20V Itbs.

[Heath.]

alright some random dude on facebook just burst my bubble hard out.

 

to run 20v itbs on my 16v 4age bigport... do i need (HAVE TO) run a new ecu.... or can i run the standard one as i am still using the standard injectors?

[It's_AUDM_Yo]

You don't have to from what I've read and been told.

But realistically you will hardly even notice the difference with ITB's and it will probably feel worse than it did without them.

Also it will only run on the standard ecu/loom if you have a MAP sensor.

 

Not a standard engine not a standard ecu is the general rule.

 

 

Edit: this is not my first hand knowledge but I've researched it heaps and it seems to be the general consensus.

Edited November 19, 2012 by It's_AUDM_Yo

[Heath.]

hummmmm...

 

Well i was talkin to the boys at work. and well lets face it... its a 4 banger still so I'm not looking to smoke 26's off the lights. i know it will be slow still but for what i want i want some responsive power. and thats what i have been told these itbs will achieve.

[It's_AUDM_Yo]

^refer to stuff I just added

Is your bigport audm? It probably won't work at all.

[parrot]

It's been done on a bigport but it took a lot of work to get it to run reasonably with a standard ECU.

 

You need an aftermarket ECU. Or run a factory 20 valve ECU, but that will be a major headache too, and not making full use of the engines potential

[Heath.]

sorry man i forgot to put it in. i have a 16v 4age bigport. out of a (jdm) ae82. thus making it an imported 4age. (basted and half to find parts for)

so what is goin to happen if i plug it all in with the standard ecu? it will run bad how?

 

i am very sorry for the noob questions. but everyone is helpling me out so much!

[It's_AUDM_Yo]

Ah so does that make it MAP sensor? If it is its doable apparently it will run lean or something. If you got a piggy back ecu I reckon you could sort it.

 

If its AFM I seriously wouldn't bother trying with the standard ecu.

[ke70dave]

As far as i understand, the problem is that 4 quads don't produce anywhere near the same vacuum signal (MAP) as the standard inlet manifold.

 

In saying that though, a MAP signal is only good for about the first ~3% of throttle possition, after that its all over the shop and i belive that the ecu then relies on the TPS signal more

 

I was actually helping a mate wire up a bigport engine on the weekend, which had 4 quads on it. It "came from japan" with an apexi SAFC, which as far as i can tell all it does is interupt the map signal, and sends the ecu a modified map signal based on TPS position and RPM.

 

Unfortunately we had blocked injecors so i couldnt have a play, but i hope to in the future, I never played with a SAFC before this seemed damn simple to wire up though.

 

Whats the cost on an apexi SAFC? if you can get one cheap as it might be worth giving it a go, but the reality is a full aftermarket ecomputer will always be a better option as the SAFC doesnt do anythign with the ignition advance, which is where your power is made.

[Heath.]

Alriiighhht well i know that my bigport runs a MAP sensor not a afm. Sooo i should be all sweet. Is there anything else i should know??

[carbonboy]

Alriiighhht well i know that my bigport runs a MAP sensor not a afm. Sooo i should be all sweet.

 

You need an aftermarket ECU. Or run a factory 20 valve ECU, but that will be a major headache too, and not making full use of the engines potential

 

I know of a few 16v engines running 20v ITB's, they all run beautifully, they all run aftermarket ECU's. The ones I've seen running factory ECU's (be it 16v or 20v) don't run so well & seem to always have persistent 'problems'. :)

[Heath.]

Well... I guess ill see how it goes and come back with what i find. Thanks guys!

[Taz_Rx]

hummmmm...

 

Well i was talkin to the boys at work. and well lets face it... its a 4 banger still so I'm not looking to smoke 26's off the lights. i know it will be slow still but for what i want i want some responsive power. and thats what i have been told these itbs will achieve.

 

Funny you should mention response....... I'm currently trying to optimise throttle response through adjusting the accelerate enrich and decel enleanment settings. Much easier said than done.....with an aftermarket ecu!!

 

That combined with the change of vacuum/load from the different t/b and manifold as dave mentioned is most likely going to put the factory map up the shit.

 

I seriously can't see you getting any real benefit from the conversion without tunability. Chances are it will run worse than it does now!

[ke70dave]

Following on from what taz said,

 

The really great advantage of an aftermarket ecu is you can get inside and watch it working live and see what its doing, this is fantastic for diagnosis.

 

With a standard ecu its more or less a "magical box" with inputs and outputs, and if you go changing some of those inputs (ie your itbs), you really have no idea what the ecu is going to do with it! hope for the best type thing.

 

Many times ive been passenger in my mates car and ive been staring at a fuel map with the load cell changing a few times a second, engine hesitates, i note which load cell it was, make an adjustment, try it again!

[LittleRedSpirit]

For response tuning, the transient enrich is key.

 

I have found a couple of tuning tricks with the adaptronic that let the car come alive when the throttle is used.

 

First one was discovering map prediction and filling the table in, that made an amazing difference, way better than tps based transient enrich as it projects and multiplies enrichment from the map, so its all referenced nicely and it works better if your tune is better. If you use this feature I find on a 20v you'd be looking at 225% gain % over 450ms. So that translates to a linear decaying enrichment of 225% of the difference in the 2 map segments you are moving between at any one time, that peters out after 450ms.

 

Also I found it better to have a higher and more consistent level of high Map enrichment at any temp. Its a good way of getting that extra fuel the moment the map sensor senses atmospheric pressure. It also allows you to have a leaner tune that will be perfect for steady state running conditions, but to still be able to have extra enrichment when load is increased and the throttle is cracked, it works great.

 

With itbs its hard to not have them lean out at the exact moment you crack the throttles and allow a tonne more air in there. Its not like a carby where the air brings the fuel, and the delay in low down response is to do with the limitations in the physical system. You need to meter for a change before it can be made, so for that first instant, you can see a lean moment. Plus it wouldn't be such an issue if the motor was on cam and spinning a bit faster, it would be primed and ready to spin faster, but when its spinning at idle, and has low airspeed and volume running through the engine, its hard to make it jump off the bottom. Once your over 2000rpm response is a lot better just naturally. But its real hard to get an itb car to jump off idle like a set of FCR carbs.

Edited November 20, 2012 by LittleRedSpirit

[Heath.]

Wow awesome respones for everyone!! Thanks heaps!

But there is a reason why i do not have an after market computer and all the awesome shit i would love to have. Its beacuse i am a first year apprentice. And get paid a bog boat load of f&ck all.

 

So. I was thinking alone the lines of a reflash once everything is done. And actually running. I know from this there will be little to no power difference.. But hopefully (note the hopfully) the re-flash idea could work. If anyone has actually tryed it and failed please tell me.. But if you havnt don't say anything! Hahaha sooo many people bursting my bubble.

 

The idea seems to work... As a standard ecu has to a degree of 'learning' it can do. So maybe... Juust maybe it could 'learn' to run its self with the itbs with this Re of the Flash