Thirdgen89GTA

iTrader: (5)

If it were a stock TPI, the Pistons would have gone to the MOOOOOOOON.

QwkTrip

iTrader: (22)

You are in desperate need of some gears my man!

Thirdgen89GTA

iTrader: (5)

yeah. 2nd and 3rd last Fooooorereeeverrrr. But it still pulls hard.

It doesn't feel like it slows down that much between 3rd and 4th gear. But thats probably because the difference in 3rd and 4th gear is nowhere near the difference between 1st and 2nd.

I have an M29 T56, which is the wide ratio T56. So my gearing goes 3.36::1, 2.07:1, 1:35:1, and overdrives are .80:1, and .62:1.

Thirdgen89GTA

iTrader: (5)

So lol. I’ll have to put up a pic when I get to my tuning laptop. But completely forgot the obd1 data stream can’t read higher than 6300rpm.

Did a long 3rd gear pull today, peaked at 6900rpm.

Thirdgen89GTA

iTrader: (5)

6900rpm makes me giggle. Part of me wants to send it to 7k+ because it was built to do it. But the cam doesn't make power there, so I'd just be spinning it to spin it.


6900rpm plus in a GTA

Thirdgen89GTA

iTrader: (5)

Apparently I don’t have to try and break 7k. I already did in a previous log!!

7072rpm. Holy crap. That was a 3rd year pull.



7000rpm+ go like hell!!!

TTOP350

iTrader: (8)

I shift at 8k and let the pistons help close the valves...... J/K Its fun to make them spin for sure

Thirdgen89GTA

iTrader: (5)

They sound better the faster they spin.

Thirdgen89GTA

iTrader: (5)

So, because I'm bored. I started collating the datalogs looking at averages and things.

And when I graphed the MAF gm/s out I saw a trend I thought was interesting.

I put all the WOT 3rd gear pull datalogs into a single spreadsheet by RPM. Then I created a pivot table that grouped all of the entries into 250rpm groups and averaged the MAF gm/s readings out.

And I came up with this chart. Which, if you think about it makes perfect sense and tells me exactly where my peak power is going to be, and even a bit of an idea how much power it is probably making too.


Avg MAF gm/s 3rd gear WOT pull

QwkTrip

iTrader: (22)

You can sort of calculate engine torque from the VE table at the MAP and RPM values you run at.

Torque [lb-ft] = (VE / 100) * (Engine displacement in cubic inches) * (RPM) / 4235

and

HP = Torque * RPM / 5252

Or you can just put it on a dyno and not guess.

Thirdgen89GTA

iTrader: (5)

There is also the MAF equation, but that doesn't take into account VE or fueling.

Still, if the engine is making about 450hp crank then its doing about right for when I built it in simulation. Desktop Dyno is a bit over-rated on #'s, I treat it like old school gross HP ratings from the 70's and that puts it close to 500. So account for accessories and 450hp crank is probably about right. If it was making between 400-420whp I'd be happy, its about what I wanted. A set of gears would make it feel more lively.

I downloaded TunerPro which seems to have a much more updated definition file for the EE LT1 pcm. Thinking of scheduling dyno time and just having them load it up for RPM sweeps at different loads to gather logs along with WB02 data.

QwkTrip

iTrader: (22)

I got my glasses and fixed my post.