Prospeed tuning? Is it worth it? Anyone have it.

[kingtal0n]

Wait now, I never said how big of a cam, or how many RPM. If you spun that engine to 12,000rpm or 18,000rpm I guarantee you could get an extra 80 or 120 horsepower out of it. I realize nobody will do that but the fact is any engines from anywhere in the world that are already nearing peak 100% VE (as yours seem to be) can ONLY increase RPM or increase air density for more power. A little 2% here and 7% there from tuning port lengths and fuel/timing is negligible. And if I had to choose between RPM and air density, which one is safer? Just thinking of the big picture here, not the automotive manufacturer but rather taking into account that ALL internal combustion engines operate on the same principles.

 

[docjohn]

I'm always talking about what we have done to the car that allows day to day street/track driving not requiring frequent rebuilds. Your theoretical air pump, fuel in, higher rpm has technical merit but not something I could use.

 

[Honcho]

The JGTC C35B used on the ARTA NSX produces around 500 hp with big Toda "VTEC killer" cams, dry sump with a redline around 10,000 rpm, 3.5L displacement and MoTec engine management on high-octane race gas. It is also a race car engine: peaky, temperamental, and worthless to drive on the street. The Doc is right about moderating your expectations for gains on a 3.0 NSX. He should know, as he ran the Comptech IEM package for years, which includes most of the mods you described. As for fuel pressure- we (the community) tried that. Doesn't work. You need to tune each load cell in the map and set the fuel at the right AFR. Remember, these engines were hand built so there is some variance between them. Different engines need fuel in different places. A good ECU tune along these lines will net you around 20 whp. Budget a full day on the dyno, as the NSX fuel map has a lot of cells. DDozier can probably explain in more detail.

 

[kingtal0n]

Different engines need fuel in different places. A good ECU tune along these lines will net you around 20 whp. Budget a full day on the dyno, as the NSX fuel map has a lot of cells. DDozier can probably explain in more detail.

And this right here sums up this threads, "can I order a rom tune in the mail" question, doesn't it.

Im not sure if caught my drift but, I am anti-rpm, anti-radical engine. But the fact remains that 10whp from exhaust does the same thing that 10whp from boost does. Saying that the engine needs "forged pistons and a rebuild" still applies if you pass the threshold for low-rpm naturally aspirated modification pump gas limit, be it due to the open face, the head gasket, the cast pistons, and so forth. There are ways to deal with compression ratio (meth injection) without a rebuild. Everything from race fuel, to a switching tank sump can be used to overcome that obstacle on the street. But the internals themselves; yes this is a problem on many engines. But again, to repeat in another way, power is power. If adding an exhaust system would yield 100 horsepower it would be just as dangerous as adding the same amount of power with boost, if not more.

 

[docjohn]

If you read all the threads on this prospeed mod esp with Honcho involved then you come to learn that having that dyno day with manual painstaking programming is the right way to go.

 

[kingtal0n]

If you read all the threads on this prospeed mod esp with Honcho involved then you come to learn that having that dyno day with manual painstaking programming is the right way to go.

Oh I completely agree, dyno me all day long, any car can pick up tid bits here and there. Like you said 20whp right?

But I personally would never do anything for 20whp, or 30whp. I won't even touch an engine unless I am getting 70+ horsepower out of the deal. I see folks buying up 10 different parts for their naturally aspirated engines and spending that 10k like water... for a mere 20-50 horsepower? And I just think wow, you could have left the engine alone, and just added Xpsi of boost for the same thing. And that would leave the headroom (room to grow) for the future, in case you do decide to go forward with a rebuild, then you can twist the knob and have another 100+ horsepower.

 

[docjohn]

the beautiful thing about ones hard earned money and possessions.....yours to do as you see fit.

 

[kingtal0n]

My friend, I come in peace. I only want to learn more about your particular engine, and in the process, bring some fundamental ICE theory to the table where it may do some good. Your sig actually implies that you "do with your money as others see fit" and perhaps that is because your profession is not linked to ICE theory, not that theory ever does anybody any good anyways. Are you doctor by any chance? That is my intended career path, but I am not there yet (finishing my master's first). The body is alot like an engine, the oil pump is like the heart, the lungs are like the combustion chamber (sort of), the brain is like the ECU (also sort of ). metabolic pathways in the body are complex whereas in an engine it is fairly straightforward. I suppose it also wouldn't hurt to point out that physics plays a large role in both, ...

Can you tell me what movie follows your line of "I come in peace"...hint : it was uttered by Dolf Lundgren..

sorry I am unfamiliar with television and movies, some of my time is spent studying, the rest I try to be active, weightlifting, sprinting, any opposites of sitting in front of a computer (or TV)
This is the part where I lecture you about posture and joints, cartilage and bone remodeling. Did you know cowboys used to form bones on the insides of their thighs? If you use part of the body constantly over time it will take measures to protect and build itself from future wear, to better sustain that wear. A baby has to start walking before a large process on the femur will develop to sustain the rigors of walking. An Astronaut in zero gravity will lose muscle over time because gravity is no longer present as a stimulus. All of these examples show us that when used a certain way, the body will adapt, with bone formation or muscle development or hormone output and many other variables. So sitting in a chair all day long is just as much of a stimulus as any of these, the body will adapt to that stimulus, every bone in your body is able to re-form (bone is alive as much as your liver or heart is) to adapt.

 

[docjohn]

My sig is an inside joke .....Can you tell me what movie follows your line of "I come in peace"...hint : it was uttered by Dolf Lundgren..

 

[solidol]

It's all good and well except many nsx owners care less about hp gain but rather about making engine more responsive. I'd take itb over forced induction.

 

[Honcho]

It's all good and well except many nsx owners care less about hp gain but rather about making engine more responsive. I'd take itb over forced induction.

+1000

If I wanted a brute I'd be driving a C7 Vette or GT-R. I love my little black Honda.

 

[darock]

There is a big difference between a stock engine and one that has been modified. It's not only the sheer power increase but its the way the engine delivers the power. Any good built engine that I have ever driven was more alive and involving. Modifying TO ME means that you optimize the engine by bringing its character more into foreground without ruining it.

I know you can make tons of power with a turbocharger but that will ruin the character of the engine. A good supercharger is a different story but still, it will lack the responsiveness a proper NA setup will give you. That's also my biggest problem with modern turbocharged engines. They have no personality whatsoever. Driven the typical Audi turbo four in the ridiculous KTM xBow chassis and it did go like stink but was totally boring in terms of power delivery.

Regarding the RDX injector swap. I read a lot recently about all kinds of mods but nowhere is stated, how the swap kit addresses the latency issue with those injectors. Swapping for a newer style injector with a full dyno tune of the engine is definitely a really good idea if you already have some bolt ons to support extra power and to really make use of those. I would do it, but not with injectors that are slower than the original ones.

Bernhard