LS1 Fbody vs. Corvette

[Saxxon68]

Hi folks, many of you have purchased honeycomb screens from me, and until now seems I have understood the LS1 title.

In an Fbody an LS1 seems to be 86mm, and in a Corvette it is 100mm. This is stock only and many folks change their set up from there. My question is how many LS1 titles were made? Is it only Fbody and Vette or did some other rigs come with LS1 motor.
Someone was asking for a 75mm screen for a LS1 and I have never heard of this small of intake for LS1 V8.

[WS6FirebirdTA00]

LS1 titles? Are you talking about MAFs?

The factor MAF is 75 mm on the Fbody and I thought the same on the Corvettes. Then the LS6 used an 85 mm MAF, or at least that is what I thought.

I could be wrong, but I do know the Fbody factory sensor is the 75 mm and most upgrade to the 85.

[LSxpwrdZ]

All fbody LS1s used the same aluminum housing MAF that the older LT1's also used which is 75mm. They come factory with the honeycomb already but alot of people descreen for some stupid reason (guessing from the shitty advice floating on the web).

The 85mm plastic housing MAF was used on the SLP optioned SS Camaros and I believe the full option Firehawks. The C5's didn't get this newer MAF until 2001 when the Z06 came out. Not exactly sure if the base LS1 cars of that year received them or not but do know the later years did. GM trucks and vans have used that same larger MAF since 99 or 00. Some versions came with honeycomb from factory and others did not.

If I can find a spare one around the shop I'll snap you a couple pictures with some measurments.

[printmanjackson]

why is de-screening bad? I can see if someone didn't have the ability to tune it afterwards. The Corvette Z06 didn't come with a MAF screen

[WS6FirebirdTA00]

The screen will help prevent fluctuations in the MAF, or at least it should. I have run a screened and descreened MAF in my car and saw no difference. It really depends how the rest of your intake system is.

[LSxpwrdZ]

Yes just like WS6 said, it straightens the airflow out to pass over the MAF elements and gives much more stable Hz readings in the system. Think of it as a natural filter for the MAF reading. The more stable you can get the MAF sensor readings the more stable you will get the airflow readings for the PCM to apply fuel.

The C5Z didn't have a screen in it's MAF sensor because it wasn't needed. You'll also notice that the placement for the factory MAF sensor is way down in the end of the intake bridge as well which makes it much less suceptable to turbulence caused by the throttle blade and camshaft reversion (if a larger camshaft is used).

I had a car the other day with a 85mm screened MAF that acted stupid still on a Fbody and what I believe was the culprit was the large cam that was in the engine. Just have to learn to manipulate the filter coefficients to stabilize the actual airflow calculation.