Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK2 - > Engine Performance/Intakes/Exhausts

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 04-04-2011, 07:10 PM
Bmwister's Avatar
Member
 
Join Date: Oct 2010
Posts: 546
Thanks: 11
Thanked 13 Times in 9 Posts
Rep Power: 2064
Bmwister has a reputation beyond reputeBmwister has a reputation beyond reputeBmwister has a reputation beyond reputeBmwister has a reputation beyond repute
HEMI Torque Curve from dyno

I stumbled across this today and thought forum members would find it helpful. Considering the numerous posts comparing the Pentastar and 5.7L hemi, I thought this dyno test of the current 5.7L Hemi clearly shows how fat the power band truly is. Even though the test was performed on a Charger RT, the graph is a valid representation of what we have in the WK2.

Reference:
http://blogs.insideline.com/straight...harger-rt.html



---
__________________

__________________
An expert is one who knows more and more about less and less until he knows absolutely everything about nothing.
---
2013 GC Ltd Hemi (2nd Jeep)
Reply With Quote
  #2  
Old 04-04-2011, 07:30 PM
Member
My Jeep: 2008 5.7L WK
 
Join Date: Jan 2010
Location: mid-Michigan
Posts: 450
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 2206
Walt has a reputation beyond reputeWalt has a reputation beyond repute
Re: HEMI Torque Curve from dyno

Quote:
Originally Posted by Bmwister View Post
I stumbled across this ... dyno test of the current 5.7L Hemi clearly shows how fat the power band truly is. Even though the test was performed on a Charger RT, the graph is a valid representation of what we have in the WK2...
Thank you.

Here's another one for the earlier HEMI's: (click to enlarge)
Attached Images
File Type: jpg HEMI Curve.jpg (62.7 KB, 126 views)
__________________

__________________
'08 WK Limited, 5.7L HEMI, Quadra-Trac II, Bright Silver Metallic, Class IV Hitch, Michelin LTX M/S tires, Billet Technology oil catch can, Fumoto oil drain valve.
Reply With Quote
  #3  
Old 04-04-2011, 07:34 PM
moosehead's Avatar
Horseshoe for the Donkeys

My Jeep: 2011 5.7L WK2
 
Join Date: Sep 2010
Location: CO Rockies
Posts: 3,168
Thanks: 218
Thanked 97 Times in 83 Posts
Rep Power: 1620713
moosehead has a reputation beyond reputemoosehead has a reputation beyond reputemoosehead has a reputation beyond reputemoosehead has a reputation beyond reputemoosehead has a reputation beyond reputemoosehead has a reputation beyond reputemoosehead has a reputation beyond reputemoosehead has a reputation beyond reputemoosehead has a reputation beyond reputemoosehead has a reputation beyond reputemoosehead has a reputation beyond repute
Re: HEMI Torque Curve from dyno

Spun all 4 tires today accidentally while finally breaking free of rush hour gridlock. OK, maybe spun is a bit of an overstatement, but let's say the audible chirp surprised the crap outta me and maybe those around the 5k lb beast. Bring on the tuners. Thanks Bmwister.
__________________
2011 JGC Oland Hemi / Borla Catback Proto / Hemifever Tune on DS Trinity / Flyin Ryan PTB / Volant CAI / Bwoody Sway Links / BT Catch Can & Underhood Kit / Jon's Tinted Tails / SRT8 Hood, Steering Wheel, Shiftknob, Pedals / Firestone Dest AT's & Winter 18's / Focal 165 Component Fronts, Alpine PDX 5 Amp, Rockford Fosgate P3 10" Sub & Fiberglass Enclosure / PS2 Grill, Mirrors & Liftgate Strip / Tow Hooks & Skids / JW Speaker LED Foglights / Debadged, Tint, Clear Bra / Sharkfin / Vled & Putco LED's / JRoll Uber-Tech Cabin Filter / RA & Yak Roof Rack / Lit Sills, Slush & Cargo Mats
Reply With Quote
  #4  
Old 04-04-2011, 07:52 PM
Member
My Jeep: 2008 5.7L WK
 
Join Date: Jan 2010
Location: mid-Michigan
Posts: 450
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 2206
Walt has a reputation beyond reputeWalt has a reputation beyond repute
Re: HEMI Torque Curve from dyno

Remember that the torque and HP curves must cross at 5,252 RPM.

HP = (torque x rpm) / 5252. Torque must be in ft-lbs.
__________________
'08 WK Limited, 5.7L HEMI, Quadra-Trac II, Bright Silver Metallic, Class IV Hitch, Michelin LTX M/S tires, Billet Technology oil catch can, Fumoto oil drain valve.
Reply With Quote
  #5  
Old 04-04-2011, 11:11 PM
MasterWK's Avatar
Senior Member
My Jeep: 2010 5.7L WK
 
Join Date: Jan 2011
Location: Denver, Colorado
Posts: 1,141
Thanks: 3
Thanked 6 Times in 6 Posts
Rep Power: 2515
MasterWK has a reputation beyond repute
Re: HEMI Torque Curve from dyno

I screech my tires everyday pulling out of school in my 5.7! left turns are the easiest if you're looking for sound! stomp the gas and jerk the wheel a little
__________________
-Ryan
[SIGPIC][/SIGPIC]
Reply With Quote
  #6  
Old 04-05-2011, 07:24 AM
Member
 
Join Date: Mar 2011
Posts: 499
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 31641
77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute77rednecktruck has a reputation beyond repute
Re: HEMI Torque Curve from dyno

Quote:
Originally Posted by Walt View Post
Remember that the torque and HP curves must cross at 5,252 RPM.

HP = (torque x rpm) / 5252. Torque must be in ft-lbs.
where did that come from???
__________________
Reply With Quote
  #7  
Old 04-05-2011, 08:11 AM
the1jake's Avatar
Premium Member
My Jeep: 2011 3.6L WK2
 
Join Date: Dec 2010
Location: Valley Forge U S A
Posts: 358
Thanks: 2
Thanked 3 Times in 2 Posts
Rep Power: 2247
the1jake has a reputation beyond reputethe1jake has a reputation beyond reputethe1jake has a reputation beyond reputethe1jake has a reputation beyond reputethe1jake has a reputation beyond reputethe1jake has a reputation beyond reputethe1jake has a reputation beyond reputethe1jake has a reputation beyond reputethe1jake has a reputation beyond reputethe1jake has a reputation beyond reputethe1jake has a reputation beyond repute
Re: HEMI Torque Curve from dyno

That torque curve chart should be fairly accurate.

Don't forget to mention that the 2011 Dodge Charger R/T does the 1/4 mile in 13.7 seconds. (sorry, couldn't resist guys)


I can't find the Road & Track full spec for the Grand Cherokee, but this is for the Charger. (note: PDF file)
http://www.roadandtrack.com/var/ezfl...4a6f8f2a3c.pdf
__________________
2011 Jeep Grand Cherokee Overland. Dark Charcoal. 18" black cast aluminum wheels. 275/65/R18 Nitto Terra Grapplers. (replaced the Firestone A/Ts in the pic) Rock rails. Skid plates. Tow hooks. Huskyliners. 44K miles as of 11/13.

http://www.jeepgarage.org/attachments/signaturepics/sigpic5916_1.gif
Reply With Quote
  #8  
Old 04-05-2011, 09:10 AM
ibleedoil's Avatar
Premium Member
 
Join Date: Jan 2011
Location: Edmonton, AB
Posts: 91
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1454
ibleedoil is on a distinguished road
Re: HEMI Torque Curve from dyno

Does the charger have the same output of our Hemi's? I know the truck version has 30 more hp and has a different top end (heads/intake)

Edit: Never mind. just looked back and saw that max torque and hp match ours.
__________________
2011 Overland 4x4
- Hemi
- Off-Road II
- ACC
- Natural Green Pearl / Saddle Brown
Reply With Quote
  #9  
Old 04-05-2011, 11:06 AM
Bmwister's Avatar
Member
 
Join Date: Oct 2010
Posts: 546
Thanks: 11
Thanked 13 Times in 9 Posts
Rep Power: 2064
Bmwister has a reputation beyond reputeBmwister has a reputation beyond reputeBmwister has a reputation beyond reputeBmwister has a reputation beyond repute
Re: HEMI Torque Curve from dyno

Quote:
Originally Posted by Walt View Post
Remember that the torque and HP curves must cross at 5,252 RPM.

HP = (torque x rpm) / 5252. Torque must be in ft-lbs.
Quote:
Originally Posted by 77rednecktruck View Post
where did that come from???
You and I and other techies probably already know where the 5252 constant comes from, but for those who do not: http://www.howstuffworks.com/question622.htm


--
__________________
An expert is one who knows more and more about less and less until he knows absolutely everything about nothing.
---
2013 GC Ltd Hemi (2nd Jeep)
Reply With Quote
  #10  
Old 04-06-2011, 06:32 PM
Member
 
Join Date: Mar 2011
Posts: 76
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1367
edogg23 is on a distinguished road
Re: HEMI Torque Curve from dyno

Quote:
Originally Posted by ibleedoil View Post
Does the charger have the same output of our Hemi's? I know the truck version has 30 more hp and has a different top end (heads/intake)

Edit: Never mind. just looked back and saw that max torque and hp match ours.
Manufacturer HP and TQ are at the crank, the dyno is at the wheels. So numbers on the dyno are usually about 15% lower than what it is making at the crank depending on the drivetrain loss.
__________________
Reply With Quote
  #11  
Old 04-06-2011, 06:53 PM
Bmwister's Avatar
Member
 
Join Date: Oct 2010
Posts: 546
Thanks: 11
Thanked 13 Times in 9 Posts
Rep Power: 2064
Bmwister has a reputation beyond reputeBmwister has a reputation beyond reputeBmwister has a reputation beyond reputeBmwister has a reputation beyond repute
Re: HEMI Torque Curve from dyno

Quote:
Originally Posted by edogg23 View Post
Manufacturer HP and TQ are at the crank, the dyno is at the wheels. So numbers on the dyno are usually about 15% lower than what it is making at the crank depending on the drivetrain loss.
That is an accepted guideline. I assumed people would ignore the actual posted numbers themselves; it is the posted curve that is the key point. The curve is an accurate indicator of the broad powerband. It is merely coincidence that the at-the-wheel reading in the IL test is almost identical to the published crank figures.

Different dynos will give different numbers especially if they didn't properly dial in the correction conditions. I doubt the manufacturer's published Hemi HP and torque numbers are at-the-wheel measurements otherwise they'd have to publish different numbers for 4WD and 2WD vehicles.
__________________
An expert is one who knows more and more about less and less until he knows absolutely everything about nothing.
---
2013 GC Ltd Hemi (2nd Jeep)
Reply With Quote
  #12  
Old 04-07-2011, 09:45 PM
Member
My Jeep: 2008 5.7L WK
 
Join Date: Jan 2010
Location: mid-Michigan
Posts: 450
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 2206
Walt has a reputation beyond reputeWalt has a reputation beyond repute
Re: HEMI Torque Curve from dyno

Quote:
Originally Posted by Bmwister View Post
You and I and other techies probably already know where the 5252 constant comes from, but for those who do not: http://www.howstuffworks.com/question622.htm --
Heh heh. It actually comes from my Thermodynamics text. That's why I like long-legged engines over screaming over-square toys.
__________________

__________________
'08 WK Limited, 5.7L HEMI, Quadra-Trac II, Bright Silver Metallic, Class IV Hitch, Michelin LTX M/S tires, Billet Technology oil catch can, Fumoto oil drain valve.
Reply With Quote
Reply

Thread Tools
Display Modes

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 Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
05 Hemi Torque Converters? TheBackRoads Grand Cherokee - WK 4 04-05-2011 10:42 AM
HEMI torque/rpm diagram franco1961 Engine Performance/Intakes/Exhausts 9 03-08-2011 11:13 AM
Is there a "learning curve" with changes on production models? rdalcanto Grand Cherokee - WK2 - 5 11-03-2010 09:01 PM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 09:19 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community