I'm looking for a DBW pedal, what pedal are you using?
Gary
Gary
RYU's "properly molested" NSX build thread
- Thread starter RYU
- Start date
- Joined
- 27 May 2010
- Messages
- 42
Love this, beautiful and inspirational
I'm using a Pedal Position Sensor from an 08 Acura TSX, but the spring tension is just too soft. I have to spend time modifying it to make it stiffer. It's so soft that when you're trying to hold a perfect pedal position with your foot it will bounce around in during bumpy terrain. It's annoying during those moments.
I'll probably go with the OEM 95+ NSX pedal setup.
Here's a quick video of how I did things. Kind of ghetto but this is just to test everything as a proof of concept. Everything works using the stock throttle cable, but again.. pedal feel is too soft right now.
This is going to be the updates of updates. Let's post some numbers.
3.6L ITB with HF cats
Red Line: Open Trumpets: 341wHP/288lb-ft
Green Line: CF Airbox installed 331wHP/271lb-ft
Notice the smoothed out torque curve and removal of that peaky torque dip/spike at VTEC. Whomever said the airbox robs a lot of power was wrong. The problem is the exhaust restriction. The cool part also is the flat torque curve itself. Car revs super peppy, pretty much like a race motor. The not cool part.. can't hold idle very well but I'll eventually fix that. I have ideas. Another not cool part, the top of the power curve drops after 7k. It's not the airbox restriction. It's the exhaust restriction.
Dyno conditions: 60-65F ambient. Dynapack known to be a heartbreaker. Safe to say this is a 350whp motor for bragging purposes and 400hp to the crank. It's a round easy number I can remember LOL
Next Steps:
* Engine still has some issues so unfortunately it needs to come out.
* While it's out we're going to install some Toda cams of my own spec
* Idle control with the AEM and DBW ITBs pretty much suck. Need to install an IACV and see how that does.
3.6L ITB with HF cats
Red Line: Open Trumpets: 341wHP/288lb-ft
Green Line: CF Airbox installed 331wHP/271lb-ft
Notice the smoothed out torque curve and removal of that peaky torque dip/spike at VTEC. Whomever said the airbox robs a lot of power was wrong. The problem is the exhaust restriction. The cool part also is the flat torque curve itself. Car revs super peppy, pretty much like a race motor. The not cool part.. can't hold idle very well but I'll eventually fix that. I have ideas. Another not cool part, the top of the power curve drops after 7k. It's not the airbox restriction. It's the exhaust restriction.
Dyno conditions: 60-65F ambient. Dynapack known to be a heartbreaker. Safe to say this is a 350whp motor for bragging purposes and 400hp to the crank. It's a round easy number I can remember LOL
Next Steps:
* Engine still has some issues so unfortunately it needs to come out.
* While it's out we're going to install some Toda cams of my own spec
* Idle control with the AEM and DBW ITBs pretty much suck. Need to install an IACV and see how that does.
Amazing work. As to the exhaust, if you think about it the Le Mans GT2 engines used massive headers (huge collectors) running into straight pipes and exiting out the center bumper. That's probably where they found that extra 20-30 hp at 9,000+ rpm.
I reckon you're right. It's a lot of extra expense for that part of the RPM i'm rarely at so i'm going to let it simmer until I get super bored again.
Right now... the DBW tuning is kicking my ass. It's just not quite feeling how it should. Still have ideas to try so i'm not going back to the cable yet!.
Can you expand on the issues you're feeling with the DBW Regan?
Too early to tell at this point. I need to find some more spare time to tune the pedal to throttle body mapping in the AEM. The AEM doesn't seem to be so good at these things but too early to tell.
That or drive it off a cliff. I haven't decided. HA!Time for Haltech
@Gary W & @blaketjones
I was reading @stuntman's latest article and was reminded of my lack of updates here. In the last few weeks I disabled my DBW and went back to good old cable throttle. There were 2 main reasons why I did this.
1. Pedal Feel was too soft - If you noticed in the video I ran a pedal position sensor at the end of the OEM 91-94 throttle cable. Initially I thought this would feel more or less the same since i've driven a TSX (my brother has one) and the throttle pedal pressure was fine. That did not translate at all in my NSX. The throttle pedal was far far too soft and it was nearly impossible to get any feedback from the throttle pedal - I HATED IT. Billy did it the right way and incorporated the stock NSX 95+ throttle pedal itself and PPS.
2. Calibration of the DBW with the AEM Infinity was lacking - I'm still unsure on this part but my main goal for converting to DBW was to take full control of the PPS calibration to the DBW motor. I wanted to create my own pedal ramp map. As you guys may know ITBs can be very sensitive on initial tip in. At tip in a 3% throttle opening is a lot of air. In a cable driven setup you can mitigate that through some compromise via a progressive elliptically shaped bellcrank. With a DBW, in theory, you can create your own progressivity curve where, for example, a 3% pedal position can be as little as perhaps 0.5% throttle opening. Well, I lost patience trying to set this up. I played with the Infinity DBW tables for hours and really couldn't get to a happy compromise.
It was around this time I was brainstorming with @illwillem and he helped me think through better how to add more progressivity in the cable driven linkages. So that's where i'm at today. The throttle feels pretty good - not perfect but enough to make me happy, which is a tall order these days.
I will tackle the DBW ITB setup another day. I know it can be done, but the ITB itself in a V style motor adds a whole order of magnitude in complexity. Getting both banks to balance is a tricky tight rope act especially the first time you do it. Now I can balance my ITBs in 30 mins which I check at every oil change or sooner.
I was reading @stuntman's latest article and was reminded of my lack of updates here. In the last few weeks I disabled my DBW and went back to good old cable throttle. There were 2 main reasons why I did this.
1. Pedal Feel was too soft - If you noticed in the video I ran a pedal position sensor at the end of the OEM 91-94 throttle cable. Initially I thought this would feel more or less the same since i've driven a TSX (my brother has one) and the throttle pedal pressure was fine. That did not translate at all in my NSX. The throttle pedal was far far too soft and it was nearly impossible to get any feedback from the throttle pedal - I HATED IT. Billy did it the right way and incorporated the stock NSX 95+ throttle pedal itself and PPS.
2. Calibration of the DBW with the AEM Infinity was lacking - I'm still unsure on this part but my main goal for converting to DBW was to take full control of the PPS calibration to the DBW motor. I wanted to create my own pedal ramp map. As you guys may know ITBs can be very sensitive on initial tip in. At tip in a 3% throttle opening is a lot of air. In a cable driven setup you can mitigate that through some compromise via a progressive elliptically shaped bellcrank. With a DBW, in theory, you can create your own progressivity curve where, for example, a 3% pedal position can be as little as perhaps 0.5% throttle opening. Well, I lost patience trying to set this up. I played with the Infinity DBW tables for hours and really couldn't get to a happy compromise.
It was around this time I was brainstorming with @illwillem and he helped me think through better how to add more progressivity in the cable driven linkages. So that's where i'm at today. The throttle feels pretty good - not perfect but enough to make me happy, which is a tall order these days.
I will tackle the DBW ITB setup another day. I know it can be done, but the ITB itself in a V style motor adds a whole order of magnitude in complexity. Getting both banks to balance is a tricky tight rope act especially the first time you do it. Now I can balance my ITBs in 30 mins which I check at every oil change or sooner.
After some time and redo's the car has now logged 500 miles on the new 3.6L. Too early to report back but things are looking quite good so far. Once I hit 1000 i'll post up a summary or a video in case anyone is interested.
1000 miles reached and here's the update as promised
I longed for the anonymityLooks great! what happened to SENNA1?
I'm looking at my welts now and wondering the same thing!I can't believe you put up with biting fly's for 20 minutes..."the show must go on"...
You are too kind old friend!
Ahem?!
No seriously though Regan I'm so happy to see the car out and about. Great video and thank you for braving the flies! I hope you come to XPO so I can see and hear the engine in person.
Can you talk more about the vacuum pump and tank system? I'm really curious how you solved it.
Haha! Roman received the check I mailed him lolAhem?!
No seriously though Regan I'm so happy to see the car out and about. Great video and thank you for braving the flies! I hope you come to XPO so I can see and hear the engine in person.
Can you talk more about the vacuum pump and tank system? I'm really curious how you solved it.
Since the motor only produces vacuum on decel it's not nearly enough to keep the brake booster happy. Since I hate manual brakes I had to find a solution. Thank goodness the musclecar guys have been dealing with this problem forever ago so lots of options available.
The first 3.6 had mild cams. That produces enough vacuum to need only a pump.
The Toda C's need the vacuum pump and a reservoir because they're more aggressive still.
I wanted an OEM solution and after some research there are actually modern OEM vehicles that still use a vacuum pump for similar applications. I chose a Volvo vacuum pump. I'm still playing around with the reservoir sizing and for now I picked up a 1litre eBay tank. This tank and pump combined with a rather complicated check valve system allows vacuum to be stored in the reservoir whenever the brake booster needs it. Except for the random whizzing of the pump you can't tell the difference in braking performance.
Would be nice not to need the pump but given the trade-off it's worth it.
Let me know if anyone has questions. NA builds aren't too popular here so I wouldn't be surprised if I'm the first to have this setup on the NSX.
I'll post pictures later if anyone is interested. It's not in it's final position... Hell... So many things in the car needs to be put back together permanently. That's on the list when the weather (and bugs) cool down
I always enjoy reading about "what's next?" just so much awesome.
