Nick D

Do they have more capabilities like in foreign cars? Please don't rip on me for comparing the two, but several people have told me that it is worth asking. Thanks.

foff667

iTrader: (2)

They have DIFFERENT capabilities, the factory pcm's for the most part have better resolution and many more tables than an aftermarket pcm/injection system. However because the aftermarket systems are purpose built they can, in some cases, have some neat features that the OEM's never thought of or simply didn't impliment.

slow

iTrader: (7)

well said, the nice thing about the lsx pcm is there is so many options for tuning the oem hardware, that there is little need to convert for a street car. A dedicated race car, there are some cool features the stand alone systems provide, but any 800 rwhp or less car, I would tune on the oem pcm.

Ryan

Nick D

Thanks, that is enough to keep those individuals off my back. I appreciate it guys.

Bmotorsports

That depends.

Is it a $10,000 Magnetti Marelli, Bosch or Motec ECU as used in forms of racing requiring extreme control over all advanced parameters? If so, then yes there are many additional capabilities which are fully programmable providing many potential benefits to a calibrator / tuner.

Or is it a $500 megasquirt system that can only handle two injector banks for a bank to bank injection system which was built to be DIY and dirt cheap? Is so, then no it is far less advanced than the stock PCM with few additional benefits.

Most market products fall in between but HP Tuners / EFI Live have proven that when properly utilized, the stock PCMs can meet or exceed the capabilities of systems running up to $5k or more.

ebturbo

I am new to HP Tuners but not new at all to Standalone Engine Management. Can you please tell me the resolution of the fuel and spark tables and some of the different correction table that are avail in the factory ECU.

EB Turbo

brianfromhawaii

iTrader: (3)

resolution in speed density is by incriments of 5... spark tables in a 99+ is 1.2g/s max, but u can trick and manipulate that table by messing with the injector flow rate and VE table

ebturbo

I don't mean to be rude but, that doesn't answer my question. The Standalone systems I'm used to were run in anything from IRL(back in the day), world challenge, Daytona Prototypes(before spec bosch and still currently in chassis data), Grand-am, they had the spec ecu for a while in trans am.

The resolution is 20x40 for spark and fuel. With the breakpoints to be infinitely adjustable. I can run in aplhaN or speed density. N mostly for NA cars but it you want we can tune N with a boost correction. We usually use speed density with a MAP(we dont use MAF) for turbo or supercharger applications. We can setup to crank in wasted spark and batch fire for ease of starting and then once a certain rpm threshold is hit it can switch to sequential/sequential. we have a selectable map switch, we have full boost control, we can do boost is a function of gear up to 5 gears. 3 stages of nitrous control. variable cam timing(lift and or phasing). DBW control, single or dual wideband control, closed loop control and the list goes on. we don't have crazy VE table or corrections for injector sizes, no LTFT, no high and low speed stuff. we do have Lambda setpoint which is a table with the same break points as fuel table and has desired AFR in lambda for the input. which the ECU will try to correct to reach the desired Lambda for the cell.

EB Turbo

Mike454SS

iTrader: (4)

EB Turbo, the stock spark table in an LS1 PCM is 25 (RPM 400-8000, 200 RPM increments from 400 to 2400, then 400 from there up) by 29 (Airmass 0.08 g/cylinder to 1.20) Can't change breakpoints on RPM...but by lying in the VE table, or a few other places, you can kinda change those airmass breakpoints, and thus the slope of the Y axis of the table.

The stock fuel tables (which I guess is the VE table...but it is based on the injector flowrate table and a few other things) is 20 (RPM, 400 to 8000 every 400 RPM by 19 (KPa from 15 to 105)...though you can only really change the end result for AFR with that table if you turn closed loop fueling off...and since it is how the PCM calculates cylinder airmass...it also changes what happens with spark...and if closed loop fueling is on, and you've lied in that table for a different end result than stoich, then the spark gets screwed up too...and then the spark table also needs lying.

When we run a 2 or 3 bar OS on an LS1 PCM, we still do not get boost control that changes per gear, closed loop is only available on the narrowband, not on a wideband, though we can change the switchpoints of the narrow band, which gives us a little lambda control. DBW control is there, though I haven't played with it, so I don't really know how extensive it is, though there's a warning that it can permanently damage a PCM too. With a custom OS we can run Alpha N with the VE Multiplier table that gets added...there is some cam phasing control on the newer computers, but not the LS1 and we have very good knock control.

It sounds to me like for a lot of what you probably need from your aftermarket ECU's...they're certainly better for your application...but for a street car...or a weekend warrior...or the average guys drag strip trailer queen, their price wouldn't be justified, and I feel they'd lose some of the nuances that make a factory PCM a very nice piece to have, such as long term fuel trims, some really really well done airflow modeling that allows very nice correction for atmospheric pressure, temperature, how coolant temp and intake air temp affect VE...simple things too like air conditioning control...and the fact that they're already wiring, and fully operational when you buy the car...and the really nice OBD2 diagnostics that can be great for nailing down a problem with a sensor or something else in the drivetrain.

I'm also trying to avoid being rude, I don't know much about most standalones, other than that if the application for them isn't right...they cost an awful lot of money.

I hope I've been of some help.

ebturbo

What is the VE table? and how would you lie on it? with good standalones everything is very straight forward. you don't need to "Lie" to get what you want.


What is the injector flowrate table?

for standalones, In open loop the ECU only does what it says in the fuel table plus all of the correction tables(batt voltage, air temp, water temp, etc)... It wont make any correction off of the Lambda. so if your fueling tables are spot on you don't really need closed loop but it never hurts unless you have a bad lambda.

how can you lie in a table?

standalone don't have switch points to change. I think this is only a stock ecu thing.

this is a very cool thing to play with but, it depends on what they let you do. i know AEM EMS has it locked out on their ECU's because they dont want people messing with it.

what is a custom OS? I think for you NA guys Alpha N is the only way you should be tuning your cars.

I think for anyone who has a modified car a standalone is a good idea but the price difference definitely makes your way a lot more appealing. Long term fuel trims are not really needed. standalone companies think that your tune should be good enough that STFT is the only thing that is needed. and with data logging you will see any small problem that you have and correct it. So your map should be so on that even in closed loop you are seeing a less then +-3% correction.

What most people who do not use standalones often see are the real extremes of standalones. people know MoTec and megasquirt. MoTec is the most expensive but not the best. Megasquirt is the least expensive and definately the worst but, for the cost it can be appealing to most. With 10x10 tables, batch and wasted it can be very frustrating to tune. the better systems out there come from Pectel, McLaren, EFI USA, EFI Italy, Magnetti Marelli, and Bosch motorsports. all have good ECU's in the $2-3k price range that will do a lot. just about all of the Pectel ECU's will do 10-12cyls in sequential/ sequential. Pectel will run any trigger sequence but they like to have hall effect triggers. most 8cyl ECU's will run you about $4-5k(these are usually in the higher end of the ECU range) with about another $2k for a professionl harness and sensors. another thing is that with good standalones you can use any sensor you want(even factory). but most of the time you want to use better higher grade transducer sensors. there is so much that is appealing about standalones that I think untill you use one you wont know what you've been missing.

EB Turbo

Bmotorsports

Most people don't have $4-5k to drop on any of the above mentioned ECUs with solid harnesses and all appropriate sensors. Hell, even if they only sold for $1k, most people would still have problems tuning the vehicles and would be making rudimentary harness mistakes. Tuning OEM ECUs has opened up a world previously unavailable that offers 90% of the feature set with a solid OEM base tune that is vehicle specific. It also largely eliminates the many wiring issues that crop up whenever you have a non-pro doing the work. The OEM ECUs are fine for the vast majority of the supported late model GM applications running to 1000Hp+ in drag applications.

Do aftermarket ECUs have their place? Absolutely, for a professional installer and tuner. However, for the vast majority of vehicles, situations and tuners with less experience, the OEM ECU will offer more capability than the $4-5k ECU because they will not take the time to fully utilize the advanced features available.

Almost every race team we deal with runs standalone for very good reasons. Almost every individual we deal with (on late model GM & Ford applications) is best served with an OEM re-tuned ECU. Imports get the short end and have a variety of piggyback, cheap standalones and limited ECU tuning available.

If you are a professional Pectel, DTA, Electromotive, Motec, Autronic, EFI Technology, MM, Bosch Motorsports, Link, etc make some good options. However, once you get all the logging, all the sensors, the harnesses and labor you are talking about a $10k investment. Remember that it really doesn't make sense to go with one of these ECUs and not have a full data acquisition package with shock pots, GPS, accelerometers, steering angle, etc. Otherwise you are wasting a lot of money and capability. This is why the pros can go faster... data analysis with suspension & chassis tuning are where you spend more time when you realize WHERE and HOW you are losing time. The average Joe tends to spend their time and money on the engine and how much power they can make not how much they can they can plant.

ebturbo

I think tuning an aftermarket ECU is easier then tuning a stock one. there are a lot less redundant tables. Everything is way more straight forward. and for the harnessing, you see some pretty amazing things on these forums. there is a lot of good information on them and you can be surprised on what people with a good head on their shoulder can do with it.

even an amateur can get the same results as a professional team. It just depends on how much time and money they put into their system. I am only 23. I have only been working on data and engine management systems for a year now. I have read many books, taught myself how to use many different analysis programs and have installed a few systems on cars now. I believe I am pretty good with this stuff and, its just because I put the effort into it.

Imports probably have more options then the domestics. they have Hondata, Chrome, cobb access ports, Apexi Power FC, HKS fcon Pro, AEM EMS for almost all late model EFI Japanese cars.

I think this answers the OP's question. Yes, standalones are better then OEM PCM. They do cost a lot of money. and if you wanna go fast you've got to spend the money. for the budget racer, their money is better spent on engine and suspension mods. they can rely on time slips and lap times to tune their cars.

EB Turbo

Bmotorsports

The OEM systems have a base tune that is nearly dead on for each vehicle and requires minor modifications of a few tables on a dyno to get running properly. No wiring, no installation, no sensor questions, etc. Aftermarket ECUs are great and have their place. We work with more aftermarket ECUs than we do OEM tunes from HP Tuners, EFI Live, SCT, Cobb, etc but when there is a good OEM tuning system available we rarely go standalone unless the customer has a budget and specific needs that cannot be met otherwise. I see a lot of strong harnessing knowledge on some forums but in general, what I see in the field scares the hell out of me. Even from a lot of Motorsports Shops. Seriously, it is awful.


Time = Money. If someone has vast reserves of free time and concurrently more money than would be required for an OEM tuning package like HP Tuners, then you are right you can potentially get more out of a very good system. This combination is extremely rare to say the least. You need to add some common sense and intelligence to the mix as well to fully understand and utilize the systems. No matter what you do, you will be spending more time and money by a wide margin on a standalone for a variety of reasons already discussed. This is wise only for a small minority.

Again, we sell and deal with these systems and have experience with them. Most of the "import" piggybacks could be used on domestics as well. There are some good tools out there for very specific vehicle applications but few if any that cover as many cars with as much depth as HP Tuners & EFI Live. Where good OEM tuning systems are available for imports, I would argue this is a better choice than a more expensive standalone. AEM plug n play standalones are convenient because they come with a base tune for most applications.

Are standalones more capable? Yes, but you are still looking at over $5k in total time & money before you get to a point where there are any dramatic benefits vs a $500 competing system from HP Tuners or EFI Live. It just doesn't make sense for the vast majority of people. You can still get good engine data using these systems and you would be vastly better off spending the difference on datalogging which will tell you where and how you are losing time. Anyone considering either system will already be looking into engine mods and how to make more power. Assuming competence in this area (engine mods and tuning), the place where time is best spent is in data analysis and suspension / chassis tuning.