First gear held to 75% throttle? [Archive] - Cherokee SRT8 Forum

: First gear held to 75% throttle?


GNXtoWS6
03-11-2007, 12:19 PM
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!

Black_SRT8
03-11-2007, 12:48 PM
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).

BuilderBill
03-11-2007, 01:11 PM
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.

HoustonSRT-8
03-11-2007, 01:36 PM
Oh yeah, don't believe anything quoted from Hennessey.

GotStroke?
03-11-2007, 02:00 PM
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?

Black_SRT8
03-11-2007, 02:28 PM
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/showpost.php?p=4474338&postcount=17

http://www.srtforums.com/forums/showpost.php?p=4474458&postcount=48

http://www.srtforums.com/forums/showpost.php?p=4474536&postcount=71

http://www.srtforums.com/forums/showpost.php?p=4474383&postcount=33

GotStroke?
03-11-2007, 02:40 PM
Thanks for the clarification!

BuilderBill
03-11-2007, 03:43 PM
Here you go bud... Four SRT Eng answers to the 75% question. The last link directly addresses your question.


http://www.srtforums.com/forums/showpost.php?p=4474338&postcount=17

http://www.srtforums.com/forums/showpost.php?p=4474458&postcount=48

http://www.srtforums.com/forums/showpost.php?p=4474536&postcount=71

http://www.srtforums.com/forums/showpost.php?p=4474383&postcount=33
Amazing....great research. On our own again as usual. Thanks engineers.

FastSRT8GC
03-11-2007, 06:38 PM
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.

GNXtoWS6
03-12-2007, 09:11 AM
Great info guys, I think I am going to really like this forum!

GRNENVY
03-12-2007, 07:53 PM
Yeah I need to try pulling that fuse tomarrow like you showed me.
Yo dude your truck sounded really good today. Funny thing my neibor instant mess me asked me if I did my exhaust. lolol Lets hit Bradenton thursday nite see what these trucks can do.




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.