on the dyno with comptech cams...

[austrian type-R]

hi!

today I was on the dyno with C30A 3.0i engine with just 11.5:1 CR Pistons at 0,5mm overbore, comptech cams, cam gears, overbore TB, 410cc RDX injectors and AEM ECU. Taitec headers, Taitec Center Exit and Procar cat converters

Dynoed at 352,8hp and 331,2nm to the engine. I am happy with the results.

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stock VS this tuned engine

 

[Ponyboy]

Wow, that is a great result! I think in US terms, that's just a shade over 347hp which is phenomenal.

Sheesh, you're just down 17hp from my 3.6L. Obviously, there are a lot of variables to contend with but, still, what a great result. Did you get vid?

 

[RYU]

Amazing! Any thoughts on upping the redline? I do see the tq start to trail off

 

[docjohn]

awesome:smile: nice to know the synergy of your mods works so well.......and maybe you helped bump up the price of used comtech cams

 

[L_RAO]

Good information.

A few questions:

1. Do you have an AFR plot?
2. Do you have a vacuum plot?
3. It looks like the dyno operator stopped just past 8000 RPM. Was there any particular reason? When I dyno'd my Comptech cams we stopped at 8000 RPM because my supporting mods weren't in place (valvesprings, oil pump gear).

I've been told that the Comptechs are good to 9000 RPM, and that I just need to make sure everything else is happy up there.

 

[bngl3rt]

Which AEM box do you have?

 

[austrian type-R]

I use AEM V2. The AF Ratio is Lambda 0,88 through the complete rpm band. At idle it is 0,90 cause the engine runs not good with Lambda 1,00 (where it should usualy be on street engines). We had 4hp more peak power than on the dynoplot shown above with Lambda 0,90 on WOT but to be on the safe side my tuner setted the AF at 0,88. This engine will run only on the track. The partial throttel was tuned 1 hour after tweaking out the power at WOT.

I use supertech valve Train and TODA oil gear. There is no reason to rev higher than 8000rpm. My tuner said the bottle neck is the stock intake manidfold. He tuned an 3.0 C30A engine with with just 3 litre displacement using SOS ITB and TODA cams to 390bhp. So my numbers here prove the potential of the NSX engine with just i/h/e/cams + the parts you Need to run this safe. It is a shame that Honda did not tune the NSX-R engine to 350hp or something. It is easy to get out more hp from this powerplant as you see.

I have an ADAC STREIGHT GEAR TRANSMISSION from the old ADAC GT NSX runned in 1993 on german race tracks. The gear Ratio tops out at 235kmh at 8200rpm. Exedy dual carbon clutch is used as well. The LSD is some Kind of Honda R&D. It is not a Standard one.

 

[stuntman]

I use AEM V2. The AF Ratio is Lambda 0,88 through the complete rpm band. At idle it is 0,90 cause the engine runs not good with Lambda 1,00 (where it should usualy be on street engines). We had 4hp more peak power than on the dynoplot shown above with Lambda 0,90 on WOT but to be on the safe side my tuner setted the AF at 0,88. This engine will run only on the track. The partial throttel was tuned 1 hour after tweaking out the power at WOT.

I use supertech valve Train and TODA oil gear. There is no reason to rev higher than 8000rpm. My tuner said the bottle neck is the stock intake manidfold. He tuned an 3.0 C30A engine with with just 3 litre displacement using SOS ITB and TODA cams to 390bhp. So my numbers here prove the potential of the NSX engine with just i/h/e/cams + the parts you Need to run this safe. It is a shame that Honda did not tune the NSX-R engine to 350hp or something. It is easy to get out more hp from this powerplant as you see.

I have an ADAC STREIGHT GEAR TRANSMISSION from the old ADAC GT NSX runned in 1993 on german race tracks. The gear Ratio tops out at 235kmh at 8200rpm. Exedy dual carbon clutch is used as well. The LSD is some Kind of Honda R&D. It is not a Standard one.

Assuming a 15% drive train loss, your motor is making 415bhp..

 

[austrian type-R]

hi. no my motor is making 352,8hp = bhp = hp to the engine

 

[RYU]

Should be about 300whp (to the wheels). This must really fun to drive.

 

[sparky]

hi. no my motor is making 352,8hp = bhp = hp to the engine

I assume you were measuring at wheels and that 352.8 figure is multiplied up to compensate for estimated drive train loss.
Do you have actual peak dyno rwhp readings / curve?

 

[Ponyboy]

Hmph…I have never seen a dyno plot already compensating at a crank hp. Totally overlooked that in the pic. Be interesting to see what drivetrain loss was set to. For most cars, it's around 15% but I'd thought that MR cars have a lower %, from 11-13%.

 

[liftnot]

hi. no my motor is making 352,8hp = bhp = hp to the engine

but the pix you show is a chassis dyno not an engine dyno thus Billy's correction factor. Dogs are more efficient the helical, by how much, I don;t know. If you have Billy deburr all the sharp edges, you might gain a few more hp....but knowing its from Honda Racing, they might have done it.
Props to you doing things the right way.

 

[stuntman]

Hmph…I have never seen a dyno plot already compensating at a crank hp. Totally overlooked that in the pic. Be interesting to see what drivetrain loss was set to. For most cars, it's around 15% but I'd thought that MR cars have a lower %, from 11-13%.

IIRC, the 270bhp C30A often dynoes around 230whp. 230/270 = 0.851 (or 14.8%)

but the pix you show is a chassis dyno not an engine dyno thus Billy's correction factor. Dogs are more efficient the helical, by how much, I don;t know. If you have Billy deburr all the sharp edges, you might gain a few more hp....but knowing its from Honda Racing, they might have done it.
Props to you doing things the right way.

Straight-cut gears really aren't any more efficient than helical, and gears in general are extremely efficient. The biggest drivetrain loss component is the ring & Pinion. Honda gears are pretty good from the factory and REM & WPC Treating a R&P could yield a few HP.

Hub dynos are quite a bit different than rollers so the (~300whp) is hard to gauge how it compares to a typical DynoJet run.

 

[Ponyboy]

IIRC, the 270bhp C30A often dynoes around 230whp. 230/270 = 0.851 (or 14.8%)

Ha! I was using 235rwhp so it covers the deviation of 5hp either way. 235/.87 = 270ish.

 

[austrian type-R]

This dayn works like a roll dyno. At red line you press the clutch and let spool down the dyno and it does measuring the lost power in drivetrain like on the Bosch Dyno I was in the old days. My tuner also compared cars which runned on the old Bosch dyno and now on this one and the bhp are extremely equal (we are talkiong from 1-3hp difference). I have to contact the tuningshop if they can print me out the sheet where we can see the drivetrain power loose.


Here you see an typical Bosch Dynoprint. Power which is lost in drivetrain is getting higher when driving in higher gear. You see this in the plot below. This was from my street NSX with Taitec headers, LWGT and stock cats, Procar Airbox.

 

[stuntman]

This dayn works like a roll dyno. At red line you press the clutch and let spool down the dyno and it does measuring the lost power in drivetrain like on the Bosch Dyno I was in the old days. My tuner also compared cars which runned on the old Bosch dyno and now on this one and the bhp are extremely equal (we are talkiong from 1-3hp difference). I have to contact the tuningshop if they can print me out the sheet where we can see the drivetrain power loose.

Here you see an typical Bosch Dynoprint. Power which is lost in drivetrain is getting higher when driving in higher gear. You see this in the plot below. This was from my street NSX with Taitec headers, LWGT and stock cats, Procar Airbox.

I don't think you have more drivetrain loss in higher gears but rather lower gears have artificially higher torque due to the gear's inherent torque multiplication, which is why you typically want to dyno a car in a gear closest to 1:1 ratio, so you don't have an artificially high and inaccurate reading.

 

[jaja]

I would be tempted to say there would be more losses when in gears of the lowest ratio simply due to the speed. Higher speed = more friction. The engine will output the same amount of power regardless of the gear, so the torque produced at the crank will also be independent of gear. But at the wheels, higher speed, more lost power due to higher.

Also, the idealized 1:1 ratio I believe has to do with the operating range of the dyno. I think this applies primarily to "inertial" dynos. I'll have to look into why more, but I believe a lower gear ratio will remove the influence of the drivetrains inertia, (like engine breaking in 1st gear, that lurch). This results in a more accurate dyno reading.

Thoughts?

 

[RYU]

The dyno debate will go on thru the end of time. There are a lot of variables that simply make it difficult to compare apples to apples. They are tools used to tuning. The HP/tq ratings are really just a guideline especially when comparing cars on different dynos. Loading on the hub dynos can get a little weird. We try not to use them.

 

[BATMANs]

So what's the verdict on what sorta power this is really making?

 

[stuntman]

I would be tempted to say there would be more losses when in gears of the lowest ratio simply due to the speed. Higher speed = more friction. The engine will output the same amount of power regardless of the gear, so the torque produced at the crank will also be independent of gear. But at the wheels, higher speed, more lost power due to higher.

Also, the idealized 1:1 ratio I believe has to do with the operating range of the dyno. I think this applies primarily to "inertial" dynos. I'll have to look into why more, but I believe a lower gear ratio will remove the influence of the drivetrains inertia, (like engine breaking in 1st gear, that lurch). This results in a more accurate dyno reading.

Thoughts?

Not really. While the engine output remains the same, gears affect and multiply the torque output between the motor and the wheels (where we are measuring power), so being in a 1:1 ratio gear reduces any gearing effect that the would alter the dynos reading.

Dynoing should be in the gear closest to 1:1 which is 4th in the nsx.

So what's the verdict on what sorta power this is really making?

While dynos can be greatly different from brand to brand or location to location, he made ~50whp gain from his mods (I/h/e/cams). From what I gather a stock car makes around 230s on a dynojet and 260s with I/h/e, so cams are worth a ballpark ~20whp and would a car on the 280-290whp range.

 

[jwmelvin]

...being in a 1:1 ratio gear reduces any gearing effect that the would alter the dynos reading.

Are you saying that the output from a dyno does not consider and adjust for the actual gear ratio used? That seems highly improbable.

 

[stuntman]

Are you saying that the output from a dyno does not consider and adjust for the actual gear ratio used? That seems highly improbable.

I have not been on a dyno that needs to know the gear ratio, wheel and tire diameter as inputs. Mostly dyno in the gear closest to 1:1. Dynoing in different gears yield different #s as does the weight and diameter of wheels and tires.

 

[RYU]

Each dyno has so many settings, loading factors, compensation metrics, in the algorithm that converts wheel power to an actual load reading. How the loading is programmed also makes a big difference. One time we had the dyno at the wrong setting. It assumed our 3rd gear pull was to simulate a long hill climb. It scared us when we realized the load got stronger as we neared redline. In essence, the dyno compensated and added so much load that we would never get to redline.

What Billy said about weather, tire diameter, gear ratio, and even tire pressure, location of the dyno motor as it creates heat, and many other factors all affect the output. The fact is, most tuning shops tune their dyno based on the manufacturers recommendation and its tuned at an average baseline to get an average reading. YMMV. It's the incremental change in HP/TQ is the number you really want.

I try to pick a dyno location and stick with it. It's the only way to not add too many variables. Superflow, Dynojet, maybe Mustang tend to be ok. The big drum style is my tuner's preference. The loading on the hub style dynos can get a little weird - best way I can describe. I don't use them for any serious kind of tuning but they can still be a good tool and safer than doing a bunch of 0-120mph runs on the hwy! haha

 

[Nero Tenebre]

I think the net gain is pretty much what these old comptech mods used to get back in the day. Only difference seems to be the bigger injectors and tuning here should take that a step further.

I agree the NSX-R is weak on numbers and they should have done more to make the car better since we all know the chassis is capable. Very nice gains, enough to transform the car and keep the NA spirit of factory tuned NSXs.

I made 278whp with I/H/E/INJECTORS/TUNE so that's about 50whp more than stock without much doing. I can't wait till a worthy throttle body and intake manifold hit the market to see how far I can ride the NA ride before going boost. If it adds the expected 20-30whp I will also pass 300whp in natural aspiration form without the high compression pistons or cams/gears or ITBs. IMO that would be pretty good for "bolt on" mods and no internal engine work which would make boosting impossible after.

If you get a proper intake manifold (see other thread) then you could potentially hit 330whp which will be 100whp over stock! Of course the gains will not be cumulative but I would expect to see improvement with each but time will tell.