ronaldrcan

I recently sent this question to Tadge and was told he does not answer modification questions. Can one of you knowledgeable techies possible clue me in? Mr Tadge J, I have read lately the claims that aftermarket air boxes and less restrictive air filters are gaining up to 50 hp. That, because of less restriction, the boost increases 1 to 2 pounds. If this is true shouldn't the boost increase even more if the air filter is removed ? Why did my time go from 11.0 to 11.3 with filter removed? The car is totally stock including air box. 2015 ZO6 C7 Running Ron

JerryU

^^^^
Tadge answered a question regarding low restriction air intake systems for the forum, you can look up the whole response but here is what I abstracted (you can't expect him to answer questions from every Vette owner!):

"We do not routinely test aftermarket induction systems or any other aftermarket parts for that matter. We have our hands full designing, building and testing our production hardware. Although simple in concept, induction systems play an important role in many vehicle performance areas. Aside from the exhaust, there is no greater noise source on a performance vehicle.

Induction systems generally have many tuning elements that ensure the quality of the sound emanating from it are pleasing and harmonious with the exhaust note. These tuning elements also dampen the sound energy to help with pass-by requirements. Aftermarket companies don't have to worry about it, but as the OEM, we must guarantee that our products are quiet enough to be driven at full throttle by a microphone by the side of the road and meet certain decibel levels. There are pass-by laws in many states and pretty universal around the world.

Another important element in the induction system is the mass air flow sensor or MAF. Engines can only run at their optimal efficiency if they have very precise data on the amount of air flowing into them. Although most people think of air flow into an engine as fairly continuous, it really is not. The opening and closing of valves and reciprocating nature of internal combustion engines means the air flow is really a series of pulses which make measuring the exact flow challenging. Intake engineers spend a lot of time optimizing the system to get excellent signal quality out of the MAF. In addition to efficiency, or fuel economy, the precise metering of air and fuel is directly correlated with tail pipe emissions, an area of extreme scrutiny by government agencies for we manufacturers."

Assuming your 0.3 time difference was not due to your skill, the air temp etc it could be, without a filter the MAF was getting an inconsistent signal from the more turbulent air movement past it. It is located right after the filter!

I added a low restriction intake system, filter and tube, on the 2014 Z51 I sold. Removed it prior and will install it on my Grand Sport on order. A poster had his Vette dyno'd before and after installing one from the same manufacturer and got 10 more HP. He used a low restriction paper filter and I have the even less restrictive oiled cloth filter from the same company. The filter itself is larger than the OEM so in addition to less restrictive filter material the size is less restrictive as is the slightly larger, smoother bend intake tube.

The main benefit is that sucking sound at WOT! Although the manufacturer states 17 more hp, 10 is probably more like what you can expect. However there is still a filter present and air flow will be controlled similar to the OEM past the MAF. I look at it as it was half the cost/hp gain than NPP!

As an example of the "noise issue," as Tadge discussed, I have a 14 inch diameter 5 inch high K&N oiled cloth air filter on the 8.2 liter engine in my street rod. It also has long tube headers that empty into 3 inch pipes and straight through Borlas with the outlet right before the rear wheels. (There is no room to get the exhaust past the 16.5 inch wide Mickey Thompson's tucked in a tubbed, 4 bar link rear!) At WOT the intake makes as much noise as the exhaust! Great sound. So as Tadge stated, GM needs to meet max sound level requirements.

ronaldrcan

JerryU Thank u so much for your response to my Question, it was technical and very well stated. Just what I needed. I just went over the 36,000 mile mark ( in 18 months) and have had nothing go wrong with the car. I run it in the 1/4 mile and also in the 1/8 mile about once a month and have never had an issue(except what tires work best). Thanks again for taking your time.

JoeD-C8

I don't race my car but after some research I found that this filter was highly recommended and required no change in intake configuration. Slightly off of topic.

"After engine dyno testing & chassis dyno testing Lingenfelter has found the best air intake combination is the factory C7 Corvette air box along with the Green Air Filter element."

vbdenny

Switched to a K&N filter but just in the stock airbox. Feels like I gained 5hp. Ha.

ronaldrcan

Thanks for your response. Did you notice in increase in boost? the way I understand it , less restriction results in a pound or two of more boost and thiss is where the extra horse power comes from

robert miller

No way you will get 1 to 2 lbs of boost from just a filter on the stock set up on the car. Hell if your looking for that just pulley down & get it retuned.

But no way would I run a car all the time on the street without a filter on it. Track would be a diff story. Robert

ronaldrcan

I was inclined to agree with you, 35 to 50 hp from a less restrictive intake , NO WAY. But as I researched it by making phone calls to the manufacturer who referred me to some of his customers who dynoed there results I had to consider it. What seems to happen is the MAS picks up more air flowing and the resulting changes causes the boost to increase slightly usually around one pound. I did some research when I put headers on a car and the HP went down and found that less restriction on the exhaust caused the boost to go down thus loosing HP . When I got this project done ( headers, heads, cam, intake, bigger supercharger I had over 200 HP gain but then could not attribute how much HP came from what item.) But this boost up versus boost down has got me really interested in what is behind it. If you or anyone could give me some technical reason why this occurs I would love to understand it better. As for running without a filter I would never do that. Except for the twice down the track to verify my experiment, in which I lost boost and thus ,3 in time . this was explained to me being caused by the air going past the MAP in turbulance . Regardless my conclusion is they are getting 40 HP gains from the boost that increases not from the filters. If the boost was controlled to stay at the systems origina pressure there would be little change in hp from the filter system itself. Your feedback positive or negative will be welcomed.

0JUICED1

These LT4 blowers are spun very hard from the factory and benefit from a cold air intake. 30-35rwhp are very common on AFE and Halltech installs without a tune.

ronaldrcan

Thanks Juiced1 that is a very good point. I will add it to the list I am making

CCA Corvette Parts

Don't want to get into the back and forth about intakes, but we
sell a ton of these...

https://www.corvettepartsandaccessor...ow-engineering

Tks
Chip