Higher than Normal Cylinder Airmass

[roadtrip942]

2006 z06 28k
PRC 265 Heads 390cfm, milled .020
TSP LS7R Cam 248/256 .622/.648 114+3
Halltech MF103 Superbee
Ported Intake and TB by Peak Performance
Pfadt 1-7/8 Headers, No-CATS
New GM MAF
ZR1 Injectors 56.4lb
ATI Underdrive pulley
(Stock Mufflers)
8-3-13 Dyno 562hp/496tq

3-2-13 Stock dyno 433hp with a old Halltech Killerbee and Jet Performance MAF
After a dyno tune 456hp with airbox and MAF.

The same day I dynoed stock, a 2009 Z06 with 11k dynoed 460hp bone stock. The dyno shop said mine was the lowest he had seen come through his shop. It was not what I wanted to hear, but I accepted it. I went home and did a compression test and the cylinders.
1-193 2-195
3-193 4-198
5-200 6-197
7-193 8-200


The issue= With all the new mods it only dynoed 562hp/496tq. I was expecting at least 575hp but it was down on power so I added the pulley , milled the heads , and ported the intake and tb.

My data log shows over 100 g/cyl airmass above 3,800rpm, even 120g/cyl at 5,600rpm.. My tuner said he had not seen a car run over 100g/cyl unless it had forced induction on it.

Why would it run over 100 g/cyl on my car and not other Z06's?

The MAF is getting close to maxing out so we were going to adjust that this weekend it is 9,100hz and I'm out of adjustment at 9,800hz.


Looking for answers, Im not a master tuner but trying to learn my setup.

https://www.dropbox.com/s/erosuvm40g...am%20B-Rad.hpt
https://www.dropbox.com/s/o23fx0u7g8...0new%20MAF.hpl

[Ben Charles]

Don't worry about dyno numbers, they can vary greatly. Take it to the track and see what it MPH's. Your setup without a doubt should read that high G/cyl, near stock ls7's read 1.00 g/cyl (that's actually 100 VE for them) Your NO WHERE NEAR maxing out the g/sec limit on your setup, you don't have a 512 limit and the Hz your seeing there is still plenty room.

If I was you I would get another tuner.

[SultanHassanMasTuning]

are you running pure pump, are you tuning or a different tuner?

[roadtrip942]

91 octane out of the pump

I took the car to a local tuner. I have my own software but I haven't messed with very much, mainly data logging at the track. LT1 edit is different than HP Tuners but I'm trying to learn what I can.

It looks like my injector constant is not accurate and causing the rest of the tune to be off (MAF).

Does anyone have the ls9 injector values for the ls7 PCM?

[ingsteve]

i think you can copy them from a zr1 stock tune in the repository...

[roadtrip942]

i think you can copy them from a zr1 stock tune in the repository...

I have a stock ZR1 tune to reference but Z06 tunes are all setup against KPA or Vac and ZR1 tunes are all setup against PSI Or boost. Some of the tables are twice as long on the zr1. It's not as easy as cut and paste. I read a little about guys having to convert PSI to KPA.

[edmundu]

How are you able to run soo much timing, on 91 no less? Also, location helps out in determining your power, as elevation effects NA much more so than FI cars...

I would have thought you would be able to use the ZR1 values, up until it hits boost....

[roadtrip942]

Amarillo Elevation -3600'
Average Summer Month Density Alitiude 5,500-7,000'

I have been told that we can run 2-3 more timing up here on the mountain because of altitude. If you look at any factory tune gm has more timing at 85,90,95 KPA than 100 KPA. My car will rarely see 90-91 KPA with the key on engine off. Most of the time it's 89kpa.

[roadtrip942]

So it looks like my injector constant is off it should be 52.5 not 56.4 and this is causing some side effects. I guess I'm going to put the stock injectors back in and dial in the tune until I can find the ls9 injector values.

[edmundu]

Ahhh...elevation!