Maximum power from a stock M42.

[avt007]

An update- I have just finished the season, running a CAI, Dinan chip, 2" exhaust. I'm pretty happy overall, but I'm looking now for more power via a different chip, or custom tune.
There are a couple options via the WAR chip, or Ostrich, to do your own custom tunes, but I'm having serious doubts about going that route.
Dyno costs are high, and without decent datalogging available from OBD1, I think it would be tough to do it yourself.

Thoughts?

[TobyB]

I think it's a tale of 2 rabbit holes-

1-there's only incremental power to be found in the stock system, and learning how to make
it work right (or better) is going to take real time. You can add data logging, that's not
so hard, but it adds time and money. If you do things like deck the head and run higher
octane fuel, you may find a hard limit in the capabilities of the stock system. And you
still have that damned flapper door. Which may or may not be required by your rules set. If it
is, then I'd stay stock- system...

2- pony up for an aftermarket injection system that is more capable and less inscrutable.
Now this rabbit hole's less deep and probably has more internet help available, but it's not
cheap, either, and you have to start from almost ground zero. But it does let you
use a MAF, (if allowed, or unprotested),give you access to real- time data,
and much more resolution in tuning.
But again, until you do mechanical things, the gains will be anywhere from negative to,
at best, incremental.

Now, if you're in a race class where incremental gains matter, and you can change the ECU
guts, then I'd go aftermarket injection, just for the control and access to data....

he says, having thought about it a little...

t

[avt007]

Thanks for the input, Toby. My class does not allow engine mods, or aftermarket injection.
Only a chip is allowed, with everything else completely stock other than a CAI and header.

Given those rules, I'm leaning towards a Mark D chip, and leave the custom tuning alone, unless I can get good data to verify any gains or losses.

[TobyB]

I think that's wise. It's pretty much what we do with M20's in Pro3,
although most front- running engines are built to the limit of the numbers.

t

[avt007]

Over the winter I'll do a compression test, probably pull the head, clean up the valves, maybe rings if needed, clean the injectors, etc.

basically make sure I'm getting the most out a stock engine.