Flywheel & driveshaft, Adjustable Panhard Rod, BMR adj. uca & lca, BMR relo. brackets, BMR Springs with 1.5" drop, BMR adj. swaybar, BMR tubular K member 1/2 drop motor mounts & BMR tubular A arms, steeda alu. rad. support, aluminum water pump pully, 85mm BBK TB, Rear seat delete. Boss oil cooler, Battery in trunk. AC delete, Evap delete
brianw64 is offline   Reply With Quote
Old 08-22-2012, 11:27 AM   #7
Registered Member
Regular
 
Napoleon85's Avatar
 
Join Date: Aug 2011
Region: Ohio
Posts: 3,045
The short answer is, "it depends." way are you comparing it to (3.15. 3.31, 3.55, 3.73, 3.90)? Basically, you can tell (kinda) if you have an old dyno graph with the gears you want to compare to and a rpm-wheel speed calculator. But it varies from car, dyno, day, and a million other things.
__________________
Official Exhaust Thread Troller
Napoleon85 is offline   Reply With Quote
Old 08-22-2012, 11:41 AM   #8
Registered Member
Regular
 
Join Date: Jul 2012
Region: Florida
Posts: 441
Re: hp loss with 4.10 gears

I understand there is a million variables... all im saying is it doesnt matter what your setup is if you dyno with 3.31 gears you will have a considerable hp increase over dyno'ing with 4.10's regardless of the mods or anything and i was only wondering what the loss was on average for the gears and i got my answer...it could be as much as 20 plus hp ....and thats nice to know, not that it matters really but its nice to know the loss.
__________________
Boss IM, with Araid cai, bama 93 race tune, GT500 cat back, jba off-road x-pipe & longtubes, mgw shifter,4.10 gears, Aluminum Flywheel & driveshaft, Adjustable Panhard Rod, BMR adj. uca & lca, BMR relo. brackets, BMR Springs with 1.5" drop, BMR adj. swaybar, BMR tubular K member 1/2 drop motor mounts & BMR tubular A arms, steeda alu. rad. support, aluminum water pump pully, 85mm BBK TB, Rear seat delete. Boss oil cooler, Battery in trunk. AC delete, Evap delete
brianw64 is offline   Reply With Quote
Old 08-22-2012, 12:00 PM   #9
The Blue Dragon
Regular
Supporter
 
GrabberBlue5.0's Avatar
 
Join Date: Feb 2012
Location: Louisville
Region: Kentucky
Posts: 5,661
Quote:
Originally Posted by brianw64
its all good guys?? im only asking...i could really care less what the dyno tells me, i just wanted an estimate in what i lose with 4.10 gears? and i just read that it could be 20 hp on the dyno and if i lose 20 hp on the dyno then yeah i would like to know that...and as for how my car feels? well i love it...im only asking a question here and thats what i thought these forums were for?

---------- Post added at 12:14 PM ---------- Previous post was at 12:11 PM ----------

430 rwhp sounds alot better in my head rather than 407 after all the mods and money, but numbers mean diddly if you cant drive it.
I'm just making sure you don't get your head wrapped around it too much is all. Dyno numbers are cool but at the end of the day don't mean much with how easily they can be messed up by a number of variables. And I k ow you know, just reinforcing
__________________
New quick exhaust video

AUGUST 2012 MOTM!!!!
GrabberBlue5.0 is offline   Reply With Quote
Old 08-22-2012, 12:02 PM   #10
Registered Member
Regular
 
Napoleon85's Avatar
 
Join Date: Aug 2011
Region: Ohio
Posts: 3,045
Re: hp loss with 4.10 gears

Quote:
Originally Posted by brianw64 View Post
I understand there is a million variables... all im saying is it doesnt matter what your setup is if you dyno with 3.31 gears you will have a considerable hp increase over dyno'ing with 4.10's regardless of the mods or anything and i was only wondering what the loss was on average for the gears and i got my answer...it could be as much as 20 plus hp ....and thats nice to know, not that it matters really but its nice to know the loss.
Well it isn't really a flat number ... that's why it's so complicated. A percentage of loss would be a better way to express it, but it's really tied to the wheel speed/redline/efective gear ratio relationship. Tire size has an effect on the dyno results as well for the same reason.

So, assuming stock tire size and rev limiter ...

Click image for larger version

Name:	Gears.PNG
Views:	215
Size:	4.4 KB
ID:	65055

As you can see the wheel speed is slower as you put steeper gears in the car, despite the engine turning at the same RPM. This causes the dyno to read less power progressively for each gear.

So if you were to use 3.31 as a baseline, you would see approximately 92.98% of the power with 3.55s, 88.88% with 3.73s, and 80.70% with 4.10s. This is a gross estimation, and will likely be way off, but if you insist on having some form of comparison, you can take you dyno sheets with 3.31s and multiply by that percentage to get a ballpark estimate of where you will be now (were it the same dyno, same car, same day).

If you don't have a baseline dyno, then there really isn't anything to do but take a completely uneducated guess. The numbers you put down will vary based on the fuel you're running, the weather conditions, and the calibration of the dyno, not to mention all of the factors discussed above. You can take a stock car to a well calibrated dyno and a poorly (intentionally or unintentionally) calibrated dyno and see huge variances, so there is no way for us to guess what numbers your car will put down.
__________________
Official Exhaust Thread Troller
Napoleon85 is offline   Reply With Quote
Old 08-22-2012, 12:13 PM   #11
Registered Member
Regular
 
Join Date: Jul 2012
Region: Florida
Posts: 441
Re: hp loss with 4.10 gears

yeah i made the mistake of not getting my car dyno'd before and after, I already have the 4.10's and love them but i was just curious to what i was giving up on the dyno, i was 407 with the 4.10's and i was just on kennebell's website and they say you would lose 18 hp with 3.73's and more with 4.10's so it was just a thought no real big deal but it wouldve been nice to know what it was before and after.
__________________
Boss IM, with Araid cai, bama 93 race tune, GT500 cat back, jba off-road x-pipe & longtubes, mgw shifter,4.10 gears, Aluminum Flywheel & driveshaft, Adjustable Panhard Rod, BMR adj. uca & lca, BMR relo. brackets, BMR Springs with 1.5" drop, BMR adj. swaybar, BMR tubular K member 1/2 drop motor mounts & BMR tubular A arms, steeda alu. rad. support, aluminum water pump pully, 85mm BBK TB, Rear seat delete. Boss oil cooler, Battery in trunk. AC delete, Evap delete
brianw64 is offline   Reply With Quote
Old 08-22-2012, 12:27 PM   #12
Registered Member
Regular
 
Napoleon85's Avatar
 
Join Date: Aug 2011
Region: Ohio
Posts: 3,045
Re: hp loss with 4.10 gears

Quote:
Originally Posted by brianw64 View Post
yeah i made the mistake of not getting my car dyno'd before and after, I already have the 4.10's and love them but i was just curious to what i was giving up on the dyno, i was 407 with the 4.10's and i was just on kennebell's website and they say you would lose 18 hp with 3.73's and more with 4.10's so it was just a thought no real big deal but it wouldve been nice to know what it was before and after.
You're down about 20% TQ for the same RPM range, which is what I was referring to by "power" and is the number that's the most important. HP is a function of RPM and TQ.

The forumla for HP is HP = 2╥(T)(RPM) / 33000

T= TQ in lb/ft
RPM = the corresponding RPM of the engine at the corresponding moment of the TQ number above

So if you take your peak torque, multiply it by 0.807 and then plug that number into the formula above, you will have an approximation of what your HP number may have been.


Now ... I think you owe me a beer.

---------- Post added at 01:27 PM ---------- Previous post was at 01:25 PM ----------

Also, if you don't have a torque number for the exact same spot as your peak HP number, you could use the following formula to derive torque from the peak HP reading, then proceed as above.

T = HP(33000) / 2╥(RPM)
__________________
Official Exhaust Thread Troller
Napoleon85 is offline   Reply With Quote
Old 08-22-2012, 01:04 PM   #13
Registered Member
Regular
 
Skulls98GT's Avatar
 
Join Date: Jun 2012
Location: Little Falls
Region: Minnesota
Posts: 456
Quote:
Originally Posted by Napoleon85

You're down about 20% TQ for the same RPM range, which is what I was referring to by "power" and is the number that's the most important. HP is a function of RPM and TQ.

The forumla for HP is HP = 2╥(T)(RPM) / 33000

T= TQ in lb/ft
RPM = the corresponding RPM of the engine at the corresponding moment of the TQ number above

So if you take your peak torque, multiply it by 0.807 and then plug that number into the formula above, you will have an approximation of what your HP number may have been.

Now ... I think you owe me a beer.

---------- Post added at 01:27 PM ---------- Previous post was at 01:25 PM ----------

Also, if you don't have a torque number for the exact same spot as your peak HP number, you could use the following formula to derive torque from the peak HP reading, then proceed as above.

T = HP(33000) / 2╥(RPM)
Is there an app for that.
Skulls98GT is offline   Reply With Quote
Old 08-22-2012, 01:07 PM   #14
Registered Member
Regular
 
Napoleon85's Avatar
 
Join Date: Aug 2011
Region: Ohio
Posts: 3,045
Quote:
Originally Posted by Skulls98GT

Is there an app for that.


Click image for larger version

Name:	image-486770984.jpg
Views:	1178
Size:	224.6 KB
ID:	65061
__________________
Official Exhaust Thread Troller
Napoleon85 is offline   Reply With Quote
Old 08-22-2012, 01:16 PM   #15
Registered Member
Regular
 
Edens5's Avatar
 
Join Date: Apr 2012
Region: Pennsylvania
Posts: 361
Hahahahaahahaha^^^ that made my day.
Edens5 is offline   Reply With Quote
Old 08-22-2012, 01:31 PM   #16
Registered Member
Regular
 
Skulls98GT's Avatar
 
Join Date: Jun 2012
Location: Little Falls
Region: Minnesota
Posts: 456
Quote:
Originally Posted by Napoleon85
LMFAO
Skulls98GT is offline   Reply With Quote
Old 08-22-2012, 02:36 PM   #17
Registered Member
Regular
 
Join Date: Jul 2012
Region: Florida
Posts: 441
Re: hp loss with 4.10 gears

my torque was 355 so i will give u that beer but u gotto do that math for me...lol

---------- Post added at 03:22 PM ---------- Previous post was at 03:15 PM ----------

hp 407 tq355 @ 6700rpms?

---------- Post added at 03:25 PM ---------- Previous post was at 03:22 PM ----------

i wrote that crap all wrong im trying to load my chart?

---------- Post added at 03:31 PM ---------- Previous post was at 03:25 PM ----------

i cant load my graph, but it looks like its 355 tq @ 4700 rpms

---------- Post added at 03:36 PM ---------- Previous post was at 03:31 PM ----------

ok i will try that again peak tq was 355 @ 4700rpms and hp was 407 @ 6700rpms does that make sense?
__________________
Boss IM, with Araid cai, bama 93 race tune, GT500 cat back, jba off-road x-pipe & longtubes, mgw shifter,4.10 gears, Aluminum Flywheel & driveshaft, Adjustable Panhard Rod, BMR adj. uca & lca, BMR relo. brackets, BMR Springs with 1.5" drop, BMR adj. swaybar, BMR tubular K member 1/2 drop motor mounts & BMR tubular A arms, steeda alu. rad. support, aluminum water pump pully, 85mm BBK TB, Rear seat delete. Boss oil cooler, Battery in trunk. AC delete, Evap delete
brianw64 is offline   Reply With Quote
Reply

Lower Navigation
Go Back   Mustang Evolution > 1979-2015 Mustang GT || Tech and Talk > 2011-2014 Mustang GT

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


» Like Us On Facebook



05:08 PM


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0

MustangEvolution.com is in no way associated with or endorsed by Ford Motor Company.