look at the pics above, the hamburger's o-ring dips down too.

 

The inside differences probably just makes one or the other whistle louder. The big question is if the H is wider than the 3/4" of the A.

 

I don't have the dyno sheet, but on my third gen 383, my dyno tuner was getting pissed bc i was down on power. He took the spacer off, and bolted the TB back on using shorter bolts and i gained 10 rwhp and 8 ftlbs of torque.
Not sure if anybody knew him, but the guy that did that for me was Jamy from Akron Horsepower.

 

Hmm...

 

Yeah but did you have ls6 heads and an ls4 intake?

 

I installed mine last night & I love that "whistle"

But there is something that I thought I should address:


You'll should notice that MonteSS8707 is set up different from mine.
notice his spacer is facing "upside down" I think! Someone help me out here:








Now on The Crusader's:



notice the the flat end faces up!!
Do you guys see the tip of that light green stock gasket?? Well thats the pointy part of our upper intake, Throttle body, & throttle body spacer as well!



This is a Hamburger pic for reference only. This pic of the TB Spacer is also upside down as well! (to stand it up!!)
I too have the AiRaid throttle body. And both Hamburger and AiRaid are pretty much identicle.
Any how, You'll see how the gasket "groove" comes into a point. Now on our upper intake, you'll notice that you will see the same point on the TOP of our intakes, not the bottom. So I just match it shape for shape! Kept the original gasket on because it seems to seal better!! The AiRaid gasket may not be thick enough!





Someone let me know if it's even this serious!! One would presume so! But just thought I give you guys more insight on this mod!! But anyway I could certainly feel a increase in power! I need to moniter the gas & see if any increase on that as well! But over all I like the "spool" sound & of course the power increase!

 

http://store.summitracing.com/largei...g=mvc-5022.jpg

heres another tb spacer option this one looks different that the others
and another
http://cpwstore.carpartswholesale.co...y+spacer+42105

 

On the Airaid spacer the flat part of the spacer with the serial number goes up. This matches the throttle body and intake. If this is still unclear, I will take picture of the spacer and my throttle body for clarity.

 

Exactly!! thanks for your input on this!! I want to make sure that my fellow LS4 guys install this TB spacer correctly!! While I was installing I had "MonteSS8707's" pic up for image reference, and I noticed the boo-boo!! But I hope he see's this & corrects it! as a matter of fact I will PM him now.....

 

what are those oval aluminum brackets/extenders in the kit for???

I notice that Motorvation kit has them too:

http://static.summitracing.com/globa...e/mvc-5022.jpg

 

the intake tube is attached to a mounting point on some vehicles. sorta like the metal bracket a k&n cai kit has for our vehicles. instead of bending that you would use the adapter to change the mounting point.

probably used on the intended application trailblazers and envoys.

 

agreed those oval brackets are useless for us!!

But that spacer is not!!!

 

Ok, just threw it on. Stock intake. The whistling is very soft, I was concerned that it might be annoying, but it is very subdued, hard/impossible to hear with the window up unless fairly hard (but not WOT) on the gas.

I logged a series of speeds, intake temp, throttle position, all sorts of stuff at specific points in my trip home from work. Will log the same under the same conditions tomorrow and see if there is any empirical evidence showing change (less acutal throttle positions and the like after the spacer was added). First impressions is that it pulls slightly better/harder at low/normal throttle positions, but if I can't measure it, gonna call shenanigans on it. Had two WOT bursts from 40-65 and will see if any time drops off from that. I know exactly where I dropped the hammer on it, so road flatness should not be a big factor.

We shall see. Install was a breeze (for doing in almost pitch blackness with a weak flashlight, took about 45 minutes) and I did NOT need the 3/8" hose with the stock intake.

 

Be interesting to see a comparison of MAF or VE airflow to ETC% with and without the spacer.

The only way more power can be made is if this thing allows the engine to take in more air, so you might want to compare IAT or MAT between the two data sets as well to filter out density changes due to temperature differences.

Just my .02, but if you are hearing a "whistle", to me that indicates that the spacer is creating turbulence. Except in the combustion chamber, turbulence is generally considered a bad thing, since it reduces airflow...

 

yeah i think he is right about the wistle i have been looking for one that is just smooth instead of spiraled or textured or whatever did they use those throttle bodys on any other cars?

 

I dont have the first dyno run printed out but i have my final dyno run.

 

Data shows an average of 8% less throttle opening at 55 MPH cruise over the same road. On the only good matching 40-65 run I had, the times were so close as to be statistically insignificant in my opinion. Over a 5 second WOT period, with the spacer, it shows 2 mph faster, but I place no credence in it due to variations in the road/operator even though I hit the throttle at the same marker on my trip. Showed ~6% greater GFM at low to medium commanded throttle and no change in A/F ratio or GFM at WOT. There was no difference in corrected maximum absolute intake manifold pressure. I could not get a good run from a stop due to wheelspin with or without the spacer. It certainly feels stronger down low and the cruise control held speed up hills where it would normally drop 1-2 MPH. The big one, which surprised the hell out of me was in the 5000-6000 WOT bursts in first. The runs show the spacer took (in all three tests) off between 0.1 and 0.3 seconds from the time to run that 1000 RPM. While I did the best I could to do them at the same point on the road, there is obviously a huge chance of error building up, but it did NOT go back and forth around the same point as the other inconclusive (to me) measurements. It cut time each and every time. Subjectively it certainly seemed to pull harder above 5000 RPM and below ~3000 RPM.

I would say there is a benefit to it, in the low/medium midrange and up top, which increases my enjoyment of the car during normal driving and I believe you may be able to measure a difference in the quartermile, but it would not be anything more than driver skill (or lack thereof) would add/subtract on a track.

My next long highway trip, I will see if there is any economy benefit (I track my mileage very closely), might be with the smaller throttle openings needed at cruise, but I would expect it to be minor if anything.

 

Interesting!!!! I still need a true dyno comparison, stock with and without. Sorry but I'm a huge skeptic.

 

Sittingmongoose says he dyno'd 9hp/17tq increase with the spacer added.

I work on these motors all the time in the MC SS and the Impala SS at my work. I've never taken a good look at them in terms of performance mods though. Today I looked at mine and notice how bottle-necked the LS4 intake manifold is right after the TB flange. It is molded like this to clear the oil pressure sensor. I never realized how restrictive the manifold is until I found this pic on a fiero website (TiredGXP's ??):

Comparison of an LS4 vs. LS2 intake


Its rediculous how choked off it is, and so abruptly after the throttle body. I bet the reason we are seeing gains with the TB spacer on this intake is because of this restriction. It bottle-necks so close to the throttle body that the air can't build up any velocity, like a 3 lane to 1 lane merge in rush hour traffic. The spacer gives the incoming air an extra inch of playing room to taper into the restrictive intake, resulting in extra velocity. I don't think the funny patterns inside the spacer do anything for performance at all, just for looks.

I was considering this TB spacer, but now I'm going to look into swapping an LS2 intake before I go any further.

 

I'm not saying its impossible, I just need dyno proof, with an actual hp/tq numbers!

I just have a hard time with believing that a measly 9.5 cubic inches of air in the intake will give you a measurable amount of hp/tq!