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 07-16-2012, 12:21 AM
JeremyJamesDec15's Avatar
Member
My Jeep: 2012 5.7L WK2
 
Join Date: Jul 2012
Location: Akron, Ohio
Posts: 27
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 797
JeremyJamesDec15 is on a distinguished road
Exclamation How to get HP at the tires?

I have a 2012 WK2 overland summit with the 5.7, I have added a Mopar Cold Air Intake, A Corsa Cat Back Exhaust, I am rumming Royal Purple oil in it. No matter what I do it seems like I am not gaining or cant feel any extra HP. I previously had a 08 WK with the 5.7 which had ALOT! more balls then my 2012. I know they dropped the gearing down to get better gas milage, but my 5.7Hemi feels like a v6 on a good day.

Any comments or help here?
__________________

__________________
Jeremy James
Reply With Quote
  #2  
Old 07-16-2012, 06:04 AM
Member
 
Join Date: Mar 2011
Posts: 499
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 31600
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: How to get HP at the tires?

just need to wait for a tuner. Intake and exhaust is probably only a few HP anyway, probably won't feel it.
__________________

__________________
Reply With Quote
  #3  
Old 07-16-2012, 08:36 AM
JeremyJamesDec15's Avatar
Member
My Jeep: 2012 5.7L WK2
 
Join Date: Jul 2012
Location: Akron, Ohio
Posts: 27
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 797
JeremyJamesDec15 is on a distinguished road
Re: How to get HP at the tires?

But would a tuner even do much since it's geared so low. A tuner can change the axle gearing.
__________________
Jeremy James
Reply With Quote
  #4  
Old 07-16-2012, 09:35 AM
Member
My Jeep: 2011 5.7L WK2
 
Join Date: Jan 2012
Location: Clifton, VA
Posts: 217
Thanks: 5
Thanked 2 Times in 2 Posts
Rep Power: 1158
montgb is on a distinguished road
Re: How to get HP at the tires?

Apparently B&G Performance is stating that they can tune the 5.7L WK2 in addition to the SRT8. Check the WK2 SRT8 forum for more details.

Edit: Here you go - 2012 jEEP srt8 Flashed ECU WOW!!
__________________
2011 70th Anniversary WK2 5.7L HEMI | Bronze Star Pearl
| Volant CAI | Corsa Cat-back Exhaust | FR Ported Throttle Body | Altitude Front Grill | Altitude Rear Brow | Altitude Headlights
Reply With Quote
  #5  
Old 07-16-2012, 01:53 PM
Member
 
Join Date: Mar 2011
Posts: 499
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 31600
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: How to get HP at the tires?

Quote:
Originally Posted by JeremyJamesDec15 View Post
But would a tuner even do much since it's geared so low. A tuner can change the axle gearing.

The Hemi leaves a lot on the table with the piss poor programming. A tuner cannot change rear end ratios but will make a big enough power increase to have you feel it right away. Plus, changing shift points and other settings will greatly alter the way the vehicle runs and feels. They also allow for other mods such as cams and forced induction, you cannot do that now without the tuner.
__________________
Reply With Quote
  #6  
Old 07-16-2012, 04:54 PM
ColdCase's Avatar
Senior Member
 
Join Date: Apr 2011
Posts: 1,445
Thanks: 0
Thanked 26 Times in 25 Posts
Rep Power: 26439
ColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond repute
Re: How to get HP at the tires?

The tranny shift points are the biggest culprit with regards to how good the V8 feels, and a tuner can alter the shift points and make them stiffer.

Unfortunately, and its pretty well known, throwing a CAI or exhaust on the new JGCs does nothing for performance, they are simply noise makers. Although there may be a difference felt initially, the computer will adjust it back to pretty much stock after a few ignitions cycles.

Personally, mine jumps off the line with authority, certainly not a V6. It is the slow cruising throttle response that's annoying to me, along with the delayed down shifts. Running in sport mode 5th or in tow/haul mode does wonders to feel and driving satisfaction with a corresponding significant hit in mpg. My Hemi did not loosen up to around 10,000 miles, however.

Oh, always use mid or high octane for max performance, and switch to synthetic oil.
__________________
Reply With Quote
  #7  
Old 07-16-2012, 05:22 PM
Member
My Jeep: 2007 6.1L WK
 
Join Date: Feb 2012
Posts: 21
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 933
Tim H Calgary is on a distinguished road
Re: How to get HP at the tires?

Catback does nothing performance wise. CAI isn't much of a gain either depending on how restrictive the intake is. My original round of mods (headers, exhaust, cam and a CAI only gave me about 40whp with a CMR tune from Johan. If I could do it over again I would just go straight to the SC. Just my 2 cents.
__________________
Reply With Quote
  #8  
Old 07-16-2012, 07:51 PM
Member
My Jeep: 2011 5.7L WK2
 
Join Date: Jan 2012
Location: Clifton, VA
Posts: 217
Thanks: 5
Thanked 2 Times in 2 Posts
Rep Power: 1158
montgb is on a distinguished road
Re: How to get HP at the tires?

Quote:
Originally Posted by Tim H Calgary View Post
Catback does nothing performance wise. CAI isn't much of a gain either depending on how restrictive the intake is. My original round of mods (headers, exhaust, cam and a CAI only gave me about 40whp with a CMR tune from Johan. If I could do it over again I would just go straight to the SC. Just my 2 cents.
I assume you're just talking about the effects of a cat-back on the WK2, which would provide a bump of about 7-12whp. In other cases, I've seen a cat-back unleash 25+whp, especially when secondary cats and/or resonators are eliminated.
__________________
2011 70th Anniversary WK2 5.7L HEMI | Bronze Star Pearl
| Volant CAI | Corsa Cat-back Exhaust | FR Ported Throttle Body | Altitude Front Grill | Altitude Rear Brow | Altitude Headlights
Reply With Quote
  #9  
Old 07-16-2012, 08:46 PM
JeremyJamesDec15's Avatar
Member
My Jeep: 2012 5.7L WK2
 
Join Date: Jul 2012
Location: Akron, Ohio
Posts: 27
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 797
JeremyJamesDec15 is on a distinguished road
Question Re: How to get HP at the tires?

Quote:
Originally Posted by ColdCase View Post
The tranny shift points are the biggest culprit with regards to how good the V8 feels, and a tuner can alter the shift points and make them stiffer.

Unfortunately, and its pretty well known, throwing a CAI or exhaust on the new JGCs does nothing for performance, they are simply noise makers. Although there may be a difference felt initially, the computer will adjust it back to pretty much stock after a few ignitions cycles.

Personally, mine jumps off the line with authority, certainly not a V6. It is the slow cruising throttle response that's annoying to me, along with the delayed down shifts. Running in sport mode 5th or in tow/haul mode does wonders to feel and driving satisfaction with a corresponding significant hit in mpg. My Hemi did not loosen up to around 10,000 miles, however.

Oh, always use mid or high octane for max performance, and switch to synthetic oil.
I only have 2500 miles on mine but I am running Royal Purple full synthetic oil in it. According to the owners Manual it states in RED BOLD print to not use premium fuel in it, it states to use 89 or 87 which I use 89. Will premium fuel harm the jeep and or what are the positives and negitives to using premium fuel?
__________________
Jeremy James
Reply With Quote
  #10  
Old 07-16-2012, 09:00 PM
ColdCase's Avatar
Senior Member
 
Join Date: Apr 2011
Posts: 1,445
Thanks: 0
Thanked 26 Times in 25 Posts
Rep Power: 26439
ColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond reputeColdCase has a reputation beyond repute
Re: How to get HP at the tires?

Quote:
Originally Posted by montgb View Post
I assume you're just talking about the effects of a cat-back on the WK2, which would provide a bump of about 7-12whp. In other cases, I've seen a cat-back unleash 25+whp, especially when secondary cats and/or resonators are eliminated.
I've seen my share of interpreted/manipulated dyno charts.. like statistics, you can present the same results in a number of ways to prove about anything...

Is that gain peak or across the board, immediately after install, a ECU reset or after at least 10 engine hours, 10 ignition cycles. Same temp/humidity, different days? What about torque?

I've read that anything +/- 10% is within margins of error and therefor pretty meaningless. The same engine/setup will run 10hp different from day to day for this type of engine. The data collected for the dyno charts I've seen was collected using flawed procedures, most conveniently leave out important fine print and are probably not worth the paper they are printed on.... except for perhaps marketing.
__________________
Reply With Quote
  #11  
Old 07-16-2012, 09:06 PM
JeremyJamesDec15's Avatar
Member
My Jeep: 2012 5.7L WK2
 
Join Date: Jul 2012
Location: Akron, Ohio
Posts: 27
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 797
JeremyJamesDec15 is on a distinguished road
Re: How to get HP at the tires?

Quote:
Originally Posted by ColdCase View Post
I've seen my share of interpreted/manipulated dyno charts.. like statistics, you can present the same results in a number of ways to prove about anything...

Is that gain peak or across the board, immediately after install, a ECU reset or after at least 10 engine hours, 10 ignition cycles. Same temp/humidity, different days? What about torque?

I've read that anything +/- 10% is within margins of error and therefor pretty meaningless. The same engine/setup will run 10hp different from day to day for this type of engine. The data collected for the dyno charts I've seen was collected using flawed procedures, most conveniently leave out important fine print and are probably not worth the paper they are printed on.... except for perhaps marketing.
All I know is for the 1500 bucks I spent on a CAI and a Cat back I was hoping to notice something. But most my Tech's at the dealership say the axle is just geared so low for fuel economy that there is not alot I can do to "feel' the additional HP. All I know is my 08 5.7 WK had twice the balls so it felt like it.
__________________
Jeremy James
Reply With Quote
  #12  
Old 07-16-2012, 09:17 PM
JeremyJamesDec15's Avatar
Member
My Jeep: 2012 5.7L WK2
 
Join Date: Jul 2012
Location: Akron, Ohio
Posts: 27
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 797
JeremyJamesDec15 is on a distinguished road
Re: How to get HP at the tires?

I really cant wait till a tuner comes out. I dont like the idea if sending my computer out to get flashed or what not. Yea it may work but for once I am down without my jeep, two I personally dont know the guy messing with the computer on my $50K jeep and three it's not like with a tuner where if I can go back to stock by simply pulling out my tuner and reflashing it on my own. No offence to you if your one of the guys doing this work.
__________________

__________________
Jeremy James
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
Has anybody put SRT wheels/tires on an Overland? Do tires stick out at all? Thx elp_jc Suspension/Driveline/Brakes/Wheels/Tires 42 10-10-2013 11:03 AM
Lift & Tires or Wheels & Tires zrlee Suspension/Driveline/Brakes/Wheels/Tires 2 08-03-2011 11:58 PM
Difference between factory-installed Limited 18" tires vs. Offroad Group 18" tires? rb3wreath Suspension/Driveline/Brakes/Wheels/Tires 2 07-12-2011 11:28 AM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 10:09 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