Q: Want Feedback on AT Shifting on the Track.... - TCCoA Forums
 
LinkBack Thread Tools
post #1 of 7 (permalink) Old 06-12-2011, 10:28 AM Thread Starter
Seasoned PostWhore
 
S4gunn's Avatar
 
Join Date: Dec 2010
Location: SF, CA
Age: 41
Posts: 2,613
Garage
Q: Want Feedback on AT Shifting on the Track....

As I mentioned in my main thread and my cooling thread, my 24 Hours of Lemons team took out our tbird for the first time on the track this past Friday. It worked way better than we expected.

While perhaps more of an annoyance and performance limitation than an overall realiability concern, we experienced some annoying behavior from our 4R70W transmission in this 95 Ford Thunderbird that I wanted to check in with you folks on...

NON ISSUES
1) Cooling: Using our A/C condensor as an ATF cooler worked awesomely. On the highway, our ATF temps were ~150. On the track, it stayed mostly at 180F and barely peaked over 200F under the worst condition. We aren't worried about this part of the transmission system.
2) JMOD worked perfectly fine.

CONCERN
3) Car doesn't upshift at WOT as often as we want.
Alan @ Dirty Dog was right. At least at Thunderhill, we spent a LOT of time in 2nd. One slightly annoying thing was that on some of the straights, the stupid transmission wouldn't shift into 3rd even at ~4000+RPM without us letting off the gas and hammering back down the pedal. At that point, we would be pretty much running ~80MPH and the engine was definitely struggling to accelerate the car beyond that speed (likely b/c we were pretty far outside our power band). It took a little practice but eventually we could get the car to decide to upshift when we wanted and and everything would be fine.

Q: Do you guys think replacing the gears and going from 3.27:1 to 3.73:1 (so the engine will spin ~15% faster for the same speed and the car will want to upshift more often) help up address this concern? My guess is that we'd trade potential reliability (we know our 3.27 rear diff works, we've never modified a diff before so we are introducing a new point of failure) for increased acceleration and the car potentially spending more time in 3rd than 2nd.

From what I understand, this might not be an issue at Infineon b/c the track is MUCH more curvy with fewer straights. Esp if we risk screwing things up by mucking around inside our rear pumpkin. The team is divided but i'm personally leaning towards the "if it aint broke, let's not try and fix it BEFORE our Lemons debut."


Thanks in advance for your comments.
Regards,
-g

My TCCOA iTrader Rating: (44 / 100% w/ 50+ transactions)

24 Hours of Lemons 2017 Sear Pointless Organizer's Choice
2018 Upgrade: does your TBIRD make Fritos? Mine does
http://goo.gl/csaet4
S4gunn is offline  
Sponsored Links
Advertisement
 
post #2 of 7 (permalink) Old 06-12-2011, 10:59 AM
PostWhore
 
driller's Avatar
 
Join Date: Nov 2005
Location: Morgantown, WV
Posts: 1,266
Send a message via AIM to driller
Can you change your tire size?
driller is offline  
post #3 of 7 (permalink) Old 06-12-2011, 11:20 AM Thread Starter
Seasoned PostWhore
 
S4gunn's Avatar
 
Join Date: Dec 2010
Location: SF, CA
Age: 41
Posts: 2,613
Garage
If you are talking about going from 15" wheels to 17", we could but we aren't willing to due to cost.


If you are talking about the overall diameter of the tires (while still remaining on a 15" wheel), that's our plan.
http://forums.tccoa.com/showthread.php?t=135611

My TCCOA iTrader Rating: (44 / 100% w/ 50+ transactions)

24 Hours of Lemons 2017 Sear Pointless Organizer's Choice
2018 Upgrade: does your TBIRD make Fritos? Mine does
http://goo.gl/csaet4
S4gunn is offline  
Sponsored Links
Advertisement
 
post #4 of 7 (permalink) Old 06-12-2011, 11:51 AM
PostWhore
 
driller's Avatar
 
Join Date: Nov 2005
Location: Morgantown, WV
Posts: 1,266
Send a message via AIM to driller
Yep, tire diameter.
driller is offline  
post #5 of 7 (permalink) Old 06-12-2011, 12:43 PM
No, Mr. Lemmywinks, No!!!

Moderator
 
Grog6's Avatar
 
Join Date: Jun 2005
Location: Harriman, TN
Age: 56
Posts: 10,039
Garage
I'd go the rear end route, if it was me.

The tranny planetaries aren't fully lubed in 1st and 2nd, only in 3rd and 4th, from a post SirWill made years ago.

Slammin in 2nd will eventually fry that planetary, imho.

Maybe it's not as much of a problem as I think...

Red '96 Cougar XR-7 240k mi. '02 4R70W, PST DS : '03 PI engine, 04 maf, 24lb injectors, 2.5" exhaust, '02 4r70w + Jmod, DirtyD0g TC + cooler + 3/8" lines, 255 walbro fp. Alpine system.
Black '96 Cougar XR-7 (Lazarus) 210k mi PI Intake, '02 4R70W, Jmod, PST DS, GrogTune, Konis, Mark LCA+Poly, racecougar Custom Engine Chain, and JL and racecougar Bracing.
Black '97 Tbird Limited Edition, '02 4R70W, 255 walbro, PST DS, PBR Brakes&SS lines, Toicko Blues & Springs, GrogTune.


"War Is Peace. Freedom Is Slavery. Ignorance Is Strength." - George Orwell.
Truth Isn't Truth. - Rudy Giuliani, 2018 Award winner, “Most Outrageous Diversion” by MSNBC for this quote
Grog6 is offline  
post #6 of 7 (permalink) Old 06-12-2011, 01:47 PM
PostWhore
 
driller's Avatar
 
Join Date: Nov 2005
Location: Morgantown, WV
Posts: 1,266
Send a message via AIM to driller
Quote:
Originally Posted by Grog6 View Post
I'd go the rear end route, if it was me.

The tranny planetaries aren't fully lubed in 1st and 2nd, only in 3rd and 4th, from a post SirWill made years ago.

Slammin in 2nd will eventually fry that planetary, imho.

Maybe it's not as much of a problem as I think...
How you get there is a variable, but I agree that you would want to be in 3rd most of the time.
driller is offline  
post #7 of 7 (permalink) Old 06-12-2011, 10:36 PM
PostWhore
 
Join Date: Apr 2008
Posts: 1,716
Send a message via Yahoo to 94 Thunderbird XX
Quote:
Originally Posted by S4gunn View Post
....we've never modified a diff before so we are [potentially] introducing a new point of failure....... Esp if we risk screwing things up by mucking around inside our rear pumpkin.
IMO, the IRS 8.8 ranks right up there with the Ford 9" and the Mopar 8 3/4 in the ease of setup....if for no other reason than you can do it with the relative comfort of having it up on a sturdy workbench.

You don't want to setup a Dana 60. lol

Delete my account.
94 Thunderbird XX is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the TCCoA Forums 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











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

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