How far can a piggyback system take you?

[BigT]

What happens when you have 720cc injectors and your tuning with an afc or gmmaft or any piggyback for that matter? Uncontrollable timing advance. We all know that piggyback tuning can only do so much. Until now. www.ecuplus.com (http://www.ecuplus.com) I tried doing some searches regarding this, but didnt come across too much in the dsm world. The evo guys seem to be liking it however it is still somewhat new and you can only find so much. Yes, it tunes your fuel the same way any piggyback would for our cars, by "lying" to the ecu, but this thing has full control of timing +/- 15 degrees. It also can log knock voltage, can run the ODB II system, log many parameters and at a better rate than a pocket logger would, wideband ready, and can log boost with the use of a GM or AEM map sensor, among many other things. On top of that, you can run a GM MAS sensor without the need of the maft translator box. I am contemplating purchasing this over DSMlink because of cost factor, its superior piggyback tuning abilities, and i dont plan on running 10's or 9's for that matter. Just wondering what the rest of you think.

[gtluke]

the question is, how fast can you go on a MAF meter. the maf is a pile of shit, and the dsm one has its limitations.
when this dsm+ can do map sensor instead of or combined with MAF, then it'll be totally worth it.

this thing for now looks like another dsmlink alternative.

[iboostdoyou]

it claims to run the gm maf without the need for the translator box, almost solving the restrictive maf issue of our stock sensors, as well as shelling out another 200 for the translator and goofy tuning. Also, i dont believe T is planning on maxing out the flow of his stock sensor anytime soon. If i knew more about it or knew someone that could help me tune using the exact program i would consider it

[BigT]

I probably won't be using the gm sensor function with the ecu+. Granted the dsmlink guys have gone pretty fast with it. Maybe i'll try it out since the cost of using one will be the sensor and plug(which isnt really that much) What does the stock 2g mas max out at? Something like 425whp?....which is probably as for as I will go for quite some time. Correct me if i'm wrong. I'm thinking i can get this thing plug and play for 599 plus shipping. I already have a wideband. No need to buy another ECU and no need to pay for socketing. Just wire up and go. My car is a street car. I'd like it to be a rather fast street car, but not a "racecar". So far i'm leaning towards picking this thing up over dsmlink.

[atc250r]

Unless I'm missing something here you're still going to have timing issues. Whether you're reducing the air signal by using an SAFC, Translator, or VPC you will still skew the timing curves. The only way to avoid that is to have the injector compensation done inside the chip. Jeff at DSMChips.com does an awesome job and his chips offer things like adjustable stutterbox, no lift to shift, CEL as shift light at 7500 rpm, along with a bunch of other things. He even does ECU chips to work with VPC's and MAF-T's. Oh, and it cost me $20 to have my ECU socketed and the caps replaced, not much of a hassle or cost if you ask me.

John

[BigT]

How would it skew the timing curves? If I see that my timing is being stretchy from 4.5k to redline and the knock wont go away no matter how much fuel I add, i'll just pull the timing back up to 15degrees, if need be, from 4.5k to redline. Isnt that solving the problem? I'm by no means a tuning guru so if i am mistake, correct me please.

[Muggus]

If your interested im probably gonna be selling my vpc soon, ill let you know. Im probably gonna be asking $550 if i do sell it, which is what i paid. Has both sensors and a 90 harness which is useless to you but your better off hardwiring it. The air temp sensor is already mounted in a buschus TB elbow so no need to weld any bungs.

[MikeL]

EFI's PMS claimed to control timing as well in a piggyback configuration, but did a poor job of it, in the end it was more of the same. You cannot scale the injectors properly with a piggyback. You can surely make it work for drag passes, but everyday driving you will find some issues.

[BigT]

What kind of problems do you suspect for everyday driving, Mike? I dont think it should be that bad. An evo guy picked up roughly 35 more whp and up to 50ftlbs over his dynoflash ECU.


This is my dyno sheet i made 333.3 hp but he sent me my pull for 327.9 by accident. By the way this dyno reads low. The the dotted lines are what i put down with dynoflash and solid is what i but down after it was tuned on ecu plus. My mods are ECU+, 272 cams, turboback, MBC, and a intake.
ENJOY
http://ecuplus.com/forums/files/bccamevo_189.jpg


....Some shop tuned the car for him, and you can see it totally killed the dynoflash dyno tune.(not the standard mail-in flash) The kid actually went to a dealer with his ECU to flash it back to stock.

[MikeL]

dynoflash is NOT a piggyback, you can directly edit the ecu code with a flash, which allows you to scale the injectors correctly and stay on the "correct" airflow table, which gives you the "correct" timing curve and makes tuning alot easier. Piggybacks have to modify, ie lower, the airflow signal to compensate for the injectors, this works well up to a level, but if you are taking out 25-40% of the airflow just to make up for your injectors, the car will be trying to run 35dg timing all of the time.

[BigT]

Yes, i kno that dynoflash is not a piggy back. And, my post and that dynosheet shows that ECU+ kicked the dynoflash's ass.

MikeL: Piggybacks have to modify, ie lower, the airflow signal to compensate for the injectors, this works well up to a level, but if you are taking out 25-40% of the airflow just to make up for your injectors, the car will be trying to run 35dg timing all of the time.


Mike, i know how a piggyback works and what the consequences that can and will be at a certain level. What I question is....Say i'm running 35degrees advance due to pulling out too much airflow, why wouldnt i be able to bring that advance down since i have control of it +/- 15 degrees with ECU+?. That way i'll be at a 20 degree or am i missing something?

[MikeL]

IF it can control timing correctly, which I stated, the old PMS system claimed to do, but did not do well, it shouldn't make a difference at WOT. I have not used an ECU+ so I am not claiming that it cannot work. If you understand how all of this works so well, I don't see the point of asking how "far" it can go, you should be able to figure it out. But if you want a guess, I'll say "to the moooon"

I don't see how that dyno chart proves anything, I think the idea of having someone send you a "tuned" ecu based on a online form of mods is dumb, every car is a little different, and sometimes small changes can affect power in a big way, so having a car that you can't tune dynoed, and then tuning the same car on a dyno to a "good" tune I would expect good gains.