Tuning larger LT-5 cams

[XfireZ51]

Originally Posted by tomtom72

Dom, I would like to add my Thank You also. No, I don't understand much of this. I haven't yet to plow thru the corvette FI book by Mr. Probst. I got side tracked with night courses for my job.

I am going to ask what could be a really novice Q. This fine tuning that you are doing would only benefit an LT5 that has it's cams timed correctly, right?

TIA

Tom

Tom,

Probst's FI book is a good place to start, but frankly it was too general for me. To really learn about tuning, I would visit thirdgen.org and their
DIY Prom forum. Many valuable articles and stickies available like
Tuning 101. Also, many knowledgeable posters and moderators on there sharing lots of good information.
As to you question, there's no doubt that you want to base a tune on mechanicals that are correct. The objective of a tune is actually to have the ECM intervene as little as possible. IOW, VE and SA tables that are close to optimal as possible w the ECM making "minor" changes or adjustments as dictated by operating conditions, ie driving through the mountains or varying elevations. However, every motor is different even tho they are the same. The right tune for one stock LT-5 is not necessarily optimal for another. Close but not necessarily optimal. I retuned my motor after adding just the Fidanza as an example.
When we pulled the motor out of #474, Pete checked the cam timing. I don't recall the exact #s but the intakes were something like 109/120.
However, I had tuned that motor just a few weeks before to produce ~400rwhp on a ported top end w headers/MF exhaust. So you can attempt to optimize the motor performance with the conditions you have.
But the performance you achieve will be limited by how optimal the mechanical condition of the motor is.