I have read good things on both. Lingenfelter is running a special through today on their's but which is better? I know they are both different but I don't full understand bottom feeders to non bottom feeders and such? Which dyno's better etc.. Thanks

 

Personally I would stick with Halltech do to possible water injestion with bottom feeder. My credentials are that I had hydolock with a bottom feeder. Also Halltech does have a cold air feed that is secondary and isolated from direct water. Third would be the larger filter size of Halltech vs others, the larger the area the less effect it has on flow by the square. Below are my graphs of before and after. These graphs are after nearly 10 hours of tweaking on a dyno, two sessions. What concerns me is the advertised and pictured graphs of an increase at the low end and mid range, not having a warm and fussy with that. These aftermarket front ends help with flow and that would be at the higher rpm's as shown in my graphs. Also remember it's not the peak so much as the delta RWHP above 6K rpm's. One significant mod is to increase the Rev range so as to use that delta. The second graph is with an extremely accurate dyno and was compared to several stock C5 Z06's and was consistantly 10 hp higher. Unfortunately there wasn't any other C6's there that day.

 

Jim brings up a good point, most members want to buy a part, install it, and see results. It is nice to be able to spend 10 hours doing dyno and tuning work, but how many people can realistically do that??


Literally dozens of members have purchased our unit in the last few weeks, and seen noticeable imrovements in horsepower and torque instantly, without any computer programming. If you do have the luxury of being able to put the car on a dyno and do some tuning, then you will see even bigger gains. Another thing to point out is that a few of them have gotten caught in downpours after installing our intake, one member even went so far as to take his apart, and test for moisture in key areas immediatly after, and guess what? no issues. There is a slight risk of water ingestion with a bottom feeder, but it's not the "taboo" that some would like you to believe.

Feel free to let me know if I can answer any questions for you,
Ed

 

Not trying to detract from you system, just presented my findings. As far as water, it's not the downpour that one has to worry about. It's when you have standing water and the front wheels cause a wake similar to a boat and that magnifies the depth, that’s what got me. As far as staying away from water is like saying I don't need seat belts. To explain, it's when you are in traffic and standing water comes up on you with traffic behind, you don't have to luxury of just slowing down or going around. Since you've warned people it's really on them to decide.

 

What he said...

Rick

 

If I'm reading the graphs correctly, it looks like the majority of the improvement was due to the tune rather than to replacing the air cleaner assembly.

 

My point exactly, if your looking for the better product, then the LPE intake is the way to go.

 

 

Both had about a 10hp increase but the intake was cheaper.

 

Was curious as to how you drew that conclusion from the text you responded to.

 

This is the reason I won't be going with a "bottom feeder". I will not be putting my car at risk of hydro lock just for a few extra ponies. Another important point that's being missed is the filter is directly in the air stream that just above the ground. This air stream is DIRTIER and filled with debris, and as speed increases so is the likely hood of this debris penetrating your airfilter making its way into you engine.

 

I've often wondered about this. Personally I went with the haltech stinger + CAI. In my opinion, the bottom breathers probably put out more power than the Stinger will. However, there is the increased risk of hydro-lock. I believe this risk is miniscule, but personally I felt the Stinger was better for me. The Stinger can also be reverted back to stock in 10-15minutes, while with bottom breathers, you'd need to buy and replaces the stock shroud you cut open.

I've had a bottom breathing intake kit on my 98 Z28 for 7 years. The setup is roughly identical to what a bottom breathing intake would be like on a C6. What KGB6 says is very true. The airstream from the bottom of the car is DIRTY as hell. My air filter would be black along the edges after about 10k miles. Another 10k and the entire filter element filthy. The edges had piled on cake and grime, while the center was simply black. I'd also find all sorts of debris, things like small pebbles to various insects (flies, bees, etc) that just get sucked up. I got fed up with trying to clean the damn thing all the time and just bought new k&n filter elements every 30k miles.

This brings to mind another point. Someone had posted on here recently a third party test of various air intake elements. It was proven in this test, that though the oiled cotton elements (basically all the after market air intake elements) flowed a small percentage better than the stock paper element (something like 7-10%), it also let through a large percent more dirt (50-60% more Dirt). Of course percentages are not conclusive in and of itself without firm numbers backing them up, this finding is eyebrow-raising in itself. I'm certain that bottom breathing intakes would exacerbate this problem more than a non-bottom breathing unit would.

My conclusions:

Bottom breathers: More power, possibly more problems.
Non-bottom breathers: Less power than bottom breathers, less possible problems than bottom-breathers.

 

I think the jury is still out on the power difference between bottom and above shroud methods. I measured the air temp at speed with the above shroud method with no modifications and the temp was within a degree of ambient. So the cold air thing maybe in question but Halltech is providing an indirect flow anyway. The ram air thing is just plain BS. Another thing to look at is the surface area of the filter. The bottom feeder’s surface area isn’t all that great as compared to the ones above the shroud. The flow resistance degreases with the square of the filter area, look at the difference and do the math.

 

There is only one way to settle this

An independent head to head test

 

By looking at the dyno graph. Your second and third runs (after tuning) basically lay on top of each other up to 5K rpm, then start to improve. When you compare this to the baseline run, it shows small gains up to 5K rpm, then a big increase after 5K. It's a little decieving if you just compare peak numbers.

 

But that is exactly what one would expect with a free flow intake system, very little at low rpms where the flow isn't threatened. All the systems will do that so it's just how it is accomplished, above or below the shroud. I don't think quality of any system is in question here. Your correct in saying that peak power is deceiving and it's the delta between before and after at high rpms that is important. It was determined that the lines fall on one another with the before and after filter install. Also and most important that the before and after filter fell on the line exactly the same before and after tune. In other words with or without tune the effect was only at the high end. Now if your saying that yours has and increase at low rpm's that I'd have to see because all my tests don't show that at all.

If I were in the business of manufacturing and marketing this type of product, I would have done a comparative analysis of all my competition. This would have been investing in the 1000 to 1500 to buy all the current products and spending two days on a dyno with the same car testing them. One would also have to do a full tune after each unit was tested to eliminate that computer variable. Then of course repeatability tests to insure data stayed intact.

 

That's exactly what I'm saying Jim, I know you saw the dyno graph last week posted by a 21st century customer, baselined with kooks, highflow cats, corsa, and halltech air intake, changed to an LPE intake, no tuning changes, and picked up HP and TQ across the board! The peaks were 9 HP and 20 FT LB!!!!!

Are you saying you didn't see this? If so, let me know, I saved a copy.

I agree with your theoretical testing procedure 100%, becuase that's exactly what we did! You want a deal on the pile of stuff we have out behind the shop?

Ed

 

I seen that one but disregarded it do to the fact that there is no way in my mind that freeing up the intake on the C6 will give you that much of an increase on the low end of the band. Now when I pushed back I received no explanation of the testing method. The track record of most after market guys on proper testing is dismal at best. For example I got a similar graph but it was do to the car liking heat the lower was when it was just warm and the second when engine was hot, looks suprisingly similar.

 

Would it be possible to see an independently conducted test of both systems under tightly controlled conditions to settle this once and for all?

I am sure all of your customers would love to see this happen