The lack of boost sensing was the biggest deficit I saw with DirectScan
compared to Turbo Link. It is more complex to use than TL, but at
least it can be done. Rather than trying to reiterate what Mark said,
I have simply cut & pasted (with minor editing) the pertinent parts
of our e-mail conversations here. Enjoy, and good luck!
Mark, I was just reading http://www.turbobuick.com threadid 52751 , and you mentioned
you had your WBO2 logging in directscan and being reported as MAT. Was
it an involved process to do this? Can a similar thing be done for
boost sensing?? (BTW, electronics are something I know little about,
except how to plug 'em in and use them, so please excuse my ignorance. :-D
)
Regards,
Dean Nelson
Mark Clute wrote:
Hi Dean,
Logging boost isn't too difficult,
all the plug and play hardware is already out there. You just need
to purchase the turbolink boost harness, along with a 3 bar map sensor, and
plug it all in. It converts the map signal and sends it into the mat
harness then you can read the temperature change as boost once you build
a lookup conversion table.
I created a table, using a high quality gauge like a Mac or Snap-On and one of those Mityvac hand pumps, and for each psi I put on the map sensor I recorded the temp on DS. That's all there is to it, except for accounting for barometric changes in which case you need to turn the key on and engine off and verify your zero reading from time to time.
Hope that helps,
Mark
No problem on the info. Let em see if I can answer the rest of your questions. If you feel your VDO's are accurate then go with them. I just found that my 0-30 VDO was reading low by 1 psi, and a friend with the hand pump had a Snap-On, so I used it.
Since the Mityvac only goes to about 24 then I guess you'd need to find someone with a compressor and regulator. Maybe you could adjust down that low and get the higher readings. That's the only way I'd know to go about it.
For the conversion table you do this, write down boost in one column from 1 to 23 (or wherever you want to stop), then as you apply each psi with your Mityvac, with DS running, you look to see what MAT temp is showing. When your done, you have your lookup table. I printed the table I built in real small print, and then taped it next to my laptop screen so I can easily reference it when I'm looking at the DS file.
The barometric pressure thing is this. You
don't need any gauge, you just have to be aware that on any given day the
barometric pressure may be higher or lower than the day you made your table,
and this will throw off your numbers a bit as the map sensor only knows
that zero is the temp reported by DS when the key is on and the engine is
off. If its a high pressure day then the DS temp reading my be higher
and on a low pressure day it may be lower but I'm not sure it it works that
way or the reverse. Hopefully that's a better explanation.
Another way to look at is this. Lets say your running 18 psi (gauge pressure), and the barometric pressure is 29.5 inches of mercury as reported by the weather channel for your area, and DS shows a MAT temp of 65 degrees. Now lets say the next day a high pressure front comes in and the barometric pressure is 30.5, your still running 18 psi on the gauge, but DS may now show 67 degrees. This because the map sensor has no way to compensate for the pressure change. Ken's Turbo Link has a feature where you turn the key on, and in the TL software you can zero the boost sensing. That's the same thing you'd have to do with DS. Turn the key on engine off and see what the MAT temp is so this would be your zero psi starting point if you wanted to maintain comparability between runs on different days.
Well, I'm typed out for now, hopefully that will get ya going.
Mark