Rom tunes and big turbos..

[Jez]

I considered a mail order tune after doing a few mods on my Silvia, granted I dont have a big turbo or any other wild mods but I opted for a daughter board and some dyno time.

With my limited knowledge and experiance there is no substitute for dyno time, to many small variables to be taken into account IMO.

[4x4le]

Originally Posted by Jez

I considered a mail order tune after doing a few mods on my Silvia, granted I dont have a big turbo or any other wild mods but I opted for a daughter board and some dyno time.

With my limited knowledge and experiance there is no substitute for dyno time, to many small variables to be taken into account IMO.

This is so very true. I tuned stockish s13 sr's back to back. Both have fmics and exhausts but were still stock maf, t25, and stock injectors. Both ended up liking the exact same 10 psi the best, no gains were seen (tuned for tuned) over 10lbs, but one I had to run over 80% duty cycle on in order to get the air fuel ratios where I wanted them. The other I could literally flood out to a stumble with fuel If I tried to run that much pulse width. The timing maps were quite different too. Their graphs looked nearly identical, power, tq, afrs and the curves on all of the above however their tunes were VERY different. These were nearly identical setups!!!!!!!!!!

Now start adding aftermarket parts and built engines and see how different stuff turns out. Something as simple as maf location, or the age of the injectors seem to be vital.