Quick question... Is this normal?

[Dave_Harris]

Can someone take a look at the PL file and tell me if the fact that im only dropping 500 rpms when shifting is normal? This is the first real all out run I've done since the new tranny and converter. (over 2 yeasr ago). The converter is one of Dusty's. Even though it's been 2 years, I've prob. only have 500 miles or so on them. This was a pretty soft launch (1.8 60 on it's way to a 11.47 et at 122). I thought it odd that I have to go into OD before hitting the stripe.

The car is a 86, stroker, GT6162e turbo, alky, SLIC, stock untouched heads. Moser M9 rearend with 3.50 gears and a spool.

Not locking up the converter

Thanks!

Dave

 

[Dusty Bradford]

I can't view the file from the computer I'm on. What rpm did you shift at?

 

[Dave_Harris]

1/2 5800 2/3 5500 3/4 5500 approx

 

[Dusty Bradford]

122mph should be fine in 3rd gear with the 3.50 ratio. What rpm did it cross the traps?

It's dropping to 5000rpm after each gear change?

 

[pacecarta]

why do you feel that at 5500 you need to be in fourth with your combo , and what size rear tires are you running with the 3.50 gears

not that this was your question but seeing as how you posted the log
you need to get a better handle on that boost , 23-4 at the start but crept to 28 and started to knock
if im reading the wideband correctly its at 11.3-4 at that boost not where you want to be with alky and pump gas
and at 25* timing , somehow you cranked the 3-4 timing cell to 141 , were you on race gas???

 

[imjoesnuffy]

1/2 5800 2/3 5500 3/4 5500 approx

Thats not what the datalog shows.

1/2 shift was at 5649
2/3 shift was at 5371
3/4 shift was at 5553

What size tire? Assuming it is a 28 inch tire. Assuming the 13 mph difference you picked up in 4th gear. Puts Converter slippage at 21%.


Looking at the log, looks like you didn't have the pedal to the floor for part of the run, once in third. Your TPS was at 4.07. Take out the floor mat next time. A touch of MAF dropout as well.

You might be out of fuel pump or need to make some changes to your tune, it leaned out to 11.26 and you got some knock (1.4KR) at 27 psi in 4th gear. Injector duty cycle looked good though. Leave it in third and wind it out, to get better data.

 

[Dave_Harris]

why do you feel that at 5500 you need to be in fourth with your combo , and what size rear tires are you running with the 3.50 gears

Being only third trip down the track, didnt want to zing it to high.

not that this was your question but seeing as how you posted the log
you need to get a better handle on that boost , 23-4 at the start but crept to 28 and started to knock

I'm working on this as we speak

if im reading the wideband correctly its at 11.3-4 at that boost not where you want to be with alky and pump gas
and at 25* timing , somehow you cranked the 3-4 timing cell to 141 , were you on race gas???

Yes, VP110.

 

[Dave_Harris]

Thats not what the datalog shows.

1/2 shift was at 5649
2/3 shift was at 5371
3/4 shift was at 5553

Was working off memory, didn't have PL file at work....

What size tire? Assuming it is a 28 inch tire. Assuming the 13 mph difference you picked up in 4th gear. Puts Converter slippage at 21%.

Yes, 28 inch Hoosier QTP

Looking at the log, looks like you didn't have the pedal to the floor for part of the run, once in third. Your TPS was at 4.07. Take out the floor mat next time. A touch of MAF dropout as well.

No floor mat, or carpet for that matter, had just finished cage, and hadn't put everything back yet Must of been me....

I noticed that MAF spike, might have a MAF going out. It spiked like that 3 times during the previous run

You might be out of fuel pump or need to make some changes to your tune, it leaned out to 11.26 and you got some knock (1.4KR) at 27 psi in 4th gear. Injector duty cycle looked good though. Leave it in third and wind it out, to get better data.

Added fuel to top end, havent gotten a chance to run it again.

 

[Dave_Harris]

It's dropping to 5000rpm after each gear change?

5649 - 5146 1-2 gear change
5371 - 5119 2-3 gear change
5553 - 5228 3-4 gear change

Through traps 5300 in 4th. Shifted into 4th approx 9 secs into a 11.4 sec run

Yes, I'm sure I can run this combo up over 6k and avoid going into 4th, but my question is that is seems like I should have more of a rpm range than I've got even shifting at 5500. Maybe not, i dunno, I'm used to old school munci 4 speeds

If that is normal, and expected, great :biggrin: Just checkin!

 

[Dave_Harris]

Built my sig, everything should be below:

 

[Dusty Bradford]

Shifting to overdrive has most likely exaggerated your converter slip %. If you shift at 5700 and it drops to 5200, it's not optimal but it shouldn't be near 21%. Since your crossing the traps at 5300 and the converter is only dropping to 5200 the converter is right at it's coupling point. I bet holding it out in 3rd gear you will see a good bit of difference.

 

[Dave_Harris]

Thanks for the replies and suggestions guys, I'll try shifting manually and hitting higher shift points next time out, and I guess after that it's time to drop the pan and grind a little off the gov. weight.

Thanks again -

Dave