Karman Vortex to HotWire
Karman Vortex to HotWire
Hello All,
Having seen some of the posts regarding the Karman Vortex MAF meter on our beloved Evo8s, I think I now understand the system and how it works.
Last weekend I took apart my intake box just to see the KV unit, and yes, it certainly looks like a restriction.
Shiv discussed awhile ago that the XEDE could be tweeked to produce a MAF waveform using a MAP sensor and temp. sensor, BUT a MAP installation seems a little 'much' for my shadetree mechanic skills.
I've had this thought in the back of my head about doing a Hotwire system.
Would the benefits really be there, in using a hotwire to open up / smooth out the intake? I know BMWs use a lot of hotwire systems. How reliable are they? What type of calibration, if any, is needed?
Thanks,
jcnel.
Having seen some of the posts regarding the Karman Vortex MAF meter on our beloved Evo8s, I think I now understand the system and how it works.
Last weekend I took apart my intake box just to see the KV unit, and yes, it certainly looks like a restriction.
Shiv discussed awhile ago that the XEDE could be tweeked to produce a MAF waveform using a MAP sensor and temp. sensor, BUT a MAP installation seems a little 'much' for my shadetree mechanic skills.
I've had this thought in the back of my head about doing a Hotwire system.
Would the benefits really be there, in using a hotwire to open up / smooth out the intake? I know BMWs use a lot of hotwire systems. How reliable are they? What type of calibration, if any, is needed?
Thanks,
jcnel.
for a forced induction
For a forced induction motor...my gut feeling is there is probably not all that much restriction...
The cost of a hot wire conversion may be less of a gain, than say a cam set. but...I could be proved wrong.
yet I've had in the back of my mind a list of pros and cons regarding the KV system.
Pros.
1.) Easy Setup and calibration. The computer gets a "waveform" that's really easy to relate to airflow. The waveform is nice and linear, and relatively easy to manage / modify.
2.) I suppose for arguments sake, these KV units are pretty easy to manufacture.
Cons.
1.) I'm not totally convinced that KV system likes to idle well. There seems to be a tradeoff here. A relatively small KV path promotes more low-speed airflow and the air "eddies" continue to be formed fast enough for the computer to figure things out, and/or make the KV path large enough to promote low-restriction at high airspeed (high boost case).
Mitsu. has put these KV systems on for many years now...there seems to be some internal resistance on using anything else, even on their NA motors.
Anyways...I'm rambling on...I suppose some discussion on this issue would at least help me grasp the Air Measurement issues a little better.
What are your thoughts?
Thanks,
jcnel.
The cost of a hot wire conversion may be less of a gain, than say a cam set. but...I could be proved wrong.
yet I've had in the back of my mind a list of pros and cons regarding the KV system.
Pros.
1.) Easy Setup and calibration. The computer gets a "waveform" that's really easy to relate to airflow. The waveform is nice and linear, and relatively easy to manage / modify.
2.) I suppose for arguments sake, these KV units are pretty easy to manufacture.
Cons.
1.) I'm not totally convinced that KV system likes to idle well. There seems to be a tradeoff here. A relatively small KV path promotes more low-speed airflow and the air "eddies" continue to be formed fast enough for the computer to figure things out, and/or make the KV path large enough to promote low-restriction at high airspeed (high boost case).
Mitsu. has put these KV systems on for many years now...there seems to be some internal resistance on using anything else, even on their NA motors.
Anyways...I'm rambling on...I suppose some discussion on this issue would at least help me grasp the Air Measurement issues a little better.
What are your thoughts?
Thanks,
jcnel.
very good
A good post that I've just found:
https://www.evolutionm.net/forums/sh...d/t-50854.html
Thanks,
jcnel.
https://www.evolutionm.net/forums/sh...d/t-50854.html
Thanks,
jcnel.
Re: for a forced induction
Originally posted by jcnel_evo8
For a forced induction motor...my gut feeling is there is probably not all that much restriction...
The cost of a hot wire conversion may be less of a gain, than say a cam set. but...I could be proved wrong.
yet I've had in the back of my mind a list of pros and cons regarding the KV system.
Pros.
1.) Easy Setup and calibration. The computer gets a "waveform" that's really easy to relate to airflow. The waveform is nice and linear, and relatively easy to manage / modify.
2.) I suppose for arguments sake, these KV units are pretty easy to manufacture.
Cons.
1.) I'm not totally convinced that KV system likes to idle well. There seems to be a tradeoff here. A relatively small KV path promotes more low-speed airflow and the air "eddies" continue to be formed fast enough for the computer to figure things out, and/or make the KV path large enough to promote low-restriction at high airspeed (high boost case).
Mitsu. has put these KV systems on for many years now...there seems to be some internal resistance on using anything else, even on their NA motors.
Anyways...I'm rambling on...I suppose some discussion on this issue would at least help me grasp the Air Measurement issues a little better.
What are your thoughts?
Thanks,
jcnel.
For a forced induction motor...my gut feeling is there is probably not all that much restriction...
The cost of a hot wire conversion may be less of a gain, than say a cam set. but...I could be proved wrong.
yet I've had in the back of my mind a list of pros and cons regarding the KV system.
Pros.
1.) Easy Setup and calibration. The computer gets a "waveform" that's really easy to relate to airflow. The waveform is nice and linear, and relatively easy to manage / modify.
2.) I suppose for arguments sake, these KV units are pretty easy to manufacture.
Cons.
1.) I'm not totally convinced that KV system likes to idle well. There seems to be a tradeoff here. A relatively small KV path promotes more low-speed airflow and the air "eddies" continue to be formed fast enough for the computer to figure things out, and/or make the KV path large enough to promote low-restriction at high airspeed (high boost case).
Mitsu. has put these KV systems on for many years now...there seems to be some internal resistance on using anything else, even on their NA motors.
Anyways...I'm rambling on...I suppose some discussion on this issue would at least help me grasp the Air Measurement issues a little better.
What are your thoughts?
Thanks,
jcnel.
Now if you get us a good intake manifold I think that would be awesome 
as far as
Hmmm...good point...
As far as *my* effort goes, I just need to read up on what makes a Hotwire tick. Being an electrical engineer, it doesn't sound too hard to get things working.
Perhaps, its, time to break out the o-scope and start taking some readings off of the MAF that's currently in the Mitsu.
Later,
jcnel.
As far as *my* effort goes, I just need to read up on what makes a Hotwire tick. Being an electrical engineer, it doesn't sound too hard to get things working.
Perhaps, its, time to break out the o-scope and start taking some readings off of the MAF that's currently in the Mitsu.
Later,
jcnel.
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