acc pump

[beefcake]

when i installed it i knew it was a cardinal sin, i mounted it sideways nipple forwards
its higher than the manifold so i thought t may be passable , looks not .

[20B]

so increasing the sens , does that give you more fuel ?

No, it ramps the fuel accel you ALREADY have in much quicker.
I came up with this basic analogy when I'm thinking about tuning these parts -
Accel sensitivity - Like the cam on a carby, more sensitivity more aggressive delivery of fuel settings you have set.
Accel clamp - imagine this as a bucket, more clamp means more fuel in that bucket which is immediately tipped into the engine.
Accel clamp comp - normally used for cold start, colder engine needs more clamp ( bucket ).
Accel clamp decel - this is how quickly the bucket is taken away from pouring into the engine.

Hope my crummy explanation helps

Once your done here you get to do ignition advance accel settings he he he.

[beefcake]

you are my motec analogy terminology thingmagingy spec man that is exactly how my brain works , all these years of being a mechanic im not one to be nerdy on what things are called, hence my trouble learning new terms for the same old subject

I now have 100% confidence to go and get it sorted

Ignition, hmm i got 8 deg in it flat out

but ive got map sensor issues to play with first

[MarkMc]

I'll explain in Carburetter terms.

Clamp: The maximum amount of fuel that can be delivered by the accel enrichment. Like the size of the well on a carbie accel pump.

Sensitivety: How much reaction the accel enrichment gives for a certain rate of throttle change. Like the spring tension or cam in a carbie.

Decay: How quickly the fuel goes away, haven't got a really good carbie analogy for this but lets just say once the ECU puts it in you can alter how fast it pulls it out.

Easiest tuning. Put in any clamp, say 30. And start with a low sensitivety, say 30. Drive along and hit the throttle and you will get a hesitation. go up in the sensitivety by 10 you should notice the hesitation gets better. If you get to 100 and the hesitation is still there go up in the clamp and then start with lower sensitivety again and repeat. The decay will need to be set so that the engine doesn't stay rich after the initial hit of the throttle, start with 2. Experience will make the job quicker but this is a good way to start.

[beefcake]

perfect answers as well mate, thanks heaps guys, this weekend im going to be trying out the new map sensor, if its found to be that i have a worn map sensor then im quite sure its also whats now causing my sudden flat spots that i started this thread about .
If its all ok, then i can easily adjust the flat spot out now

Ps Mr motec , do you think its possible for me to run 8 id2000 injectors on my m2r , im preparing to step up to methanol soon and im worried i have to buy a new computer, can i pair the injectors , or can i buy some sort of expander
Thanks heaps from brad

[beefcake]

well i gotta give all you guys a massive thumbs up, i sorted out my acc pump settings at the track in no time, the descriptions yous gave me opened up my way of thinking and after initially thinking it was too lean causing the flat spots , it was too rich , buy alot, i virtually halved my clamp table settings and it doesnt pop an fart anytime
its smooth and enjoyable again .


Only one issue im having now , the data is telling me i have 35~37 psi boost on my runs, but i know its only 21psi , on the dyno its 21 , and my guage when i glance at it on teh track is hovering around the 21 psi mark .

Now removing 14.7 it gives me the true value, hence my question is did i select the wrong 3 bar settings for my delco/aca 3 bar map sensor, i chose 300 for my settings.
When i turn just the ignition on it reads 100kpa/14.7 psi , when it idles at 1500rpm it reads roughly 69 kpa or 10psi , is it a data error or me again

the log of the A/F ratio against revs and (adjusted) boost is good so im not too worried about the health aspect of it , just my data logging is a bit wonky to read , and if i adjust the map settings somehow, is it destined to a complete new full tune on the dyno again

[Holmz]

...

Absolutely.

[beefcake]

absolutely for which aspect Mr holmz

[SprinterTRD]

Its all about what we need to measure.
In a engine we need to measure vaccume and pressure the simplest scale to do this is "absolute" pressure which starts from a perfect vaccume of 0KPA. All pressure measurements are positive using this scale

In the real world at sea level we have a presure of aproximately 100KPA (14.7lb in the old units). When boost is applied you are adding to the 100KPA atmospheric pressure. Which is what you see in your logging.

Now consider you have your oxy bottle and its empty. If you used the absolute scale the dial would indicate 100KPA when its empty, this could be miss interpreted as still having some gas left.

It makes more sense to use a scale that takes in consideration the atmospheric pressure to read 0. This is called "gauge" pressure. Using this scale you would need a scale with negative numbers and positive numbers

Your cal is correct fot the GM sensor.

[Holmz]

absolutely for which aspect Mr holmz

"Absolute" meaning for Pressure.


Sprinter's words are good.

So you could create a math(s) channel that subtracts 14.7 and label that as "gauge" and then you have another channel that is easier on the eyes...
But with the high temps in Perth and the cyclones it would probably need to be less than 14.7 <Starting another thread>