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
 
  #61  
Old 10-07-2011, 09:08 AM
Senior Member
 
Join Date: Sep 2010
Location: brOOklyn
Posts: 1,237
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 2674
JoeSchmoe007 has a reputation beyond reputeJoeSchmoe007 has a reputation beyond repute
Re: Accelleration in the v8 vs v6

Quote:
Originally Posted by Slowgan View Post
so is there a clear cut answer as to which accelerates faster? and by how much?
V8 is faster but drive both before you buy. None of them is "traffic light terror" as my old '98 ZJ was with 5.2 V8. When you step on accelerator there is a lag on both of them from the stop and while moving as well. Reasons seem to be transmission gearing ratios and electronic throttle control tuned for fuel efficiency.
__________________

__________________
Reply With Quote
  #62  
Old 10-07-2011, 01:01 PM
Member
 
Join Date: Sep 2011
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1062
jbeans is on a distinguished road
Re: Accelleration in the v8 vs v6

the v6 has almost 300 HP and the v8 has about 370... not much of a difference and running 2 more cylinders. The Hemi should put out more for the added weight - about 500lbs. I have a boat and tow it easily with the v6 - weight is about 3300lbs with trailer. here in Miami its all flat roads, maybe if i lived where uphill driving is common i would want the extra torque... whatever you buy you will be happy. Go with an Overland!
__________________

__________________
Reply With Quote
  #63  
Old 10-08-2011, 09:18 AM
Member
My Jeep: 2012 3.6L WK2
 
Join Date: Sep 2011
Location: Cherry Valley, IL
Posts: 343
Thanks: 0
Thanked 6 Times in 4 Posts
Rep Power: 4512
brandont has a reputation beyond reputebrandont has a reputation beyond reputebrandont has a reputation beyond reputebrandont has a reputation beyond reputebrandont has a reputation beyond reputebrandont has a reputation beyond reputebrandont has a reputation beyond reputebrandont has a reputation beyond reputebrandont has a reputation beyond reputebrandont has a reputation beyond reputebrandont has a reputation beyond repute
Re: Accelleration in the v8 vs v6

The V8 offers gobs of torque which is what you feel when you drive the car. As the saying goes people drive torque but buy HP. The feeling of great power when you tip in the throttle is torque - that's what people like. HP is actually a measure of efficiency not outright power. So theoretically two equal HP cars could do the same work if each car had the proper gearing to do that work. While the V8 definitely has more power, especially in-gear and low end, they are actually pretty close if you rev the V6 out.

C&D numbers seem to bear this out:

0-60 was 8.2 (V6) and 7.5 (V8)
1/4mi was 16.6 @ 88 (V6) and 15.8 @ 91 (V8)
30-50 was 3.8 (V6) and 3.9 (V8)
50-70 was 6.0 (V6) and 5.3 (V8)

My read of this is that the V8 gets off the line better but the V6 is pretty close once the revs come up (check the 1/4mi trap speed – nearly equal). The 0.7 second 0-60 is significant but with passing being so close I think it shows they aren’t too far off if you rev the V6.

Also of note was the observed MPG. The V6 got 19mpg while the V8 got 13mpg. These were different tests with different locations and conditions of course, but that is a pretty large difference.

Reference:
V6 Test: http://www.caranddriver.com/var/ezfl...5b7c323770.pdf
V8 Test: http://www.caranddriver.com/var/ezfl...7d241eb2f0.pdf
__________________
Reply With Quote
  #64  
Old 10-08-2011, 11:18 PM
Member
 
Join Date: Sep 2010
Posts: 104
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1516
Kev- is on a distinguished road
Re: Accelleration in the v8 vs v6

Quote:
Originally Posted by Deserthucker View Post
Don't forget the redesigned torque converter.
I saw a post about that after I'd typed my reply here. But, is it truly confirmed? I tried to check the mopar.com parts lists, the '12 torque converter has no price or availability, while for the '11 it is orderable. So, maybe it's true.
__________________
[O|||||||O]
Reply With Quote
  #65  
Old 10-08-2011, 11:41 PM
New Member
My Jeep: 2011 5.7L WK2
 
Join Date: Sep 2011
Location: Minneola, FL
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Oppy is on a distinguished road
Thumbs up Re: Accelleration in the v8 vs v6

Quote:
Originally Posted by brandont View Post
The V8 offers gobs of torque which is what you feel when you drive the car. As the saying goes people drive torque but buy HP. The feeling of great power when you tip in the throttle is torque - that's what people like. HP is actually a measure of efficiency not outright power. So theoretically two equal HP cars could do the same work if each car had the proper gearing to do that work. While the V8 definitely has more power, especially in-gear and low end, they are actually pretty close if you rev the V6 out.

C&D numbers seem to bear this out:

0-60 was 8.2 (V6) and 7.5 (V8)
1/4mi was 16.6 @ 88 (V6) and 15.8 @ 91 (V8)
30-50 was 3.8 (V6) and 3.9 (V8)
50-70 was 6.0 (V6) and 5.3 (V8)

My read of this is that the V8 gets off the line better but the V6 is pretty close once the revs come up (check the 1/4mi trap speed – nearly equal). The 0.7 second 0-60 is significant but with passing being so close I think it shows they aren’t too far off if you rev the V6.

Also of note was the observed MPG. The V6 got 19mpg while the V8 got 13mpg. These were different tests with different locations and conditions of course, but that is a pretty large difference.

Reference:
V6 Test: http://www.caranddriver.com/var/ezfl...5b7c323770.pdf
V8 Test: http://www.caranddriver.com/var/ezfl...7d241eb2f0.pdf

New guy here, thanks for the post ! had some info i was trying to pin down.

The measured temp with the v6 was 59 degrees f , so that helps the performance a lot, while it would appear the v8 got beat up in the desert and we will assume is 100 degrees f + .

Any one catch that the brake sizes are the same dunno if they get the info from jeep or not. Kinda curious on the rotor sizes from v6 to v8.

Thanks again for the post.
__________________
Reply With Quote
  #66  
Old 10-09-2011, 12:31 AM
Member
 
Join Date: Sep 2010
Posts: 104
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1516
Kev- is on a distinguished road
Re: Accelleration in the v8 vs v6

Quote:
Originally Posted by brandont View Post
The V8 offers gobs of torque which is what you feel when you drive the car. As the saying goes people drive torque but buy HP. The feeling of great power when you tip in the throttle is torque - that's what people like. HP is actually a measure of efficiency not outright power. So theoretically two equal HP cars could do the same work if each car had the proper gearing to do that work. While the V8 definitely has more power, especially in-gear and low end, they are actually pretty close if you rev the V6 out.

C&D numbers seem to bear this out:

0-60 was 8.2 (V6) and 7.5 (V8)
1/4mi was 16.6 @ 88 (V6) and 15.8 @ 91 (V8)
30-50 was 3.8 (V6) and 3.9 (V8)
50-70 was 6.0 (V6) and 5.3 (V8)

My read of this is that the V8 gets off the line better but the V6 is pretty close once the revs come up (check the 1/4mi trap speed – nearly equal). The 0.7 second 0-60 is significant but with passing being so close I think it shows they aren’t too far off if you rev the V6.
Jeep's website shows 280 hp @6400 and 260 lb/ft @ 4800 for the V6. (only place I could find it is in the 'compare models' section and 'build your own'). It lists 357 hp @5800 and 390 lb/ft @ 4200 for the HEMI.

That's 28% more hp and 50% more torque. This is not a small increase - especially the torque, which is what really matters. I couldn't find exact-match dyno results (3.6 wrangler dyno, 5.7 unknown Chrysler vehicle dyno), but the indication is that HEMI seems to be have nearly as much torque available at low RPM as the 3.6 has at peak.

When I drive a semi-powerful vehicle, I tend to not use WOT very much. In fact, I don't like to have to go WOT in order to get moving. Reports here indicate that's what the 3.6 is like to drive - have to kick it down and rev it up to get moving. Feels like it has to try-hard. The numbers support this.

The 3.6 is a much newer design, of course, so it's far more efficient. But, it's not so efficient as to make up for the displacement. If the V8 were equally new, it'd probably be putting out over 400 hp and torque with better mileage. Makes me wonder when that's going to happen.
__________________
[O|||||||O]
Reply With Quote
  #67  
Old 10-09-2011, 04:30 PM
bigpanda's Avatar
Member
 
Join Date: Feb 2011
Posts: 321
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 1962
bigpanda has a reputation beyond reputebigpanda has a reputation beyond reputebigpanda has a reputation beyond reputebigpanda has a reputation beyond reputebigpanda has a reputation beyond reputebigpanda has a reputation beyond reputebigpanda has a reputation beyond reputebigpanda has a reputation beyond reputebigpanda has a reputation beyond reputebigpanda has a reputation beyond reputebigpanda has a reputation beyond repute
Re: Accelleration in the v8 vs v6

Pentastar is not bad. Actually, it could have been a lot better one with 6 or 7 speed trans.
__________________
Life is Good!!!:thumbsup:

2011 WK2 Overland 3.6 Euro Spec.
Reply With Quote
  #68  
Old 10-10-2011, 06:58 AM
Member
My Jeep: 2011 3.6L WK2
 
Join Date: Sep 2010
Location: Ottawa, Ontario
Posts: 962
Thanks: 32
Thanked 9 Times in 8 Posts
Rep Power: 2876
Cherodude has a reputation beyond reputeCherodude has a reputation beyond reputeCherodude has a reputation beyond reputeCherodude has a reputation beyond reputeCherodude has a reputation beyond reputeCherodude has a reputation beyond reputeCherodude has a reputation beyond reputeCherodude has a reputation beyond reputeCherodude has a reputation beyond reputeCherodude has a reputation beyond reputeCherodude has a reputation beyond repute
Re: Accelleration in the v8 vs v6

V6 certainly does not have to be driven routinely with WOT. Only when passing on two lane roads with short passing zones, and I would use WOT on any engine in such places.
__________________
2011 GC OL, Natural Green/Frost, QL, ORGII, 430N, Pano, GY WSA
Reply With Quote
  #69  
Old 10-11-2011, 11:33 AM
Technosavant's Avatar
Premium Member
My Jeep: 2011 3.6L WK2
 
Join Date: Jul 2010
Location: STL, MO area
Posts: 1,282
Thanks: 0
Thanked 3 Times in 2 Posts
Rep Power: 2818
Technosavant has a reputation beyond reputeTechnosavant has a reputation beyond reputeTechnosavant has a reputation beyond reputeTechnosavant has a reputation beyond repute
Re: Accelleration in the v8 vs v6

Quote:
Originally Posted by Oppy View Post

Any one catch that the brake sizes are the same dunno if they get the info from jeep or not. Kinda curious on the rotor sizes from v6 to v8.
I believe the rotors are the same size, but the calipers on the V8 models are larger (which is why 17" rims won't fit on a Hemi-equipped WK2).
__________________
Reply With Quote
  #70  
Old 10-11-2011, 11:40 AM
Member
 
Join Date: Mar 2011
Posts: 499
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 31560
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: Accelleration in the v8 vs v6

Quote:
Originally Posted by bigpanda View Post
Pentastar is not bad. Actually, it could have been a lot better one with 6 or 7 speed trans.
the v6 hunts and downshifts enough with a 5-spd. I wouldn't want a low torque motor in a high weight vehicle with a tranny with a lot of gears. The pentastars I drove were always shifting, either up or down. It was noticable and annoying. The Hemi I have hates to downshift but it stays in 1 gear (4th) for anything except highway and complete stops.
__________________
Reply With Quote
  #71  
Old 10-11-2011, 12:26 PM
Member
 
Join Date: Jul 2011
Posts: 235
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 1333
Terminator2 is on a distinguished road
Re: Accelleration in the v8 vs v6

Quote:
Originally Posted by vikingdave View Post
The answer has always been as clear cut as it gets, the V8 without a doubt. I expect that once magazines test V8's with the new transmission programming the difference in track times will be even larger.
This right here. The old programming Hemi was running in the 7.0-8.0 0-60 range. Mine with the updated programming ran 6.3 seconds 0-60 as tested with my HP Tuners scanner. Fastest run to date is 5.92 seconds with a few mods. Needs tuning though. Hopefully superchips or diablosport will have our tuning answer soon.
__________________
Reply With Quote
  #72  
Old 10-11-2011, 11:19 PM
New Member
My Jeep: 2011 5.7L WK2
 
Join Date: Sep 2011
Location: Minneola, FL
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
Oppy is on a distinguished road
Re: Accelleration in the v8 vs v6

Quote:
Originally Posted by Technosavant View Post
I believe the rotors are the same size, but the calipers on the V8 models are larger (which is why 17" rims won't fit on a Hemi-equipped WK2).
Ah, that would explain why no 17inch wheel will mount on my wife's laredo 4x4


As to the acceleration between the 2 I have only driven the hemi based jeeps, but my wife test drove a few v6s and thought that on the highway its a fine motor , but in stop and go, it needed more "nudging" to get back up to speed than the v8s ( these were all 4x4s ).
__________________

__________________
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


Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 11:48 AM.


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