Remapping Fuel Trims + RPM Limiter

edbutler

Hey All,

I know theres plenty of speculation as to whether the GMPT-E15 ECU has actually been 'cracked' but i was wondering, what exactly can tuners actually modify with it?

Im after these things primarily:

Adjust fuelling as a recent RR showed a 11:1 - 13:1 ratio across the whole rev range, which both feels and smells rich! Especially at the torque 'dip' point of these silly engines. Doing this i mean permanently! Not just for 10 minutes after the remap as ive heard from some stories!
Reduce the 'Dip' in torque at 2500-3000rpm. Being on Piper cams im sure this is aggrevating the problem, but this rpm range is my primary cruising rpm. If its really overfuelling that much, id rather stop it!
Increase the RPM limiter. I know this is easily possible. Probably 7500rpm will do me 😉
Make the Limiter more gentle. Driving a very sensitive car and having a rev limiter that kicks you in the back of the head isnt very nice - does it close the throttle or something!??

Thanks for your input peoples 🙂

vocky

if you find somewhere that can do all of those things let me know, I will book my vx220 in straight away

otherwise I'm going standalone to get a proper map

edbutler

vocky said:
if you find somewhere that can do all of those things let me know, I will book my vx220 in straight away

otherwise I'm going standalone to get a proper map

So is it just the fuel trimming that they cannot modify? How well does your remap work and where was it from if you dont mind my asking?

Sjdickso

I dont understand about ecu mapping at all but Vocky got his done via Superchips that was done through Thorney motorsport. I am sure Vocky with confirm what was done.

vocky

my map is ok, much better than before the remap, but it still has the z22se mid range dip.

the only way to get a good map is a standalone ecu

rik1083

vocky said:
my map is ok, much better than before the remap, but it still has the z22se mid range dip.

the only way to get a good map is a standalone ecu

Contemplating the standlone ecu...
I have my eye on that new supercharger (but probably only next year at the earliest)

Is there a standlone/additional/piggyback ecu which will give me a good map now, and be able to cope with the new SC, if I get one?

vocky

best option would be a standalone like emerald / dta / megasquirt / MSD etc

you could then have it remapped for the sc conversion, only downside is you need to convert to a cable operated throttle

a difficult decision, one which keeps driving me insane, do I, don't I what..

alanoo

You still have the Skynam Sybele option like me, the DBW TB works perfectly

vocky

alanoo said:
You still have the Skynam Sybele option like me, the DBW TB works perfectly

how much are they notsure.gif

alanoo

849 + VAT, so approx 1020€

vocky

a bit more expensive than an Emerald but it does work the TB and once you have mapped your engine a decent map will be available for mine 63..

edbutler

Doo itt 🙂

rik1083

which one do courtenay use? do they fit a cable throttle?

If fitting a cable throttle, is any wiring needed - like a throttle position sensor?

alanoo

vocky said:
a bit more expensive than an Emerald but it does work the TB and once you have mapped your engine a decent map will be available for mine 63..

And most importantly you'll have a description of all the little traps we had to sort
like changing the wiring of the fuel pump relay and the radiator fan relay 🙂

Yello

"rik1083 said:

Contemplating the standlone ecu...
I have my eye on that new supercharger (but probably only next year at the earliest)

Is there a standlone/additional/piggyback ecu which will give me a good map now, and be able to cope with the new SC, if I get one?

I bougth a supercharger for my Speedster yesterday, and have been looking around on the US forums for any solution`s to the fueling issue, seems like some of them uses the AEM-Fuel/IgnitionController Piggyback. Works with our sensors and is able to retard the ignition. If nothing else comes up before I start my winter project I think I will go for the AEM unit..

rik1083

what are the pros and cons on the AEM FIC?

price seems a good place to start as a pro 🙂

rik1083

Did some big reading on the AEM FIC last night.
One advantage to it being a "piggyback" type ecu, is that you can fit it yourself and drive away without having to map it first, it effectively just echos the signals from the stock ecu, which is great for us diy types. Then later on you can tune it how and when you want to, and it all seems fairly straight forward through their map editing software.

Does the Chevy Cobaly 2.2 have the same stock ECU as us? how similar will a pre made AEM FIC tuned map from a cobalt be on our 2.2s?

Also seems like you will probably need a wideband AFR if you wanna do it properly. AEM do one of those also, so it's probably worthwhile getting that one rather than any other.

edbutler

The US and Canada use a GMPT-E16 (instead of 15) ECU - The exact differences though i do not know.

With it being a piggyback, im guessing you still need a remap to raise the rev limiter and advance ignition (unless it works one cycle behind) 🙁

Yello

A wideband lambda is always great to have in the car when you do mods on the engine,for example thats how I found out that the mine were running lean with stock injectors, and I have also used it to tune the AFR with new injectors and my SAFC NEO, the NEO is a ok unit if your not running boosted applications, and cheap. I use the Zeitronix wideband system, and am pleased with that, dont have any experience with the AEM one, but before you buy it, make shure you can log RPM, TP, Lambda and AFR. If not, go for the Zeitronix or Innovate system.

Edbutler: Yes its not possible to advance ignition with this unit, only retard it. But thats what we need if we are going for a boosted engine.. Its not ideal for a N/A engine

Yello

Found this on the CobaltSS forum. Good reading munchies..

http://www.cobaltss.net/forums/showthread.php?t=91929