3.4 5 Speed Video

[White93z34]

I just don't think a 3.4 even CAn do a 2nd gear start....

 

i've seen it i saw a 3.4 ste with that switch before

[Aaron]

I just don't think a 3.4 even CAn do a 2nd gear start....

 

i've seen it i saw a 3.4 ste with that switch before

 

I can do it in my 5-speed but I have to ride my clutch a bit, and it still feels like it is gonna stall.

 

The 3.4 just isn't a motor that you 2nd gear start in.

[99RegalGS]

at the junkyard yesterday I saw a GTP with a 2nd gear start switch.

 

And I agree with Aaron, the 3.4 doesn't like to start in 2nd.

[BIGBULS]

Ok..............so I have been pretty busy the last couple of days but let me get this straight.

 

Normal upshifts (under WOT) are at the following speeds:

 

1-2 @41mph

2-3 @80mph

3-4 @104mph

 

These don't quite match up with the video posted earlier by Grandprix34, as his shifts were at an INDICATED 44mph for 1-2, 81mph for 2-3 and held 3rd gear to 104mph with no upshift (I wonder how accurate the speedometer is?.............most modern GM speedo's ARE pretty accurate). Also, how much lag is there in the tranny/torque convertor? Because if it's getting the signal to snap off the 1-2 shift at 41mph (from the PCM) and actually DOES IT at 44mph, then we need to readjust those shift speeds that Grandprix34 wants to use. Perhaps since he wants to raise his 1-2 shift from an INDICATED 43-44mph/6300rpm to 47mph/6700rpm, he should set the ACTUAL (PCM programmed) shift speed at 44mph (since there SEEMS to be a ~3mph lag)? Make sense? There also appears to be a ~1mph lag for the 2-3...........so since *I* recomended 83mph/6250-6300rpm (to keep the tranny within it's limits), perhaps he should look at 82mph? I would still move the 3-4 to 125mph/6000rpm though..............104mph is just stupid (you are BARELY over 5K rpm at that point).

 

A little testing may be in order to match programmed shift speeds to the ACTUAL rpm of the shift (especially for 1-2).............and I'm SURE Grandprix34 would be happy to do it

 

 

 

As for the performance shift idea.................I would RUN with it. Not that many people use the 2nd gear start feature as it is, and it DOES generate a LOT of heat (hard on the trans)....................so turning it into a performance shift feature is a GREAT idea (for those that have it wired up).

 

If you guys CAN get a performance program, I would simply set the standard (normal mode) shiftpoints at the tranny's max (6500rpm 1-2 [~45.5mph...........it's right between 45 and 46 ], 6250rpm 2-3 [~82.5-83mph], 6000rpm 3-4 [~125mph]) and then go for MAX performance in the "performance mode"...............7K rpm 1-2, 6700rpm 2-3 and 6500rpm 3-4 (with a waver stating that your trans should be 100% before using this ..............or just maybe sandbag on the shifts a little [offering a *little* less performance].......maybe 6800 1-2, 6500 2-3 and 6200 3-4).

 

Like I said, some testing may be needed, but there is an opportunity here to REALLY make the most of the 60-E.

 

 

 

There is also the issue of kickdown speeds.............it appears that these are currently set at (under WOT):

 

2-1 @35mph (or is it 28mph?...the charts are weird)

3-2 @74mph

4-3 @94mph

 

Now..............raising these (especially when you have higher shiftpoints) is going to make the trans much more agressive and faster reacting.

 

First off, I'd look into allowing a gear skipping feature under WOT kickdowns, allowing the trans to go from 3rd directly to 1st, and 4th down to 2nd (it currently goes 3-2-1 and 4-3-2). DHP does this on the OBDII PCM's and it's reportedly a GREAT feature for passing, and just offers faster reactions to what your right foot commands.

 

Next I'd look at raising the kickdowns a bit. I'd set the 2-1 (or 3-1) kickdown to within ~6-8mph of the upshift speed (so if you have a 44mph 1-2 shift, set the kickdown at 36-38mph). For 3-2 (or 4-2) I'd go even a litle closer.........4-6mph below and about the same for 4-3.

 

 

 

Finally...............I notice a gear hold setup (at least that's what I think it is) in the stuff at the bottom (of the excell chart).............it says it won't allow the car to go into kickdown mode (in "L".......probably "1" or "2" on the 7 position trannies) at anything below 96-98% TPS signal. I'd move this to 100% making "2" into a TRUE 2nd gear (although the car will still START in 1st).......................then you'd have a VERY nice setup for autocrossers. All you'd need is a litle finessing of the PCM gear selection speeds (it appears to go to 1st at anything below 35mph and 2nd at anything above) to match your new WOT shiftpoints.

 

 

 

Does all of this make sense to you guys? Also, do you (any of you) see any holes in my logic?

 

 

 

 

 

 

 

And for Grandprix34.

 

Read that first section of this post CLOSELY. You might just want to set your 1-2 shift at 44mph (as the PCM sees it) to get that 6700rpm 1-2 shift we were talking about. And then set 2-3 at 82mph, and leave 3-4 at 125..........

 

Like I said..........it may take some "testing" (i.e. a few attemptws to get it right).

 

[Vegeta]

Im not sure I can do a skip shift, at least I didnt see anything in the data tables to allow it. Its probably OBD2 only. The speedo is wrong most likely, at least within 3 mph. Also, I remove the spark retard that GM puts in for shifts, maybe that keeps it from shifting? I was told it shifts faster without it though so I dunno. I woud really like to have a car here to do testing with so I can see for myself what it does. It would be best to see what the computer sees the RPM as being when it shifts instead of relying on the gauges.

 

Maybe I can do some testing at the 60V6 meet if an 4T60-E DOHC owner shows up (chris is swapping a DOHC into his car but I dunno what he is driving to the meet).

[brian89gp]

I'm sure a skip shift could be worked in. If you set the minimum time in each gear to 0 and set the downshift rates at high throttle real agressive (ie close together) you can make it skip shift. It wouldn't really be downshifting 2 gears, it would be downshifting a gear twice really fast.