ITB's and engine management.

[elwesso]

Im not sure if we've had a thread on this but I thought id start one anyway...

Ive been thinking a lot about doing ITB's on a VH45, certainly thatd be the only thing Id replace the spider with..

Ive been doing some reading and Ive seen that some people have been using the stock lower runners so that the stock fuel rail will just bolt into place. A good idea... Does anyone know what runners you need to buy to get them to work? Seems like youd need 4 #1 runners and 4 #2 runners, or maybe 2 #1, 2 #7, 2 #2 and 2 #8

However seems like getting them on the car and the throttle cables working is the least of your worries.

I ask how you guys think the best way to manage the ITB's are. Issues I see are

1. Idle- Cold and warm, how to make it idle higher when cold, would you need a custom FIC or would some ITB setups have something like that built in so youd just need to plug in a coolant hose.

2. Air metering- MAF?

I dont think it would really be hard to get each cylinder to contribute evenly. You could send your injectors to a place to have them flow tested so each one squirts the exact same amount of fuel... From there, you should be able to set the idle adjustment on the TB using a power balance test on a consult... it would take a great deal of tinkering but you could get there.

How do you think would be the best way to setup management on an ITB setup? it seems ot me you could keep the stock ECU, build an airbox to hook to the VH MAF and then use a filter. Kinda takes the cool factor out of it but oh well. Personally Im not the kind of person to go to a standalone when you could easily make the stock ECU work for it, but Im not sure how thatd work outside of making an airbox?

Furthermore, do you think running ITB's will really gain anything unless your running an extreme setup, like John dixon's with a really hot cam and stuff?

[gs14racer]

The easiest way i have found is to ditch the maf all together. You would have to run a map sensor, and some sort of piggy back to translate the map signal to the stock ecu.

Theres a product called MAP2ecu. It does just that, converts your car to map.

Youd have to get rid of the idle air control valve and just setting the idle manually via throttle plate control seems the easiest.

[mtcookson]

This one seems to be very good. Allows you to convert to MAP but does much, much more than that as well... like say... auto tuning with a wbo2 just to name one.

http://www.maftpro.com/

[Raxephon]

....Ive been doing some reading and Ive seen that some people have been using the stock lower runners so that the stock fuel rail will just bolt into place. A good idea... Does anyone know what runners you need to buy to get them to work? Seems like youd need 4 #1 runners and 4 #2 runners, or maybe 2 #1, 2 #7, 2 #2 and 2 #8

It should be lower intake manifolds 1 ,2, 7, 8. (2 of each)

[Raxephon]

Youd have to get rid of the idle air control valve and just setting the idle manually via throttle plate control seems the easiest.

No, you wouldn't have to get rid of the IACV, but it would require some custom plumbing.

[PopPop]

It should be lower intake manifolds 1 ,2, 7, 8. (2 of each)

I've always been asked for the 94's=1,2,7,8 just the 4 for those who were running this setup or something similar!

[elwesso]

seems like if you want it really clean looking youd want to ditch the IAC...

[SSDwellah]

Often I see N/A cars that have ITB setups (versus a turbo one like the RB26 that has a plenum before its ITBs) have a sort of balance tube across the ITBs for things like the brake booster signal and a MAP sensor. I think MAP is the only logical way to go here. I mean you could tune just load based e.g. just using TPS, RPM, and maybe air temp but I think that would be more finicky than a MAP based setup. I do agree that a MAFs setup is out of the question (unless you want 8 MAFS signals which would be ridiculous )

anyway just my $0.02

[canadiandrifter240sx]

It is in fact 1,2,7and 8 that you want. They will not just bolt up though you need to do some triming and grinding to get them to go in place. The injectors will line up iether way, inboard rail or outboard. With ITB's you would prob want them inboard it would bring the ITB's closer together makeing it easier to put a collector on top of them. As far as IAC you could use the same set up as A KADE PVC system where each runner has a nipple and a hose that collect into a tube that runs to the PVC or in the case of ITB' to the AIC. It could be done in a way that kepps it clean and would prob look pretty cool.

Chris.

[Mettler]

SSDwellah you make a good point r.e. the brake booster signal. Anyone ever tried braking in a car that's just stalled at any sort of speed? Notice the braking suddenly becomes a whole lot more difficult?

What's typically the solution for providing more vacuum to the vacuum diaphragm in cases like this, are people using diesel alternators with the vac pump on the back ?