engine remapping

[richard grigsby]

If I was to fit an aftermarket exhaust and high-flow air filter can anyone recommend a professional outlet to remap my 97 3-litre engine?

Richard

[AR]

All you need to do is either remove the clock fuse, or disconnect the battery and the ECU will compensate.

Cheers,

AR

[richard grigsby]

Thanks very much AR I will try when the time comes.

[TheSebringOne]

Ary, I can't believe its that simple! The infamous & friendly clock fuse does it again! :)

[AR]

Ary, I can't believe its that simple! The infamous & friendly clock fuse does it again! :)

Real easy and costs nothing.

[markc]

All you need to do is either remove the clock fuse, or disconnect the battery and the ECU will compensate.


Ary, I can't believe its that simple! The infamous & friendly clock fuse does it again! :)

As AR says the engine compensates rather than remaps. I think it only effects ignition settings.

AFAIK removeing the clock fuse causes the ECU to lose it's learned ignition settings. It therefore reverts to default safe settings then progressively trys advancing the ignition curve settings until it senses pre-detonation a.k.a knocking/pinging/deting via the knock sensors fitted to each bank of cylinders. Once it it detects knocking it retards the ignition until it's safe again.

In theory just driving for a while after fitting the new exhaust will do the same thing but maybe it learns/compensates a bit faster from the default settings.

The Honda PGMFI is as I understand quite tricky to properly remap. A proper remap would involve changing the ignition and fuel settings over the entire rev range at various if not all throttle openings and loads ie creating a new "map" of how much fuel gets injected and what ingition advance is used at specific revs for specific throttle openings and loads.

Some people claim that the standard Honda maps are sooo good it's hard to improve but I think that is probably rubbish. Manufacturers factory settings have to build in plenty of leeway to allow for for poor fuel quality and bad/overdue serviceing. As enthusiasts who always use good quality fuel and regularly service our p&j's we can probably take the risk of a more aggressive map to release a few ponies throughout the rev range but not many people specialise in remapping Honda PGMFI systems.

You can buy new "chips" (Dali, Mugen etc) containing remapped settings for older pre OBDII (MY'95) cars but there aren't any off the shelf options for later models. These pre-set "chips" don't take any specific mods you might have made into account and probably just increase the duty cycle of the fuel injectors and advance the ignition a little bit everywhere... it might help but it might not. A live re-map, specifically for your car with your mods would be much better but no-one routinely does this for the NSX.

The version of PGMFI fitted to the NSX is pretty old now so it probably has a small memory and therefore a fairly limited scope to hold a significantly better "map".

This is where aftermarket ECU's from people like MoTec come in giving you more computing power and therefore the ability to hold more granular fuel/ignition maps and, in theory make more power, torque and improve driveability. If only they weren't so expensive.

Cheers

Mark

[AR]

Another thing with chips is that a lot of them remove or raise the rev limiter. So for the sake of 3-6 HP which might only be weather/dyno related, best to stay stock unless doing some heavy mods.

Cheers,

AR

[markc]

Another thing with chips is that a lot of them remove or raise the rev limiter. So for the sake of 3-6 HP which might only be weather/dyno related, best to stay stock unless doing some heavy mods.

Cheers,

AR

Actually I disagree with the last part AR. I'd definately go with the live re-map, or even an off the shelf chip if I knew exactly what it did, but I'd insist that the rev limit was not moved.

If you give the engine exactly the right amount of fuel and lite that fuel mixture at exactly the right time you get more power and torque over the entire rev range. Not only do you get a peak improvement of say 10hp (on a 3/3.2 ltr engine) but you get more everywhere. Acceleration is defined by the area under the power/torque curve so overall acceleration will be stronger ie the car will be faster :)

If you're doing heavy engine mods it's even more important that the fuel/ignition map matches the mods to 1) make the most of the mods and 2) protect the engine, so a re-map becomes absolutely essential.

Mark

[AR]

My experience withe the Mugen was that it was faster midrange, but I did not want to deal with the unknown fuel cut off issue.

Here are some "testimonials" by some members from Prime/NSXCB:

http://www.nsxprime.com/forums/showpost.php?p=980245&postcount=253

http://www.nsxprime.com/forums/showpost.php?p=990564&postcount=274

http://www.nsxprime.com/forums/showpost.php?p=934419&postcount=150

So the most advance chip gives you 7.5hp, what is a standalone ECU going to squeeze?

I think better gains can be had by loosing a few pounds ( or hundreds :) ) from the car and keep the safety of the OEM ECU.

Now if we are talking FI or Hi-Comp NA then is a different story!

Cheers,

AR

[markc]

So the most advance chip gives you 7.5hp, what is a standalone ECU going to squeeze?

I think better gains can be had by loosing a few pounds ( or hundreds :) ) from the car and keep the safety of the OEM ECU.


Both valid ways of skinning the acceleration cat :)

Using a web acceleration calculator (http://www.web-cars.com/math/qtr_mile.html) and a nominal 300hp, 3000lb car ie pretty similar to a stock NSX. Adding 10hp OR losing 100lbs have virtually exactly the same effect on performance.

Niether is better than the other for acceleration, do both and the benefits are aggregated :)

Lighter weight pays dividends in handling and braking though but you can only strip so much out of a road car before it starts to feel bare or noisy or under equipped.

Cheers

Mark

[NoelWatson]

Both valid ways of skinning the acceleration cat :)

Using a web acceleration calculator (http://www.web-cars.com/math/qtr_mile.html) and a nominal 300hp, 3000lb car ie pretty similar to a stock NSX. Adding 10hp OR losing 100lbs have virtually exactly the same effect on performance.

Niether is better than the other for acceleration, do both and the benefits are aggregated :)

Lighter weight pays dividends in handling and braking though but you can only strip so much out of a road car before it starts to feel bare or noisy or under equipped.

Cheers

Mark


IIRC our cars run fairly rich once in VTEC, so there may be some scope for leaning the mixture out a bit and gaining some bhp. Raising the rev limiter by a few hundred rpm would assist with acceleration, but I guess engine wear will be increasing exponentially.

[Senninha]

Being a fan of the Lotus cars, weight saving has always been a chosen route to extract extra performance, way before expensive changes to find performance.

Map changes are as Mark says pretty much non-existent or prohibitive by price for the na NSX.

I had the opportuntity to witness a live remap to an Imprezza a few weeks back. My mate (and Boss) has a highly modified STI. Equipped with laptop duly plugged in and cables running from under the bonnet, we set about a pretty mind numbing experience of running up and down a quiet road. All of this was to build the new map and was done in each gear, from x rpm to y rpm.

Once complete, the tuner was then able to 'seal' the new settings before Ed was let loose. The results .. a sub 4 second to 60 sprint (with 3 passengers) and with 1.9bar of boost available from just under 2k rpm to 7.5k rpm, this thing simply flies!!

Great experience overall but not one to be repeated in an NA NSX.

regards, Paul

[markc]

I had my old Porsche 993 live re-mapped (it uses a Bosch Motronic M2 ECU) to match an upgraded exhaust system and I can confirm that when done properly it works very well for NA cars.

I got improvements across the rev range with a peak improvement of 19hp, for exhaust and re-map to match, on the same day.

If anyone offered the same service for the NSX (for a similar price) I'd be down there tomorrow :)

Mark

[simonprelude]

If anyone offered the same service for the NSX (for a similar price) I'd be down there tomorrow :)

+1

After having the S2000 mapped with an AEM ECU I was getting around a 15 - 20 bhp increase (at the wheels) over stock across pretty much all the rev range.

[AR]

Both valid ways of skinning the acceleration cat :)

Using a web acceleration calculator (http://www.web-cars.com/math/qtr_mile.html) and a nominal 300hp, 3000lb car ie pretty similar to a stock NSX. Adding 10hp OR losing 100lbs have virtually exactly the same effect on performance.

Niether is better than the other for acceleration, do both and the benefits are aggregated :)

Lighter weight pays dividends in handling and braking though but you can only strip so much out of a road car before it starts to feel bare or noisy or under equipped.

Cheers

Mark

So 300 pounds is like 30hp, I lost 11 pounds since the New Year started. I plan to keep the good years's resolution going. That could net me another 5 HP in a few months! :)

[TheSebringOne]

Just had a look at MOTECH's website with nothing listed for the NSX, but if not listed you can ring them up. Prices range bewteen 399 to 450 pounds for mainstream cars. I think if they can do a NSX, due to their rarity & low demand, price woud be substantially higher?

[TheSebringOne]

:eek: Help, my thread counter has gone back from 1896 to 896!! Also all old threads are at 896 now!? Wheres my 1000 gone! :(

[Silver Surfer]

Oh dear, it seems you have been given the 1000 post penalty. :D;)

SS

[TheSebringOne]

SS, have you been given the same penalty? So I 'm not alone then? :(

[simonprelude]

Just had a look at MOTECH's website with nothing listed for the NSX, but if not listed you can ring them up. Prices range bewteen 399 to 450 pounds for mainstream cars. I think if they can do a NSX, due to their rarity & low demand, price woud be substantially higher?

Motech do an ECU for the NA2, the Type S with ITB's for sale in Hong Kong has one fitted.
Also a google search brings up Rob's car so think he has one now.

[simonprelude]

http://www.jamesleung.hk/showcarimages.asp?carid=CID0065&imgs=17

Motec M48

[AR]

I bet that costs a fortune! To buy and to tune.

Why not AEM?

Cheers,

AR

[simonprelude]

I bet that costs a fortune! To buy and to tune.

Why not AEM?

Cheers,

AR

AEM don't do an OBD2 ECU for the NSX :(

http://www.aempower.com/ViewProduct.aspx?ProductID=1316

[AR]

AEM don't do an OBD2 ECU for the NSX :(

http://www.aempower.com/ViewProduct.aspx?ProductID=1316

Have a look, not a complete stand alone but it has what you need for a "remap" on an OBD II.

Cheers,

AR

[markc]

Just had a look at MOTECH's website with nothing listed for the NSX, but if not listed you can ring them up. Prices range bewteen 399 to 450 pounds for mainstream cars. I think if they can do a NSX, due to their rarity & low demand, price woud be substantially higher?


Motech do an ECU for the NA2, the Type S with ITB's for sale in Hong Kong has one fitted.
Also a google search brings up Rob's car so think he has one now.


Have a look, not a complete stand alone but it has what you need for a "remap" on an OBD II.

Cheers,

AR

There's Motech and MoTec...

Motech are an outfit oop North that can re-map/chip tune the standard fit ECU of many cars. They mainly list turbo (petrol and diesel) cars in their catalogue because they're the easiest to get more power from. 90%+ of these are newish OBDII compliant vehicles.

MoTec make standalone ECU such as the M48 fitted to the Type S/Zero in the pic. The M600 is their latest model for 6 cylinder cars. MoTec stuff is much serious kit :)

There is still no real reason why a standard MY'95 on NSX ECU (OBDII compliant) couldn't be re-mapped but no-one with the equipment and skill has the time or inclination because of the tiny market :(

Cheers

Mark

[NSXGB]

Are there any more or less options for the earlier cars? I know a very clever tuner with a rolling road who could be persuaded to have a play. He has good contacts in Japan too, he specialises in Skylines.

[simonprelude]

If I had an early car I would have no hesitation to have the AEM EMS and use Mase to tune it the next time he is in the UK.

[NSXGB]

If I had an early car I would have no hesitation to have the AEM EMS and use Mase to tune it the next time he is in the UK.

....something else to bring back from America then?!