Itb tuning problem.

[zof484]

Hello guys.

My friend installed 48mm itbs on his k20a2 rallycross mr2.
We are using hondata prb kpro and have this problem with tuning.

We are not using map sensor so its alpha-n.

The problem is when we put map values for closed throtle 1 and fully open 100
the car wont start.
When we put those values 50-140 or 100-100 the car will start but everything we
do to fuel maps nothing seems to change anything.

No matter how much we add or take off fuel nothing is working.

And another strange thing is when the car starts and idles
its in the 7-8 columns.
Why is that?

I think it suppose to be in 2-3 columns at the idle.
Any help?
Thanks

[Spunkster]

The map sensor must still be connected and reading vacuum for it to work.

[zof484]

Ok thanks for reply.

Will it get enough vacuum from one runner or should it be
connected to all?

[Spunkster]

You will need some kind of vacuum accumulator.

[JDM TUNING]

Having similar issues with alpha-n and TWM itb's.I can get it tuned upto 70% throttle, thereafter it cuts the injectors.
I did however remove the map sensor, which will be refitted tomorrow morning....... damn.
Will most probly Tee the map sensor into the vacuum feed to the brake booster. Its fed off a common rail linking all 4 throttles.

[JDM TUNING]

Sorted.... sweet like sugar!

[zof484]

So now i have kinsler itbs installed and still problems with tuning.
The tps is reading 8-80% not 0-100% like it was with manifold.
Is that a problem?

And car wont start with alpha n.
It will start with map but theres no sense with that cause it idles
at 80kpa.

How much vacuum there should be at idle?

[Spunkster]

Do you have a vacuum accumulator?

[zof484]

Do you have a vacuum accumulator?

Yes i do.
4 hoses from each runner are connected into vacuum block. From the block, one hose goes
into brake booster and one 4" long hose is where the map sensor is.

I also tried another map but its still the same.
No matter what calibration i start with its not working with alpha-n.
Sometimes it starts but shut down immediatley.

I will ask Kinsler about that tps calibration.

[Spunkster]

Have you tried calibrating the TPS in Parameters?

[zof484]

Have you tried calibrating the TPS in Parameters?

Yes i have.
In parameters tps is reading now 6.4%-80.7%.
In display its 0-100%.

I put map sensor only into one runner now and get it to idle on 1000 rpm for maybe 5 minutes.
It idles pretty good but the map is jumping from 60-90kPa and so is afr and ignition is like 0-6.

Setup is pretty rough. k20a2, cnc head, dc4, kinsler 60mm.
How much ignition should be on idle with itbs?

[Spunkster]

That I do not know. You probably would be better off talking to a dealer that has more experince tuning ITBs. Unfortunately I have no firsthand experience tuning ITBs.

[zof484]

That I do not know. You probably would be better off talking to a dealer that has more experince tuning ITBs. Unfortunately I have no firsthand experience tuning ITBs.

Ok. Unfortunately in Finland nobody knows how to tune itbs with kpro. :)

I just dont get it. Why it doesnt work with alpha-n?

How big or small this accumulator should be?
Is this small vacuum block what is used on turbo engines enough?