The snorkel is the OEM piece that the Downforce intake scoop replaces. It has an intake scoop side and a long, blocked off resonance tube on the other side. Seen here on the left without the resonance tube attached.
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Downforce i take vs cold air intake
- Thread starter makija
- Start date
The snorkel is the OEM piece that the Downforce intake scoop replaces. It has an intake scoop side and a long, blocked off resonance tube on the other side. Seen here on the left without the resonance tube attached.
Is the concern here air intake temps or ram air?
In my opinion why not just keep the factory air box but use a foam filter with the downforce scoop. I will vouch for the down force scoop, I saw the difference in air temps on my car with and without it by a few degrees. When the ambient temp was 24 C with out the scoop my itb air box temps where over 35 C. With the scoop installed the following day with the same ambient temp and same route driven my intake temps stayed 3-4 C above ambient. That includes stop and go traffic as well as freeway driving.
In my opinion why not just keep the factory air box but use a foam filter with the downforce scoop. I will vouch for the down force scoop, I saw the difference in air temps on my car with and without it by a few degrees. When the ambient temp was 24 C with out the scoop my itb air box temps where over 35 C. With the scoop installed the following day with the same ambient temp and same route driven my intake temps stayed 3-4 C above ambient. That includes stop and go traffic as well as freeway driving.
Since I already have a scoop in place, would I want the scoop to:
(a) feed into the bellmouth (that would take away from the function of the bellmouth, which is to smooth the airflow as the engine is sucking it in), or
(b) feed a structure that encloses the bellmouth?
(a) feed into the bellmouth (that would take away from the function of the bellmouth, which is to smooth the airflow as the engine is sucking it in), or
(b) feed a structure that encloses the bellmouth?
The snorkel is the OEM piece that the Downforce intake scoop replaces. It has an intake scoop side and a long, blocked off resonance tube on the other side. Seen here on the left without the resonance tube attached.
The analogy that I like to explain to people in real world sense is that when people blow candles out they create an aperture in their mouths that is properly mated to their diaphragm/lung abilities - hence the smaller aperture of the mouth.
No one blows out candles with their mouth agape.
I'm not sure what you're trying to ask or describe here but...
The idea came up to completely remove the scoop and replace it with a simple bellmouth that pulls air from the fender into the stock airbox. While you'll lose the Ram Air effect from the scoop, you'll benefit from a reduction of debris going into the airbox and maximize the airflow through the opening because of the added bellmouth.
OEM snorkel with that stupid resonator kills the sound of the NSX having "soul".
I remember prior to installing the SOS SC I was running the DF scoop and NSX intake sounded like it was an F car. I loved it.
After the SOS SC was installed it took that sound away...... one of the reasons why I wouldn't mind a stroker all engine NSX project down the line.....
I remember prior to installing the SOS SC I was running the DF scoop and NSX intake sounded like it was an F car. I loved it.
After the SOS SC was installed it took that sound away...... one of the reasons why I wouldn't mind a stroker all engine NSX project down the line.....
Oh, OK. In that case, that shouldn't be an issue. I have a silicone 3.5"-->3.0" reducer/coupler that should mate the BPi 3.5" bellmouth to the fender opening nicely. I might experiment with that this weekend and I'll report back.
The conversation should end here lol. Actual dyno, stock NSX.... 1 hp. And, it was on a 3.2 where there actually is supposed to be a slight restriction in the intake tract.
Here is a stock NSX with stock airbox and gutted cats(with KN filter) compared to a DF scoop with foam filter mod, going into a three inch pipe directly to throttle body on the same car. No other mods. The gains are all up top and not so much down low. Although you did bring up a good point because all of my intake data has been done on NA1 engines. The only NA2 data I have with these intakes is with SC . I cannot vouch for how this setup would do on NA2 naturally aspirated. As for the constant attention to engine flex, all intakes I make are attached via a bubble coupling which allows for flex. I have even done wiggins clamp setups on these for the guys who like to spend the big money for whatever reason they see is relevant haha.
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The snorkel is the OEM piece that the Downforce intake scoop replaces. It has an intake scoop side and a long, blocked off resonance tube on the other side. Seen here on the left without the resonance tube attached.
Remember the reason for the shape of the DF scoop is that it is a copy of the same scoop Honda used on the LeMans GT NSX. That car spent most of the race at 100+ mph on the very fast Sarthe circuit, so ram air was the main goal.
Since our cars are mostly street driven, I think a large bellmouth sticking out of the 3" fender opening would be ideal because ram air is not really an issue.
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Was the engine management system the same in both runs? Looking at the chart, in dynorun.010 the rev limiter seems to have kicked in at 7700 rpm and in dynorun.012.drf, at 7950 rpm.
If the rpm weren't measured from the tachometer pickup loop in the engine compartment but were calculated from the roller speed, lots of mistakes can creep in. Different rear tire sizes that weren't taken into account, different amounts of tire wear which are almost never taken into account, different amounts of slip, etc. can all impact the results. If the runs were carried out on different days, the calibration of the dyno may have drifted and if the temperature wasn't the same, that will also impact the results – especially if the "uncorrected" figures were reported. I say that because one dyno said my car puts 408 hp to the rear wheels and another said 270 rwhp and the car was in the exact same state of tune and had the exact same mods during both runs.
To see what impact a new air filter, intake tubing, etc. has, it would be good to do a baseline run and then test the same car on the same dyno on the same day with a modification, measuring the rpm from the tachometer pickup loop in the engine compartment.
Don’t make it so small! The cross section of the entrance opening in the stock Honda airbox is equivalent to a 3.6" circle.
Edit: it would also be interesting what the effect would be of just popping the 2" resonator off the stock intake snorkel and putting a bellmouth on there instead. Since the resonator is round, it shouldn't be too difficult to find a 2" round bellmouth to fit. And the main intake opening of the snorkel plus the resonator opening together have a cross section equivalent to a single 3.7" opening. The path of the airflow wouldn't be as straight as with a Downforce scoop or a 3.6" bellmouth but it would probably keep the air filter cleaner than either. It would be interesting how that flows.
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It may be worth mentioning that the air/fuel is not sucked into an engine but rather pushed into any cylinder where the air pressure inside the cylinder is lower than the air pressure outside that cylinder.
Does examining the flow dynamics of air being pushed into an intake system rather than pulled suggest any improvements or is it all the same thing?
Does examining the flow dynamics of air being pushed into an intake system rather than pulled suggest any improvements or is it all the same thing?
In 2008, a couple of NSX owners in England got together for a dyno day. The facility didn't just measure torque and power but also the ambient air pressure and the air pressure in the entrance of the intake manifold (by T-ing into one of the vacuum tubes there). By comparing those two pressure measurements, we can check how much of a pressure drop was caused by everything upstream of the intake manifold.
In those bone stock NA2s, there was very little pressure drop through the intake system at low rpm and at higher rpm, it reached 37 millibars.
How many horsepower that drop in air pressure cost can be calculated with dyno correction factors. Applying those, the restriction seems to have reduced the peak power generated by 11-12 horsepower.
That's how many horsepower the stock NA2s at that dyno day could have gained by completely getting rid of the entire restriction caused by everything upstream of the intake manifold. To achieve that, they would need to lose their intake snorkels, airboxes, air filters, bellows, and throttle bodies and just bolt optimally-shaped bellmouths to the entrances of their intake manifolds instead. And remove the rear hatch glass and the engine compartment lid so that the engines still inhale cool air from outside. Without a throttle body, the engine's power output could no longer be modulated so it wouldn't be very practical for stop-and-go driving. But based on the pressure drop data logged, the engines could probably have produced 11-12 more peak horsepower that way.
In the real world, you want to have a throttle on your NSX and an air filter. Every throttle, air filter, intake tube, etc. causes some restriction so you're never going to be able to get the restriction down to 0 (unless you use a roof-mounted intake like that on an NSX-R GT to try and achieve a ram-air effect, maybe). Based on the data logs from that dyno day in England, the stock airbox and air filter don't seem to be strangling stock NSXs so modifications in that area shouldn't be able to bring large horsepower gains.
It would be great if we had more pressure drop measurements for the stock intake system to corroborate the English measurements and data for the individual components: snorkel, air filter, throttle body, etc. If we had data for aftermarket alternatives as well, see could see how restrictive various configurations really are. Every mechanical system can be improved upon. But for stock NSXs, based on the data we have, it doesn’t look like Honda's airbox / air filter can be improved much in terms of horsepower. The intake noise is a different matter, of course.
In those bone stock NA2s, there was very little pressure drop through the intake system at low rpm and at higher rpm, it reached 37 millibars.
How many horsepower that drop in air pressure cost can be calculated with dyno correction factors. Applying those, the restriction seems to have reduced the peak power generated by 11-12 horsepower.
That's how many horsepower the stock NA2s at that dyno day could have gained by completely getting rid of the entire restriction caused by everything upstream of the intake manifold. To achieve that, they would need to lose their intake snorkels, airboxes, air filters, bellows, and throttle bodies and just bolt optimally-shaped bellmouths to the entrances of their intake manifolds instead. And remove the rear hatch glass and the engine compartment lid so that the engines still inhale cool air from outside. Without a throttle body, the engine's power output could no longer be modulated so it wouldn't be very practical for stop-and-go driving. But based on the pressure drop data logged, the engines could probably have produced 11-12 more peak horsepower that way.
In the real world, you want to have a throttle on your NSX and an air filter. Every throttle, air filter, intake tube, etc. causes some restriction so you're never going to be able to get the restriction down to 0 (unless you use a roof-mounted intake like that on an NSX-R GT to try and achieve a ram-air effect, maybe). Based on the data logs from that dyno day in England, the stock airbox and air filter don't seem to be strangling stock NSXs so modifications in that area shouldn't be able to bring large horsepower gains.
It would be great if we had more pressure drop measurements for the stock intake system to corroborate the English measurements and data for the individual components: snorkel, air filter, throttle body, etc. If we had data for aftermarket alternatives as well, see could see how restrictive various configurations really are. Every mechanical system can be improved upon. But for stock NSXs, based on the data we have, it doesn’t look like Honda's airbox / air filter can be improved much in terms of horsepower. The intake noise is a different matter, of course.
In 2008, a couple of NSX owners in England got together for a dyno day. The facility didn't just measure torque and power but also the ambient air pressure and the air pressure in the entrance of the intake manifold (by T-ing into one of the vacuum tubes there). By comparing those two pressure measurements, we can check how much of a pressure drop was caused by everything upstream of the intake manifold.
In those bone stock NA2s, there was very little pressure drop through the intake system at low rpm and at higher rpm, it reached 37 millibars.
How many horsepower that drop in air pressure cost can be calculated with dyno correction factors. Applying those, the restriction seems to have reduced the peak power generated by 11-12 horsepower.
That's how many horsepower the stock NA2s at that dyno day could have gained by completely getting rid of the entire restriction caused by everything upstream of the intake manifold. To achieve that, they would need to lose their intake snorkels, airboxes, air filters, bellows, and throttle bodies and just bolt optimally-shaped bellmouths to the entrances of their intake manifolds instead. And remove the rear hatch glass and the engine compartment lid so that the engines still inhale cool air from outside. Without a throttle body, the engine's power output could no longer be modulated so it wouldn't be very practical for stop-and-go driving. But based on the pressure drop data logged, the engines could probably have produced 11-12 more peak horsepower that way.
In the real world, you want to have a throttle on your NSX and an air filter. Every throttle, air filter, intake tube, etc. causes some restriction so you're never going to be able to get the restriction down to 0 (unless you use a roof-mounted intake like that on an NSX-R GT to try and achieve a ram-air effect, maybe). Based on the data logs from that dyno day in England, the stock airbox and air filter don't seem to be strangling stock NSXs so modifications in that area shouldn't be able to bring large horsepower gains.
It would be great if we had more pressure drop measurements for the stock intake system to corroborate the English measurements and data for the individual components: snorkel, air filter, throttle body, etc. If we had data for aftermarket alternatives as well, see could see how restrictive various configurations really are. Every mechanical system can be improved upon. But for stock NSXs, based on the data we have, it doesn’t look like Honda's airbox / air filter can be improved much in terms of horsepower. The intake noise is a different matter, of course.
In the real world, there are dyno results showing this notion to be very conditional. You are showing a set of circumstances on a given day in a different location, different elevation, without the dyno results. Even if you had the results from that day is does nothing to compare with data you would get at my location. I have 13 different sets of data on 13 different NSXs both naturally aspirated and supercharged and every single one of them has shown power gains getting rid of the factory airbox and installing a proper intake. All of my results are done on the east coast of the US. I can change my correction factor on the dyno to represent Europe and the numbers read lower. Reason being is the atmospheric conditions. When there isn't as much ambient air density, hp gains (whether they are 1hp or 10) will be lower than here where I am (elevation about 500ft.) My dyno is programmed for my elevation and it has a weather station to add to its calculations ambient temperature of the dyno room environment. Since you are more about putting things on paper than getting real world results, how about you start a thread that monitors every single intake on a nsx and it's power gains all over the world then take the average gain and compile the data.
The OP wanted to know if he would be better off by sticking with the stock airbox or by getting a downforce scoop. He also is interested in getting a suprecharger as well. The logical thing for him to do would be to get the intake that would better suit his future setup right? It seems I have given more data here to support my argument. I have yet to see one dyno sheet showing a loss after an intake. Please stop the madness!!! haha
That pressure drop chart above shows the difference between the atmospheric air pressure (1014 hPa while the 2003 was on the dyno and 1012 hPa while the 1997 Type-S was on the dyno, for what it's worth), and the pressure in the entrance of the intake manifolds. Whether you carry out that measurement at pretty much sea level in England or at pretty much sea level on the Eastern Seaboard of the US, the pressure loss caused by the stock intake system in a stock NA2 is going to be the same.
In case you want to see the horsepower and torque curves for the two bone stock NA2s, here they are:
Saying the power at the wheels was "measured" in the second graph is somewhat of a misnomer, of course. Dynos measure torque and multiply that by the engine rpm to calculate the horsepower. If the dyno wasn't calibrated recently, the torque measurement may well be off and therefore the calculated horsepower will be off as well. If the rpm weren't measured from the tachometer pickup loop in the engine compartment or directly from the engine management system but were guessed based on the dyno's roller speed, the horsepower calculation will be based on a guess. Then that calculated result should be adjusted with a correction factor to what the rwhp curve likely would have been had you carried out the run in standard atmospheric conditions. To do that, you need to measure your current air temperature and current air pressure (note: as you can tell by the air pressure measured during the English dyno day, there must have been a high pressure system prevalent on that day) and plug that data into the formula. After all that, you'll have calculated your "corrected" rear wheel hp figures.
Then some dynos estimate crank hp figures based on the rwhp figures. There are various ways of doing that and the results depend on which method you use.
There are so many opportunities for inaccuracies that I really think dyno results can best be compared if they were carried out on the same dyno on the same day and the engine speed was actually measured, not just guessed based on the roller speed. A dyno can be a great tool for tuning engine management systems, measuring the impact modifications have, and comparing cars at a dyno day. But even if dynos are used properly, since so few of them are regularly calibrated, I think the absolute numbers they spit out shouldn't be taken as the gospel, they should be compared to the other numbers the dyno spit out on that day.
Maybe my suggestion for the OP was lost in the discussion but as I stated in my first post in this thread, if he doesn't mind the air filter getting dirty quickly, I'd recommend replacing the OEM intake snorkel with the Downforce scoop and being done with it. He'll get as much "ram air" effect as he can, the path of the airflow will be smooth, the smallest diameter in the intake system upstream of the throttle body will be 3.4", and he'll have a reasonably large filter to keep the air clean with minimal restriction.
If your dyno tests show that the intakes you developed make more power than the intake Comptech developed, could you explain why?
P.S.: If you measure the pressure drop caused by your intakes and by the Comptech, stock, Downforce, etc. intakes you are replacing, using something like a $30 Dwyer Magnehelic differential pressure gauge to carry out the measurement, you'd have an additional selling point.
In case you want to see the horsepower and torque curves for the two bone stock NA2s, here they are:
Saying the power at the wheels was "measured" in the second graph is somewhat of a misnomer, of course. Dynos measure torque and multiply that by the engine rpm to calculate the horsepower. If the dyno wasn't calibrated recently, the torque measurement may well be off and therefore the calculated horsepower will be off as well. If the rpm weren't measured from the tachometer pickup loop in the engine compartment or directly from the engine management system but were guessed based on the dyno's roller speed, the horsepower calculation will be based on a guess. Then that calculated result should be adjusted with a correction factor to what the rwhp curve likely would have been had you carried out the run in standard atmospheric conditions. To do that, you need to measure your current air temperature and current air pressure (note: as you can tell by the air pressure measured during the English dyno day, there must have been a high pressure system prevalent on that day) and plug that data into the formula. After all that, you'll have calculated your "corrected" rear wheel hp figures.
Then some dynos estimate crank hp figures based on the rwhp figures. There are various ways of doing that and the results depend on which method you use.
There are so many opportunities for inaccuracies that I really think dyno results can best be compared if they were carried out on the same dyno on the same day and the engine speed was actually measured, not just guessed based on the roller speed. A dyno can be a great tool for tuning engine management systems, measuring the impact modifications have, and comparing cars at a dyno day. But even if dynos are used properly, since so few of them are regularly calibrated, I think the absolute numbers they spit out shouldn't be taken as the gospel, they should be compared to the other numbers the dyno spit out on that day.
Maybe my suggestion for the OP was lost in the discussion but as I stated in my first post in this thread, if he doesn't mind the air filter getting dirty quickly, I'd recommend replacing the OEM intake snorkel with the Downforce scoop and being done with it. He'll get as much "ram air" effect as he can, the path of the airflow will be smooth, the smallest diameter in the intake system upstream of the throttle body will be 3.4", and he'll have a reasonably large filter to keep the air clean with minimal restriction.
If your dyno tests show that the intakes you developed make more power than the intake Comptech developed, could you explain why?
P.S.: If you measure the pressure drop caused by your intakes and by the Comptech, stock, Downforce, etc. intakes you are replacing, using something like a $30 Dwyer Magnehelic differential pressure gauge to carry out the measurement, you'd have an additional selling point.
That pressure drop chart above shows the difference between the atmospheric air pressure (1014 hPa while the 2003 was on the dyno and 1012 hPa while the 1997 Type-S was on the dyno, for what it's worth), and the pressure in the entrance of the intake manifolds. Whether you carry out that measurement at pretty much sea level in England or at pretty much sea level on the Eastern Seaboard of the US, the pressure loss caused by the stock intake system in a stock NA2 is going to be the same.
In case you want to see the horsepower and torque curves for the two bone stock NA2s, here they are:
Saying the power at the wheels was "measured" in the second graph is somewhat of a misnomer, of course. Dynos measure torque and multiply that by the engine rpm to calculate the horsepower. If the dyno wasn't calibrated recently, the torque measurement may well be off and therefore the calculated horsepower will be off as well. If the rpm weren't measured from the tachometer pickup loop in the engine compartment or directly from the engine management system but were guessed based on the dyno's roller speed, the horsepower calculation will be based on a guess. Then that calculated result should be adjusted with a correction factor to what the rwhp curve likely would have been had you carried out the run in standard atmospheric conditions. To do that, you need to measure your current air temperature and current air pressure (note: as you can tell by the air pressure measured during the English dyno day, there must have been a high pressure system prevalent on that day) and plug that data into the formula. After all that, you'll have calculated your "corrected" rear wheel hp figures.
Then some dynos estimate crank hp figures based on the rwhp figures. There are various ways of doing that and the results depend on which method you use.
There are so many opportunities for inaccuracies that I really think dyno results can best be compared if they were carried out on the same dyno on the same day and the engine speed was actually measured, not just guessed based on the roller speed. A dyno can be a great tool for tuning engine management systems, measuring the impact modifications have, and comparing cars at a dyno day. But even if dynos are used properly, since so few of them are regularly calibrated, I think the absolute numbers they spit out shouldn't be taken as the gospel, they should be compared to the other numbers the dyno spit out on that day.
Maybe my suggestion for the OP was lost in the discussion but as I stated in my first post in this thread, if he doesn't mind the air filter getting dirty quickly, I'd recommend replacing the OEM intake snorkel with the Downforce scoop and being done with it. He'll get as much "ram air" effect as he can, the path of the airflow will be smooth, the smallest diameter in the intake system upstream of the throttle body will be 3.4", and he'll have a reasonably large filter to keep the air clean with minimal restriction.
If your dyno tests show that the intakes you developed make more power than the intake Comptech developed, could you explain why?
P.S.: If you measure the pressure drop caused by your intakes and by the Comptech, stock, Downforce, etc. intakes you are replacing, using something like a $30 Dwyer Magnehelic differential pressure gauge to carry out the measurement, you'd have an additional selling point.
Typically the selling point to the average customer is a dyno graph. They mostly don't care about the why, if they are buying a performance part for more power that's all they care about. You give them more power, they are happy. This is what I am paid to do and have been paid to do for almost 14 years. If everyone is looking for a super long scientific explanation with this equation and that equation for just an intake, forget it. My work is based on results. The calculations I prefer to do are mapping engines on compressor graphs, building VE tables in engine management systems, tuning EBP on a turbo setup, etc. If I'm really bored I'll calculate the VE of s specific engine configuration. Most people I deal with just want power. 90 Percent of my builds are turbocharged so I'm designing turbo kits all of the time. Most of my high power front drive NA builds get ITBS and ram air boxes in front of the vehicle (which actually produce positive pressure at the drag strip and on the street) They could care less about everything we have been discussing for an intake; a part that eventually gets thrown out whenever you step up your game in regards to power with most other vehicles. I started making intakes for the NSX almost 8 years ago. I began with the basics, did some basic math, and then evolved into more a more complex setup that yielded a decent result. When AEM started making the first real power producing intakes for Imports a loooong time ago, all they did was post dyno results. They didn't have to make paragraph after paragraph explaining why. They sold like hot cakes.
My dyno does not control load like most others. It is a dynojet (as shown in the graphs I posted). It has a mechanical drum that does not need calibrated. It is among the most consistent dynos on the market (a whole other discussion) but I know how all of the other dynos work and how they calculate power. My dyno however is pretty much spot on at a 12 percent loss to BHP on every stock vehicle I have tested with a transverse mounted engine(manual transmission). On rear drive again the losses are near spot on with longitudinal mounted engine (roughly 15 percent with manual trans) It calculates WHP in the same way by using measured torque and an RPM signal. In all of my back to back data there are as many consistencies as one could ask for short of doing the intake install on the dyno. The ambient air temps were nearly identical, the pressure reading was nearly identical, and every car was running the same tank of fuel. I don't post comparisons if there is no merit to them. I don't make and sell product that doesn't produce repeated results. I love those graphs though. I wish I had a Type S to throw on the dyno here..must be nice
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I don't need a long scientific explanation of why your intake makes more power. A brief explanation would be fine. It's not intuitively clear to me why a smaller-bore intake with a smaller filter lets the engine breathe easier than the bigger-bore systems Honda's Formula 1 engineers developed at the factory and Comptech's CART engineers designed in California. But of course, anything is possible. I don't want this to seem rude but there's an old German saying: "Auch ein blindes Huhn findet mal ein Korn." Translated: "Sometimes even a blind chicken finds a kernel of corn." Maybe you stumbled upon a winning smaller-bore design even if you can't explain why it works so well or maybe you don’t want to explain it for intellectual property reasons. But without an explanation, all we have to back up claims that aren't intuitively logical considering the cross sections of the stock intake system are empirical measurements.
LoveFab have an interesting perspective on those. They developed a new exhaust system for NSXs in 2009 and measured the gain versus stock. First they measured the stock rwhp and came up with 229.0 rwhp. Then they built and installed their new exhaust system and went back to the same dyno and measured 274.5 rwhp, or a gain of 45.5 hp at the wheels - fantastic. Just to be sure those results were accurate, they went back to the same dyno in 2010 and carried out both measurements on the same day. This time, gain at the wheels was 22.3 hp - still a very good result. The "stock" measurement was higher than before and the "modified" measurement was lower. LoveFab's lesson learned was, "The best comparison results can only be gathered by testing components as close to back-to-back as possible."
If a dyno doesn't measure the current barometric pressure following SAE guidelines and doesn't measure engine rpm directly from the car's electronics, its measurements won't be particularly accurate. To reduce the inaccuracies, it would be good to at least carry out the measurements on the same day. Since a pressure drop measurement has a lot less potential sources of error, I think that would be a great supplement to dyno measurements. If a smaller-bore intake really does allow an engine to breathe easier than bigger-bore alternatives, it would be great to think through why. If there's a breakthrough you don't want to talk about yet, patent it and start advertising!
Yeah, the Type-S in England is nice and I think they have a few Type-Rs as well. It's too bad Honda never sold any of those with the steering wheel on the left side of the car!
LoveFab have an interesting perspective on those. They developed a new exhaust system for NSXs in 2009 and measured the gain versus stock. First they measured the stock rwhp and came up with 229.0 rwhp. Then they built and installed their new exhaust system and went back to the same dyno and measured 274.5 rwhp, or a gain of 45.5 hp at the wheels - fantastic. Just to be sure those results were accurate, they went back to the same dyno in 2010 and carried out both measurements on the same day. This time, gain at the wheels was 22.3 hp - still a very good result. The "stock" measurement was higher than before and the "modified" measurement was lower. LoveFab's lesson learned was, "The best comparison results can only be gathered by testing components as close to back-to-back as possible."
If a dyno doesn't measure the current barometric pressure following SAE guidelines and doesn't measure engine rpm directly from the car's electronics, its measurements won't be particularly accurate. To reduce the inaccuracies, it would be good to at least carry out the measurements on the same day. Since a pressure drop measurement has a lot less potential sources of error, I think that would be a great supplement to dyno measurements. If a smaller-bore intake really does allow an engine to breathe easier than bigger-bore alternatives, it would be great to think through why. If there's a breakthrough you don't want to talk about yet, patent it and start advertising!
Yeah, the Type-S in England is nice and I think they have a few Type-Rs as well. It's too bad Honda never sold any of those with the steering wheel on the left side of the car!
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That's why I like Senna's left hand drive Honda NSX. That is my dream car.
On the subject of "Auch ein blindes Huhn findet mal ein Korn," that made me laugh so hard I almost shot beer through the nose. Every single part I have developed for every single vehicle that has been through my shop has produced results. Again, it is my business. You will soon learn a little more about my product development here now that I own an NSX and have taken a more serious interest in R&D on them
On the subject of using my using a smaller bore intake; even though it is smaller than the openings on the stock airbox, my pipe diameter is still bigger than the throttle body. I'll use an old saying, "a chain is only as strong as it's weakest link." That is more than hint enough. If you cannot make the distinction on your own about why my intake has shown improvements both NA and FI VS a stock airbox then I cannot help you any further. There is nothing more clear about dyno results as it is the industry standard for measuring power improvements no matter how big or small, or what dyno you have tested with. If you stick with the same dyno, try to keep run conditions to a constant, then back it up with track times, (I test at drag strips too) then the results are glaringly obvious. I have stated before on this thread that I try to keep my back-to-back comparisons as close to back-to-back as possible so that puts me on the same page with Lovefab. So again, we are at a stalemate
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Just as a FYI for those that might be interested in my findings.
I took my Downforce scoop out last night with the intention of selling it. So what I ended up with was the OEM opening to the fender with no snorkel attached.
Drove it this morning to the disappointment of a quieter engine sound in the cabin with the windows down and the intake sound definitely moves more toward the rear (which makes sense given the location of the intake opening).
Though it's still definitely louder than stock, the intake noise isn't nearly as loud in the cabin as it is with the Downforce scoop installed. Reason probably being that the scoop acts as a megaphone, concentrating the sound through the body opening and closer to the window.
That all being said, I'm putting it back in despite the added dirt it brings in. It just makes the driving experience that much more enjoyable. :biggrin:
I took my Downforce scoop out last night with the intention of selling it. So what I ended up with was the OEM opening to the fender with no snorkel attached.
Drove it this morning to the disappointment of a quieter engine sound in the cabin with the windows down and the intake sound definitely moves more toward the rear (which makes sense given the location of the intake opening).
Though it's still definitely louder than stock, the intake noise isn't nearly as loud in the cabin as it is with the Downforce scoop installed. Reason probably being that the scoop acts as a megaphone, concentrating the sound through the body opening and closer to the window.
That all being said, I'm putting it back in despite the added dirt it brings in. It just makes the driving experience that much more enjoyable. :biggrin:
Haha, I'm happy you laughed and appreciate your sense of humor. I look forward to seeing what you develop and am glad you are developing parts for 1st generation NSXs. And of course, I look forward to the dyno tests and maybe some pressure drop measurements thrown in here and there.
Hapa88: It's interesting that you want to put the Downforce scoop back on to get more engine sound into the cabin. I was thinking about buying the lower half of a stock airbox just so that I can channel the induction sound out of the car better with a Downforce scoop. My wife finds the induction sound of my naturally-aspirated NSX with a Comptech airbox so loud that she plugs her ears if we travel over 140-150 mph for any length of time on the Autobahn. When the VVIS valves open up and VTEC kicks in it is a beautiful sound, but there is sure is a lot of it. Is the Downforce scoop loud even with the window up? Loud when it's down and quiet when it's up would be nice.
Ha! I wish we had this problem in the U.S.
Funny you mention that. Since I live in LA, I'm lucky if I can get up to 60mph on an onramp before I have to slow down to a halt on the 405fwy!
Kidding aside, I've only been to 140 mph once and the suction noise of the windows was louder than the intake from what I could remember.
I would think that the Downforce scoop will just make the intake noise louder overall if anything.
In the picture Hapa88 posted of the OEM intake snorkel in post #51, its intake opening looks really small compared to that of the Downforce scoop. Compared to other intake snorkels, the NSX's looks large. Here's a picture of an OEM BMW intake snorkel next to an NSX's.
The exit openings where they attach to the airboxs are about the same size, but look at those intake openings. I guess BMW wanted to silence the engine by making it breathe through a small opening while Honda let the engine breathe relatively freely and quieted it with a resonator (not pictured) instead.
When you put the downforce scoop back on, could you check whether the intake noise at full throttle when the windows are up becomes louder compared to now? I would love to hear your impression.
If your windows get sucked away from their seals at high speeds, that can probably be cured by adjusting the windows carefully. My windows also pulled away from their seals at high speeds until I adjusted them to the lower end of the clearances specified in the Service Manual. Now they don't pop their seals anymore, even at top speed.
Thankfully, driving fast here is nothing unusual. Last time my wife and I drove to Munich, the Autobahn had little traffic and we were running at our BMW's 155 mph speed limiter. My wife didn't notice since she had fallen asleep. In the NSX she would have had to stay awake to plug her ears!
The exit openings where they attach to the airboxs are about the same size, but look at those intake openings. I guess BMW wanted to silence the engine by making it breathe through a small opening while Honda let the engine breathe relatively freely and quieted it with a resonator (not pictured) instead.
When you put the downforce scoop back on, could you check whether the intake noise at full throttle when the windows are up becomes louder compared to now? I would love to hear your impression.
If your windows get sucked away from their seals at high speeds, that can probably be cured by adjusting the windows carefully. My windows also pulled away from their seals at high speeds until I adjusted them to the lower end of the clearances specified in the Service Manual. Now they don't pop their seals anymore, even at top speed.
Thankfully, driving fast here is nothing unusual. Last time my wife and I drove to Munich, the Autobahn had little traffic and we were running at our BMW's 155 mph speed limiter. My wife didn't notice since she had fallen asleep. In the NSX she would have had to stay awake to plug her ears!
So I had the chance to play around with my car yesterday.
I took a 3.5" BPi velocity stack, and used a 3.5"-->3.0" coupler/reducer, was able to take out my Cantrell Concepts air intake scoop and fit the BPi velocity stack in its place. The opening in the fenderwell is not a perfect circle, so the BPi by itself won't mate up to the opening.
Results/Impressions:
The car is definitely quieter at idle and at cruise, and seems to get through the RPMs a little faster. My butt dyno says its an improvement.
Since it's a quick swap, the next time I have some dyno time I'll do some back-to-back testing. I think for fitment purposes a 3.0" BPi stack *might* be a better fit.
I took a 3.5" BPi velocity stack, and used a 3.5"-->3.0" coupler/reducer, was able to take out my Cantrell Concepts air intake scoop and fit the BPi velocity stack in its place. The opening in the fenderwell is not a perfect circle, so the BPi by itself won't mate up to the opening.
Results/Impressions:
The car is definitely quieter at idle and at cruise, and seems to get through the RPMs a little faster. My butt dyno says its an improvement.
Since it's a quick swap, the next time I have some dyno time I'll do some back-to-back testing. I think for fitment purposes a 3.0" BPi stack *might* be a better fit.
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