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+1. Well said. Honda did only compromise on things where excessive costs or reliability were a concern, like headers fro example. Engineering a bigger throttle body is of nearly no costs at all.
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Big Bore Throttle Body. A worthy mod? Which one is best?
- Thread starter Stick-e-rice
- Start date
+1. Well said. Honda did only compromise on things where excessive costs or reliability were a concern, like headers fro example. Engineering a bigger throttle body is of nearly no costs at all.
I have read that site, very good info, but that was a modified NSX one, what the japanese tuners are doing AFAIK is a modified Q45 real big bore one and using a piggyback fuel computer or standalone.
I am sure that the Honda one is "optimal", but that does not mean that a bigger TB can't yield more, or does it?
Cheers,
Ary
Also they gave us a badly designed RWG to induce failure of the coil packs, bad amps, snap rings, notchy gears...should I keep going?
Think how heavy and restrictive the OEM exhaust is!
I know I am straying from the TB but it must have been a compromise between performance and gas guzzler.
Cheers,
AR
- Joined
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Yes, please.
coil packs -> very easy solution
bad amps -> Bose related
snap ring -> this was Hondas fault, ok
notchy gears -> not on a 5 speed
Electronics in general: If someone expects the electronics to live more than 15 or 20 years he'd be surprised how short the life of these components can be in nowadays cars. Moreover it gets very expensive if the warranty is over.
Actually, I'm a little bit surprised that there were so few and solvable electronic issues with this car. Think about a todays car which is loaded with electronics and how much of the 50 modules are working after 15 years. Good luck! :tongue:
This is very strongly related to the preferences because not everybody wants an exhaust that can wake up your neighbors in the middle of the night. The exhaust is very, very quite and not that restrictive regarding the SPL. Find another one that is quieter but less restrictive. :wink:
Back to topic: The throttle body is not restrictive on a non-boosted car. If you find 1-2 hp that's within the variance of the dyno. But your money pocket will let someone believe that it was worth it. Just my 0.02.
An optimal TB would be one that allows all the air to pass through unrestricted, which is what the OEM TB is. One could run any sized TB they want in a normally aspirated NSX and it would result in no additional power gains. There are plenty of big-bore options available that do not show consistent gains until FI is introduced. Any gains due to larger/different TBs are probably due to the old one needing to be cleaned.
There's no measurable restriction in either the TB or intake manifold on a non-FI/stroker NSX motor. Even with aftermarket I/H/E the all the air the engine can suck passes right through those areas.Focusing on the throttle body for power gains in an NA NSX is simply the wrong approach. What works in some cars doesn't necessarily work in others. The intake, filter, TB, IM, headers and exhaust systems of the NSX are all separate entities that perform in different ways than on other cars.
Yeah well, for the money it can't hurt either.
and it does help with throttle response.
and it does help with throttle response.
How does spending even a dollar for something with no measuable gain translate to not hurting?
If increased throttle response is what you want try cleaning your existing throttle body.
This will determine the bottleneck: I like their articles - good reading.
http://www.autospeed.com/cms/article.html?&A=0629
Who's willing to try?
To get the benefits of a big TB, the intake needs to be port-matched. Otherwise, you have a big tube dumping into a little one, and that will actually cost you performance.
Your performance is dictated mostly by the weakest link in your intake (same thing goes for exhaust). Where's the bottleneck?
Kinda like sticking a 1000CFM carb on a 300ci. Kinda cool, you can brag to your friends, but you wasted some money.
http://www.autospeed.com/cms/article.html?&A=0629
Who's willing to try?
To get the benefits of a big TB, the intake needs to be port-matched. Otherwise, you have a big tube dumping into a little one, and that will actually cost you performance.
Your performance is dictated mostly by the weakest link in your intake (same thing goes for exhaust). Where's the bottleneck?
Kinda like sticking a 1000CFM carb on a 300ci. Kinda cool, you can brag to your friends, but you wasted some money.
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Because now your presuming something was wrong with my TB which is "fiction". Now presume my TB was perfectly clean when I took it off but yet I got better throttle response and you would have a "fact".
If it's fact show me proof. Because there's no way possible that you could be convincing yourself your throttle response improved. The butt dyno never lies, eh?
The gain in throttle response you'll get with a BBTB is so insignificant it's amusing that you think you could even feel it.
If you think you do, that's all that matters. It was money well spent to you. But before anyone spends ~$300 for a BBTB on an NA NSX I think they ought to know the truth. There are so many better ways to spend $300 on an NSX than for this practically useless mod. If you get a BBTB for a normally aspirated NSX that is money truly wasted, IMO.
baynsac
Guest
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Hey Chris or anyone at SOS what do you think about this above ??? Do I need to port match my manifold ??
Yes, please.
coil packs -> very easy solution
bad amps -> Bose related
snap ring -> this was Hondas fault, ok
notchy gears -> not on a 5 speed
Electronics in general: If someone expects the electronics to live more than 15 or 20 years he'd be surprised how short the life of these components can be in nowadays cars. Moreover it gets very expensive if the warranty is over.
Actually, I'm a little bit surprised that there were so few and solvable electronic issues with this car. Think about a todays car which is loaded with electronics and how much of the 50 modules are working after 15 years. Good luck! :tongue:
And windows that like to fail and roll up vvvveeeeerrrrrrryyyyyyyy slooooowly. AC controls that fizz out to blow only at full high. ABS that likes to groan, whine, and screech at start up. That tiny fan in front of the ebrake lever that likes to buzz. Oh yeah and a cassette deck in a 2005 $90k car. That's all the electrical I can recall at the moment.
You deff. have to port match the intake manifold. It's not that had to do. I use to do these for my customers.
I have used BBTB on many hondas/Nissans/supra. There is a gain from mid to top end but not much on NA cars. It's had to show dyno proof, cause on a car that you dyno 3 times without changing anything you get different results all 3 times. So it's hard to prove this. BBTB help more on NA cars with bigger cams that require more air.
Lets see if i can explain this in simple terms:
What is needed in a NA app to make more power? Give up?
Answer: Air and Fuel. (you already knew that)
So once you have upgraded your stock headers and exhaust system to better flowing ones, now you need to up grade your inlet via better intake that can flow more air into the intake. So if you open up the TB you are letting in more air. If you do not port match your intake mani than it is becoming the bottle neck. Once you port match your manifold you've got a good consistent flow going into the heads. Now the cams need be upgraded to take full advantage of the extra air, the height and duration will let that good flow of air in thru the valves and in the cumbustion chamber. Now don't forget about FUEL this is where the extra fuel is needed for that extra air you have provided. Getting a good tune on the ecu is the best way to get full use of that air.
So you see it's a chain to things that are needed to get it right and to take full advantage.
Honda did their R&D and make everything how they wanted it, cause they have to satisfy eveyone, the car have to be realiable, not to loud, give good gas milage, drive smooth with out to many hicups.
I hope this answers many questions.
I'm willing to try this on my NSX if people want a test car.. :biggrin:
Rahim
I have used BBTB on many hondas/Nissans/supra. There is a gain from mid to top end but not much on NA cars. It's had to show dyno proof, cause on a car that you dyno 3 times without changing anything you get different results all 3 times. So it's hard to prove this. BBTB help more on NA cars with bigger cams that require more air.
Lets see if i can explain this in simple terms:
What is needed in a NA app to make more power? Give up?
Answer: Air and Fuel. (you already knew that)
So once you have upgraded your stock headers and exhaust system to better flowing ones, now you need to up grade your inlet via better intake that can flow more air into the intake. So if you open up the TB you are letting in more air. If you do not port match your intake mani than it is becoming the bottle neck. Once you port match your manifold you've got a good consistent flow going into the heads. Now the cams need be upgraded to take full advantage of the extra air, the height and duration will let that good flow of air in thru the valves and in the cumbustion chamber. Now don't forget about FUEL this is where the extra fuel is needed for that extra air you have provided. Getting a good tune on the ecu is the best way to get full use of that air.
So you see it's a chain to things that are needed to get it right and to take full advantage.
Honda did their R&D and make everything how they wanted it, cause they have to satisfy eveyone, the car have to be realiable, not to loud, give good gas milage, drive smooth with out to many hicups.
I hope this answers many questions.
I'm willing to try this on my NSX if people want a test car.. :biggrin:
Rahim
baynsac
Guest
When you have a well design car that has a very efficient normally aspirated power plant - AKA NSX or basically any Honda DOHC equipped cars.
This so called big throttle body really don't do much. Under normal driving circumstances, the engine will suck in as much air as needed through the system; there is no bottleneck with the stock TB. Under stock ECU, the result could change slightly with different air filter system, header and exhaust.
The urban myth of BTB and DF/Cantrell/TAITEC scoop does absolutely nothing. It does however, creates a cool whistle sound. In fact, the scoop will collect more dirt, but that's not what we're talking here.
HOWEVER, it could be a huge benefit if you FI the car.
If you really want to get as much HP out of the NSX engine in NA form - after H/I/E, you can have your NSX tuned for extra 10 or ponies, but to see any dramatic increase, you will need to do ITB and tune by some one what knows job.
This so called big throttle body really don't do much. Under normal driving circumstances, the engine will suck in as much air as needed through the system; there is no bottleneck with the stock TB. Under stock ECU, the result could change slightly with different air filter system, header and exhaust.
The urban myth of BTB and DF/Cantrell/TAITEC scoop does absolutely nothing. It does however, creates a cool whistle sound. In fact, the scoop will collect more dirt, but that's not what we're talking here.
HOWEVER, it could be a huge benefit if you FI the car.
If you really want to get as much HP out of the NSX engine in NA form - after H/I/E, you can have your NSX tuned for extra 10 or ponies, but to see any dramatic increase, you will need to do ITB and tune by some one what knows job.
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Clearly you do not have much experience tuning or modding NSXs. If you did you would realize that what works on other cars doesn't always work on NSXs.
You are incorrectly assuming that the intake system of the NSX is inherently restrictive. It's not. The NA NSX motor gets plenty of air from the stock intake system (airbox, TB, IM). Even when more free-flowing exhausts and headers or more aggressive cams are installed the stock intake system provides nearly 100% of the air the engine can suck. Yes, the stock intake system is that efficient.
Virtually all of air the NA NSX engine can combust is being delivered by the stock intake systems. Only when the air needs of the engine increase dramatically through FI or increased displacement does the intake system measurably rob the engine of air. It is not uncommon for the TB and IM mods to free up 10 hp each on FI NSXs.
The stock airbox and filter is extremely efficient. No one has had success improving upon it consistently or measurably. The throttle body and intake manifold are also very free-flowing. Widening any of these areas is like widening a doorway when everyone can already walk through at the same time.
In addition the OEM universal tune is about as effective as you're ever going to come across. Many highly talented tuners have attempted to improve it with mixed results at best. Just as much success as failure. If better tuning resulted in more power you'd see more people purchase AEMs for NA NSXs. They don't. At best one might be able to squeeze 10 hp out of a better tune but that's a very liberal estimate and will not be the case for most NSXs.
Chris at SOS has always been very clear that the TB and IM mods are designed for FI/stroker NSXs, period. He's not going to talk anybody out of one as they are in business to make money but if pressed he will tell you that you should not expect any consistent, measurable gains from either the BBTB or IM porting on an NA NSX.
My recommendation is always to leave the intake systems intact and replace the headers (on NA1 NSXs) and exhaust. Better cams are an option as well as upgrading the 3.0L valves/springs to the 3.2L versions. Only if one intends to go FI should they even consider a BBTB or IM porting. At that point any AM cams have to go anyway as they are generally designed for NA NSXs.
Other than that, that's it folks. It is not easy or cheap to get more power out of an NA NSX. The stock intake and tuning are remarkably efficient. To say Honda did their R & D is a huge understatement. On an NA2 NSX exhaust and cams are about the only things one can modify with any measurable results. If you want more power FI is really the only way to go about it. At that point TB and IM bottlenecks can develop but not before.
So let me ask you one simple question. As you stated that one can't make anymore powerin the NA form besides E/H and the inake system can't be improved to gain power. Well than why do they use ITBs on the NSX? I guess the race devisions are spending all that money on ITB are carzy since the stock intake system is up to par.
There is always room for improvement. Honda developed the NSX in the late 80s, and cars have come along way since. If the NSX was so perfect then why did they go with the 3.2L later on? Why does the NSX have so many issues? You need to think out side the box. There is still so much technology out there and so much room for improvement. If Honda thought like you did then they would have never developed the Vtec system. Now they have the I-vtec which also adjusts the cam gears electronically.
I'm not trying to argue with you or anyone, I was just trying to explain how things work in an engine.
Rahim
Best way would be to take your BBTB and the stock intake mani to a machine shop and have them port match the mani.
Uh, ITBs are only necessary or effective when the engine is using enough air (e.g. FI/stroker) to create a bottleneck at the already-bored-out TB or IM. You don't really think slapping ITBs on a stock motor is going to increase power do you?
Obviously you don't understand the fundamentals of car modification nor do you have a grasp on how intake and exhaust systems work. As I said, what works on other cars doesn't always work on NSXs.
Thinking "outside the box" has nothing to do with it. Things like VTEC are not "improvements". They are innovations that are implemented. Your statement that the NSX's horsepower can't be increased because it isn't perfect as Honda updated and upgraded the car or that it requires maintenance is absurd. We are talking about the car that you have sitting in your driveway. That's the palate you have to work with. I'm not clear on what Honda has to do with anything at this point. Honda effectively overbuilt the intake system, underbuilt the NA1 headers and exhaust system and provided a rocking universal tune that can't really be consistently improved upon.
People have been monkeying with NSXs for over 17 years. It's pretty clear by now what works and what doesn't. Headers for an NA1 work. Headers for an NA2 don't, etc. There are ways to get more power from an NA NSX but modifying the intake system is not the way to go about it. I am not making this up out of thin air. Many, many people who have forgotten more about tuning that I will ever know have been screwing around with every possible method of power extraction and have consistently come up short. Again, there are things that work and things that don't.
The only things that one can do to measurably increase power in an NA NA1 NSX are headers, exhaust and cams. The combination of NA2 valves/springs, ECU mods, BBTB, IM porting and more aggressive tuning--all together--might get the average NSX 5-15 hp. All of those mods combined get far less power than headers alone! It's just simply not there.
So do what you want to do. It seems that you have convinced yourself that porting your intake manifold and having a BBTB will unlock the door to NA power (because it may have done so on a Civic, etc.) But please don't irresponsibly state that this will create gains unless you have consistent, repeatable proof that it does. Suckers are born every minute and the truth is that there is no evidence to suggest that the BBTB or IM porting will produce any consistently measurable power gains on NA cars. If you think it's just not possible that the intake system and tuning cannot be improved upon then go spend the thousands to modify them and show us some before and after dynos at each stage. I'll be using those thousands to get one step closer to a supercharger.
Reality check
There is a very simple way to determine if the stock TB & manifold are restrictive - do cars with ITBs make more power? If so, the answer is unequivocally yes; if not, then no. Its that simple.
My understanding, from speaking with Japanese nsx owners with ITBs on their cars, is that they (claim to) pick up anywhere from 15-25 hp on the dyno, depending on the other external modifications. Cams seem to be a big factor. I have not dyno tested a set of ITBs on a street car myself.
That said, I personally have no doubt that the intake system (as a whole) is less than ideal. It is designed based on a set of compromises that are not the same trade-offs desired by someone who's primary goal is more power. That does not make the oem design 'bad,' it is just a reality of production cars.
How much power there is to be gained and whether it is worth the cost/effort is another debate. . .
There is a very simple way to determine if the stock TB & manifold are restrictive - do cars with ITBs make more power? If so, the answer is unequivocally yes; if not, then no. Its that simple.
My understanding, from speaking with Japanese nsx owners with ITBs on their cars, is that they (claim to) pick up anywhere from 15-25 hp on the dyno, depending on the other external modifications. Cams seem to be a big factor. I have not dyno tested a set of ITBs on a street car myself.
That said, I personally have no doubt that the intake system (as a whole) is less than ideal. It is designed based on a set of compromises that are not the same trade-offs desired by someone who's primary goal is more power. That does not make the oem design 'bad,' it is just a reality of production cars.
How much power there is to be gained and whether it is worth the cost/effort is another debate. . .
Re: Reality check
That would be true. However since Toda, for one, does not recommend their ITB setup for 100% bone-stock motors and SOS intimates the same I can imagine it would be very difficult to find examples of this or any before/after dynos with the ITBs being the only variable.
Why they don't recommend it I do not know. Perhaps Chris can offer some insight. Could it be because there will be NO GAINS?
This is a quote from Toda to Vance Hu after inquiring about ITBs in 2006:
Vance,
Thank you for your prompt response.
The major problem is you would need to wire up aftermarket fuel management system and the potential gains with sport injection kit might be minimum. These are designed for fully built (Internally) engines and you shouldn’t let the cool factor to get involved.
Best regards,
TODA Racing USA
Cams alone could completely account for horsepower gains of 15-25 hp. ECU mods and tuning could account for most of that gain on the right NSX. If there are any other mods other than exhaust and headers this example is worthless.
What gives you no doubt? This is 100% speculation. What makes you so sure?
I can tell you what makes me sure the stock intake system is quite effective: no one has ever shown consistent, repeatable proof that any modification to the stock intake system produces measurable gains.
Hopefully, you can show me some data that proves me wrong.
That would be true. However since Toda, for one, does not recommend their ITB setup for 100% bone-stock motors and SOS intimates the same I can imagine it would be very difficult to find examples of this or any before/after dynos with the ITBs being the only variable.
Why they don't recommend it I do not know. Perhaps Chris can offer some insight. Could it be because there will be NO GAINS?
This is a quote from Toda to Vance Hu after inquiring about ITBs in 2006:
Vance,
Thank you for your prompt response.
The major problem is you would need to wire up aftermarket fuel management system and the potential gains with sport injection kit might be minimum. These are designed for fully built (Internally) engines and you shouldn’t let the cool factor to get involved.
Best regards,
TODA Racing USA
Cams alone could completely account for horsepower gains of 15-25 hp. ECU mods and tuning could account for most of that gain on the right NSX. If there are any other mods other than exhaust and headers this example is worthless.
What gives you no doubt? This is 100% speculation. What makes you so sure?
I can tell you what makes me sure the stock intake system is quite effective: no one has ever shown consistent, repeatable proof that any modification to the stock intake system produces measurable gains.
Hopefully, you can show me some data that proves me wrong.
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Re: Reality check
And 100% stock motors have what to do with this discussion?
Easily - a few seconds using the 'search' function on this site produced the following quotes from Chris at SoS regarding the dyno testing of their ITB system.
Regarding a 3.3L car:
Before the throttles were installed, the car dynoed at a max power rating of 311 rear wheel horsepower. . . [after ITB installation] The car dynoed at 336 rear wheel horsepower and 255 lb/ft torque.
That's a 25 whp increase with the other mechanical mods (header, exhaust, cams, etc.) remaining exactly the same. About what I would expect in that situation, based on my 'speculation.'
And again, after more development work on their ITB set:
. . .setup that generates increases of more than 30 hp on a 3.3L engine. In our testing of the 3.8L engine, we've shown that the intake manifold is even more restrictive than in the 3.3L application, so we expect even greater results.
So now I ask you, what proof do you have that the stock intake system is not restrictive at all on a motor with all the basic NA mods - or are you just posting pure speculation?
And 100% stock motors have what to do with this discussion?
Easily - a few seconds using the 'search' function on this site produced the following quotes from Chris at SoS regarding the dyno testing of their ITB system.
Regarding a 3.3L car:
Before the throttles were installed, the car dynoed at a max power rating of 311 rear wheel horsepower. . . [after ITB installation] The car dynoed at 336 rear wheel horsepower and 255 lb/ft torque.
That's a 25 whp increase with the other mechanical mods (header, exhaust, cams, etc.) remaining exactly the same. About what I would expect in that situation, based on my 'speculation.'
And again, after more development work on their ITB set:
. . .setup that generates increases of more than 30 hp on a 3.3L engine. In our testing of the 3.8L engine, we've shown that the intake manifold is even more restrictive than in the 3.3L application, so we expect even greater results.
So now I ask you, what proof do you have that the stock intake system is not restrictive at all on a motor with all the basic NA mods - or are you just posting pure speculation?
Re: Reality check
The first example is valid; the second is not. I am talking about NA motors with stock internals only.
I simply point to the lack of evidence. That is not speculation. You are asserting it works therefore you show me proof. I don't have to show proof that something doesn't exist. That's not how it works.
You've shown me one isolated manufacturer dyno. Any more?
The first example is valid; the second is not. I am talking about NA motors with stock internals only.
I simply point to the lack of evidence. That is not speculation. You are asserting it works therefore you show me proof. I don't have to show proof that something doesn't exist. That's not how it works.
You've shown me one isolated manufacturer dyno. Any more?
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