Do upgraded heads require a tune? - Third Generation F-Body Message Boards

SDalt404 · 03-09-2009, 07:12 AM

I am going from stock heads to a set of trick flows. I am curious if this will REQUIRE a tune or if I can still run the car hard without one. Also will it affect drivability. My logic says that the air flow is metered by the mass air flow meter so it shouldn't make that big of a difference.

RBob · 03-09-2009, 08:08 AM

Spark advance requirements will change. You'll be able to drive the car with what is in there now. But best results will be from you re-tuning it.

RBob.

SDalt404 · 03-09-2009, 08:42 AM

If you were to guess, what would you say the power gains from swapping heads is? 75hp?

90c350 · 03-09-2009, 12:54 PM

35 to 40hp if tuned right!

Ronny · 03-09-2009, 02:16 PM

I read once that MAF is limited in the amount of air flow it can monitor. Once you see increased airflow/horsepower the MAF may have to go. Search.

pandin · 03-11-2009, 06:59 PM

With 19# injectors, it is unlikely to max the Maf. You would need to be bigger than 24# to even get close.

SDalt404 · 03-11-2009, 07:43 PM

What does injector size have to do with how much air maf can meter?

tequilaboy · 03-11-2009, 08:01 PM

Interestingly enough, with a 13:1 AFR, 19 lb injectors and the MAF will max almost simultaneously.

RBob · 03-12-2009, 11:49 AM

Once the MAF reading is max'd fuel can continue to be added via the PE tables. This is a common method. Note that the injectors still need to be properly sized. As I am not saying that this will continue to add fuel once the injector DC is at or above 100%.

RBob.

SDalt404 · 03-12-2009, 07:05 PM

How much power can you make with 19lb injectors?

pandin · 03-12-2009, 07:45 PM

A data log will tell you alot about where you are on air flow and injector flow.

As to max HP with 19# injectors 300 FWHP by calculation @ 43.5 psi fp 100% duty cycle .5bsfc.

Maybe someone with a similar setup could give a dyno rating.

SDalt404 · 03-12-2009, 08:17 PM

Right now I use tunerpro RT for tuning and datalogging. What would you recommend for tuning? What would you recommend for datalogging?

pandin · 03-13-2009, 09:03 AM

Those are fine for tuning and data logging, they are what I use.

What is your max Maf grams/sec and your max injector ms and at what rpm do they happen? They should repeat as you go up the gears.

Ronny · 03-13-2009, 10:15 AM

This is what I found for you. Save to your favorites.

http://www.users.bigpond.net.au/ben_...ctorsizing.xls

SDalt404 · 03-13-2009, 01:14 PM

thanks for that calculator. I will definitely be using that!

pandin · 03-13-2009, 03:17 PM

Try this, it has been added to and "a work in progress", just remove the".txt".

SDalt404 · 03-13-2009, 04:13 PM

Thanks big time!