Slater

I am a little confused about the vacuum reading you get on the VAFC when you do the -40% "boost hack" settings and DSM 450cc injectors.

I would think that you would never "read" more htan 1psi or the ECU would throw a CEL. But a few on here claim that they are getting accurate pressure readings from the VAFC (in bar obviously).

So my question is, can I just read boost from the VAFC instead of buying a boost gauge? I'm trying to be as stealth as possible and if the AFC already gives me the information (digitally too) I wouldn't want to fart with an inaccurate mechanical gauge.

TIA,
- Slater

Smashback

Yes, it reads all your boost but since it modifies the map signal the ECU will not. My mechanical gauge is very accurate, so I'm not sure what you are referring to there. I would think a plain black face gauge would be more stealth than a big blue light up display with lots of numbers flashing around on it.

One cool thing though about the AFC is the peak hold function...

dbman96

Yeah you can definitely use the VAFC as a boost gauge (peak-hold is cool!) and it even has the "analog gauge" style display for quick visual reference. You just have to learn to think in kg/cm^2 and not in PSI.

rioninja

I'm using my vafc as my boost gauge. Works like a charm.
also, read my post:
https://honda-tech.com/zerothread?id=162603

Slater

...an inexpensive mechanical unit, like Autometer, which are notoriously innaccurate. I found that out searching the archives and I guess you get what you pay for. I would love to shell out $250+ for a Greddy or Apexi unit, but my line of thinking was why pay for something redundant that I already have (i.e. VAFC readout)? And I would take that $250 and get a nice Tial WG...know what I mean?

Now, granted, it's not the *best" way to do it, but I'm on a budget and I already have the VAFC. So a boost gauge is one less thing I have to buy and figure out where to mount...

- Slater

Slater

...my VAFC installation redefines the word "stealth". And it's not hidden away in a glovebox or ashtray...



- Slater

P.S. - Thanks for the info everyone! Mucho appreciated! Can't wait to start boooooosting

Smashback

I definitely know where you are coming from. I had the Autometer, which really isn't that bad, but I just replaced my A/f and boost gauges with Apexi boost and egt gauges. One thing is they are a little bigger, so they're easier to read, and they respond very quickly. If it weren't for the fact that I want to see the gauges while I'm racing without looking down, I would just use the AFC for my only boost gauge too.

zojirushi

in the analog guage, it doesn't go past 0 psi....

dbman96

Ah well I guess it's my turn to wear the Jackass hat. Stupid VAFC.

VTC_CiViC

My VAFC and AVCR read identical boost 100% of the time untill about .72 bar where the AFC stops reading (I'm guessing that's the limit of the MAP sensor), so in my case, I could use the AFC as an accurate boost gauge

falcongsr

for now i have an autometer vac/boost gauge. it may not be accurate, but its consistent, which is the most important part.

rioninja

Incorrect, VAFCs will read up to 28.44psi.
You have to go into the [etc] section of the vafc, and i believe graph type/scale or something similar. There you can set it to either +1.0 or +2.0.
Of course i recommend setting it to +1.0, because thats over 14psi, which is more than the stock map is good for.