4EAT - Power Brake Launch Hitting Rev Limiter - Subaru Forester Owners Forum
User Tag List

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
post #1 of 18 (permalink) Old 04-29-2010, 10:49 AM Thread Starter
Forum Member
 
Canonshooter's Avatar
 
Join Date: Dec 2006
Location: Bedford, NH
Posts: 1,967
Car Year: 2007
Car Model: Forester XT
Transmission: 4EAT
Gallery: 0
Feedback Score: 4 reviews
4EAT - Power Brake Launch Hitting Rev Limiter

I notice that when I power brake/launch that the engine hits the rev limiter before the 4EAT shifts into second gear. I have only "launched" this way once but with a trip to the strip scheduled for tomorrow evening, I'm hoping to get some feedback on the best way to overcome this. If I hammer it from a roll, there is no shifting issues.

My first thought is to launch as described above and as the tach crosses 6k RPM, do a quick off-blip of the throttle and see if that induces the shift.

The other thought is to launch in first and manually shift - though I'm not sure that will solve the problem.

Or, I could just roll out and then nail it, though my ET will no doubt suffer.

If I could get some insight on this before beating on my car any further, it would be appreciated!
Canonshooter is offline  
Sponsored Links
Advertisement
 
post #2 of 18 (permalink) Old 04-29-2010, 01:22 PM
 
Tuned200's Avatar
 
Join Date: Jan 2008
Location: Florence, KY
Posts: 21,693
Car Year: 2007
Car Model: FSXT / FSTI
Transmission: 4EAT / 6 MT
Gallery: 2
Garage
Feedback Score: 60 reviews
Jim, I have the same issues. The harder the launch, the more it delays on the 1-2 shift. Same results for rolling into it. While I dont think its normal, I will say mine has done the same exact thing.

I have also tried manually shifting it at 5k, with no improved results. My best time of 12.97 could have been down in the 12.8 or even 12.7's with a solid 1-2 shift. I have a trans cooler but im thinking the tcu needs programmed, which their is no programmer for them. So basically, after rambling, yea, mine does the same and I just roll with it(hard outta the hole)

2007 Forester STI - The Gray Goose
2007 XT Sport 4EAT - Maverick
2006 Forester XT -Sold- Blu-Blur
2010 Forester X - Sold-The Green Goblin
Tuned200 is offline  
post #3 of 18 (permalink) Old 04-29-2010, 03:33 PM Thread Starter
Forum Member
 
Canonshooter's Avatar
 
Join Date: Dec 2006
Location: Bedford, NH
Posts: 1,967
Car Year: 2007
Car Model: Forester XT
Transmission: 4EAT
Gallery: 0
Feedback Score: 4 reviews
Brian, does coming off the gas a touch induce the shift?
Canonshooter is offline  
post #4 of 18 (permalink) Old 04-29-2010, 05:24 PM
Forum Member
 
g00fy's Avatar
 
Join Date: Mar 2006
Location: Lake Hopatcong, NJ
Posts: 2,177
Car Year: 2005
Car Model: Forester XT
Transmission: 4EAT
Gallery: 0
Feedback Score: 3 reviews
I've had the same issue multiple times. Even with my built trans. However after my last rebuild by IPT i have not experienced the problem... However i haven't launched it much since the last rebuild...

Jr Tuned 35R'd 05XT Area1320 Block & IPT Race 4eat
g00fy is offline  
post #5 of 18 (permalink) Old 04-30-2010, 02:03 PM
 
Tuned200's Avatar
 
Join Date: Jan 2008
Location: Florence, KY
Posts: 21,693
Car Year: 2007
Car Model: FSXT / FSTI
Transmission: 4EAT / 6 MT
Gallery: 2
Garage
Feedback Score: 60 reviews
Jim, I really cant answer that. Im a hold it to the wood guy and I dont lift(unless their are problems.

My tip for the day.

Bring the following

Note pad.
Tire pressure gauge
Cheapo $10 walmart pressure sprayer(like for stain or bug stuff)

Keep an eye on tire pressure. Record it, also record what your times are and how the car ran and when it shifted after every run.

Use the new clean sprayer to help cool the car between runs, and even sit a bag of ice on the tmic and intake manifold.

2007 Forester STI - The Gray Goose
2007 XT Sport 4EAT - Maverick
2006 Forester XT -Sold- Blu-Blur
2010 Forester X - Sold-The Green Goblin
Tuned200 is offline  
post #6 of 18 (permalink) Old 04-30-2010, 03:51 PM
Forum Member
 
SkateandDestroy's Avatar
 
Join Date: Dec 2006
Location: New Jersey
Posts: 857
Car Year: 04
Car Model: XT 68HTA
Transmission: 12.20@113
Gallery: 0
Feedback Score: 2 reviews
I have the built IPT Trans and have never hit the rev limiter shifting manually. Only time it has happened was due to driver error. I've never ran the car in either "3" or "D" at the track so I can't say if that makes a difference though.

However I did just do the MultiPlate Transfer Clutch Lock-Up Switch today. I plan to test it at the track soon. Hopefully get my launches down from 2 to 1.7 with it.
SkateandDestroy is offline  
post #7 of 18 (permalink) Old 05-07-2010, 06:22 PM Thread Starter
Forum Member
 
Canonshooter's Avatar
 
Join Date: Dec 2006
Location: Bedford, NH
Posts: 1,967
Car Year: 2007
Car Model: Forester XT
Transmission: 4EAT
Gallery: 0
Feedback Score: 4 reviews
BTW, the one pass I took down the 1320 with the lame launch the tranny shifted just fine.
Canonshooter is offline  
post #8 of 18 (permalink) Old 05-07-2010, 07:17 PM
Forum Member
 
SkateandDestroy's Avatar
 
Join Date: Dec 2006
Location: New Jersey
Posts: 857
Car Year: 04
Car Model: XT 68HTA
Transmission: 12.20@113
Gallery: 0
Feedback Score: 2 reviews
Did you just leave it in "3" or "D"? Did you catch where it was shifting, was it going up to redline?
SkateandDestroy is offline  
post #9 of 18 (permalink) Old 05-07-2010, 09:45 PM
Forum Member
 
funkymonkey1002's Avatar
 
Join Date: Jan 2006
Location: Boston
Posts: 9,013
Car Year: 2004
Car Model: 2.5 XT
Transmission: 4eat
Gallery: 0
Feedback Score: 8 reviews
Quote:
Originally Posted by Canonshooter View Post
Brian, does coming off the gas a touch induce the shift?
Lifting off will get it to upshift. I'd launch in 1st as that will give you full MPT lockup. However, you have to shift quite a bit before you actually want the shift to occur. 1st and 2nd are just too close it seems. I really wish all 4eat equipped FXTs got the VTD center diff, the longer I have the car the more I hate the MPT setup. My mpt seems to be wearing out from all the 2nd gear snow drifting I've done the past few years.

04xt/4eat, 16g, STI bits and bobs
funkymonkey1002 is offline  
post #10 of 18 (permalink) Old 05-08-2010, 05:58 PM
Forum Member
 
Join Date: Dec 2009
Location: Tri-State NY/NJ/CT
Posts: 160
Car Year: 04/5
Car Model: FXT
Transmission: 6spd
Gallery: 0
Feedback Score: 0 reviews
Man that 07 6spd is starting to make its way to my car... The more I read the 4eat threads, the more I feel like I am going to blow up any AUTO I get.

Jr
juniorAWD is offline  
post #11 of 18 (permalink) Old 05-08-2010, 07:47 PM
Forum Member
 
funkymonkey1002's Avatar
 
Join Date: Jan 2006
Location: Boston
Posts: 9,013
Car Year: 2004
Car Model: 2.5 XT
Transmission: 4eat
Gallery: 0
Feedback Score: 8 reviews
Quote:
Originally Posted by juniorAWD View Post
Man that 07 6spd is starting to make its way to my car... The more I read the 4eat threads, the more I feel like I am going to blow up any AUTO I get.

Jr
imo the stock auto is stronger than the stock 5mt if you don't overheat it or split the front diff casing. If all FXT's came with the VTD, I'd take it over any of the manual offerings, but the MPT just ruins it for performance driving. I wish they had DCCD for the auto!

04xt/4eat, 16g, STI bits and bobs
funkymonkey1002 is offline  
post #12 of 18 (permalink) Old 05-08-2010, 11:30 PM
Forum Member
 
g00fy's Avatar
 
Join Date: Mar 2006
Location: Lake Hopatcong, NJ
Posts: 2,177
Car Year: 2005
Car Model: Forester XT
Transmission: 4EAT
Gallery: 0
Feedback Score: 3 reviews
Quote:
Originally Posted by juniorAWD View Post
Man that 07 6spd is starting to make its way to my car... The more I read the 4eat threads, the more I feel like I am going to blow up any AUTO I get.

Jr
Go for the gold and put a built LGT 5EAT w/sportshift in. I think you may also be able to get a front LSD for it too

Jr Tuned 35R'd 05XT Area1320 Block & IPT Race 4eat
g00fy is offline  
post #13 of 18 (permalink) Old 05-09-2010, 03:18 PM
Forum Member
 
Join Date: Dec 2009
Location: Tri-State NY/NJ/CT
Posts: 160
Car Year: 04/5
Car Model: FXT
Transmission: 6spd
Gallery: 0
Feedback Score: 0 reviews
Quote:
Originally Posted by g00fy View Post
Go for the gold and put a built LGT 5EAT w/sportshift in. I think you may also be able to get a front LSD for it too
Point me in the right direction. I just blew the stocker up.. Figures!
juniorAWD is offline  
post #14 of 18 (permalink) Old 05-09-2010, 03:26 PM Thread Starter
Forum Member
 
Canonshooter's Avatar
 
Join Date: Dec 2006
Location: Bedford, NH
Posts: 1,967
Car Year: 2007
Car Model: Forester XT
Transmission: 4EAT
Gallery: 0
Feedback Score: 4 reviews
Quote:
Originally Posted by SkateandDestroy View Post
Did you just leave it in "3" or "D"? Did you catch where it was shifting, was it going up to redline?
Left it in "3" the entire time. Didn't watch the tach but seemed to shift at the usual points.

FWIW, I very rarely get more than just a very short squeal from the front tires. It seems to transfer to the rear wheels very quickly.
Canonshooter is offline  
post #15 of 18 (permalink) Old 05-09-2010, 03:28 PM
Smooshed FOTY 2011
 
Blue Fox's Avatar
 
Join Date: Oct 2008
Location: Durango, Colorado
Posts: 5,387
Car Year: 2005
Car Model: Lifted 2.5 XT
Transmission: 5-Speed MT
Gallery: 0
Feedback Score: 3 reviews
I'm thinking it's due to the higher horsepower you guys are running. I've launched mine a few times, and it just goes to redline and shifts fine. You guys are running a lot of extra power, and running throughout the RPM range at a much higher rate of speed than stock. I'm thinking this could possibly be, in a word, "confusing" the system a bit as it gets to redline a hell of a lot faster than stock would. This, of course, is just a guess, but it seems that everyone having the issue all have high-horsepower modifications. Just a thought.

2004 XT - RIP
2005 XT - 5MT - 2" LIFT JOURNAL
Blue Fox is offline  
Sponsored Links
Advertisement
 
Reply

  Subaru Forester Owners Forum > Technical Forums and Vehicle Assistance > Engine Management, Tuning and Datalogging

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Subaru Forester Owners 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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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:

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 Search this Thread
Show Printable Version Show Printable Version
Email this Page Email this Page
Search this Thread:

Advanced Search
Display Modes
Linear Mode Linear Mode



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