Track LS3 A6 C6 - Sometimes won't shift to 4th

[xstang]

A6 w/2.73s

I went to Ennis this weekend and my car is flying. I ran an 11.7 at 121mph with a Vararam and tune only. My only issue is the fact that the car won't shift to 4th about 1 in every four runs before going through the traps. It bumbs the limiter before eventually shifting. I haven't really messed with any tranny stuff except removing TM.. When I hit the limiter, my trap speeds were 117-118 instead of 120-121.. I was hoping there is an easy fix. I didn't log the runs, but I was just thinking about reducing the rpm shift point a little for 4th. Should that do the tric, or is it something else?

[xstang]

Here is the log... It looks like it gets stuck at 117mph....

9068 05:50.1 5992 111
9069 05:50.1 6012 111
9070 05:50.2 6010 111
9071 05:50.2 6034 111
9072 05:50.2 6038 112
9073 05:50.2 6041 112
9074 05:50.3 6046 112
9075 05:50.3 6063 112
9076 05:50.3 6068 112
9077 05:50.3 6068 112
9078 05:50.4 6080 112
9079 05:50.4 6074 113
9080 05:50.4 6111 113
9081 05:50.4 6100 113
9082 05:50.5 6101 113
9083 05:50.5 6123 113
9084 05:50.5 6127 114
9085 05:50.5 6135 114
9086 05:50.6 6150 114
9087 05:50.6 6158 114
9088 05:50.6 6159 114
9089 05:50.6 6161 114
9090 05:50.7 6176 114
9091 05:50.7 6186 114
9092 05:50.7 6204 115
9093 05:50.7 6226 115
9094 05:50.8 6222 115
9095 05:50.8 6210 116
9096 05:50.8 6211 116
9097 05:50.8 6236 116
9098 05:50.9 6245 116
9099 05:50.9 6249 116
9100 05:50.9 6236 116
9101 05:50.9 6255 116
9102 05:51.0 6242 116
9103 05:51.0 6276 116
9104 05:51.0 6278 116
9105 05:51.0 6288 116
9106 05:51.1 6300 117
9107 05:51.1 6305 117
9108 05:51.1 6314 117
9109 05:51.1 6313 117
9110 05:51.2 6312 117
9111 05:51.2 6305 117
9112 05:51.2 6295 117
9113 05:51.2 6291 117
9114 05:51.3 6330 117
9115 05:51.3 6320 117
9116 05:51.3 6312 117
9117 05:51.3 6325 117
9118 05:51.4 6305 117
9119 05:51.4 6321 117
9120 05:51.4 6292 117
9121 05:51.4 6259 118
9122 05:51.5 6217 118
9123 05:51.5 6158 118
9124 05:51.5 6088 119
9125 05:51.5 6002 119
9126 05:51.6 5938 119
9127 05:51.6 5839 119
9128 05:51.6 5742 119
9129 05:51.6 5638 119
9130 05:51.7 5510 121

[bigbrian442]

Have you checked to see if the MPH is met for the 4th gear shift?

[xstang]

Someone emailed me with the fix... Upped the MPH 3-4 shift by 5 mph and everything works perfect now... Thanks!

[mustangjonGT]

Someone emailed me with the fix... Upped the MPH 3-4 shift by 5 mph and everything works perfect now... Thanks!

My buddy's 08 Vette is having this same problem with nitrous. It will not shift into 4th gear and he ends up at around 6800rpms or so in third. So does he add or subtract 5mph to the 3-4 shift?

[Cantalope Kid]

OMFG! 11.7's with an LS3 backed by an automatic 6 speed with highway gas savings 2.73's? I'm in love...

Problem solved.

3-4 shift point mph = (current value) +5 mph

[8850]

Someone emailed me with the fix... Upped the MPH 3-4 shift by 5 mph and everything works perfect now... Thanks!

With 5 mph more do you stay in 3rd all the way? I have the same problem occasionally. I'm shifting at just over 6300 rpm now. Isn't 5 more mph a little too high?

[mustangjonGT]

OMFG! 11.7's with an LS3 backed by an automatic 6 speed with highway gas savings 2.73's? I'm in love...

Problem solved.

3-4 shift point mph = (current value) +5 mph

Ok we will try that out. My friends best time is 11.63 N/A and 10.86 with a 125shot. He only has the problen on the n20, it stays in 3rd till the end and he traps 131mph at 6800-7200 rpms. Hopefully adding the mph helps out.

[Cantalope Kid]

With 5 mph more do you stay in 3rd all the way? I have the same problem occasionally. I'm shifting at just over 6300 rpm now. Isn't 5 more mph a little too high?

Assume so. 5mph at that speed is going to happen very quickly...up your shift rpm and rev limiter if you get close or you may bouce of it when it finally does shift.

[8850]

Assume so. 5mph at that speed is going to happen very quickly...up your shift rpm and rev limiter if you get close or you may bouce of it when it finally does shift.

Seems to me there would be a better fix if we knew these A6 tranny commands better. HPT has added so much more control now. We should be able to shift at stock rpm without problems.