Jaycar Digital Fuel Adjuster

txateu · Post by **txateu** » Fri Apr 27, 2007 8:32 pm

i was redaing up about them, ansd they say its perfect for AFM upgrades... does that mean i could swap a s13 hotwire onto my exa and just adjust the voltage to the comp? cause that would be sweet as...
whats the voltage running from the afm? is it 1V ?

SammyET · Post by **SammyET** » Fri Apr 27, 2007 11:53 pm

i dont like your chances

wombat · Post by **wombat** » Sat Apr 28, 2007 5:21 am

yeah sammy's dead on. you can't swap a hotwire, because they operate very differently. the vane type which is in the et uses 2 sensors; one which is the flap which measures actual airflow, and another which is a temperature sensor. the net effect of these two is a measure of oxygen density. now i can't remember the textbook definition for the hotwire, but i'm pretty sure it works by the ecu pumping voltage into the wire to keep it at a certain temperature, and the amount of voltage required to keep it constant is the way they calculate the fuel there. again, can't remember properly with the hotwire, but i do know for sure it's a no go.

txateu · Post by **txateu** » Sun Apr 29, 2007 2:55 pm

ok well hotwire idea gets the arse, still i realy thing the digital adjusts a great idea

wombat · Post by **wombat** » Sun Apr 29, 2007 6:57 pm

yeah man i totally agree. finally can run bigger injectors with the standard management. the only time i've ever read a bad word about the dfa is from people who've tried to make the kit themselves and stuffed something up.

hey, about your airflow meter replacement, have a look at this for an idea:
http://autospeed.drive.com.au/cms/A_2424/article.html
http://autospeed.drive.com.au/cms/A_2449/article.html

also, i've noticed that the ebay seller has posted another dfa:
http://cgi.ebay.com.au/Digital-Fuel-Adj ... dZViewItem

SammyET · Post by **SammyET** » Mon Apr 30, 2007 1:31 am

Correct me if i am wrong this time.. but i have heard that on WOT the afm is completely open by as low as 2500 rpm.. which means that the ecu derives the injector pulse from an inbuilt map in this situation.. now i would assume that u couldnt tweak the voltage from the AFM as the ecu isnt even using it..

Post by **Ash** » Mon Apr 30, 2007 3:16 am

^^thats what i thought to.

SashET · Post by **SashET** » Mon Apr 30, 2007 7:40 am

The time and effort that you would put into a DFA, you could just as easily hunt down a Microtech or Wolf and get that running in your car. Then you can play with everything on the engine (timing, fuel, fuel pump, thermo fans etc.) and not just the fuel. Great in theory but in practice, dont wast your time and money! I've found that the best mod you can do on these cars is fuk off the air flow meter and replace it with the computers MAP sensor. Just my two cents anyway.

Cheers
Sash

wombat · Post by **wombat** » Mon Apr 30, 2007 8:18 am

totally valid point, but bit of a price diff

SashET · Post by **SashET** » Mon Apr 30, 2007 8:50 am

wombat wrote:totally valid point, but bit of a price diff

I bought my MT8 for $400.00, wired it in myself (with a little help from tassuperkart), probably $50.00 worth of connectors. So the only other thing I need is $150.00 worth of dyno time which your going to need with a DFA anyway. So all up I'll have spent $600.00. Now add your costs up and compare.

DFA - $79.95 (Build it yourself kit where a million things can go wrong and you'll end up starting again or scratching your head for a while!)
Hand Controller - $59.95 (See comment above)
Dyno Time - $150 + (You will need more time as its not as easy to tune as a programmable ECU, but lets be optimistic)
Misc. Shits & Bits - $50.00

Total: $339.90

Almost the price of my MT8! Might be half the price, but it also has less than half the features. In fact it only has 1 feature (fuel control).

Hunt down a Microtech from either ebay, nissanexa forum, this forum, FJ20.com forum, nissansilvia.com forum, skylinesaustralia.com forum, boostcruising.com forum etc.

You wont look back m8! Again, just my 69 cents worth!

Cheers
Sash

redbaron1991 · Post by **redbaron1991** » Mon Apr 30, 2007 10:19 am

wanna find me an mt8 for $400 ?

SashET · Post by **SashET** » Mon Apr 30, 2007 10:52 am

redbaron1991 wrote:wanna find me an mt8 for $400 ?

LOL, they are there M8, you just have to look.

Mine was advertised for $550 - $600 (cant remember exactly) but when you wave $400 cold hard cash in their face it puts poeple on the spot and then their emotions get the better of them (to your benefit of course). Well thats how I did it anyway. Some others might have different tricks up thier sleeves.

Cheers
Sash

wombat · Post by **wombat** » Mon Apr 30, 2007 8:38 pm

SammyET wrote:Correct me if i am wrong this time.. but i have heard that on WOT the afm is completely open by as low as 2500 rpm.. which means that the ecu derives the injector pulse from an inbuilt map in this situation.. now i would assume that u couldnt tweak the voltage from the AFM as the ecu isnt even using it..

yeah i heard something like that a little while ago, but there was another guy running around the nissanexa forum apparently who had quite a bit of power with his e15et tuned with a dfa. has anyone done any measurements on this to confirm it?

Ben Hewitson · Post by **Ben Hewitson** » Tue May 01, 2007 8:20 am

someone talk with TravsET cause he ran 140kws out of a stock setup and a DFA..

SammyET · Post by **SammyET** » Tue May 01, 2007 5:30 pm

was that power with a stable AF ratio though?? or was it boosted off its head making "unreliable" power??