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Discussion Starter #1
I've seen various maps by various people and I don't think I've seen one where they bother to ensure that the transition from the high cam to the low cam is always smooth. I.e. To ensure that any possible transition at any rpm where both cam maps are applicable that there isn't a huge difference in the cam angle between the low and high maps. Taking the effort to smooth this transition makes for a much nicer transition that seems much more sympathetic mechanically. The stock map doesn't have this issue as it is an off/on vtec point where as most after Market maps use a manifold pressure based range where you could be on either cam.

This is often noticeable around the vtec point holding the throttle at a pressure point that literally results in the cams trying to flick between the two angles which it can't do!

The flash pro software doesn't help so I have to stick the maps in excel and cross map them both which is often tricky as the rpm indices should be very different for both maps!
 

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yes this is true.
I changed the vtec window pressure a litle (bigger values) to prevent the crossover at "low speed" causing that. it helped.
 

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Discussion Starter #3
Thats one way to do it but then I find you need much larger throttle angles to avoid then being on the wrong cam when wanting moderate acceleration but not flat out, eg modulating the throttle in the wet through some bends.


It is much worse I think with. Larger throttle body as there are larger throttle steps and you dont need much throttle angle to get a large manifold pressure even tweaking the throttle map accordingly
 

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not having that problem and using the spoon tb.

the "problem" i had was at highway at a normal speed and the transition to hi cam was not smooth as the hondata maps have a very low vtec pressure at some rpm. taking the throttle off made same hesitation between the hi and low cam. Even the groupN cal made this.
i also tweak a litle the fd2 throttle map.

Now is very good, but your way is better but much more work.
 

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i forgot to say this blade.
I did not tune my car as many usa tuners do. They generaly make a hi cam map puting the same cam angle in every of the 10 column at a x rpm. For example they put 45 cam at 6000 rpm in all column (1 to 10).

i don't make that. I put how honda did it. At a x rpm the columns have different values.

my map have this at 6000 rpm (all 10 colums):

36 36 36 36 36 39 42 46 46 46

the normal usa maps would have this

46 46 46 46 46 46 46 46 46 46

i did like this: I started with the fd2 rrc map and changed the cam angles at hi cams to suit the spoon cams (almost identical). But when i made this i also made the same changes at low cam to compensate. So my car is running very smoth (i think).

i also had to change all rmp index values to compensate the fd2 cam angles (they are set different on the fd2 maps)
 

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In the first 2 cols on high cam try and start with same cam angles as you have at that rpm on low cam. Makes the transition very smooth as if its not you can feel quite a jerk as the cams rotate quickly as it goes low cam. ;)

Giving up my secrets here! :lol:
 

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Discussion Starter #7 (Edited)
In the first 2 cols on high cam try and start with same cam angles as you have at that rpm on low cam. Makes the transition very smooth as if its not you can feel quite a jerk as the cams rotate quickly as it goes low cam. ;)

Giving up my secrets here! :lol:
Not really as that's what I said I do in my opening post! Lol!

Nuno - that's exactly what I'm referring to, the US maps with a flat cam angle in alll columns. Also see the same thing on the "race" cals (MAP) from Hondata.

Of course if it is race car you don't car about the transition to low cam as you should always be on the high one!

It would have been nice if there was a blend feature between the two maps to make this job easier.

I might write a program to do it :D

It's not just the jerk paul, but you can actually be on a balanced throttle and be tickling the pressure point where vtec kicks in, and if there is a big difference in the cam angle then it sounds almost like det! It isn't det of course. This is at the lower column positions as it is not a significant throttle opening - for example, holding throttle at 5krpm where the vtec pressure is quite low. Putting the pressure up doesn't work for my driving style.
 
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