Alright, to make a long story short...my car is in the shop now to have the intercooler mounted, a new downpipe made, and the setup itself reviewed..IE AFC settings, etc.

Setup as I gave to the shop
2000 civic
15g greddy kit
apexi front mount
V-AFC
RC 440's

My friend just bought a car from the mechanic I took my car too. (The car, a sentra with a brand new silvia motor, runs flawlessly and is incredibly quick at 10psi). When I originally took the car in, the mechanic strongly reccomended using an FMU and a Fuel pressure regulator (And a gauge) to establish a 'baseline'..as a precautionary measure to make sure the motor will always have enough fuel. I inititially hesistated, but gave in because it was a precautionary measure. He also mentioned changing out the wastegate spring? I'm not quite sure about this. I left the shop..came back home

Fast forward to yesterday, I drop the car off at nighttime with the FMU I got from a buddy of mine. Today comes and I speak with him on the phone, he tells me the intercooler is great..pressure tested and runs well. He also asks me if I have a bigger fuel pump...I say no. He says "You're definitly gonna have to upgrade that, it wouldn't fuel a stock gsr" I said alright..after he convinced me that the RC 440's would suck the fuel rail dry at redline..even though I've talked to people who have the hack w/ stock fuel pump. Last but not least, he mentions how he put a missing link on the map sensor. I thought to myself "Wow". He was telling me about how if the ecu sees boost that it cuts fuel....and how that would be terrible at high rpms. I brought up how the AFC manipulates the MAP sensor voltage/signal..but he insisted that it was preventative maintenence. I say Roger that. Hang up. I come on the computer....go to Apexi's website, and reaffirm my initial notion. Then, I come here and read the first few pages of the afc hack thread, where people were saying how shitty their cars ran with the hack and the missing link.. So I call him back....And I tell him about what the apex website said and how the previous owner of the AFC/Injectors had put down 227/209 at 11 psi without any CEL's..or fuel cut, or whatever. I also mention that the guy told me that boosting above 10 psi with the stuff isn't the best idea. The mechanic tells me again that the missing link is just preventative. I say, so are you only going to AFC to lean the car out at idle..and he says No. So I ask him how he's going to tune the settings (Mind you on the street, no dyno), even though the MAP sensor isn't going to be accurate and he says that in the past, he'd used the same setup and it worked great..-40% for idle all the way up to around -28%. Now, I'm not sure what he's doing at all. He knows my budget is $800 total..I'm really confused, and a bit worried that he's going to charge me more than I can afford. I honestly don't want my car running like **** cause I can't focus at work or lead a productive life because I spend so much time worrying about it. This car really means more to me than most anything (well a girlfriend would mean alot too, as would a path to what I want to do eventually).

I do understand that it is a lot of text..if you don't feel like reading it, that's cool. If you could give some constructive criticism or input, personal experience or opinion, I'd greatly appreciate it. Thank you for the time

PS. The turbo doesn't leak oil, is there any other possibility it could still be broken? I just need a little confirmation.




Modified by illicon2003 at 6:58 PM 7/2/2004

 

if you dont trust him than take the car back without the fuel management and do it all yourself...telling him what he needs to do cause u read it off the internet will juss **** him off...

 

Yes, I didn't mention reading anything on the internet. IMHO,It really shouldn't **** anyone off, except those who think they know everything (whether they do or don't) and who don't have the time, effort, or the desire to research. There's more good information on the internet than one could learn in a lifetime. It's just a bit frustrating at times to sift through the bogus BS to find the good stuff.

I trust his mechanical abilities 100%, and I trust him with my car. I'm a little bit less confident in his a/f related stuff. I just think that the FMU, FPR are overkill and that the missing link might cause more problems short term than it will solve long term. Plus, the misc stuff is starting to add up, I can't afford more than an $800 bill. I don't know if he will charge more.

 

Doesn't sound like he has any clue what he's doing. Go with your initial impressions.

-PHiZ

 

Ive been running the hack for about 2 months now. Its not exactly the safest thing but if your on a budget, hey, it works.

all of the FMU and upgrading the fuel pump and him telling you that the 450's will suck the fuel rail dry is all bullshit. Ive been running with stock 96 EX (d16y8) fuel pump running 8-9 lbs of boost and it never ever hitting over a 12.5 air fuel ratio (dyno proven/tuned with A/F Charts, I'd post them up but I dont have the charts anymore)

Personally I would take the car back and do everything yourself. you save money in the long run anyway, and you know that its getting done correctly the first time. there are tons of threads on the "hack" and countless people are using it.

If you need more specific info about the hack, PM me, and ill try and answer your questions as best as possible.

Jon

 

This is a classic example of your mechanic just simply not understanding the concept behind the AFC hack. They know about the FMU and FPR etc...so they can only recommend you in what they know. All that is needed is your AFC and injectors. Everything can stay stock. This is of course assuming that you wanna do the hack?

 

well yeah that was the plan. he's really really confident though and said it has worked for him in the past flawlessly. I'm just really confused, that's all.

 

PS: This is what made the most sense to me..from turbod16. any other reccomendations?
shifty35
Rated PG-13


Joined: 17 Jun 2004
Posts: 72

Posted: Fri Jul 02, 2004 11:51 pm

--------------------------------------------------------------------------------
Sounds like you need new friends. The V-AFC works by reading the signal off the MAP sensor. It then lowers the signal going into the ECU so that the ECU will not see boost. The ECU will think you have a regular set of injectors, etc. and will not throw a MAP code. In addition, it cuts the fuel below normal (-40%, etc.) which is good because the injectors are almost twice as big.

Let's pretend we add a missing link to the V-AFC. Here's what happens:

The MAP sensor never sees a pressure higher than atmospheric pressure. Therefore, the V-AFC never knows what your boost level is.
Thinking you are always at a vacuum, the V-AFC will still lower the MAP signal in order to maintain a -40% or whatever fuel cut. In this setup, NOTHING KNOWS WHAT BOOST LEVEL YOU ARE RUNNING. At least with an FMU, the fuel pressure is scaled based on the boost level. However, a car is still technically tuneable with the V-AFC and missing link, but it would be much more difficult, because it wouldn't do it's job the way it should.

Moral of the Story:

Get Uberdata. (Shameless plug for a great program...)

(uberdata is out of the question).

 

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