wadzii

Put itbs on the car map pressure wont drop and the vac ports are usually small and obviously on a runner where velocity is higher.

On my car the fuel maps are flat but I have a map compensation table that takes care of adjusting the fuel for the drop in pressure.

Gernby

I'm not saying you're wrong, but I think there are lots of things about ITB's that might change the behavior of the MAP sensor. From the little bit that I've seen about ITB's, it seems that each ITB has it's own vacuum line going to a vacuum tank, and the MAP sensor reads the pressure of the tank. Since it seems that the velocity of the air flowing past the vacuum ports inside the ITBs would be pulsing at different intervals between the 4 ports, I wouldn't expect the same behavior from the MAP sensor as I would from the single port inside an OEM TB.

I'd like to tap a MAP sensor into the PCV line, since that seems like it would give a better reading of the actual pressure inside the manifold.

Gernby

I forget what you are using to tune. Is it an AEM EMS?

The fuel maps in my FlashPro are very flat up top, but my injector pulse width increases at high RPM. I've never understood why the IPW would climb while MAP fell, since the fuel tables supposedly use MAP to determine IPW.

wadzii

Gernby, the inconsistency between the fuel map and what you log pretty much sums up why I refuse to use anything Hondata. No matter what you put in the maps you never REALLY know what the ecu is actually doing. Hondata ecu's have been that way ever since the old old obd1 mess.

I'm using aem ems.

You will get different readings when you change the map sensor location, but from my experience you will see the same thing. ie. if it starts at 0 and drops to -5 at the tb, then you move the sensor it might start at -5 but drop to -10.

Here are pics of the pistons, my camera doesnt work good enough to get good pics of the block, but you can imagine..

also it made 225 hp 20 miles before I parked the car to tear it down.. not bad for a completely trashed motor with the top ring smeared into the piston. All 4 looked this way.

Conclusion.. dont build your motor with 3-4 thou too much p-w clearance.










We are now pretty sure this was the cause of the power not pickup like it should, extra friction and loss of ring seal due to the piston moving around at high rpms.

Once I get the motor back together I'll be re-doing all the cam, header and intake tests.

Gernby

[QUOTE=wadzii,Feb 9 2011, 08:16 PM] Gernby, the inconsistency between the fuel map and what you log pretty much sums up why I refuse to use anything Hondata.

wadzii

i'm sure its some limitation to modifying the stock ecu, dont care.. if i put 10 in the fuel map i want 10 coming out. You wont get that with any stock ecu based tuning solution.

Gernby

I did a quick test to see if manifold pressure really does drop as much as the MAP indicates. The car ran fine, but I'm surprised at how the MAP curve looked with it relocated. The red lines indicate MAP and AFR with the MAP sensor in the factory location. The green lines indicate the same for the relocated MAP sensor. I did the same test 3 times, and the curves were practically identical each time, so the wavy MAP and AFR isn't due to random "noise". Both datalogs were done with the same FlashPro tune within an hour of each other.

Gernby

Can you provide more info about the TB and TB adapter that you got for the '06+ IM? I'm considering a drive-by-cable conversion, but can't find a TB adapter plate

chris_barry

Do you know what the sample rate is of the MAP sensor input. If the cylinder pulses near the MAP pickup are almost the same frequency as the sampling rate you can see a low frequency pulsing of the MAP. ( like a double balanced mixer is used to sample high frequencies with a lower sub multiple).

The placement of a MAP sensor right near the input of a cylinder runner ( or in your case a pair) can cause this.

wadzii

I used a k-series dbw throttle body adapter, one bolt hole doesn't line up but it seals up no problem.

there are a lot of options for bigger dbw throttle bodies. The honda v6's came with up to 72mm dbw throttle bodies. Converting to cable would probably be way too much trouble for anything other than ITB's