First I have the post down further on this board reguarding a 165 ecm swap.I read the very helpful site for that but have one more question.Is there any sensors the 87 tpi has that the 85 does not(other than mas burn off relay?).Second is would an 87 vette chip work for my 87 ecm and tpi.If yes then what effects will the 3:08 gear raio inside the chip effect if I have 3:42?The dealer did need the gear ratio for the correct prom.What programing advantages does the vette chip have over an 87 formula 350 chip(fuel,spark tables).If I used 19 lb injectors at 50 psi would'nt that make them flow around 24 lb hr.My pump would handle 50 psi,I'm sure.I ended up buying both chips for $30 each from gm through my friend.

 

When you crank the pressure up the volume goes down that a pump can deliver, takes a heathy pump to run at 50 PSI.

There are difference vette to f body

rear end ratio affects the timing curve.

For a MAF system the only answer is the 89 code and edit to work.

 

Would the 89 be the best choice because thats the only maf year that had 3:42 in the prom?What will likely happen if I plug the vette chip in my ecm tomorrow?And what kind of effect will 3:42 gears have on the timing curve for 3:23(formula 350 chip).Would it be the expected same as heavier weights on a vac hei?Or will it not be so bad with my low reving 400 cid?One more thing is there any other change in the 87 harness other than the maf burnoff?Thanks in advance for the help.I aspire to be a great tuner someday.Because I feel efi tuning is the future.People like grumpy and glen will be looked on as the guru's(even more so than now).

 

Anybody else?

 

how does the rear end ratio effect timing?

 

Generally you can "get up" on the spark curve a little quicker with lower gears (higher numerically). It is something you have to play with because without a "spark correction table vs gear or MPH", it's kind of difficult to make a spark curve the works for all gears.

I generally find "knock" is more pronounced when accelerating in higher gears, especially at the 2-3 up shift (I seldom am going fast enough to invoke a WOT 3-4 up shift).