Injector & Mass Air swap w/out a tune?????

[393strokervert]

I currently have 30# injectors & a C&L meter. I need a New Mass Air (probably going with PRO-M). I personally think the 30's are on the small side for my 393 stroker. I would like to upgrade to 36's as I already have a PRO-M 77mm meter cal'd for 36's but I might even go up to 42's & get a new Mass Air.
my question is, can I swap in the new injectors & Mass Air without getting a tune?
also, what are you guy's thought's on injectors sizes for my setup?
any help or suggestions would be great. Thanks, Joe
P.S. my ECM is from a 94 Cobra & was tuned/chipped (by the shop that built it) for the stroker motor by the previous owner.

 

[final5-0]

Without a way to optimize the pcm settings, you have to resort to the cheat
method devised by aftermarket meter manufactures

This is where the meter is calibrated for a certain size injector

What happens is ... as you move farther and farther away from using
a meter ... caled ... for 19's ... you encounter low pulsewidth driving
conditions (idle & cruise) which are too fat

Now ... 24's are not too much of an issue
and
30's have been known to ... some of the time ... not be too bad

But ... larger sized inj's such as 36's & 42's and larger will most likely
cause an issue

The deal is ......
At those low pulsewidth conditions, the large inj's are sloppy at the
threshold of being just above no flow or off condition which is typically
where you would be at idle and curise

Another thing which it just awful about the ... Cheat Method

It throws your load factors W A Y outta whack in the pcm
and
Load is what the 94-95 pcm's use to administer fuel/spark

And the final bad thing to say about the cheat method

The meter is what is used to determind load

therefore

You wanna have a meter that accurately reports airflow to the pcm

Not a meter that cheats the facts or reports a lie to the pcm

Grady

 

[393strokervert]

so,what if I get 42's,a matching Pro-m 90 meter & get it dyno tuned. will that be fine??

 

[dls322]

Get it tuned. You will be happy you did. Probably will unleash allot of power that was wasted before

 

[final5-0]

so,what if I get 42's,a matching Pro-m 90 meter & get it dyno tuned. will that be fine??

Sure

As long as your tuner knows his stuff

I'd get references from 94-95 folk he has tuned to see how pleased
they are with his handy work

Very important ... If your guy checks out ....

D O N' T buy the meter/inj's until you talk to him for his opinion :Word:

After all ... HE not Me is going to be punching the buttons

Grady