93 corvette experiance needed..

**Axman** · 04-30-2016

looking for some guidance to tune my 93 Corvette, I rebuilt the LT-1 and added the hot cam kit with the 1.6 rockers, Edelbrock air gap manifold w/BBK52mm T/B and a 95 style MSD vented opti-spark. The unit starts and runs but not as it should, way to rich it seems on start up and even after it has warmed up at idle. I have been beating down the net trying to gather as much information as i can to tune this thing, seems like there is alot more information on the F-bodys and not so much on the Y-body espicially the 93 (one year wonder from my gathered info). I live in interior Alaska and have no access to a dyno or a speed shop for local experiance. I purchased the ALDL comunication cable, C-2 chips, G-1 chip adapter Ostrich and burn 2 from the Moates site and downloaded the tuner pro on an old windows XP computer trying to gain all the information I can before I try to jump head first into this ordeal. Any help or advice would be greatly apreciated.

I would also like to thank the originator and keepers of this site for letting me play,

Axman

**johnny_b** · 05-03-2016

Hey Axman,

I have a similar setup. When I first started tuning with that cam it idled way rich, the blms always pegged at 108 at idle in closed loop. pending you have no mechanical issues like vacuum leaks, o2 sensors, etc. you might start adjusting the idle up 900-950rpm for auto and a little lower for manual. lower the ve tables in areas that your new cam idles in if its showing rich. the lt4 hotcam is going to move less air at idle/lower rpm, and more air at higher rpms relative to your old cam.

as far as spark advance at idle mine tended to like 33*-34* the most. I would say start at 28* at least and work up from there and see what "feels" best for idle. with that cam the valve overlap always messes with narrowband o2 sensors at idle in closed loop. with mine i can always tell when closed loop kicks in because the idle quality instantly degrades, surging etc. there's some people who run open loop only or have found ways to force it back into open loop at idle.

I would also take a look at some of the o2 sensor settings if they're available. to help stabilize things with that cam.

for part throttle driving i would suggest starting with adjusting the VE tables based off of datalogs/histograms/spreadsheets etc. (im not sure if VEMaster is available for the $DA based PCM but its worth looking into)
also look at adjusting your BLM cell boundaries for both MAP and RPM. this will make sure the blm cells are spread a bit more evenly based off the new driving conditions that new cam will tend to operate in.

sounds like you have all the hardware/software you need for tuning, just need to find proper .xdf and .adx files with Tunerpro RT and your ostritch.

I would also suggest picking up a wideband O2 to help with tuning.

**Axman** · 05-03-2016

jonny_b,
Thanks for sharing......
I work at a remote location here in Ak, two weeks on, two weeks off. I have one more week at work (lots more EFI tuning DD time) and plan to hook up all my new equipment and see what I can do when I return home. You mentioned wideband O2, will the ECM read the wideband sensors or would I need to tap new sensors to each bank and install an aftermarket gauge? Either way do you have a recommendation on manufacture's and who to order from?

**johnny_b** · 05-03-2016

a common practice for logging wideband data is either through the A/C pressure sensor or the EGR valve connection. it takes a little bit of setting up in order to get it to display right with certain datalogging software but its very possible. most of the wideband kits come with a gauge, as for a certain brand the most common people seem to use is FAST, Innovative, or AEM uego. They can be found on Amazon, ebay, etc. just google wideband o2 sensor kits.

as for mounting there are a couple different options. people usually just weld-in one bung on whatever bank/side tends to run leanest for safety. you could have bungs welded on both sides and just plug one when its not in use. that way if you ever wanted to check the other bank for your tune you could.

another option is too not weld-in any additional bungs and simply use one of the factory narrowband sensor's bungs and disable closed-loop mode.

**Axman** · 05-03-2016

Thanks for the quick reply there jonny_b,
looking at the FAST dual probe unit, says it data logs and like you mentioned I could probably plug the bungs (maybe use it on another vehicle) after honing in the tune.

Lots to wrap my head around here this early in my tuning career.

**johnny_b** · 05-03-2016

The dual probe unit I've seen that but never used it. I don't remember what the price difference was but I've read where some more experienced tuners say its not completely necessary.

yeah i know it can seem like a lot of info at first but you sound like your off on the right path.