I finally have everything I need to start burning my own chips. I've already read over every piece of tuning info twice. Just wondering if any of you experienced guys could give me some basic tuning guidelines for my spark tables and whatnot, just to make sure i'm headed in the right direction. My mods are listed in the sig, and the cam's profile is 112 LSA 206/212 .480/.487. Thanks for any help.

 

It helps to know what code version you're using, as different control systems are tuned in different ways. I.E. tuning a SD car and tuning a MAF car are very different processes (although the general idea is the same.)

The best place to start is with the obvious constant stuff...injector sizing, rev limiter, cooling fan temps, and other options. Then do part-throttle fueling, then work with spark timing, then do WOT fueling and transient stuff.

Take some datalogs and figure out where you need more/less fuel, and adjust to compensate. If it's pretty badly lean or rich across the board, you can change the injector constant to get it close. Then you can use the other tables to get it tweaked in.


Read everything again, and do it with your tuning program open so you can play with the tables and stuff to see how it all works. You'll be surprised how much more you can understand that way.

 

your spark tables really shouldn't need drastic modifications. There is no magic number for advance, but the general concensus is that 32-38 is the typical range for best power. Your camshaft is super mild, and porting/polishing the heads might increase flow, but won't really make the mixture burn any faster or slower. I'd say that you should try the stock tune for spark timing and see how it works. Like J said, take a few datalogs and mark any problem areas. Your car should idle fine for the most part... maybe 20 deg timing there, with your total advance coming in around 3000 RPM. In the areas of deceleration (low load/decreasing rpm) you can set the advance a little higher. I dunno a lot about tuning fuel control with MAF sensors tho, which is what the 89 n' earlier cars came with.

 

Yeah, I'm using the 89 ARAP tune, so hopefully it will be pretty close to what i need. Thanks for the advice though, that's exactly what i was looking for.

 

I would pull a bunch of timing out of that bin before being used. ARAP is a performance bin that was used on the aluminum headed 'Vettes. Too much timing for the iron headed L98's.

May want to check the timing tables from bins intended for a f-body 350 TPI first.

RBob.

 

So if the ARAP is too hot, then what bin would i be looking for? I forgot to mention that I only have a 2.73 rear, so what tuning would be involved with my crappy current gear ratio?