Kadunza S54 ITB Adapter Plate Project

[blackm50]

subscribed for updates , got a set of s54 itbs sitting in the garage.

[RobertK]

Still slowly waiting for my fab guy to finalize a throttle linkage assembly. Will post updates as they come.

[ForcedFirebird]

For someone running a standalone, will the vacuum "log" provide an adequate map signal? I wouldn't want to run alpha N because I intend to run FI as well.

I have not had any luck tuning ITB's in Speed Density. It CAN work, but the resolutions sucks as you will be reading about 80kpa at idle. I have read where people use a large vacuum manifold and buffers to slow/mix the pulses. I put a vacuum gauge on a vacuum block and the needle bounced erratically and was only pulling about 8" on average with a huge swing between.

We will be putting a turbo on an ITB m20 soon. I plan on using a hybrid alpha-N speed density (MAP), but will have to cross that bridge when we get to it. Hoping I can have the MAP signal in the plenum (pre-throttles)

[digger]

I have not had any luck tuning ITB's in Speed Density. It CAN work, but the resolutions sucks as you will be reading about 80kpa at idle. I have read where people use a large vacuum manifold and buffers to slow/mix the pulses. I put a vacuum gauge on a vacuum block and the needle bounced erratically and was only pulling about 8" on average with a huge swing between.

We will be putting a turbo on an ITB m20 soon. I plan on using a hybrid alpha-N speed density (MAP), but will have to cross that bridge when we get to it. Hoping I can have the MAP signal in the plenum (pre-throttles)

i've heard that some ECUs can sample at a defined crank angle and therefor you can sample at 1 runner only when the piston velocity is high and get a really good signal

[ThatOneEuroE30]

cant wait for this. plan for mt2 car is s52 itb

[Bimmer_man]

I hope your fab guy gets these done this is such an amazing idea.

[E30 Wagen]

m50 runners 1&4 drawing (flow is 3.2L 100% VE 8000rpm) 11% variance



angled entry runners 1&4 drawing (flow is 3.2L 100% VE 8000rpm)
2.5% variance



no questions that the angled entry provides better distribution. with the OEM runners 3 & 4 see more flow than its neighbours due to the poor design. air just dumps into the volume and the velocity of the air means it has difficulty turning corners.

most people flow test individual runners but that is useless for looking at distribution

I've never seen these pictures before. Wow... I guess I've never considered there were would be such a flow imbalance on the stock manifold, and now I get the purpose of the angled manifold design. Learn something new everyday... I'm guessing the m20 design is actually better than the m50 at distributing air flow?

[digger]

Not really, imo where the throttle body bolts on the two closest runners 3&4 are located poorly that air will have difficulty making the sharp bend . Also the shape of each runner is different with some having really tight bend.

[RobertK]

I actually took the project from my original fab guy and it is now been given to Evolution Motorsport Fabrication to help finish the throttle linkage development.

[blackm50]

@Robertk so your adapter is finalized and just waiting on the linkage?

[RobertK]

Yes. I got word this past week from my new fab shop that they are very close to having it sorted out.

[blackm50]

Yes. I got word this past week from my new fab shop that they are very close to having it sorted out.

So how's the progress on this going? Any pictures??

[RobertK]

New fab guy says he's pretty close to having a final solution. I should see him tomorrow so I will check progress.

[Kershaw]

Very cool, in for updates.

[blackm50]

New fab guy says he's pretty close to having a final solution. I should see him tomorrow so I will check progress.

How's it coming along , any good news?