Corvette Z06 Forum banner

1 - 16 of 16 Posts

·
Z06 Maniac!!
Joined
·
1,541 Posts
Discussion Starter #1
This is not about racing. It is more about my lack of skill at drag racing and what these beasts can do with a mild head and cam package. I was happy with my trap of 120.95, but my et sucks at 12.3 with a 2.05 60'. The 1/8 was 8.121 @ 93.16. I shifted 1 to 2 at 6500 rpms as fast as I could without power shifting so as to avoid wheel spin. The 2 to 3 shift was a power shift at 6500 and the 3 to 4 shift was a power shift at 6200. I should have taken her to 6500 before shifting to 4th, but I got antsy.;)

My DRM package uses stock valves, stock tb, stock airbridge, has factory cats still on it, and does not use underdrive pulleys. I was on my factory tires all 4 at 30 psi cold.
 

·
Z06 Maniac!!
Joined
·
1,541 Posts
Discussion Starter #4
Brian, stock fuel injectors and the air fuel ratio is dead nuts on all across the rev band.
 

·
Registered
Joined
·
568 Posts
Brian, stock fuel injectors and the air fuel ratio is dead nuts on all across the rev band.
Thanks Ron.. That is very interesting.

I'd read that the injector duty cycle on a stock car is close to 90%, but perhaps that wasn't correct. Any idea how much your injectors are firing?
 

·
Registered
Joined
·
2,388 Posts
I hope they aren't running at 90% duty-cycle :eek:. The fuel injector experts (ie, RC Engineering) will tell you never to run fuel injectors above 80~85% d/c. Most injecors start loosing fuel delivery control above this level.

Obviously, the stock Z06 injectors are capable of supporting alot more than stock HP. Anyone know what is the actual HP limit of the stock injectors?
 

·
Registered
Joined
·
568 Posts
After a quick search I found the post that I recalled. The source was Jim Halltech. Maybe he can comment:

http://z06vette.com/forums/showthread.php?s=&threadid=4711&highlight=cycle+injector

The injectors are so lean, that once any intake is installed, ours or others, the injectors are at over 90% duty cycle and above.

They are rated at 255 cc/min at 43 psi or 24.3 lbs./min static. This rating is the same as our 2000 LS1 injector size. Think we are just trying to sell injectors?

Test them yourself and then test last years Z06 injectors which are bigger.
 

·
Registered
Joined
·
2,388 Posts
Humm ... hard to believe Jim's comments if Rippied.Z06's car shows good A/F ratio on a dyno and puts down 480+ FWHP. If his stock injectors couldn't support that much HP it would definately show on the A/F sniffer.

Rippied.Z06 -- you didn't happen to bump up the fuel pressure -- did you?

The math doesn't add up :D.
 

·
Registered
Joined
·
2,388 Posts
BADASSZ06 -- Ya, I think Jim Hall was talking about the 2002 Z injectors.

Jim Hall says: "They are rated at 255 cc/min at 43 psi or 24.3 lbs./min static. This rating is the same as our 2000 LS1 injector size. Think we are just trying to sell injectors?

Test them yourself and then test last years Z06 injectors which are bigger. "
Keep reading to see what he means by this statement.

In the thread reference above, Jim also says: "The 2002 injectors testing at 24.3 lbs./hr. are the same size as our 2000 LS1 injectors tested last year. I can get the exact comparison if anyone is interested."

Oh come on -- I really doubt that GM is going to put smaller injectors in a motor that gained 20 HP from 2001 to 2002. I think you tested some plugged up injectors, or the test method/operator was hosed :D.

The only way this could happen is if the BSFC of the 2002 engine decreased significantly over the 2001, or the 2002s are running on the verg of burning holes in the pistions due to leaness.


Go see this link: http://www.c5registry.com./2k2z06/page4.htm
----------------------
"An increase in air flow significant enough to provide 20 more horsepower also demanded a small change in the engine’s fuel and spark curves. This was done with slight alterations in the PCM calibration. There was no change in injectors or fuel pressure. "
-----------------------

So, this means that the 2002 Z06 injectors are the same as the 2001 Z06 injectors -- not smaller like Jim reported :D.
 

·
Z06 Maniac!!
Joined
·
1,541 Posts
Discussion Starter #12
The fuel pressure hasn't been touched. It seems GM may have down sized the injectors on the '02 if I read Jim's post correctly. On my '01, no problems so far.

Frank, if you saw my 120.95, how did those Corsa Indys sound. :D Tomorrow Susan and I are off to Lake Geneva Wi. for some oval track racing on Sat. Concrete walls everywhere. :eek: I put new brake pads in tonight, all 4 wheels. That is the 4th set so far. :cheers:
 

·
Registered
Joined
·
1,300 Posts
Just as a thought of possible et's I had a 5.0 mustang that used to run 120-122mph in the qtr.
Now I had slicks and a great hooking suspension so I could come out of the hole at 5,800-6,000rpm on the two step line lock release dump of the clutch.
Car ran 11.3-11.5's depending on the track. Once you grap low 1.6 or 1.5 '60 times you'll be there.
Never seen the front wheels come off the ground in a vette:eek:
 

·
Registered
Joined
·
2,388 Posts
Rippied.Z06 said:
The fuel pressure hasn't been touched. It seems GM may have down sized the injectors on the '02 if I read Jim's post correctly. On my '01, no problems so far.
I doubt it, based on this info.

Go see this link: http://www.c5registry.com./2k2z06/page4.htm
They are talking about the 2002 Z06
----------------------
"An increase in air flow significant enough to provide 20 more horsepower also demanded a small change in the engine’s fuel and spark curves. This was done with slight alterations in the PCM calibration. There was no change in injectors or fuel pressure. "
-----------------------

I think Jim needs to research it some more :D. Just because a 'test' might indicate something doesn't mean its the correct information. People run tests, and people make mistakes :D.
 
1 - 16 of 16 Posts
Top