BURL

I've searched the Forum and about 50 pages on the net. Everybody talks about MAF modifications, swaps, aftermarket units, certain year specs, screen removal, port/polishing and on and on. Yet I have been unable to find a page simply listing the MAF and Throttle Body sizes for each year of the C5's. I also understand the Z06 was different (size? No screen?)?

If anyone could post this info or just give me a link to where it is posted I would greatly appreciate it. Guess I'm just overlooking it somehow - seems such a simple spec.!?

Thanks in advance.

My Vette Life

I could be wrong on this but I think if you swap the MAF, you may need to retune.

BURL

Please re-read my question. Thanks

My Vette Life

oops..

Throttle body on all C5s is 78mm, stock.

MAF on 01 and later is 85mm

BURL

What about Z06 MAF ? 85 MM? No screen?

Thanks

Gordy M

The Z06 came without a screen but the PCM ran a tune-both firmware and software-to compensate for the lack of a screen. All C5's from 01-04 had the 85mm MAF. The standard C5 had firmware in the PCM that was based around the airflow and turbulence with the MAF (screened) and accordion coupler. That was the reason many who made changes w/o a tune had problems with stumbling on decel, mid range performance loss, etc.

BURL

So if one were to use the Z06 screen-less MAF and (I assume) a straight coupler then it would be possible to modify the tune to make this MAF/coupler perform correctly on say a LS1? If so are special (relative to the MAF) table modifications modifications required or would the problem be taken care of in the standard process of a tune?

Another question, I assume the screen in the MAF is designed to change turbulent air flow into laminar flow for better air flow measurement.? Seems that the change to laminar flow would in fact also increase air flow.? So, why was the screen removed from the Z06?

RonSSNova

Hey Burl,

You can use either the screened or unscreened MAF and a straight coupler on the LS1.
You will need to retune the MAF airflow curve.

The data to enter is available on the LS1 How To web site.

In either case, fine tuning will be beneficial due to the air cleaner setup you choose.

And yes the screen is there to straighten the flow.
I guess GM found it unnessary

Ron

Gordy M

GM removed the screen on the Z06 when they were trying to get better throttle response. The DBW has a lag built into the firmware so when you punch it 1/2 throttle it responds to something like 1/4 throttle and gradually opening to 1/2. Several competent tuners, like COW, have gone through the exercise to find out a solution. If you had 100% DBW throttle response you would have a very hard time driving into your garage.

RonSSNova

Not really buying that. The Camaro LS1 has a cable throttle that opens as fast as you can press it......

The rate on the C5 can be increased. Those guys know the limits of doing that. If you go too far you brick the PCM.

Adding a 90mm TB (if you have an aftermarket intake or an adapter) quickens the throttle response considerably because you have a larger area to open. My C5 has excellent response with the LS2 TB.

The airflow numbers between the screened and unscreened MAF are very small.

Ron