First gear held to 75% throttle? - Cherokee SRT8 Forum
WK1 General Performance Discussion If you are planning on modifying your Jeep Grand Cherokee SRT8 with a performance enhancing modification, this is the section to post about it.

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 11 (permalink) Old 03-11-2007, 11:19 AM Thread Starter
Junior Member
 
Join Date: Mar 2007
Location: Portland OR
Posts: 27
Thanks: 0
Thanked 0 Times in 0 Posts
First gear held to 75% throttle?

Interesting article about the Hennessey SRT600 even though it fried the converter on the test. You would have to be insane to buy anything from them. Sorry I could not post the URL, this site won't let you until after 4 posts. Here is an excerpt;

"To the SRT8s already formidable 420-hp V-8, Hennessey Performance Engineering adds an even 200 as part of the $27,900 SRT600 package, which is available for any 6.1- or 5.7-liter Hemi (5.7s make 550 horsepower) and comes with a two-year engine warranty. The extra power comes courtesy of a Garrett turbo mounted underneath the transmission pushing six pounds of boost, an air-to-air intercooler, and an upgraded fuel-pump-and-pressure regulator. Rods and pistons are replaced, the engine is bored out slightly, adding 59cc, and the compression ratio is reduced from 10.3:1 to 9.5. Flow through the ported-and-polished cylinder heads increases by a claimed 20 percent. The factory engine computer is reprogrammed to up the fuel delivery accordingly and allow the throttle to open all the way. Stock SRT8s electronically limit the throttle to 75 percent in first gear, and Hennessey claims the throttle mod alone, available by itself for $895, is worth 0.1 second in acceleration times."



Note the comment about the SRT8 first gear throttle being held to 75%. Is this taken care of by the B&G tuning? Hennessey sells something for $895 to overcome it?????

I am a newbie and did search so forgive my SRT8 ignorance. I just bought a BLack 07 online and I'm trading in my 05 SRT10 Quad Cab. I have the B&G tune on my SRT10 and it makes a huge difference on the truck. It sounds like it does not make the same impact on the SRT8's. I do know I want that extra 25% throttle in 1st gear though.

I have to say how impressed I was on test drives of these GC SRT8's, it would smoke my truck on a stop light to stop light run and thus I have to have one!
GNXtoWS6 is offline  
Sponsored Links
Advertisement
 
post #2 of 11 (permalink) Old 03-11-2007, 11:48 AM
Major Contributing Member
 
Black_SRT8's Avatar
 
Join Date: Jul 2006
Location: Rollingstone, USA
Posts: 1,057
Thanks: 0
Thanked 0 Times in 0 Posts
Re: First gear held to 75% throttle?

SRT Eng's say it is a myth. The misconception is attributed to the use of aftermarket diagnostic tools (instead of using the factory Starscan).
Black_SRT8 is offline  
post #3 of 11 (permalink) Old 03-11-2007, 12:11 PM
Elite Contributing Member
 
BuilderBill's Avatar
 
Join Date: Nov 2006
Location: Charlotte, North Carolina
Posts: 5,781
Thanks: 235
Thanked 881 Times in 395 Posts
Re: First gear held to 75% throttle?

Quote:
Originally Posted by Black_SRT8
SRT Eng's say it is a myth. The misconception is attributed to the use of aftermarket diagnostic tools (instead of using the factory Starscan).
Great answer. I remember reading that also.
BuilderBill is offline  
post #4 of 11 (permalink) Old 03-11-2007, 12:36 PM
Elite Contributing Member
 
HoustonSRT-8's Avatar
 
Join Date: Dec 2006
Location: Cypress, TX
Posts: 5,291
Thanks: 52
Thanked 449 Times in 301 Posts
Garage
Re: First gear held to 75% throttle?

Oh yeah, don't believe anything quoted from Hennessey.

Steve
'15 Black over Red Vapor WK2 SRT-8 (It's got a trunk mat!)
SOLD '06 Silver WK1 SRT-8 (Borla Type-S, Predator, K&N, Eibachs, S6M Shocks, JBA A-arms, 275/315)
'06 White E55 (STAR dropped, iForged Imolas, Eurocharge tune, HE - 483whp)
'94 Black Mustang GT (cam bearings spun/scored...new HCI 331 stroker coming soon)

PITTZ said I am special
HoustonSRT-8 is offline  
post #5 of 11 (permalink) Old 03-11-2007, 01:00 PM
Banned
 
Join Date: Aug 2006
Posts: 2,169
Thanks: 0
Thanked 0 Times in 0 Posts
Re: First gear held to 75% throttle?

Jamie,
Didn't the DCX engineers also mention something about the trans not being able to calculate the 1-2 upshift quickly enough at 100% WOT in first, also that they wanted to keep the trans/driveline intact?
GotStroke? is offline  
post #6 of 11 (permalink) Old 03-11-2007, 01:28 PM
Major Contributing Member
 
Black_SRT8's Avatar
 
Join Date: Jul 2006
Location: Rollingstone, USA
Posts: 1,057
Thanks: 0
Thanked 0 Times in 0 Posts
Re: First gear held to 75% throttle?

Quote:
Originally Posted by GotStroke?
Jamie,
Didn't the DCX engineers also mention something about the trans not being able to calculate the 1-2 upshift quickly enough at 100% WOT in first, also that they wanted to keep the trans/driveline intact?

Here you go bud... Four SRT Eng answers to the 75% question. The last link directly addresses your question.


http://www.srtforums.com/forums/show...8&postcount=17

http://www.srtforums.com/forums/show...8&postcount=48

http://www.srtforums.com/forums/show...6&postcount=71

http://www.srtforums.com/forums/show...3&postcount=33
Black_SRT8 is offline  
post #7 of 11 (permalink) Old 03-11-2007, 01:40 PM
Banned
 
Join Date: Aug 2006
Posts: 2,169
Thanks: 0
Thanked 0 Times in 0 Posts
Re: First gear held to 75% throttle?

Thanks for the clarification!
GotStroke? is offline  
post #8 of 11 (permalink) Old 03-11-2007, 02:43 PM
Elite Contributing Member
 
BuilderBill's Avatar
 
Join Date: Nov 2006
Location: Charlotte, North Carolina
Posts: 5,781
Thanks: 235
Thanked 881 Times in 395 Posts
Re: First gear held to 75% throttle?

Quote:
Originally Posted by Black_SRT8
Amazing....great research. On our own again as usual. Thanks engineers.
BuilderBill is offline  
post #9 of 11 (permalink) Old 03-11-2007, 05:38 PM
Major Contributing Member
 
FastSRT8GC's Avatar
 
Join Date: Feb 2007
Location: TAMPA, FL
Posts: 1,429
Thanks: 0
Thanked 0 Times in 0 Posts
Re: First gear held to 75% throttle?

I am sure something is being limited in first. If you remove the ABS/Traction Control, First gear is a totally different animal. You can tell something is being held back by the computer. Try it, I am 99% sure it has more go w/o TCM.
FastSRT8GC is offline  
post #10 of 11 (permalink) Old 03-12-2007, 08:11 AM Thread Starter
Junior Member
 
Join Date: Mar 2007
Location: Portland OR
Posts: 27
Thanks: 0
Thanked 0 Times in 0 Posts
Re: First gear held to 75% throttle?

Great info guys, I think I am going to really like this forum!

2007 GC SRT8 Black K&N, snorkel, B&G computer
GNXtoWS6 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Cherokee SRT8 Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Throttle response? HoustonSRT-8 WK1 Troubleshooting / Problems Discussion / Dealer Service 10 05-06-2007 06:39 PM
Break-in Procedures AaronC WK1 SRT8 General Discussion 2 08-05-2006 07:03 AM
Just got a 2nd, 3rd, & 4th gear Dyno MegaSRT-8 WK1 Tuning/CMR/Dyno/DataLogging/Gauges 4 03-22-2006 08:43 AM

Posting Rules  
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome