The Chip

[QMCMSS]

Trying to get my mind wrapped around my chip. I am an old school guy with a couple classics they are carbureted and no computer. I recently purchased a 91 ZR1 and love the car. She came with Corsa exhaust, Top end ported, and a Hailbeck chip, stock exhaust manifolds to keep the environment safe here in California. On Marc's website it explains what the chip does to improve performance to what I assume is a stock motor. Do I need a new or modified chip to maximize the the changes from Stock on my car. . I wanted to have the car dynoed but have discovered its not so easy. All the dyno shops I spoke to said they would be happy to sell me a few runs but they were unable to make changes because they couldn't communicate with the Chip/ECM. I guess on newer cars they communicate directly with the ECM via the OBD connection and can make changes on the fly via computer software something I guess you can't do with my 1991 antique. If I do a couple runs can I send the data to Marc and ask him make a chip for my car then i would be back to the dyno for more runs to see if they worked seems expensive and inefficient. I live in the SF bay area and would love to find a dyno that is familiar with the car but as yet have had no luck. I'm not afraid to work on the car myself but haven't got around to installing the chassis dyno in my garage yet. The car has a high rpm (about 5500rpm) miss under a heavy foot, just got some NGK 3690's to put in next week, if that doesn't solve the problem I will check out the coils as soon as I figure out where they are. I'm guessing to adjust timing I need a new chip, I'm also assuming based on his website that the Hailbeck chip changes fuel air ratio and advance all along the curve. Finding stepping into a new world is exciting and fun. Thanks all for your great posts I'm learning a lot from them.

[tccrab]

It's probably safe to assume that the Haibec chip in your car is already optimized for your current configuration. If you have questions about the chip or it's programming I'd recommend you call Marc himself. He will have records of what he did for that car, and he's a really nice guy.
The coils live under the plenum, but you probably have already figured this out. They are not hard to get to, but will require a plenum pull to get to them.
What about the previous owner of the car, is he/she available to discuss the car's mods and what has been done to it?
Someone going to all the trouble of porting the top end likely has already gone though all the normal wear items. Diagnosing your miss might be tricky depending on what has been done to the car.

'Crabs

[QMCMSS]

Thanks for the reply the previous owner only did the chip, He got the car a year ago and decided it was a bit much for him. I asked him in a couple ways if he had any paper work or info on the upper end but he said it was done by the previous owner who I will attempt to track down. Any chance you are going to the ABEL Chevrolet event next week. I'm thinking of going.

[XfireZ51]

If you understand tuning carb and distributor cars, you have a basic understanding of ECM engine management. You are looking to achieve the same thing. Only the ECM can do it faster, and make many adjustments per second. Tuning a non- ECM motor is like using a chain saw for brain surgery.
Its a vast compromise. The ECM can optimize the operation of the motor over a large spectrum of operating conditions.
The VE table is your "jetting" and the SA table is your distributor advance.
You will need equipment and software. Stock ECM is not "flash" capable, so a ROM emulator is strong recommendation. But before all that, go here
http://www.thirdgen.org/forums/diy-prom/ and start reading. Particularly, read up on the stickies at the top.
http://www.thirdgen.org/forums/diy-prom/288763-prom-tuning-guide-book.html
Doubtful you will find anyone who can/will tune the LT-5 outside of our community here. The LT-5 isn't very different than any other "speed density" motor, just has some quirks to it because of secondaries etc. Then the question is "what kind of tuning?". WOT tuning is one thing, driveability/part throttle is much more involved and time consuming. And we spend so much more time at PT.
Also attached a copy of presentation I did on tuning LT-5 at 2014 Gathering.
I am warning you however that this stuff is like heroin for gearheads.

[QMCMSS]

If you understand tuning carb and distributor cars, you have a basic understanding of ECM engine management. You are looking to achieve the same thing. Only the ECM can do it faster, and make many adjustments per second. Tuning a non- ECM motor is like using a chain saw for brain surgery.
Its a vast compromise. The ECM can optimize the operation of the motor over a large spectrum of operating conditions.
The VE table is your "jetting" and the SA table is your distributor advance.
You will need equipment and software. Stock ECM is not "flash" capable, so a ROM emulator is strong recommendation. But before all that, go here
http://www.thirdgen.org/forums/diy-prom/ and start reading. Particularly, read up on the stickies at the top.
http://www.thirdgen.org/forums/diy-prom/288763-prom-tuning-guide-book.html
Doubtful you will find anyone who can/will tune the LT-5 outside of our community here. The LT-5 isn't very different than any other "speed density" motor, just has some quirks to it because of secondaries etc. Then the question is "what kind of tuning?". WOT tuning is one thing, driveability/part throttle is much more involved and time consuming. And we spend so much more time at PT.
Also attached a copy of presentation I did on tuning LT-5 at 2014 Gathering.
I am warning you however that this stuff is like heroin for gearheads.
Wow looked at the PDF and have a screamin headache. I only recently mastered my new cell phone. Would really have to up my technology game to understand it all, that said if becoming aware what I don't know is making me smarter I might be a damn genius. I plan on plugging along until I get it right but I can see I'm going to need some new tricks. The good news is so far I haven't broke anything.

[XfireZ51]

Not sure but mike100 may be nearby you and has a good grasp of basic tuning requirements.

[Franke]

One other thing is you will undoubtedly need the Field service manuals if you don' have them already if you plan on servicing your car. They are invaluable for troubleshooting and education. Marc Haibeck's site has a lot of good info as does the ZR-1 registry. Some of the Zr-1 guys on here are masters at working on this car. Check also for Dynomite's threads on here too.