Stock ecu limitations

[Paul Clark]

R33 GTR

I have tried a search but does any one no at what rpm/load the stock ecu fuel map runs out? Just wondered if there was set level whre the MAF readings are clamped in the fuel table, say above a set boost pressure.

Thanks in Advance.

[Zoltarc]

According to ROM EDITOR the R32 GTR ECU has a fuel map up to 8000 RPM. I suspect the ECU will use just use the last cell in the map for revs above 8000 RPM but can not test.

For load I do not know what "value" (and I use the term loosely) the ECU uses so I can not convert the hex value into a sensible measurement for you.

[Paul Clark]

Thanks for the response, i'm looking to see how far i could take a piggyback ecu without loosing any of the gtr's stock features.

[kismetcapitan]

how far can the stock ECU go in terms of horsepower and boost? Can it map reliably so long as the stock AFMs are not exceeded?

I'm just very curious - I've never had a stock ECU, so I never got to see its limitations...

[SamuraiSam]

Originally Posted by Paul Clark

Thanks for the response, i'm looking to see how far i could take a piggyback ecu without loosing any of the gtr's stock features.

Piggyback? You mean a door stop? Do not think for a second about putting a piggyback on your GT-R. For the love of god.

What stock features do you think you are going to lose by going with a standalone????

[Paul Clark]

Originally Posted by SamuraiSam

Piggyback? You mean a door stop? Do not think for a second about putting a piggyback on your GT-R. For the love of god.

What stock features do you think you are going to lose by going with a standalone????

overall reliability,decent diagnostics, millions of man hours of tuning, knock control. To be honest i'm never going to have monster break horsepower. I'm just looking to produce an above average daily driver and if that means a few after market mods and fine tuning that will do for me. If I can produce and effective and stable setup without going stand alone then that will do.

[n boost]

What is wrong with a piggybank mate?
Seen a few good power cars running piggybanks and also are the hks f-con not a piggybank?

[n boost]

Originally Posted by Paul Clark

overall reliability,decent diagnostics, millions of man hours of tuning, knock control. To be honest i'm never going to have monster break horsepower. I'm just looking to produce an above average daily driver and if that means a few after market mods and fine tuning that will do for me. If I can produce and effective and stable setup without going stand alone then that will do for me.

Exactly what i plan to do for now.
My hks to4r single turbo supra which was nearly 600 bhp i only used a e manage blue and had no problems and that car took beating.

[SamuraiSam]

Originally Posted by Paul Clark

overall reliability,decent diagnostics, millions of man hours of tuning, knock control. To be honest i'm never going to have monster break horsepower. I'm just looking to produce an above average daily driver and if that means a few after market mods and fine tuning that will do for me. If I can produce and effective and stable setup without going stand alone then that will do.

Everything is wrong with a piggyback. Piggybacks LIE to your stock ECU on the input side. So you end up with a different fuel output and a different timing output.

Millions of man hours of tuning? HAH. A few hundred maybe and SO WHAT?? It is NOT tuned for the fuel you are running or the mods on your engine so it doesn't make a shit lick of difference. That's like saying a Ferrari ECU would be good for your car because it was programmed with intense care paid to all parameters and designed for max power. You changed a variable - fuel or cams or turbos or MAFs or injectors or pressure regulator or downpipes or elbows or exhaust or cat converters or intake pipes or intercooler. Now you need a retune and The only thing that an extensively developed map is good for anymore is to use as a basemap in a standalone Engine Management System: Invalid point.

Diagnostics. A Power FC or HKS unit can give you ALL the info a consult port will. It will show you exactly what sensors are doing what so you know what is going on with the engine or what sensor failed: Invalid point.

Knock control: Have the car mapped by a professional, use good fuel, and you will have no knock issues. Knock Control is bogus anyways as pulling timing some time after detecting knock is NOT a safe way to run an engine.

If you insist on running a stock ECU have it chipped and reprogrammed with an EEPROM based tune. It will be as good as an equivalent standalone.

You will NEVER find a professional tuner reccomend a piggyback over a standalone on ANY car where there is an affordable plug and play option available because Piggyback fuel foolers are absolute complete garbage and should not be used.

HKS V pro is not a piggyback computer. It can be used in parallel with a stock ECU (but doesn't have to be) It reads sensors, uses its internal map, and sends outputs to the mechanical components, therefore, it is a standalone. A Greddy emanage is a piggyback computer. An Apexi AFC is a piggyback computer. Do not use them.

Before you start telling me how wrong I am and how great piggyback detonation devices are, do a tiny bit of research and maybe blow up an engine or two with a piggyback. I have been reading everything I can and taking EFI and tuning courses, and tuning as many cars as I can for the past few years.

Sorry to be such an ass, but once you understand how EFI systems work and depend on accurate inputs to function, you will understand how terrible these sensor signal distortions are on an engine you want to make power and be reliable.

[n boost]

I understand what u are saying, i myself also spend time on efi universty etc.
I know piggybanks are not the best method because they fudge signals etc but i have run a few cars on piggy banks myself including s14,s/supra,s/evos etc with good results and never really had much problems as in blowing an engine etc.
The thing is u can have a standalone ecu but if not tuned by a competent person than will u are probably worse off than a decent tuned piggy bank.
Obviously the state of tune will come into it as a 400-500 bhp car may well be within a decently mapped piggybanks capabilities but may struggle with higher bhp but a standalone will obviously offer more even at basic power levels including safety features.
I agree totally a standalone is better than a piggybank but for most road cars they seem to be fine and most importantly for some look after one's PIGGYBANK hence the name LOL!

[Zoltarc]

Originally Posted by Paul Clark

Thanks for the response, i'm looking to see how far i could take a piggyback ecu without loosing any of the gtr's stock features.

The standard R32 GTR ECU has no features to worry about loosing.

Reading the discussion it appears you are after a low cost ECU. There are plentiful quantities of these around. Look into Microtech for example.

[Zoltarc]

Originally Posted by kismetcapitan

how far can the stock ECU go in terms of horsepower and boost? Can it map reliably so long as the stock AFMs are not exceeded?

I'm just very curious - I've never had a stock ECU, so I never got to see its limitations...

There isn't a numerical limit of the ECU in terms of horsepower. The limiting factor as you have pointed out is the flow capacity of the standard AFMs. If the engine is consuming more air than the meters can sense then you have an issue.

Assuming you have a load senor (AFM) which can flow enough to produce your power goal and it has been adapted through whatever means to interface with the ECU, then the standard ECU could be remapped to support the power.
I imagine there maybe some issues along the way as all of the editors I've played with don't have options to change injector dead time and various other "advanced" options. Mapping the fuel and ignition tables would be relativity straight forward.

I believe the source code for several Honda factory Honda ECUs is well understood and various parties have released logging software, boost support and so on for the ECUs. Factory ECUs are powerful and reliable but their closed source nature cripples them.

[tokes]

Nistune.

You can bump the rev limiter, run larger MAF's, bigger injectors, etc, etc.

[Paul Clark]

This is nothing to do with cost in a way that i'm looking for the cheapest root to power. I've wasted more than my fair share money on modding cars. I'm just looking not to waste anymore. I've had dealings with the map ecu 2 piggy back unit. It allows you to remove both MAF units,alter fuel,boost,ignition timimg and a few more features. If it works out better to fit a standalone then i'll spend a few thousand on that.

[SamuraiSam]

Power FC will not cost you a few thousand. 1 thousand plus mapping plus AFM cost. Or you can have the stock ECU retuned but then you do not have the ability to make changes yourself. New fuel injectors - head to your tuner. New turbo elbows - head to your tuner. Etc. Nothing wrong with it, retuned OE ECU's are awesome as Zoltarc says. I have tuned many Hondas on chipped OEM ECU's with Hondata and Crome.