Quamen

iTrader: (14)

I am trying to make a set of ITB's for a winter project just as fun and I am trying to figure out a way to control them that will reduce the cost instead of getting a standalone. So the following is what I know so far and what I would like to figure out so any input would be much appreciated...

The stock ECU relies on a MAF sensor. From what I know a MAP sensor can be used for tuning on NA applications and has been used on certian factory NA cars.
Right now, I know that the UTEC has the capabilites to read a MAP sensor and use it for controlling fuel and timing. However, I have read that it is not able to really tune NA with a MAP sensor due to low resolution and that it would cause some drivability problems unless you are at WOT.

-Can someone confirm this or enlighten me as to what problems arise with using a MAP sensor for NA?
-Is it an issue with UTEC that makesg tuning with a MAP sensor NA fairly difficult if not impossible?

If I needed to I could possibly make a manifold that could have a MAF sensor on the inlet tube but I would perfer to use solely a MAP sensor to avoid the hassle of fitting a plenum and what not. I have also been told that ITB's have a gulp factor which can max out the voltage on a MAF or something like that. With that in mind I would like to figure out a way to switch to MAP.
I have heard that the DSM guys eliminate the MAF using a box that has MAF replicators. I am not entirely sure how this works and it is more than likely used on boosted cars which more than likely gets me no where in this instance.

Ultimately, I would like to use a piggy back unit to tune. If I can find a way to mimic the usage of a MAF so that the stock ECU stays happy and doesn't go into limp mode it could work. I will have a TPS sensor on my unit so maybe I could splice that into the stock ECU and instead of the stock TPS and then wire a resistor into the TB harness so that it still thinks it is controlling a TB.

Otherwise, could I possible use a full standalone such as megasquirt? I believe they do have a coil on plug application that could be made to work. I think that if I wired resistors into all of the right parts of the stock harness so that it still thinks it is controlling the TB and injectors (would be going to the standalone instead and being controlled) I could still keep all the accessories such as power windows, speedo, tach etc. The only issue that I see with that is I don't know if I can get an RPM signal to the standalone which could be an issue.

Thanks in advance and I hope that with this community's knowledge and help I can maybe get this to work.

As for my project, I will be machining the flanges next week and hopefully after I have some progress worth showing here in the next month or so I will post a thread with more details and such.

chimmike

iTrader: (7)

none of that is the issue at all man. Your biggest issue is the fact that the car is drive by wire, and individual throttle bodies most simply will require a cable throttle.

you'd be killing yourself and the gains on the car to not just go full standalone and making a cable throttle setup for the ITBs.

And ultimately, unless you're heavily N/A built, ITBs could possibly just be a massive waste.

Quamen

iTrader: (14)

I fully agree with you.

However, if you read above, I am doing this for fun. I am doing this to soley see if I can make a more economy friendly setup than the outragously priced ones avalible now.

I figured out a way to do it with drive by wire utliizing the stock throttle body guts but I am not sure if the motor can react quick enough since it will control all 6 throttle plates at once.

Quamen

iTrader: (14)

Also, when I am finished, if I am not able to get them to work on my own with the stock ECU I will be selling them for cost too someone who has the resources to do so.

chimmike

iTrader: (7)

I see the kits cost 6k and are ridiculous, but I think you could spend less than that on the whole project, including a full standalone, with the cable throttle conversion and some trick polished ITBs.

Quamen

iTrader: (14)

I can make them for about $600 if not less most likely.

Regardless of what anyone says I am making them and I am just looking for help.

Quamen

iTrader: (14)

Anyone have any tips as to getting a drive-by-wire setup or a cable setup to work with the UTEC?

chimmike

iTrader: (7)

well TPS is going to read the same way...the UTEC can't control drive by wire, and, well, cable throttle doesn't need to be 'controlled'. It'll read the TPS the same way though, it's either a 0-1v or 0-5v signal.

Quamen

iTrader: (14)

I am aware that the UTEC can not control DBW. However, the stock ECU can and the UTEC reads off the stock ECU so if I keep the DBW I can use UTEC and if I ever deicide to sell it or make some more (if all goes well) this could be amazingly cheap. By that I mean nearly a third of the cost of all other ITB setups w/o EMU (assuming a price of $6000).

All I will be doing if I chose to use DBW is taking the guts and motor and putting thim in a new throttle body housing. Like I stated above, I need to overcome the MAF issue. I can trick the stock ECU into thinking there is still a MAF so it stays out of limp mode and since the UTEC can have full control over everything with a MAP sensor I could get this to work with all the stock stuff.

Now I just need to figure out if this can be tuned with a MAP sensor!

Quamen

iTrader: (14)

Ok, so here are my two options and I honestly need input on this in order to decide what design to use.

Option #1:
-Full cable setup (still amazingly cheap in comparison to what is out there) with a standalone and tricking the stock ECU so that many of the normal accessories can still be used and no CEL.

Option #2:
-DBW setup using UTEC to fully control everything via MAP sensor.

I need help deciding because I am trying to figure out the variables. Many say that the UTEC could not control NA via MAP soley. If it could it would be like tuning a ITB setup for any other car for the most part.
If I run a cable setup, what standalones could control it? Megasquirt? AEM?

rcdash

iTrader: (18)

next year's G35 sedan will use dual throttle bodies, no? you could consider adapting that design... (if you get it to work, you might just have a nice OEM upgrade for everyone to benefit from)

Quamen

iTrader: (14)

Thank you for the suggestion but I am making ITB's (6 throttle bodies essentially) which means that without the use of a plenum I must rely on a MAF sensor which is the main issue.

plumpzz

iTrader: (10)

there was a japanese company that used the Q45 TB. They used stock ECU w/ a reflash. I'll dig it up, but its in japanes, and it doesn't say much except they did it for tuning purposes only. Im sure you can 'trick' the computer into thinking that theres a TB there by leaving the stock TB as well as putting in another TB. Hell you dont even need teh whole stock assembly, just the connection. You'd need to program a throttle table, and thats where the reflash comesinto play.

Quamen

iTrader: (14)

The stock ECU can be tricked by wiring resistors into the harness or by making a new plug in harness (instead of leaving the TB hanging in the engine bay) that has resistors in it.

From what I know, AAM states that they can rewrite certain aspects of the stock ECU (reflash) but I do not know if this would help me at all as I can not use a MAF sensor to control the ITB's.

Kiamo

This is just an idea I'm throwing out there, but what about just using the factory throttle control, splitting it off to the 6 seperate throttle bodies and do it that way? You could rig up your own electric motor controls on them if required (if you can't find premade small electrically driven TBs).

Row2K

iTrader: (10)

have u considered using ur gutted throttle body and the ITB's , placing that in a custom plenum housing and then adapting a larger MAF along these lines https://my350z.com/forum/intake-exhaust/192935-larger-maf-housing-installed-today-with-my-cut-lower-plenum.html to feed the ITB's with more air. Could also place the filter and MAF a lot closer to the new plenum and as close as possible to the ITB's inside the new plenum housing. I suppose you could maybe even go for a bigger MAF housing than the 3 inch one that Mayhem used, since now the 3 inch throttle body would b replaced by ITB's and would eliminate that bottle neck. ...just a suggestion.

chimmike

iTrader: (7)

again I think your best/easiest bet is to swap to a full cable setup and standalone, like AEM.

Quamen

iTrader: (14)

Bringing this back from the dead as I have still been working on an ITB manifold.

So far here is what I have. The manifold will bolt up to the stock Y-collector and will be fed by a single tube in order to allow the use of a MAF sensor. With this in mind I am trying to do some research as to if I can do the follwing:

Use a cable setup with a TPS with the same voltage reading and wire a resistor into the TB system. By doing so I could get rid of the stock TB and the stock ECU would still think it is controlling the Drive by wire via the resistor and would get the TPS signal as required by the cable system. As far as I can see the only three things the ECU need to be happy is a MAF signal, a TPS signal and a sign of resistance in the TB curcuit signifying a TB.

If I can satisfy these things would I be able to use a UTEC and tune the system as if it was the normal TB. I think I know how to take care of the loopy idle that would occur from this but idle is not my main concern. Being able to run it and tune it through out the rest of the RPM range is my main concern.

Please offer some input as this will help me determine if I should finish the project and possibly even use it on my SC project.

Thanks in advance!

Quamen

iTrader: (14)

And I think a Idle Air Control valve may be needed also

Quamen

iTrader: (14)

If that is even possible