Twin Turbo NSX is ready

[ncbluetj]

Interesting point about the big NA cams with turbos. I've always been under the impression that this type of setup wouldn't work. I'm glad to see that it, in fact, does work and, like you said, makes more power. The SOS cams always seemed way too tame and small for such a high-revving engine, especially with vtec to calm the idle. Whenever I get around to building a turbo setup, I'd like it to be very much like yours.
Have you considered having a custom manifold made and using dual throttle bodies? I always thought this would be the hot ticket for a twin turbo setup. You know, one throttle for each turbo, so that the engine has twin, completely independent turbocharging systems rather than two turbos plumbed into the same TB. A setup like that would really put your car over the top. Although it's an exceptionally well-built setup already. Well done, you should be proud.

 

[David]

Interesting point about the big NA cams with turbos. I've always been under the impression that this type of setup wouldn't work. I'm glad to see that it, in fact, does work and, like you said, makes more power. The SOS cams always seemed way too tame and small for such a high-revving engine, especially with vtec to calm the idle.

The "big cams don't work with forced induction" claim is pure 100% horse crap, perpetuated by people who don't understand how cylinder heads work. Some of the turbo drag Hondas are running Skunk2 Pro 3 cams, which are literally the biggest NA cams you can buy without grinding your own. One of the guys who does some of my tuning (Tony Paulo) picked up over 40 whp on his car by just by switching from ITR cams to Pro 3s.

Big cams work well in high boost/high hp turbo cars for the same reason they work in high-revving NA cars. However, they are only better than a moderately sized cam if you are boosting aggressively and have an efficient exhaust manifold(s).

For example, if you put a turbo S2000 on the dyno with a cast manifold, the stock cams are too big and you can actually make MORE power by grinding them down. However, with a tubular manifold, the stock cams work great. I use this example because that car has about as big an OEM cam as you will find.

BTW, the published Toda nsx cams specs are bogus. I know a couple of people who have actually measured them and they are extremely, well. . . I'll be polite and say "optimistic."

 

[Mark911]

Remember, there are several standard and even some unstandard ways to measure both duration and lift. You'd need to use the same process to compare apples to apples. In addition, ramp shapes and rates are just as important. Finally, there's no info on actual open and close timimg which dictates the amount of overlap and where the overlap occures. This, along with the other timing events influence reversion as well as dynamic compression ratio, pumping losses, and momentum filling. Displacement (bore/stroke), operating RPM, transmission type, rod ratio, valve train design, combustion chamber shape, intake cross section, and many other variables are considered when designing a camshaft. Like most things, max performance is a result of many compromises and as a result, there are many different ways to skin this cat. I don't think there is one right answer. The engine is a system and every component influences the other. Different manufactures and tuners/builders have their own "systems" approach/theories and therefore will have different requirements for all the individual components. For example, there's no way one Pro Stock team is going to gain 20 hp just by looking at another teams headwork because every other component on that engine has been designed to maximise the performance of that head and visa versa. Too bad it's not that simple.

 

[ncbluetj]

Wow, great responses guys. The subject of NSX aftermarket cams and their specs/limitations has always intrigued me. I know Chris@SOS has posted more than once that the specs they run for their big NA cams are due to limitations caused by valve/valve and valve/piston contact. He is well respected amongst the community and I would have no reason to doubt that what he says is true, but the TODA specs suggest otherwise. However David, you are not the first person I've heard say that the TODA published specs are a bit "optimistic". I don't guess anyone has actually measured and compared the two, huh? It would be really interesting to see the real differences between them.
Everything you guys said about big cams and turbos makes sense to me. Of course the correct cam choice is always dependent on a plethora of variables. However, it is interesting to know that with proper flow characteristics from your other components, you can get away with boosting on big cams.
Apologies to the OP for hijacking this thread. Back on topic now, Ivan, do you know if the crower stroker crank will be offered as a production part? Or is it a one-off custom piece? What is the stroke measurement? Sorry for all the questions, but your car is too cool for school.

 

[Total Race]

Wow, great responses guys. The subject of NSX aftermarket cams and their specs/limitations has always intrigued me. I know Chris@SOS has posted more than once that the specs they run for their big NA cams are due to limitations caused by valve/valve and valve/piston contact. He is well respected amongst the community and I would have no reason to doubt that what he says is true, but the TODA specs suggest otherwise. However David, you are not the first person I've heard say that the TODA published specs are a bit "optimistic". I don't guess anyone has actually measured and compared the two, huh? It would be really interesting to see the real differences between them.
Everything you guys said about big cams and turbos makes sense to me. Of course the correct cam choice is always dependent on a plethora of variables. However, it is interesting to know that with proper flow characteristics from your other components, you can get away with boosting on big cams.
Apologies to the OP for hijacking this thread. Back on topic now, Ivan, do you know if the crower stroker crank will be offered as a production part? Or is it a one-off custom piece? What is the stroke measurement? Sorry for all the questions, but your car is too cool for school.

I do not think that it could be a production part.. not so many requests. I custom ordered it and had to order 5 sets, that was minimum order! Two of them are still in USA. If anyone wants it then price is really cheap, just 6k+shipping. Crank has 84mm stroke vs 78mm stock. Uses 5.984" c-to-c steel billet connecting rods.

 

[Like007]

Privet
U mena pohoziy set up 3.5 Comptech s Lofab Turbo ,Toda Cams .......
Road race car. I be ne delal 25lb boost. U mena 12lb boost with 650 hp at the wheels
Pozdravlau

Igor

 

[ScienceofSpeed]

Mark & David make valid points. Our cam specs are measured at the cam with a cam lobe follower. Other manufactures may list specs at the rocker shaft, which will produce different specs due to the arc of the rocker shaft amplifying certain measurements, such as lift. Based on the limitations of the cam geometry, I do not believe that the specs listed above are measured using the same procedure we do.

Cheers,
-- Chris

 

[ncbluetj]

Chris, I agree that comparing your posted specs to TODA's posted specs is apples and oranges. Just out of curiosity, have you ever examined a pair of TODA cams yourself?
Also, on your website you have different cams offered for FI and NA applications, and you state that your NA cams are not recommended for FI engines. Do you care to comment on the above posts about using longer duration cams for FI? Have you or any of your customers ever paired your NA cams with a FI application? Sorry for all the questions, but this is one subject I'm very curious about, and I'm glad to have the experts involved in the discussion.

 

[fullracehonda]

for the past year or two it has been widely accepted in the honda b series and k series(because nobody cares about any of the other engines:tongue that NA cams work wonders in forced induction cars, you see bigger gains with the more boost your pushing, but at the same time you only want to use moderate all motor cams, nothing extreme for like 15-1 compression running on race gas NA cams though

 

[David]

you only want to use moderate all motor cams, nothing extreme for like 15-1 compression running on race gas NA cams though

Just not true. At high boost or high rpm, the big cams work great. The S2 Pro 3s in the example I used above are HUGE all motor race cams.

 

[Total Race]

Hi guys,
here is some update. Today i tuned a car and got 760hp at 18psi, pump gas. Not bad,isnt it? I think 800hp could be reached easily during next tuning sessions. Torque is linear from 5200 to 7500 and equals to 740N/m then slowling drops. I have very small and restrictive air intake filters installed in this car (besides rear fenders). I believe just intake improving will get much better high rpm torque. We will see.

 

[warren1205]

HOLY Shizznet batman! that's impressive. what's pump gas where your at?

 

[Total Race]

HOLY Shizznet batman! that's impressive. what's pump gas where your at?

thanks. we have RON98 (85MON) here, that is close to your (r+m)/2 91. people here tend to think that yours much better since our petrol makers manufactures it from RON92 by adding some additives like MTBE.

 

[Total Race]

here is a video of the dyno run if someone interested.
http://hosting.relline.ru/~vanusha/NSX/MOV01178.MPG

 

[carchitect]

Ivan congrats on your buildup and I was wonder if the OEM specs for the engine came in handy. I hope to see this car someday. Do you think you could bring it down with you for the Texas supra nationals next year?

 

[01blacks4]

Ivan congrats on your buildup and I was wonder if the OEM specs for the engine came in handy. I hope to see this car someday. Do you think you could bring it down with you for the Texas supra nationals next year?

from russia?

 

[Total Race]

Ivan congrats on your buildup and I was wonder if the OEM specs for the engine came in handy. I hope to see this car someday. Do you think you could bring it down with you for the Texas supra nationals next year?

Hi Joe, thanks! I do not think i will bring NSX, still that is not that interesting project as our 4wd supra to show. Shipping cost and also time required for delivery is very significant... We will see.

 

[Klayton]

thanks. we have RON98 (85MON) here, that is close to your (r+m)/2 91. people here tend to think that yours much better since our petrol makers manufactures it from RON92 by adding some additives like MTBE.

Hehe every tried to convert eu ron to us roz and back.. annoying. Anways those are pretty impressive numbers .. congratualtions.

 

[baynsac]

Privet
U mena pohoziy set up 3.5 Comptech s Lofab Turbo ,Toda Cams .......
Road race car. I be ne delal 25lb boost. U mena 12lb boost with 650 hp at the wheels
Pozdravlau

Igor

Igor when are we going to hear a little about your monster nsx. I came by your house and talked to you for a while about your nsx. You were going all race with the nsx. Sounds like you are getting the works...Nice, when you get a chance tell us little more about your race car nsx.



Total Race:
Whats the universal air suspension with controller & remote control? Is this a full suspension or is to raise and lower the nsx?

 

[Flexer]

Is it just me or does the graph cross at 4200 instead of 5250...........

J. R.

PS. Those poor turbo's are out of steam. Your WAY outside of the VE islands. Pushing them more to hit 800 whp while it may be possible, is going to push your AIT's up a lot running them that far out of there efficiency.

 

[lowellhigh79]

Is it just me or does the graph cross at 4200 instead of 5250...........

J. R.

PS. Those poor turbo's are out of steam. Your WAY outside of the VE islands. Pushing them more to hit 800 whp while it may be possible, is going to push your AIT's up a lot running them that far out of there efficiency.

The scales are different, although I can't seem to get them to match at 5250 either.

Regards,

Danny

 

[Flexer]

The scales are different, although I can't seem to get them to match at 5250 either.

Regards,

Danny

I know danny. I thought it was rescaled at first but I have been staring at the side measurements and it jacks them when I try and move the scale to cross at 5250. Then I thought it was a diffrent dyno then I am used to seeing in the states but its a dyno dynamics...... After a quick google search all the dyno dynamics print outs I found looked just like that one, with the numbers up both sides of the graph, but they all crossed at the magic 5250.

Am I looking at that dyno graph wrong?

J. R.

 

[Ojas]

metric y0!

5252 (an approximation of 33000/2π) is only relevant as a cross point when power is measured in HP and torque in ft-lbs., from this equation:

torque (ft-lbs) = power (in HP) x 5252 / rpm *

The chart shown has PS for units of power and newton-meters for torque. Given that...

1 PS = 0.98632 HP
1 NM = 0.737562149 ft-lbs.
torque (in NM) = power (in PS) x 1/0.98632 x 5252 / rpm x 0.737562149
torque (in NM) = power (in PS) x 3927 / rpm

3927 is what we want to look for. The power and torque cross point in the plot seems to agree with this number (or is close, given normal margin of error).

No?

 

[Flexer]

Re: metric y0!

5252 (an approximation of 33000/2π) is only relevant as a cross point when power is measured in HP and torque in ft-lbs., from this equation:

torque (ft-lbs) = power (in HP) x 5252 / rpm *

The chart shown has PS for units of power and newton-meters for torque. Given that...

1 PS = 0.98632 HP
1 NM = 0.737562149 ft-lbs.
torque (in NM) = power (in PS) x 1/0.98632 x 5252 / rpm x 0.737562149
torque (in NM) = power (in PS) x 3927 / rpm

3927 is what we want to look for. The power and torque cross point in the plot seems to agree with this number (or is close, given normal margin of error).

No?

Ojas to the rescue! Good stuff I think you cracked it. Only problem I still see is that they clearly cross at 4250, not the 3927.

We are hot on the trail now though.

J. R.

 

[lurker44]

Hi Guys,


Shortly about specs.


m&w CDI


thanks!
Ivan Kirillov
Total Race
http://www.totalrace.ru

Ivan, nice execution on the car. One thing I am curious about is the M&W CDI. Which one or ones did you use? Cheers!