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How to Make 396 Hp at the wheels

6 November 2001
Rancho Santa Margurita Ca.
Larry: There has been some contraversy in another thread about how to make 396 RWHP in an NSX With a Supercharger.....Can you share what is required as far as fuel delivery to support that kind of horsepower?
C30A - there is no controversy at all, and this is not new "rocket science". I've seen dyno plots (yes, the dyno is calibrated, thank you) of an NSX engine making 410 (or was it 401?) RWHP courtesy of a supercharger.

PS - could you turn "spell check" on? That way, when you come across as arrogant, at least you do so with proper diction.
If we dig back far enough.... didn't David post some dyno plots of his 550+HP monster?
gawd, alright already, enough. at first I found these threads (even with the aggressive and accusatory tones) informative as I am a neophyte in forced induction and the intricacies of fuel delivery / management, etc. - and I was learning.

but you keep asking the same questions over and over again, flogging a horse that has long since been dead. by now you must understand that either;

· basch thinks the stock injectors are sufficient, -or-
· the information is proprietary and he does not have the need to inform us, -or-
· perhaps both

either one is fine with me, I trust his reputation and am looking forward to my bb.
Yea!thats it! I'm gonna order one to install tomorrow as soon as I wake up,And maybe spray some NOS ontop of it.It will be one of the 1st'out there.

I've stood on the sidelines and followed this thread with a mixture of technical curiosity and exasperation. I can no longer resist, so I dive headlong into the fray ... BTW, I previously made numerous posts under the Username "DeHaldesworth", but I was absent for awhile, lost my password, and changed my ISP and email address. (Help, Lud!)

Anyway, I live in a smallish Arizona town about two hours from Basch Acura Service, and thus have had the pleasure of meeting Mark Basch a couple of times. I've visited his shop, and he has been extremely gracious to me. By profession, I am an Attorney (hold the jokes, please). In a small community like the one I live in, a good reputation is invaluable. Like anyone else, I'm sure I could make a quick buck by ripping off the people I serve. However, it would be the most expensive quick buck I ever made (as my Dad would say, "trippin' over a dollar to earn a dime"). The same is obviously true of Mark. The NSX community is indeed a small one, and the fact that Mark is recognized as the preeminent NSX authority is no accident. Do the naysayers really believe that he would commit professional suicide by making bogus claims all in the name of marketing a very specialized product to a small group of fellow enthusiasts?

From the very beginning, I have read and interpreted Mark's posts as if he was saying, "Hey guys, take a look at this cool idea we're working on -- just thought you might be interested."

That's why I'm beffudled by this thread--, out of nowhere, come posts from those who seem bent, not on a legitimate exhange of ideas, but on defaming Mark. It just doesn't make any sense to me. But that's not the worst of it -- what really irritates me is the attitude of the naysayers, as if we need to learn the "real truth" and be protected from the perils of false horsepower claims. I, for one, do not profit from your warnings and doubts -- take them somewhere else, please. Heaven knows we have enough controversy in the world right now, do we really need to pollute what is supposed to be an enjoyable diversion with the innuendo and sarcasm that has appeared here of late? My only supposition is that the annonymity of the board encourages such behvior...
nevermind, you guys are wierd. A good idea would be to research before making any forced induction purchases.

[This message has been edited by true (edited 01 December 2001).]
Justin and DeHaldesworth said it perfect..... Well said guys. Keep up the great work, Mark!! Lud, please close this topic and that other 4 page abomination that has lost all its original appeal thanks to a select couple of #$%#@&%*%(>>>>>>>>>>.......

Todd Arnold

DeHaldesworth said it more eloquently than I could even dream... I don't know Mark Basch but his reputation certainly preceeds him. There is no doubt in my mind of the integrity spoken of him by his friends and associates. Mark, I look forward to doing business with you in the future.

Thanks for all your hard work and contributions to the NSX community.
In a small community
like the one I live in, a good reputation is invaluable. Like anyone else, I'm
sure I could make a quick buck by ripping off the people I serve. However, it
would be the most expensive quick buck I ever made (as my Dad would say,
"trippin' over a dollar to earn a dime"). The same is obviously true of Mark.AS I HAD SAID EARLIER BUT MUCH MORE WELL PUT BY YOU!!Mark I assure you does not have a wild conspericy to explode all of his customers motors and his own.Furthermore, on the injector,horsepower,torque curve ,dyno argueing and or questioning I think Mark shouldn't ever disclose his trade secrets."Let the competition figure it out for themselves".As far as on paper we couldn't ever figure out how the heck Billy Glidden could dominate the Pro 5.0 circuit for years and still does on a much smaller NOS jet size than"all the competition".One thing is for sure he was bred on automotive performance from a child,as if he was "born" to be a performer.Mark Basch I believe has a true dedication and passion for what he does and his reward is knowledge of the seemingly impossible.The person who keeps demanding an explanation of why,why,why,"and you know who you are" is much like the girl you "just" meet and her "only" concern is marriage.The answer obviously is "RUN".Did you ever stop to think that YOU thru lack of any real integrity dont deserve an answer.You would probably brandish it like a child who just found his dad's gun.And I personally dont give a s#$%t that you know who I am .Mark has been nothing but patient and a gentleman in his responses to you.Which is because he is a lot smarter businessman than you think.Anyway go Mark, make them sweat and eat their lunch!!! Please...

i dont see what the big issue with 4 or 500 hp is on a turbo or supercharged nsx. ive seen porsches making over 700 at the rear wheels from a 6cyl air cooled motor. so why couldnt a properly set up nsx make 400 ?
***so why couldnt a properly set up nsx make 400 ? ***

Good question. Because 400rwhp is very close to the limit of a stock NSX motor, unlike a Supra or Porsche. A little more power, and it would cost a lot of money to reinforce it to handle that power. The trick was to see how far one could go with the stock motor by using fuel management without having to shell out 10K to reinforce it to handle much more.
The engine was not designed to push anything higher in stock form, so it takes a lot of expertise and research to pull off. Getting 400HP safely from a stock engine in an NSX is a considerable accomplishment.
Ok, here's my contribution to this ongoing battle. I think that there is a legitimate question that has not been answered here, but the attitude associated with the question and answers has been taking precedence.

It is very easy to add boost to an engine, but when done you must also add fuel pressure. Whether it is done with larger fuel pumps, injectors or computers, it is a legitimate concern.

Anyway, I haven't bothered to read the other post and I'm taking anyone's side here. This nonsense must end though. NSXPrime is looking more like an Supra forum!
Hi Guys,

After reading all these posts...I made my own conclusions...

1. The main question is that at 380+ rwhp, are the factory 240cc injectors up to the task?

2. Mark B. believes that his SC kit with stock injectors is sufficient and is putting the kit thru rigorous test miles to back it up. I am certain if Mark B. finds that the injectors to be a weak point, he will find a solution. The "BETA" point is that he is making sure it all works reliably to his satisfaction backed by his reputation.

3. No doubt that the injector COULD be a weak point. Some observations are:
---a. Injectors working near max duty is not desired. Obviously the quality of the injectors affects that...which relates to the importance of blueprinting and matching injectors.
---b. Mark B. stated that the duration of max boost of 5 psi is relatively low. Which I took that to mean that the injectors will not work near/at max duty very often, unlike a turbo. (I think there is a significant difference here between how Superchargers and Turbos produce boost.)
---c. Whether the injectors are up to the task will always be subjective as there are differences in applications...such as street, high-performance, race and endurance race. You can continue to argue that the injectors are not good for racing application, and argue that they work great for street application and both be right but get no where...

Obviously some people are not happy with the answers provided so far. Some people have the confidence in Mark B. that whatever the final kit is, he will ensure it works and is reliable, making the specs he claims.

Maybe the Honda injectors are under-rated and will work fine. Maybe they they will fail due to operating at max duty. When Mark B. is done with his BETA, he will tell us that the kit includes these parts and produce this much power and is warranted for this amount of time and is to be used for these applications only...and he will back it up with his reputation. I think that ought to be enough.

The guys that are concerned and questioning the the injectors are totally valid. (I long stopped reading about the tone and attitude of posts...you get pissed off for no reason...just not worth it.) I blew up my RX7 engine because of injectors operating and near max and failed to deliver enough fuel. I blew it up again after having larger, blue printed and matched injectors due to getting a hot charge from the intake. When you mod you car to gain performance, there are risks. It is good that difference people here with different experience point out their concerns so that the others may evaluate and learn from it and make their own decision...

I appreciate Mark B. for talking about his kit here and appreciate the concerns that are brought up. Have a nice day. (It's a beautiful sunny so cal day. Going out to hit the redline a few times in my NSX.)

91 black/red
many others...

(so many cars to blow up and so little time...)

[This message has been edited by tc29 (edited 01 December 2001).]

[This message has been edited by tc29 (edited 01 December 2001).]
So what about the 3.2 block.I heard it was reinforced from the factory.Can it handle more HP?


97 NSX-T
93 Supra TT BPU+
You know if gsgdsa87326492 and primetime_vtec are worried of blowing their motors due to the BB supercharger than just dont purchase it. Get the comptech, Gruppe M supercharger or NSX modified turbo.

Why would Mark Basch give out his secret recipe formula out to the public to make the amount of power with only 5 lbs of boost. Some NSX owners have trust with Marks Basch experience & reputation. If ghjkg4312432 and other kids are worried just get another Force induction kit, simple as that.
Originally posted by tc29:
Hi Guys,

After reading all these posts...I made my own conclusions...

A good and sensible post, though I'm not sure I agree with this part:
---b. Mark B. stated that the duration of max boost of 5 psi is relatively low. Which I took that to mean that the injectors will not work near/at max duty very often, unlike a turbo. (I think there is a significant difference here between how Superchargers and Turbos produce boost.)
91 black/red
many others...

I think it depends on how and when the SC engine bleeds off pressure rather than producing boost. I'm no expert on SC design, but since they are driven by a direct clutchless connection to the engine, they are always pushing air. If that is bled off except under certain throttle conditions etc., then they may not be on boost very often, but that would also detract from the fun significantly. If you don't bleed it off, then you have boost far more often than a turbo because it's directly related to RPM. By contrast, a turbo pushed no air unless under load, so there is no unwanted boost to blow off during normal driving. But, it's there when you want it just by dipping into the throttle a bit more regardless of RPM. If you mean that max boost is available earlier and more often, and therefore used accordingly, I guess I would agree. Which is one reason I love turbos. One thing I always enjoy during sport-motoring outings is the zero drama part-throttle passes I can make on twisty two laners. It's like having a thumping V8 that still revs to 8k.

[This message has been edited by sjs (edited 01 December 2001).]
To expand a bit on the max HP for a stock NSX bottom end, as noted above the first limitation seems to be the block itself. It is of the "open deck" design, meaning that when you pull a head off you can see the cylinders sort of standing there in the block like pipes, connected only at the bottom. Presumably this is done to save weight and perhaps improve cooling, and it's perfectly adequate for a stock engine. The 300 ZX had a similar design for their NA cars, but the turbos had a closed deck design. That's because when an engine produces HP it puts an enormous stress on the block and cylinders. The strength of both are compromised in an open deck design, not entirely unlike the way a removable top noticeably compromises the structural integrity of an NSX despite an excellent overall design. As HP output increases, the stress on the block gets high enough to permanently warp things. I'm not sure of all the details, but I can see where cylinders might get oval or no longer stand straight in line with the rods, and crank journals might not be properly aligned.

So, the fix is to cut down the block slightly and weld on a top plate which has been drilled for the pistons, water, and oil passages.

Of course there are other limits to the stock NSX engine that keep you from producing huge HP by simply adding boost. High compression cast pistons are probably the most obvious. I'm not sure what the limits are on the crank and rods, which like everything on the NSX were designed to be as light as possible yet perfectly adequate for a stock engine. (For example, the rods are made with Titanium, but are also fairly small.) It would not surprise me if the next generation car is designed in a way that caters somewhat more to after market performance add-ons. That could be both a good thing and a bad thing depending on the compromises they make to achieve it.

This topic is of particular interest to me as I'm contemplating a complete tear-down of my NSX this winter and may decide to strengthen the block while I'm at it. I'm busy preparing the garage now and hope to be starting on the car by year end. Any thoughts or insights are most welcome.

[This message has been edited by sjs (edited 01 December 2001).]
Sorry I haven't been able to get back on this topic as fast as I would have liked to have but I had some personal issues that needed to be handled.

First I think "tc29" did an excellent job of summing up the questions. From the beginning of my post I've tried to communicate that calculations are validated through testing. If the results in testing are different then there's either problems in the testing method or problems with the calculations. It's pretty simple.

So in response to "prime-VTEC" and "4g62bt2c30a" as you'll see it's quite possible to acheive the targeted power using standard engineering equations. As we all know doing so in real world is much more difficult. I think the question about the injectors is also answered through my work and will be validated by Mark's testing.

As I mentioned I had concerns with two factors being used by "4g62bt2c30a", the BSFC and the duty cycle. As you'll see I'm not sure the duty cycle is an issue as Mark has communicated. The BSFC that "4g62bt2c30a" was using I believe is incorrect for the NSX. I calculated back the BSCF for the NSX engine using know published numbers (or at least the ones I could remember). If I've used the wrong numbers (someone please check as I'm in a rush to get this done) then please update/post them with the correct numbers and results. By know means do I think I couldn't have made a mistake.

So here's my analyst.

n = effieciency
w = useful work dine by the process
J = Joule's law coefficent = 778 ft lbf per btu
Q' = heat which flows into the system during the process
P = power
Mf = mass of fuel supplied per unit time
Ma = mass of air supplied per unit time
Qc = heat of the combustion of a unit mass of fuel
F = mass ratio of fuel to air
sfc = specific fuel consumption = fuel consumed per unit of work
sac = specific air consumption = mass of air consumed per unit of work
hp = horse power = J per Kp
Kp = value of 1 hp expressed in (force x length/time) units = 33,000 lb ft min
Kp/J = 42.41645244 Btu / min ( 33,000 / 778)
Qc = heat of combustion per unit mass ~ for gasoline between (18900 & 20,460) ~ 19000

n = w / J Q'
n = P / (J * Mf * Qc)
n = (hp * 42.4) / (19000 * Mf)
P = J * Ma * F * Qc * n = J * Mf * Qc * n
sfc = Mf / P = 1 / (J * Qc * n)
sfc = 1 / (J * Qc * n)
sfc = (42.4 *60) / (Qc * n)
sac = Ma / P
sac = 1 / (J * F * Qc * n)
sac = sfc /F
hp = P/Kp
hp = n * Ma * F * Qc * (J / Kp)
hp = ( n * Mf * 19000) / (42.4 *60)

Start by solving for sfc and n for a stock 3.0 L NSX engine using what's known

Stock 3.0L NSX engine
Given Power = 270 hp
Injector size = 240cc
Tested Flow pressure = 43.5 psi
Operating pressure = 50 psi
Effective Flow rate = 257.3070084 cc [Square root of (Operating Pressure / Tested Pressure) * Injector size]
Max Flow rate = 24.50542937 lb/hr [Convert cc to lb/hr - divide cc by 10.5]
Desired Duty Cycle = 80%
Designed Flow rate/injector = 19.60434349 lb/hr [Injector duty cycle * max flow rate]
# of Injectors = 6
Then Mf = 117.626061 lbs/hr [# of Injectors * Design Flow rate]
sfc = 0.435652078 lbm/hp-hr [Mf / Power]
n = 30.75% [(hp * 42.4 * 60) / (19000 * Mf)]

If 3.0L NSX engine is SuperCharged
Given Injector size = 240 cc
Tested Flow pressure = 43.5 psi
Operating pressure = 96psi
Effective Flow rate = 356.535049 cc [Square root of (Operating Pressure / Tested Pressure) * Injector size]
Max Flow rate = 33.95571898 lb/hr [Convert cc to lb/hr - divide cc by 10.5]
Desired Duty Cycle = 80%
Designed Flow rate/injector = 27.16457518 lb/hr [Injector duty cycle * max flow rate]
# of Injectors = 6
Mf = 162.9874511 lbs/hr [# of Injectors * Design Flow rate]

And from stock 3.0L analysis these factors should not change dramatically
sfc = 0.435652078 lbm/hp-hr
n = 31%

Power = 374.1229744 hp [(effeciency * Mf * 19000) / (42.4 * 60)]

BTW I the reason why the BSFC is better is exactly because of VTEC and VVIS. It allowed the engineers to optimize the engine design across a wider range of RPM.

The reference material I used came from my old textbook used in my engine design class, ah 20 years ago! You can purchase the latest revision of this book from Amazon.com http://www.amazon.com/exec/obidos/ASIN/0262700271/002-0965198-5489657

All the above equations are covered in Chapter 1. The last chapter gets into supercharging.

Ak - In response to you question about horse power equal torque and rpm. Yes but when working with combustion engines it's easier and a more common approach to use efficiency from the thermodynamics of a cyclic process i.e burning of the fuel.

It get's a little more difficult from here as I feel like I need to teach Thermodynamics and it's been 20 years since I done much. But I'll try and give you the basics and hopefully wont' screw up too much.

We start with the first equation, n = w / J Q'. Go back and look at the diffinitions. Except we're computing the heat released versus added , w is work done by the system minus the work done on the system and where Q is the heat added to the system minus the heat released by the system.

J has to appear in any equation to maintain deminsional homogeneity when relating heat and work. J is units of work divided by units of heat and since we can express work as force times length we can use this to figure power if we can figure the heat released.

I don't know if that makes any sense but hey I took 4 years of school to understand this stuff and it's been 20 since I've looked at.


Lake Oswego, Oregon
95T Blk\Blk SportShift

[This message has been edited by hejo (edited 02 December 2001).]
Hal...I was intrigued with your post for about 4 lines...
then I became a little less intrigued...and then I gave up completely.
The math done in your post is NOT by any means beyond my ability to do..just beyond my patience..

BUT...well..to whoever wants to know...THERE YOU GO!! Now quit bothering us.
I was reading your post and If you could just explain a little clearer a few of your points. I got lost right after "Sorry", if you could go into a little more detail on the section that follows that I would appreciate it. J.K.

By the way that was a great post! I don't really understand most of it but I might just go out and buy that book you referenced and do a little reading. I am glad that there are people who understand all of this on this site! Maybe one day I will be one of them.