SLP Airlid adds up to 10+ RWHP...really??

**Guerrillakilla13** · 02-12-2012, 01:04 PM

Does the SLP Airlid really add up to 10 rwhp??

Give me some thoughts lol anybody done a dyno after adding the airlid, or even felt a difference? Thats a pretty big horsepower gain for such a simple mod.

I understand its "up to", so than what's the average gain?

**Too Fast** · 02-12-2012, 01:49 PM

Yup, it's been proven many times. Usually people report 5-10 HP at the wheels. This is, of course, a difference between a stock set-up with the hemholtz chambers, and almost any other lid that eliminates those silencers. Those OE chambers quiet the intake noise. Personally, I like the music (noise). You can only really hear the added intake music with a stock exhaust, judging from my personal experience when I had a '98 Trans Am with the stock exhaust.

**Firebirdjones** · 02-12-2012, 01:50 PM

I'm sure it's worth a few. Hard to say exactly how much because it's tough to measure on a dyno. A fan doesn't simulate the air you would have moving over the car as it would while driving.

But basically you are removing the huge baffled air intake designed to reduce noise (and as a result reduces air flow) for a debaffled lid with a larger plenum area.

It's a simple mod that's worth doing.

**Guerrillakilla13** · 02-12-2012, 03:10 PM

Thanks guys, I knew that the ls1's have restricted airflow up the butt but i didn't know why they would do that for the airlid. The noise wont bother me at all! That's pretty awesome. But just for the hell of it, how much louder does it make the engine bay?

**Firebirdjones** · 02-12-2012, 03:53 PM

I honestly don't notice a difference in noise. But I'm old and deaf

You'll hear a slight hissing noise I guess. But I don't even notice that unless I'm standing in front of the car with the hood up, and even then I'd have to crack the throttle to hear any whooshing sounds.

**planemech2** · 02-12-2012, 06:26 PM

I also did the "free ram air" mod when I got my SLP lid 12 yrs ago. Made a big difference on the SOTP gauge.

***SMWS6TA*** · 02-12-2012, 07:23 PM

Originally Posted by Firebirdjones

I'm sure it's worth a few. Hard to say exactly how much because it's tough to measure on a dyno. A fan doesn't simulate the air you would have moving over the car as it would while driving.

But basically you are removing the huge baffled air intake designed to reduce noise (and as a result reduces air flow) for a debaffled lid with a larger plenum area.

It's a simple mod that's worth doing.

Think of the SLP air lid like this. Our cars love air, lots of it. The air lid GM design makes our cars like asthmatics breathing through a straw. Give it a SLP style lid and now the kid can run marathons.

Originally Posted by Guerrillakilla13

Thanks guys, I knew that the ls1's have restricted airflow up the butt but i didn't know why they would do that for the airlid. The noise wont bother me at all! That's pretty awesome. But just for the hell of it, how much louder does it make the engine bay?

Like FBJ says below - You will notice a difference, when combined with the free air mod, when I bump the throttle body you can hear a loud sucking noise even with headers. But in the car or with the hood down, nothing. But honestly I like it.

Originally Posted by Firebirdjones

I honestly don't notice a difference in noise. But I'm old and deaf

You'll hear a slight hissing noise I guess. But I don't even notice that unless I'm standing in front of the car with the hood up, and even then I'd have to crack the throttle to hear any whooshing sounds.

Originally Posted by planemech2

I also did the "free ram air" mod when I got my SLP lid 12 yrs ago. Made a big difference on the SOTP gauge.

This mod is a must to do. Simple and takes only about 20 mins. Only negative is you will need to change your paper filters quicker or if you have an oil base filter - clean it more.

**Guerrillakilla13** · 02-12-2012, 09:08 PM

sounds promising

I don't mind if it makes that much more noise, because it'll just sound more serious and angry I'd think.

The free ram air mod sounds good! I'm not too sure about replacing the filters that much though it sounds kind of annoying..

**Too Fast** · 02-13-2012, 02:23 AM

^^^The sound I noticed was a louder, deeper intake roar under half-throttle or more. It wasn't obnoxious by any means, and not a whole lot louder, just different.

I'd rather seal the hood to the air filter than do the FRA mod. My filter stays pretty clean for a long time, and it's nice to feel a cool intake after driving (I'm not saying the FRA won't have a cool intake temp!).

Oh yeah, just get a quality paper air filter. No need for anything fancy, this has been proven many times also, especially the first time someone experiences driveability issues and finds out it is from oil on the MAF that came from their million mile filter.

**FriendOfLS1** · 02-24-2012, 09:38 AM

Does anyone offer a smooth-tract intake boot that goes between the SLP lid and throttle body to get rid of the crappy design accordian rubber piece that is between the lid and throttle body?

***SMWS6TA*** · 02-26-2012, 05:52 PM

A lot of ppl go to Lowes or Home Depot plumbing section and get something for the life of me I can't remember now it's name. Cost about $5-8 plus hose clamps. Saves you about $60-$90 for the "SLP Smooth Bellows"

**INMY01TA** · 02-26-2012, 06:35 PM

The Home Depot piece is called the Fernco mod. I got rid of my free ram air mod with a new uncut radiator cover thingy. My tuner told me alot of heat comes up from the radiator and strait into the intake probably negating any gains from it.

**98maro** · 02-27-2012, 01:43 AM

I don't how much power it adds , but I have to say you really feel the difference.
I put the slp lid, p&p TB, cleaned the maf, and replaced the accordiong piece, at the same time. Oh boy. That car pulled hard after that.
If you buy a lid, get a used one save some cash and get a ported TB from eBay. It's worth it

**88gtman** · 02-28-2012, 08:43 AM

You will gain nothing but looks from the smooth bellows. $60 to $90 for a piece of rubber is ridiculous to me. I have also seen no proof of believable gains from changing to it. Most dynos can vary about 5hp between runs. Anything gaining less than that is arguable. To each his own though.

**TA98** · 03-02-2012, 12:31 PM

my butt dyno showed no gains. But for appearence it does look a lot cleaner.

**Firebirdjones** · 03-02-2012, 12:53 PM

Anytime you can clean up the air intake track it's a benefit. Cuts down unwanted turbulance.

**transamtom** · 03-02-2012, 03:13 PM

I did testing at the dragstrip,here is my progress report for each mod,the weight reduction was the spare and rear seat.

1st time to track Sept/2010 .. 60ft 2.09 13.71 at 103.69mph bone stock

2nd time Oct/2010 ..60ft 2.001 1/8th 8.683 at 82.85mph 1/4 13.462 at 102.63mph Lid and weight reduction

3rd time Nov/2010 .. 60ft 2.08 1/4 13.37 at 106.00mph as above with 275/40/17 Yoko's/some free mods

June 7th..60ft 2.066 1/8 8.534 at 85.57mph 13.141 at 107.83mph Headers/Tune/DR's/

July 6th..60ft 2.008 1/8 8.415 at 85.84mph 13.031 at 105.95mph /RLCA's PHB/Ported TB

Aug 19th.. 60ft 2.073 1/8th 8.593 at 85.38mph 1/4 13.202 at 106.43mph/ LS6 Intake

Aug 31st.. 60ft 2.068 1/8th 8.567 at 85.60mph 13.183 at 106.10mph Magnaflow CB

Sept 5th ..60ft 2.038 1/8th 8.411 at 86.69mph 1/4 12.976 at 107.01mph /same as above

Oct 22nd..60ft 2.031 1/8th 8.363 at 87.37mph 1/4 12.887 at 108.49mph /same as above

So with hardly any improvement in 60ft except consistency the car has gone from 13.71 at 103.69mph to 12.887 at 108.49.

Thats a .823 of a second and a 4.8 MPH improvement over stock with Free Mods,LS6 Intake,CAI,LT Headers,Tune,RLCA's PHD Bar and DR's with minor weight reduction(rear seat/belts/spare)and basic maintenance.

BTW it has 126,000 miles on her not KM's and now has 50+ dragstrip passes on her that I know of.

**Guerrillakilla13** · 03-02-2012, 06:11 PM

^^^^^^ Awesome info

If i really want to get the most power from putting in a new airlid, I just need to consider buying the SLP airlid and a new TB?.. Sorry guys I sound clueless, i'm still a rookie

**Firebirdjones** · 03-02-2012, 07:05 PM

That's really all up to you.

Tom posted some interesting info and spent some time doing it. Not knocking the effort, but I see alot of fluctuation in ET and MPH, even when no changes are made. Most likely DA changes from month to month since these runs are spread out over a long period. Hard to pinpoint how well everything actually worked for you.

**transamtom** · 03-02-2012, 11:28 PM

Originally Posted by Firebirdjones

That's really all up to you.

Tom posted some interesting info and spent some time doing it. Not knocking the effort, but I see alot of fluctuation in ET and MPH, even when no changes are made. Most likely DA changes from month to month since these runs are spread out over a long period. Hard to pinpoint how well everything actually worked for you.

Yes you can really see the effect of heat and humidity on a cars ET,even the 60ft.