Good morning guys,

While waiting for my FAST to show up, I've been thinking of other ways to let the engine breathe better. I've noticed a couple things that probably will make little difference, but are cheap and easy to do. I'm looking for thoughts - good, bad or indifferent.

1. I saw that my MAF screen was damaged, probably about 10% surface area was folded over. This was caused by R&R of the intake and throttle body over the life of the car. It's now removed. I have heard mixed emotions about this one, but I don't think I had much chouce in my case. My tuner made a comment during my last tune that MAF readings were all over the place at part throttle and this may be why. I know the screen tends to straighten flow keeping it laminar, but could be a restriction above 450 rwhp. I made 460 on a mustang and 476 on a dynojet with the damaged section...

2. Does anyone have any input on swapping the stock accordion bellows with a smooth piece? Price, vendors and recorded gains (if any). I think there's a vaccuum line coming off the stocker - do aftermarket ones have this as well?

3. I have a WCC hurricane intake. There is a fiberglass piece that sits in front of the intake filter that has two holes in it, each about 5x7". It appears that only about 50% of the filter surface area is exposed. It probably isn't a choking point, but I don't see the purpose of this piece and may remove it. Has anybody done this, and if so, any notable results? Other than having the filter fully exposed, any other drawbacks you guys can think of?

I'm not trying to reinvent the wheel here, just looking to get the most out of my setup.

Thoughts?
Sean

 

Sean, I have the smooth bellow. No appreciable difference.

 

I put the smooth bellow on my car as well. No numbers or seat of the pants gain, but it does smooth air flow. Especially over 500hp, so getting close to that it is going to help

 

The MAF screen is there to smooth the air comming in, It is extremely important to ensure you have accurate AFR reading. A stable enviroment will give you the best performance at all levels.
Besides the MAF is most likely able to outflow what the engine uses. This link pretty much sums it up.
http://www.gmtips.com/3rd-degree/dox...maf-screen.htm

 

Where did you get it from? Just a 4" silicone hose from the local hardware store? Also, I think tree was a vacuum line running offthe old bellows. How did you account for that? I'm out of town on vacation so I don't remember for sure.

 

Don't take off the MAF screen. I did that on my old car and my tuner had all kinds of issues with low rpm AFR values until I replaced the MAF.

 

Didn't have much choice as the screen was visibly damaged, most likely beyond repair. About 10% of the surface area was folded over and some of the fins were torn. I think that the intake scraped across the screen some time ago when I re-installed it.

I have done plenty of research on this and the jury is still out on tue answer. Many of the well respected people here says that it makes no difference and can even gain Hp if tuned correctly.

 

This wesite has been discounted more than once on this forum. It appears that the guy is speaking of a different engine as well. My LS2 used an 85 mm throttle body, not 48 or 52. His agruments ma not have any validity if basing his opinion on that TB size.

I agree with the whole laminar straight airflow thing, but as others have said, why does the C5Z come without one? That motor is similar to the LS2, even uses the same heads and somehow GM decided to go without.

I didn't post this to get into a deep discussion about removing the MAF screen or not - that wa sthe one decision that was already made up for me. Worst case, i have to buy a new one ifthe tuner is having trouble. The other two bullets are the ones I'm really looking for opnions on.

 

First thing I have done on every maf equipped car I have owned has been to remove the screen.

Never had a tuning problem. Sean, the smooth bellow I got was from Mid America and it has a provision for the hard vacuum line. Think it was thirty bucks or so.

 

i bought the straight coupler from pep boys 15 bucks, you just drill a small hole and take the piece from the accordion and push it into the new smooth piece, its tapered in the import section

 

Jeff Creech @ Carolina Automasters did my base tune on my recent engine build (I mailed him the ECM) and I told him that I was considering taking out the MAF screen. His reply was that "I should throw the MAF in the garbage can then" if I removed the screen...obviously Jeff is not a fan on removing them.

I was also informed that Z06's didn't have the screens in the MAF (not 100% sure on that one). Regardless, I took mine out anyhow. I also took the cats out of my exhaust, you know how restrictive they are...don't live in CA and don't have VET testing in my state.

I did add the smooth coupler that I purchased from WCC, which seemed a little expensive for a piece of rubber w/ a couple of hose clamps and a little hole in the side of it...but imo it only make sense to smooth out the air flow going into the TB. Of course I could totally wrong on my thinking, but I'm still learning this stuff.

In the very near future Brian Tooley will be porting out my FAST intake and I'll have to have the engine tuned again, but I'm hoping to get near the 500 rwhp mark (currently @ 476) on my LS2.

Good luck w/ your modding!

 

Absolutely true, Z06s came from the factory with no MAF screen.
Yet removing the screen on an LS1/LS2/LS3 etc (and tuning for it accordingly) is somehow considered by some to be the work of the devil? LOL

I haven't had a MAF screen on my 2000 Z28 LS1 since it was two years old and it's been running flawlessly since day one. Same goes for my C6, screen was removed when I installed the Vararam back in 2007 and the car still idles like stock, is crazy fast and gets 31mpg on the highway.

 

I have a maf with a screen and a maf with no screen. I have run the no screen maf with no problems for years now in my daily driver. It runs great and gets great mileage.

I never bothered with the bellows. It has a little give and makes fitting the vararam easy. I have a smooth one on the shelf and never bothered to install it.

Not sure what you're talking about with the hurricane intake. If it blocks the hot air from the engine compartment, that's a good thing.

 

Thanks for all the input. I am most nervous about the MAF screen delete, but have confidence that my tuner will be able to accommodate. If not then I guess I'm buying a new one...

Hopefully this will be my last dyno tune, at least N/A. I'm trying to get the best bang for the buck with a ported FAST 102 (replacing formatto stage 2 ported stock intake), MAF screen delete and smooth bellows. I'm at 476 rwhp on a dynojet / 460 on a mustang, and think I may be able to approach 490-500 (dynojet) with the new setup.

 

Why would you even ask a question on this forum if you did not want to discuss it?

Obviously you already knew the anwser to your question.

 

Joe, this is a fiberglass piece that fits in under the hurricane intake filter. It does not separate hot air from the engine bay to the intake area. As best I can tell, it looks to serve no purpose other than potentially deflect rain and /or debris from hitting the downward facing filter element. Overall dimension is about 18"x24" and has two 5x7"ish holes in it. When I get home next week I will take some pics of it and it will give you a better idea of what I'm speaking of. Kinda hard to describe without a pic.

 

I'm looking for any specific negative impact of removing the screen. Has anybody have documented evidence that this will hurt tuning and/or performance? I have read many posts about individual opinions, but it appears to me that there isnt much hard data supporting problems with the screen removed. On the flip side, I hear there is little to be gained with the screen removed and I hear the tuning becomes increasingly difficult.

I didn't want this thread into another "leave it in because I said so" thing. The website you offered has been presented here in the past and has been debated many times over, sometimes with bruised egos. I am by no means fluent in tuner jargon and wanted to understand what effect, positive or negative, this may have on tuning, hp numbers and driveability. I have removed the MAF screen in my LT1 fbody while I was in college with no negative impact, but that was a different engine and only one data point.

If I offended you, I apologize.

 

Do not fret. I can switch mafs back and forth screen or not and the tune doesn't change. Recall I have HP tuners and self tune so I know this from more than just sotp, I have scans to back it up.

Guys pull out the screen when approaching 500 rwhp so you did the right thing. It becomes a limitation at that level. Many now switch to the blade maf like the ls3-7 at that level.

Lest you lose a moment of sleep over it, worry not. You can have my screened maf if you want it.

 

No worries. I am simply trying to assist a Brother that is all.

 

That's the one question that the "oh noes, don't EVER remove your MAF screen" naysayers can ever seem to logically answer.




Don't be, as any great tuner with the latest software/updates can very easily solve what (very) minor hurdles might (and I do mean 'might') be introduced by removing that screen.
Now, does it really help/make a huge difference in performance on a stock or bolt ons only car?
No.
But if it's already out then you can still work with it as long as the wires/sensors inside aren't damaged/altered. And if you're looking to make big power later on then it can be beneficial.