Ferocity02

iTrader: (60)

Can someone explain what the point is of a 4" LS7 MAF sensor if the stock PCM is limited to 512 g/s? With boost it's not too hard to hit this limit. Perhaps the LS7 MAF is more for NA applications to reduce intake restrictions? I think the LS7 MAF is capable of reading more than 512 g/s, but will be limited by the PCM? Is this correct?

sreve

iTrader: (3)

The tune can be scaled to get around the limit.

jimmyblue

iTrader: (11)

It would still be better than the 85mm Delphi, which
hits the 12kHz limit first (about 460g/sec). But I bet
it's mostly "bigger is better", letting people match the
rest of the plumbing on big TB setups (whether it has
much impact, or not).

Ferocity02

iTrader: (60)

True but you would lose resolution which isn't good at low airflow and idle, correct?

Alvin@PCMofNC

We use them regularly in Gen 4 applications like Trailblazer SS's, LS2 Vettes, etc. We also use them quite often in hotrod/street rod builds. They flow quite a bit more than even the 85mm units. The PCM can be scaled to get around the 512 limit.

Slowhawk

iTrader: (12)

Have seen that problem a lot. Drivability can suffer.

E-40 and E-38 computers love them but I've had problems with the older computers.

ddnspider

iTrader: (26)

Sometimes there's not always another option.....eg 98 cars with efi live.

Exidous

iTrader: (11)

If you screen the 4" tube you can get a lot of the accuracy back. I use a low density screen by saxon PC and it works very well. I get 99-101kPa at WOT on the road.

ScarabEpic22

iTrader: (1)

99-02 PCM swap might help with that, EFILive's 97-98 LS1A support isnt as detailed as the 99-02 stuff.

decipha

I use the screen door material that can be had at Lowe's or home depot, works great at straightening out the maf

T/A KID

iTrader: (12)

Helped do a buddies setup, 5inch tube/Ls7 MAF no screen/50%scaled, drives great.

ctd

iTrader: (1)

I'm trying to solve a slight bucking issue, would this screen shot be an example of a large MAF?

T/A KID

iTrader: (12)

You don't have anything referencing MAF Hz, so no one can help you

ctd

iTrader: (1)

OK MAF in fequency added. Please comment.

T/A KID

iTrader: (12)

Looks like its a bigger 4inch tube considering the Hz is around 3000 at 1700rpms. Ive never had problems with bigger tubes, however the tube shifts the MAF frequency to the left and with a bigger tube the MAF numbers need to be increased down low.

ctd

iTrader: (1)

It is a 102 TB with LS3/7 MAF in a 2001 C5 & yes a bigger tube.

I don't understand this comment?

"however the tube shifts the MAF frequency to the left and with a bigger tube the MAF numbers need to be increased down low"

T/A KID

iTrader: (12)

Say a setup with a 3.5inlet idles at 3000hz at 8 g/sec and at 2300hz that number may be 5g/sec. If you use a 4in inlet or larger it shifts the Hz to the left or down. So placing a 4inch tube on that setup would require the MAF to be adjusted so if a 4inch inlet idles at 2400hz 5 g/sec is not enough if the engine needs 8g/sec.

Hope that makes sense.