V-10 Killer

iTrader: (22)

I'm seriously considering swapping out my A4 for a TH400, but was wondering about how to avoid running out of gear at the end of the quarter. I really don't like the "just burn through money and keep changing parts til you get it" method.
Is there a sticky or database or useful link anyone could give me to help me figure out roughly how much tire size/RPM/gearing/trans gear relate?

Example input:
26" ET Drag
3.73 rear gear
1:1 ratio 3rd gear
3600-3800 stall tight converter

What output would the shift RPM's be?

If I changed to a 27" M/T or 28" ET Drag, or went up or down in rear axle ratio, how much would that affect the RPM's?

It there any info on how much shift extension you'd expect from a power adder (percentage or something)?

V-10 Killer

iTrader: (22)

Oops, found the sticky in gears and axles section.
F-body.org link still works and tells the approximate mph per gear.
Now to figure out how much shift extension will skew it.

01ssreda4

iTrader: (96)

Why would you want to lose 4th gear and lock up?

V-10 Killer

iTrader: (22)

Because for going on 5 years now, I've had issues tuning this thing, with the way it interacts with the PCM. The best my car has run was in 2006. Professional (opinions vary on this one I guess) tuning has not helped. Sometimes it will downshift when I hammer it, sometimes it doesn't. I'm just flat out tired of going from 11.1's N/A to 12.8's because of the computer part of it. I'm down to driving it ~500 miles a year because it's so frustrating. I'll pay for the trans swap and extra gas to get something that I won't have to PUSH into the 9's.

01ssreda4

iTrader: (96)

Wow, sorry to hear about your bad luck. However, have you considered maybe its an internal trans problem? Is it a built tranny? And how many tuners have worked on the car? What kind of converter are you currently running?

jakeshoe

iTrader: (14)

Sounds odd.
I would look at the internal trans aspect as well.
A low 11 second car is within the capabilites of running the 4L60E reliably if it's built right.

I can show you a method to eliminate the PCM from controlling the trans temporarily and you can manually shift it and see if it reacts like it should.

As much as I like a TH400 for it's simplicity I would recommend a 4L80E and retaining the electronic control, OD, lockup, etc if you are going to swap.

V-10 Killer

iTrader: (22)

It's a FLT Level 5 4L65E. The converter's a TCI 3800 Comp converter (2.6 STR for spray). I exchanged some e-mails months back with Chuck and Vince about it and if I remember, they also felt it was in the PCM shift command. The car will easily lift the front tires, and pull's 1.5x and 1.60x 60' times. I think that's pretty good for a 3600# car and tight converter.
What sucks is that it does it's been doing its own shifting at 5k rpm's in first-second, jumps thru 2nd reql quick (5k rpm shift again), and uses 3rd. When at 75 mph, it drops into 4th (5k again) and the TCC locks up. I have it disabled in the tune, so I can't figure it out. It's not meeting EITHER of the requirements in the WOT shift tables.
I have the utmost faith in FLT and their work, but I've had it with this PCM controlled shift crap.
I guess I could consider a manual valvebody for it......

V-10 Killer

iTrader: (22)

I wholeheartedly agree that the 4L80 is the best trans for this type of heavy strip plus streetability application. But I just spent ~$24k remodeling my house, and the funds just aren't there for that conversion.
This trans, when I leave it in a specific gear, I can run it up as high as I want, but if in PCM control, it shifts at 5k.
For example, last night, I left it in 3rd, and it did two 5k shifts, and ran to 5900 before I let out.

Oh btw, I think I'm also a bit jaded because last night, after 75 flashes trying to get it to shift right, I fried my PCM

Anniversary "Z"

iTrader: (26)

You will literally feel the load come off your back when you put in a tune that says your car is a manual