Low numbers for cammed C6 Z06

[Rawr256]

Friend has a 07 Z06 with bolt-ons and a street bully cam in the car. Pre-cam with the bolt-ons best we were able to manage was 460 rwhp. After the cam went in best we were able to get was 490 rwhp. I know it's a smaller cam and nothing to extreme so I wasn't expecting giant numbers but when he said the previous owner with just the cam and no bolt-ons did 522 rwhp it got me wondering why we couldn't even break 500.

Car has ~44k miles on it and pulls hard and doesn't seem to miss a beat. Only thing that crops up is some KR spikes at 5500 - 6k area, usually 2*. Have played with the timing in this area and it always seems to come up in that same area. Kind of have ruled it out as bogus KR because reading they have issues with burst KR in the early years of the LS7.

Basically, can someone take a look at the tune we have setup and see if there is anything that seems off or I am completely overlooking? Went in on the dyno expecting to break the 500 # and came out disappointed. Unfortunately don't have a log of the pull.

Only thing I can really think of is the car lights the tires up in 4th gear on the dyno on the first pulls we always make and wondering if maybe it is having the same issue on the other pulls, but just not as obvious.

[Snyper]

What kind of dyno?

[vette_c6]

there are many stuff you need to adjust in your tuning
specially the spark tab
i dunno why did you decrese the numbers on MX KR
get it back to stock
24 degrees timing for Zo6 is a little high ,,
i wanna be carefull
i would disagree with many stuff that you have done
base retared
MAX KR
Timing high octain

All spark correction
AC trq reduction

this is an opinion ,, people might disagree with me ,,

also ,, no body can judge without Scanner log

good Luck ,,,

keep in your mind , if the car is spinning a little in the dyno ,, u wont See HP

so let someone sit in the back
good luck

[4evervette]

What kind of dyno?

i agree with that .. had the same cam .. z06 2006 ..made 505rwhp on mustange dyno ...

few days lator 521rwhp on dyno jet ...

dont get caught with numbers take it to the drag strip ..it should trap 133mph and above ..

[Rawr256]

Car is on a dynojet. Normally wouldn't get too caught up in the numbers but they just seemed unusually low from what we were expecting. My G8 with bolt-ons put down 346 same day and wife's WS6 did 405 cam only late last year so figured it couldn't be too far off. Tried running it down the track this last weekend and without tires it was pretty much useless. Think best it trapped was 123 in 3000 da. Friend said he never hooked until he rolled into third, wot in first and second was pointless. Will have to see what it does later this year with DR.

vette_c6 -
After you mentioned some of the stuff I dl'd a stock file to compare to. I knew the car had at some point been tapped into because of the TM settings but didn't look around at some of the other stuff. Will have to make some changes and see what happens.

Car seemed to like the 24* on the dyno. Anything above was next to no gain.

[IDRIVEAG8GT]

AFR? Sounds like an over lean condition to me.

[IDRIVEAG8GT]

And WTF happened here?!

I be thinking your WBO2 that you used is not calibrated right. (See attachment)

Also as mentioned the spark table looks like it's a piece of sheet metal that a 6 year old has hammered on with a ball peen hammer for a few hours.

Lot's left on the table here, and also, what injectors are you running? The IFR table looks like piss unless you have a return style fuel system. Should be a linear transition, not jumpy. If a GM tech designed those I will go slap him.

One more thing. If you're spinning the tires on the dyno you need to spray down the the rollers with some VHT or some sort of sticky substance. I'd be pretty pissed if it was doing that to me with a mere 500WHP.

[seevi]

Friend has a 07 Z06 with bolt-ons and a street bully cam in the car. Pre-cam with the bolt-ons best we were able to manage was 460 rwhp. After the cam went in best we were able to get was 490 rwhp. I know it's a smaller cam and nothing to extreme so I wasn't expecting giant numbers but when he said the previous owner with just the cam and no bolt-ons did 522 rwhp it got me wondering why we couldn't even break 500.

Car has ~44k miles on it and pulls hard and doesn't seem to miss a beat. Only thing that crops up is some KR spikes at 5500 - 6k area, usually 2*. Have played with the timing in this area and it always seems to come up in that same area. Kind of have ruled it out as bogus KR because reading they have issues with burst KR in the early years of the LS7.

Basically, can someone take a look at the tune we have setup and see if there is anything that seems off or I am completely overlooking? Went in on the dyno expecting to break the 500 # and came out disappointed. Unfortunately don't have a log of the pull.

Only thing I can really think of is the car lights the tires up in 4th gear on the dyno on the first pulls we always make and wondering if maybe it is having the same issue on the other pulls, but just not as obvious.

That cam should get you between 525 and 545 with modest bolt-ons.

The first thing I noticed was the MAF values are lower than stock. I would presume them to be higher. Your spark tables seem out of whack as well. Where is the car located?

[Mep_q8]

That does look like a funky MAF curve. It should be more linear then anything else. Looks like G8GT find the problem, your not reading AFR correctly.

[Rawr256]

Shooting for a 12.5 AFR. Seems to run best that way and looking over previous posts it seems to be what everyone agrees on the LS7 running best. Fuel system is 100% stock. Everything injector related looks to be the same as it is stock.

Using a NGK AFX WB. When it was last on the dyno for the 490 pull my WB and the WB from the dyno read identical so pretty sure the fuel is dialed in where the PE wants it too be. Friend had mentioned that at some point in the cars life it looked like the front O2's were drapped over the header pipe and burnt up a bit so that is probably why it has a funky curve compared to the stock.

Will have to hook up with my buddy some point this week and post up a good scan. See if maybe that doesn't reveal a bit more.

[4evervette]

as the other mentioned ... High and low MAF table are not smooth( your low table end difrently where you high table starts from different point )i.e 5800HZ should be the same on both table ...

if u have any log ..do u see any knock( i would include PE ignition advance pid in the scanner) ..am just concern with your AFR spark PE correction..( i would set them to zero and use my high octane table to command what i want ..

[seevi]

Shooting for a 12.5 AFR. Seems to run best that way and looking over previous posts it seems to be what everyone agrees on the LS7 running best. Fuel system is 100% stock. Everything injector related looks to be the same as it is stock.

Using a NGK AFX WB. When it was last on the dyno for the 490 pull my WB and the WB from the dyno read identical so pretty sure the fuel is dialed in where the PE wants it too be. Friend had mentioned that at some point in the cars life it looked like the front O2's were drapped over the header pipe and burnt up a bit so that is probably why it has a funky curve compared to the stock.

Will have to hook up with my buddy some point this week and post up a good scan. See if maybe that doesn't reveal a bit more.

Another consideration in this equation that should probably be discussed is the fuel you're burning. If you're using an ethanol blend fuel (E10) your stoich is incorrect and therefore your WOT is incorrect. Also, your valves are open much longer and you need to get your airflow right. Dialing in the MAF transfer table is a must. Also, the virtual VE may need some adjustment in the under 2K RPM region.

[IDRIVEAG8GT]

Again there's lots left on the table here. I still say WBO2 problem. Does this car have cats? If so get rid of them.

[seevi]

Again, where is this car?

[Rawr256]

Seevi - Car is located in Spokane, WA. Think the E10 blend would affect it that much? Know the Stoich changes but figured the WB would help to pick up the slack for WOT to give the right A/F that's commanded in PE.

IDRIVEAG8GT - Car does have cats. Has LG LT headers, sensor is being plugged in before the cat's so no off reading there. Will recal the WB just to make sure it's not off. Did a recall a few days before we hit the dyno with it and plugging it into my G8 and wife's WS6 there hasen't been any big enough changes in the readings from it that I would think it's off but who knows.

Providing we don't get rained out, may be running the car at the track tomorrow so can get some good logs for WOT.

[seevi]

Seevi - Car is located in Spokane, WA. Think the E10 blend would affect it that much? Know the Stoich changes but figured the WB would help to pick up the slack for WOT to give the right A/F that's commanded in PE.

IDRIVEAG8GT - Car does have cats. Has LG LT headers, sensor is being plugged in before the cat's so no off reading there. Will recal the WB just to make sure it's not off. Did a recall a few days before we hit the dyno with it and plugging it into my G8 and wife's WS6 there hasen't been any big enough changes in the readings from it that I would think it's off but who knows.

Providing we don't get rained out, may be running the car at the track tomorrow so can get some good logs for WOT.

E10 is about 4% richer blend of fuel, and I have found it beneficial to make that adjustment in my practice. Stoich for 10% is about 14.1 - 14.2:1. At .87 Lambda for WOT gives you about 12:2 12.3:1. Getting the AFR right is the object for power and efficiency. As I mentioned before, your MAF tables are calibrated for less air than stock. Since your valves are open longer and your engine is getting much more dynamic cylinder air you're not getting the right AFR threw the spectrum.

Call Cory Harris at LS2 Port Works in Seattle and ask him for a tuner recommendation in your area, [email protected].

[Xjas]

E10 is about 4% richer blend of fuel, and I have found it beneficial to make that adjustment in my practice. Stoich for 10% is about 14.1 - 14.2:1. At .87 Lambda for WOT gives you about 12:2 12.3:1. Getting the AFR right is the object for power and efficiency. As I mentioned before, your MAF tables are calibrated for less air than stock. Since your valves are open longer and your engine is getting much more dynamic cylinder air you're not getting the right AFR threw the spectrum.

Call Cory Harris at LS2 Port Works in Seattle and ask him for a tuner recommendation in your area, [email protected].

Can you please explain to me how the MAF calibration is affected by the valve opening/dynamic cylinder air? since the MAF is a flowmeter measuring airflow into the engine I though the only things that would upset the MAF calibration are changes to the MAF housing (size and shape) and intake piping to the MAF that affect flow (% of total through the MAF housing) over the hot wire in the MAF. I always thought that a bigger cam would simply make the MAF register more air flow (all other things being equal), the actual calibration would be uneffected?

[seevi]

Can you please explain to me how the MAF calibration is affected by the valve opening/dynamic cylinder air? since the MAF is a flowmeter measuring airflow into the engine I though the only things that would upset the MAF calibration are changes to the MAF housing (size and shape) and intake piping to the MAF that affect flow (% of total through the MAF housing) over the hot wire in the MAF. I always thought that a bigger cam would simply make the MAF register more air flow (all other things being equal), the actual calibration would be uneffected?

The MAF transfer table reports the quantity of air the computer is”EXPECTING.”Those values are determined by engineers and calibrators on a flow bench based on the components (Heads, Intake Manifold and Cam) that the engine comes with from the factory. If you change any of those components, the amount of air coming into the engine changes proportionally and the calibrated values become incorrect. The fuel being delivered is based on those calibrations. Optimally, what you need to do is put the car on a dyno and do some steady state measuring to get actual air measurements and adjust the MAF transfer table to represent reality. You’ll probably have to go thru this process a couple of times to get the error within 3%.

You can do this on the street, but, you should have one person driving and another collecting the data, and be careful. Send my a PM with your email and I'll give you procedure to follow to collect data and send you an evaluation.

[obzidian]

Completely agree here, the tune needs a few adjustments. With that maf sorted, the combo could start to put out close to where it should. That cam, on a dynojet, "should" be able to make more power.

Can you tell us what the "boltons" were before the cam and what it has now? 490rwhp, on average, is what intake/tune/header cars make day in, day out.

Good luck.

[Xjas]

The MAF transfer table reports the quantity of air the computer is”EXPECTING.”Those values are determined by engineers and calibrators on a flow bench based on the components (Heads, Intake Manifold and Cam) that the engine comes with from the factory. If you change any of those components, the amount of air coming into the engine changes proportionally and the calibrated values become incorrect. The fuel being delivered is based on those calibrations. Optimally, what you need to do is put the car on a dyno and do some steady state measuring to get actual air measurements and adjust the MAF transfer table to represent reality. You’ll probably have to go thru this process a couple of times to get the error within 3%.

You can do this on the street, but, you should have one person driving and another collecting the data, and be careful. Send my a PM with your email and I'll give you procedure to follow to collect data and send you an evaluation.

Are you refering to the VE table (vitrual VE for gen 4s)?