Looking for ECU chip(s)

[legendrx7]

I was installing my new Grom Bluetooth and noticed the ECU had a Dinan sticker on it. I was a little excited at first because I naturally thought this would equate to more power! Then I read a few threads only to be disappointed to hear that the consensus is that it loses power.

I have removed the ECU and confirmed that the Dinan chip is socketed in place.

I was hoping to get my hands on a chip with the stock tune and/or a Dali and/or an SOS. I would like to do some dyno runs to compare the different chips before and after I install headers and remove the cats.

Anyone have an old chip laying around, or have a lead to one? Any help is greatly appreciated.

 

[docjohn]

wow that was a rare mod in the day...what year is your car and what supporting mods?

 

[legendrx7]

Mine is a 91 5 speed. Mods are light, It came with a Downforce CF intake and an HKS catback exhaust. I'll be installing Comptech headers and cat deletes and that's about it.

 

[Old Guy]

This would be a good place to start reading if you are going to fiddle with the OEM ECU

Tuning the NSX 3.0L Using the OEM ECU

Continuing the discussion over from the cam thread. I am not really familiar with the CT stuff. I had assumed that IEM refers to Intake, Exhaust, Muffler - bolt on stuff which usually has a minimal effect of volumetric efficiency. If CT limited their head modifications and camshaft such...

www.nsxprime.com

On a stock naturally aspirated engine, I have personally been at a loss to figure out why anybody thinks remapping the ECU memory (chipping) would achieve any material power improvements. Small power improvements may be achievable by tweaking some of the AFRs in some of the cells of the fuel map; but, you are second guessing the designers who set up the ECU with probably hours of testing on a programmed engine dyno cell to check all operating points. On a turbo-charged engine where the boost is electronically regulated remapping the boost, ignition and fuel can achieve significant power increases - at the risk or turning your engine into a charred lump. If you have a naturally aspirated engine with material engine modifications as discussed by @Honcho, then remapping is necessary to maximize power and potentially prevent damage by running AFRs on the wrong side of 14.7.

Depending on what type of chip Dinan used, since it is already socketed, with a Moates device you might be able to remap it back to stock. Peruse Honcho's thread and check around and you can probably find the characterizations for the OEM ECU which, depending on the chip, should allow you to map it back to the OEM tune. I am not aware of anybody selling just the memory chip with an OEM tune. I think the option for that is a replacement ECU which was still available from Acura.

 

[Honcho]

@MotorMouth93 can burn you an OEM chip, assuming you can get him a 25C512 EPROM chip.

@Old Guy is correct- nobody sells a standalone chip anymore. The main reason is that the chips never really did that much. This is because no matter what they change, it really only will affect open loop, since the car's narrowband O2 system will "tune out" any adjustments in the closed loop range- which is most of the car's engine running range- and get it back to 14.7.

But, even in open loop, the benefit is limited by the 240cc injectors, which are running close to 100% duty cycle on the stock tune. They just can't deliver enough gas for the added airflow of stuff like headers.

So, unless you add bigger fuel injectors, these tunes won't do much. But adding different injector means you have to adjust a lot in the fuel maps and other parts of the ECU. ...Aaaaaand then you have a chipped ECU running on a Moates Demon 2. I can tell you that this solution works extremely well.

All that said, John seems to think that adjusting timing will yield more benefit then fueling, which goes against most of the conventional advice on NSX tuning, where we were told not to touch timing since it usually lost power. However, he is fast becoming the expert on the NSX ECU logic, so maybe he is on to something. After all, the NSX-R base tune bumps timing a little...

 

[MotorMouth93]

I have a factory EPROM from a 1994 ECU you can have. You can either install it in the existing socket or I can solder it into the ECU for you and make it a 100% factory ECU again. I can also burn a copy of the stock tune onto a new EEPROM chip for you if you'd like which gives you some more options like real time data streaming, EGR delete, changing coils, etc.

The Dinan tune is essentially just an additional 2 degrees of timing advance at wide open throttle along with some negligible (like 0.5%) changes in the fuel maps. Largely worthless IMO.

On a mostly stock car I don't think there's much benefit to changing timing or really anything in the tune, but when you start changing things like injectors or a different intake system you'll need to adjust the timing maps to make sure the car is running safely and make sure you're making optimal torque throughout the rev range. Better atomizing injectors such as RDX injectors or other more modern fuel injectors will result in a faster burning air/fuel mixture, requiring less timing advance to make maximum brake torque and also a more efficient burn resulting in more torque.

The Honda engineers who created the factory calibrations did it with a stock engine, once you change, well, anything there will be benefits to adjusting the calibration to match.

Changing the fuel ratio will change the torque output, but not by a huge amount by itself. Since modified C30s can run in the 14s at wide open throttle though it is both safer and should make a little more power to richen the mixture up a bit, and if you're really getting into it on a dyno, the richer mix can often let you get away with a little more timing.

 

[legendrx7]

This would be a good place to start reading if you are going to fiddle with the OEM ECU

Tuning the NSX 3.0L Using the OEM ECU

Continuing the discussion over from the cam thread. I am not really familiar with the CT stuff. I had assumed that IEM refers to Intake, Exhaust, Muffler - bolt on stuff which usually has a minimal effect of volumetric efficiency. If CT limited their head modifications and camshaft such...

www.nsxprime.com

On a stock naturally aspirated engine, I have personally been at a loss to figure out why anybody thinks remapping the ECU memory (chipping) would achieve any material power improvements. Small power improvements may be achievable by tweaking some of the AFRs in some of the cells of the fuel map; but, you are second guessing the designers who set up the ECU with probably hours of testing on a programmed engine dyno cell to check all operating points. On a turbo-charged engine where the boost is electronically regulated remapping the boost, ignition and fuel can achieve significant power increases - at the risk or turning your engine into a charred lump. If you have a naturally aspirated engine with material engine modifications as discussed by @Honcho, then remapping is necessary to maximize power and potentially prevent damage by running AFRs on the wrong side of 14.7.

Depending on what type of chip Dinan used, since it is already socketed, with a Moates device you might be able to remap it back to stock. Peruse Honcho's thread and check around and you can probably find the characterizations for the OEM ECU which, depending on the chip, should allow you to map it back to the OEM tune. I am not aware of anybody selling just the memory chip with an OEM tune. I think the option for that is a replacement ECU which was still available from Acura.

thank you for your response and for the link to read up on. I wasn't planning on doing anything ecu related until I saw that mine had already been "upgraded". I was also assuming that the stock ECU could handle a standard round of upgrades (intake, headers, cat deletes, exhaust) but I also knew that from previous experience that should be backed up with an ECU calibration. But I've been dealing with turbo cars for quite a while now. So, I've obviously in need of doing some research before taking any further steps based on some statements below about being out of fuel injector with just a stock setup. I definitely want the sound of an NSX with headers, no cats, and a nice muffler (HKS in my case), but even more so, I definitely don't want to get into a motor rebuild as a result.

 

[legendrx7]

@MotorMouth93 can burn you an OEM chip, assuming you can get him a 25C512 EPROM chip.

@Old Guy is correct- nobody sells a standalone chip anymore. The main reason is that the chips never really did that much. This is because no matter what they change, it really only will affect open loop, since the car's narrowband O2 system will "tune out" any adjustments in the closed loop range- which is most of the car's engine running range- and get it back to 14.7.

But, even in open loop, the benefit is limited by the 240cc injectors, which are running close to 100% duty cycle on the stock tune. They just can't deliver enough gas for the added airflow of stuff like headers.

So, unless you add bigger fuel injectors, these tunes won't do much. But adding different injector means you have to adjust a lot in the fuel maps and other parts of the ECU. ...Aaaaaand then you have a chipped ECU running on a Moates Demon 2. I can tell you that this solution works extremely well.

All that said, John seems to think that adjusting timing will yield more benefit then fueling, which goes against most of the conventional advice on NSX tuning, where we were told not to touch timing since it usually lost power. However, he is fast becoming the expert on the NSX ECU logic, so maybe he is on to something. After all, the NSX-R base tune bumps timing a little...

Thank you for the response and great information. I could see that no one is currently selling a chip, but I was just hoping that I could get my hands on a couple old stock or used chips to do some dyno comparisons with, but now I am understanding that I can't get enough fuel to support my planned mods with my current ECU/fuel setup. I am going to have to dive deeper before taking any further steps, or maybe just leave the headers off, cats on, and go back to a stock tune. Or, it's sounding like I might need to hop on the RDX setup that is in the FS section right now.

 

[legendrx7]

I have a factory EPROM from a 1994 ECU you can have. You can either install it in the existing socket or I can solder it into the ECU for you and make it a 100% factory ECU again. I can also burn a copy of the stock tune onto a new EEPROM chip for you if you'd like which gives you some more options like real time data streaming, EGR delete, changing coils, etc.

The Dinan tune is essentially just an additional 2 degrees of timing advance at wide open throttle along with some negligible (like 0.5%) changes in the fuel maps. Largely worthless IMO.

On a mostly stock car I don't think there's much benefit to changing timing or really anything in the tune, but when you start changing things like injectors or a different intake system you'll need to adjust the timing maps to make sure the car is running safely and make sure you're making optimal torque throughout the rev range. Better atomizing injectors such as RDX injectors or other more modern fuel injectors will result in a faster burning air/fuel mixture, requiring less timing advance to make maximum brake torque and also a more efficient burn resulting in more torque.

The Honda engineers who created the factory calibrations did it with a stock engine, once you change, well, anything there will be benefits to adjusting the calibration to match.

Changing the fuel ratio will change the torque output, but not by a huge amount by itself. Since modified C30s can run in the 14s at wide open throttle though it is both safer and should make a little more power to richen the mixture up a bit, and if you're really getting into it on a dyno, the richer mix can often let you get away with a little more timing.

Thank you so much for your valued input! I wasn't expecting all of this when I made my post. I feel I'm at a crossroads here. I sure was hoping to easily put on a set of headers and delete the cats to liven up the sound of my NSX and go along well with the great sounds of the Downforce intake. At bare minimum, I would like to have a stock chip to swap out to and I'd still like to do a quick dyno comparo with the stock chip vs the Dinan, I have pretty easy access to a local dyno.

 

[MotorMouth93]

The factory injectors do actually have enough headroom for standard I/H/E modifications, just not a whole lot beyond that. I would strongly recommend avoiding the Prospeed RDX kits, and if you want to change the injectors then properly tune the car rather than use a crummy canned chip tune. There's a reason the chip tunes are no longer available, and its because none of them really do anything worthwhile.

 

[ekhonda87]

I had a Dinan chip in mine. It is my understanding that the only changes were that they added 2.25 degrees of additional timing and raised the rev limit 400rpm.