Mystery Bird

Finally got back to the track Saturday, and my eighth mile went from a high of 85 MPH to a 94 but top speed went down. So let me break it down
Best with the old v-6 pump:
60 1.82
1/8 85
ET 12.805
Trap 105.71

Best with new Walbro Pump:
60 1.85
1/8 94.02
ET 12.789
Trap 105.41

I don't understand how the eighth can go up that much but top end suffers?

AutoRoc

Picking up 11 mph on the last half of the track is a big problem. Big as in severe transmission slippage or the tune being WAY off. A wideband O2 sensor can show data in reguard to the tune. Checking trans fluid wouldn't hurt either. Your setup should see 23-25mph increase from half track to finish line.

Are you sure you picked up 9mph at half track with just the new pump? That's equivalent to picking up 100+hp. Actually.. I pick up 9mph at half track with a soft 150 shot.

Work out them bugs! Goodluck.

Mystery Bird

A new pump and a new tune with higher shift points.

I noticed with this tune I was hitting rev limiter right at 2-3 shift.

AutoRoc

Could be hitting the limiter because the trans is on it's way out. Check the fluid yet?

Mystery Bird

Fluid did smell burnt earlier this year do to valve body issues, since then I've replaced the valve body and it hasn't smelled burnt since. Fluid level is just above the top line. If it was the tranny wouldn't 1/2 slip as well? With a 10 mph increase in the 1/8 I don't think it's slipping down low. I just started shifting at 6600 RPM's, before it was 6200 and it wasn't hitting limiter.

AL SS590 M6

Looking at the numbers I think that the 94 in the eighth was a timing equipment error.
Was the eight et signifantly better?

Post up all the numbers from both slips so that we can check them out.

Mystery Bird

Here are all the times from the last two times at the track.

Reaction 60 Ft. MPH1 ET MPH2 TOD

August 8th 2009 0.289 1.904 85.08 12.855 105.71 11:33
Hot low humid 0.508 1.922 85.29 12.864 105.71 12:53
upper 70's 0.449 1.828 84.98 12.805 105.37 1:17
0.447 1.98 84.9 12.966 105.5 2:57

September 5th 2009 0.468 1.858 12.789 105.41 9:38
Hot low humid 0.161 1.948 93.95 12.868 105.4 9:47
upper 70s 0.072 1.85 93.83 12.79 105.59 10:04
Slight head wind 0.104 1.854 94.02 12.799 105.57 12:59

Mystery Bird

Wow that's a mess. Wonder why it didn't post the way I entered it? Let me try it again.

0.289 1.904 85.08 12.855 105.71 11:33
0.508 1.922 85.29 12.864 105.71 12:53
0.449 1.828 84.98 12.805 105.37 1:17
0.447 1.98 84.9 12.966 105.5 2:57

0.468 1.858 12.789 105.41 9:38
0.161 1.948 93.95 12.868 105.4 9:47
0.072 1.85 93.83 12.79 105.59 10:04
0.104 1.854 94.02 12.799 105.57 12:59

Mystery Bird

The more I think about it mabe it was timing equip error because the first run of the day it didn't give me a mph1. And how can my car run that much faster with just a new pump and tune with shift point turned up? Maybe I need to accept that's as fast as my car is going to run?

AL SS590 M6

Look at run 2 of each group.

1.922 85.29 12.864 105.71
1.948 93.95 12.868 105.4

Almost identical runs with 9mph difference in 1/8mph. That's a timing equipment error.

Mystery Bird

I would have to agree. Thanks for pointing that out.