Performance Problem

[fullboar]

I have an LT5 and appropriate 6spd. trans in a '56 Chevy. The engine has always ran below expectations for a 400+ hp motor. I'd like to eliminate the vaccum secondary butterfly system all together and run on all 16 injectors all the time. I'm convinced this system is inoperable on my motor. Can someone coach me through what's entailed and direct me to someone who can reconfigure the computer or send me to someone qualified to do this work around Houston,TX ??? Thanks.

[rhipsher]

This is the best link for fixing the secondary problems. http://www.corvetteactioncenter.com/forums/c4-corvette-zr-1/14272-1990-1995-zr-1-secondary-port-vacuum-diagnosis.html Of course if you still want to totally remove it you still can. Mine wasnt working either when I bought it 5 years ago. It was the secondary vacume solenoid. A $36 part. Then it went from unimpressive to scary warp speed.

[tccrab]

I have an LT5 and appropriate 6spd. trans in a '56 Chevy. The engine has always ran below expectations for a 400+ hp motor. I'd like to eliminate the vaccum secondary butterfly system all together and run on all 16 injectors all the time. I'm convinced this system is inoperable on my motor. Can someone coach me through what's entailed and direct me to someone who can reconfigure the computer or send me to someone qualified to do this work around Houston,TX ??? Thanks.

We MUST see pictures of your very cool car!!!!

Contact Marc Haibec, the "ZR1 Specialist" for the necessary updated prom and advice on how to remove secondaries.
http://zr1specialist.com

TomC
'Crabs

[gbrtng]

http://www.hendersonperformance.com/hpt_contact.html is in New Braunfels and Corey knows LT5s. Highly recommended.

[Kevin]

http://www.hendersonperformance.com/hpt_contact.html is in New Braunfels and Corey knows LT5s. Highly recommended.

one of the very very few people i'd trust with my car

[FU]

That makes 3 of us. Go on and talk with Corey , he'll do it right.

[Tyler Townsley]

There is an ecm software change that turns both sets of injectors on and secondarys held open. Cory has it and can do the necessary fuel recalibration. He has done the sec removal on several cars including mine. Check with him on what you want to do, it may save some time and money. Marc H is also familiar with the procedures. Credit should be given to Tod P for the software changes. It may also be your ecm is not getting a necessary flag that allows the calibration to enable the secondaries, again Cory has the necessary engine monitor software to make sure the calibration is correct.

Tyler

[XfireZ51]

I have an LT5 and appropriate 6spd. trans in a '56 Chevy. The engine has always ran below expectations for a 400+ hp motor. I'd like to eliminate the vaccum secondary butterfly system all together and run on all 16 injectors all the time. I'm convinced this system is inoperable on my motor. Can someone coach me through what's entailed and direct me to someone who can reconfigure the computer or send me to someone qualified to do this work around Houston,TX ??? Thanks.

Why do you think eliminating the secondaries is the fix?. Do you get any codes, does the car feel like its stumbling when in WOT? Getting a scan would be a good first step.

[fullboar]

Thanks for all the helpful suggestions. I'm going to try and get in touch w/ Cory and let him diagnose my problem. Pretty sure the secondarys are the problem because the car runs like it has 250 HP. Just doesn't have any spunk. Lingenfelter went through this motor when I first got it and he said it made 505 HP on his dyno. I knew John personally and that was before he passed away. Go to http://www.facebook.com/media/set/fbx/?set=a.1822662179160.102474.1618381923&l+5ac4448de8 to see some pics of my car. Thanks again guys. Sorry guys, that link won't work. I'm trying to think of another way to get the pics up but nothing yet.

[LGAFF]

you can peek between the runner with a flashlight to see if they are opening

[XfireZ51]

Thanks for all the helpful suggestions. I'm going to try and get in touch w/ Cory and let him diagnose my problem. Pretty sure the secondarys are the problem because the car runs like it has 250 HP. Just doesn't have any spunk. Lingenfelter went through this motor when I first got it and he said it made 505 HP on his dyno. I knew John personally and that was before he passed away. Go to http://www.facebook.com/media/set/fbx/?set=a.1822662179160.102474.1618381923&l+5ac4448de8 to see some pics of my car. Thanks again guys.

Is the Power Key on FULL? And you don't get a lean condition code or a
CEL light that flickers on and off when you hammer it?

[VetteMed]

you can peek between the runner with a flashlight to see if they are opening

Lee, will they open under a no-load condition regardless of throttle input?

[LGAFF]

Lee, will they open under a no-load condition regardless of throttle input?


If you are asking if you can test it without the car on, I am sure you can...but I think you need to access under the plenum......I just take the TB cover off, lean over the engine and blip the throttle...even if you can see it at first, the movement of the actuator will catch your eye....pretty obvious.

[VetteMed]

If you are asking if you can test it without the car on, I am sure you can...but I think you need to access under the plenum......I just take the TB cover off, lean over the engine and blip the throttle...even if you can see it at first, the movement of the actuator will catch your eye....pretty obvious.

Well, more out of curiosity, than for my own needs, but I didn't realize that the secondaries would open at no-load (out of gear) situations. Interesting.

[Z51JEFF]

To check the secondaries with the car off,not running.On the ECM,C plug or second plug from left find the pink-black stripe wire.Back probe this wire in the plug from the back side to make contact with the wire.With the key on listen for the pump to cycle,no start,ground this wire and the secondaries will open.Ive used a dental tool with an alligator clip connected to a wire.The ground Ive used is at the fuel regulator.This is on my 91 but the DVD I have is of at least a 92.Hope this helps.

[WB9MCW]

http://i126.photobucket.com/albums/p110/HAMMERHATE/FULLBOAR56LT54.jpg

http://i126.photobucket.com/albums/p110/HAMMERHATE/FULLBOAR56LT53.jpg

http://i126.photobucket.com/albums/p110/HAMMERHATE/FULLBOAR56LT52.jpg

My pleasure to help you post your fine
"Lingenfelter LT-5" 56 CHEVY Ride for all to see
-- Nice Job !!!

[PhillipsLT5]

SCHWEEET!

[FU]

Damn that engine is beautiful !! Need to fill that engine compartment....think turbo's !

[LGAFF]

I would be interested in how the intake/air filter bridge fits into the front of the airhorn.


Looks great

[WB9MCW]

HERE IS A 57 CHEVY THAT I HAD IN MY FILES

http://i126.photobucket.com/albums/p110/HAMMERHATE/57ChevwithLT-5d.jpg

http://i126.photobucket.com/albums/p110/HAMMERHATE/57ChevwithLT-5.jpg

http://i126.photobucket.com/albums/p110/HAMMERHATE/57ChevwithLT-5e.jpg

http://i126.photobucket.com/albums/p110/HAMMERHATE/57ChevwithLT-5b.jpg

http://i126.photobucket.com/albums/p110/HAMMERHATE/57ChevwithLT-5c.jpg

http://i126.photobucket.com/albums/p110/HAMMERHATE/57ChevwithLT-5a.jpg

[4DSZR1]

Very cool installation on the '56 whats the extension's purpose between the plenum and injector housings? Runner length increase?

Cool

[sjs]

This may be a dumb question , but what is gained by elimanting the secondaries other than a slight bit more airflow??? Other than the valet function I thought the major reason for running a split intake is to run on the smaller cam lobes and have less runner volume - thus increasing air velocity in the runners and greatly improving low and mid range torque and hp and responsiveness?? Then as rpm increases use the larger cam lobes and the extra air and fuel, wouldn't this delete just screw than cool system up?

Not judging just asking for education, as an mechanical engineer I just like to understand these things about my car... Thanks for the reply

[Kevin]

sjs:
http://www.zr1.net/forum/showthread.php?t=14531

a short discussion on just that topic