Hello all,

I have a CT SC on my s and recently bought a vafc2 for it. I plan on putting a new clutch in the car once the snow clears and was going to tune the car with the VAFC2 then. I was wondering if I should bring it to a shop to tune it or even put it on the dyno. I have a wideband so I know what the AFRs are. I did have a shop double check my fuel pressure regulator after the SC was on but I don't think they really adjusted it that much. It was only a few bucks and they just kind of did it without asking when I brought it in for something else. (I think one of the guys at the shop wanted to gun it down the freeway and used it as an excuses.)

Anyway, is it worth it to bring it to a shop or should I just do it my own? I would think it would cost at least 100 for them to street tune it and a lot more if they used a dyno. I have just had a lot of conflicting info on what to do. Some of my buddies with turbos on other cars insist I need a full stand alone with a dyno tune while others say I can just mess with the VAFC2 on my own and get better results than a tuner can.

I have a wideband FYI

 

So you want to tune a SC set-up with a VAFC? Am I missing something?

 

Its been discussed hundred's of times before but...

1) How are you going to tune with no wideband sensor? and what setup a you running, i will presume a basic one.

2) I always take a car on a dyno to get tuned, i did slightly tweak my AFR on the road but its damn dangerous and not the best to 100% guarantee same conditions.

3) It will take about 1 hour max to tune a vafc2 and lower vtec etc - so easy.

4) On an SC setup you can only lean out the mixture (applies to N/A however i did add a small of fuel successfully). You cant add fuel the stock ECU craps out. You are just altering the map sensor voltage to bring the AFR's into range.

5) You cannot alter timing with a vafc2 and actually inadvertently alter the timing. I can't be sure but IIRC when you remove fuel it pulls timing.

6) Ideally 95% of the tune will require pulling timing.

7) I did run a CTSC+AC 7psi, with bolt on's using a RRFPR and it works very well, but not brilliantly had to jack up the RRFPR to get into a acceptable AFR range.

h) To get the best of of a SC you need a standalone or failing like a greddy EMU - which i have. A most people solution.

Put it this way the car runs better than it did with a VAFC2, and yielded 20bhp more just buying running a greddy EMU - same setup.

 

Well I do have a wideband. When talking to a shop they said all I really had to do was get the AFRs in range as it was rich for the most part.

also what is IIRC?
and when U say u had 7 with the RRFPR do u mean the 4.2 pulley on an AP1? was looking to do the same thing but using the VAFC2 to help with the AFRs. Local places that tune hate emanage


I would consider selling the vafc and buying emanage if it is needed assuming I can find a shop to tune with it. I just thought that the vafc2 was better than nothing as I wouldn't have to run so rich.

 

When you decrease the MAP sensor voltage the timing increases.

 

Thanks :thumbup hondata:

So basically when i lean the mixture it adds timing.

 

IIRC = if i remember correctly .

Yes i run the stock ap2 pulley on my ap1 to get 7psi of boost (~6.5 max with boost loss due to aftercooler).

E-manage ultimate works very well just got to know how to use it, i did it myself but had a little help from people and i have prior tuning knowledge - except your riding the stock knock sensor values.

A VAFC2 is better than nothing, its okay but you can't add fuel only remove thus lean out. It does the job bringing fuelling inline, vtec can be lowered. At the end of the day you need to alter timing to get the best out of your setup, power wise and reliability.

But i wouldn't be happy with the timing issue, if you get knock - a good dyno operator/tuner will be able to see this on a graph/run but also use add on's etc to attach the the engine to detect knock (mike and software etc).

If your wanting a cheap way to bring the AFR's the vafc2 will do the trick, providing everywhere needs leaned out and you have enough adjustment scale (only 12 points IIRC).

 

Why would you try to tune a F/I setup with a crappy module that can only tune WOT above 4k rpm's? It seems to me that it would just put you in danger of running extremely lean. For example, if you were to 3/4 throttle it you would be making boost but you would basically have nothing telling the stock ecu what to do thus you could very easily run lean and destroy the motor.

 

I'm thinking the huge increase in VE would be WAY to much for the VAFC. I'm sure you could get a less than ideal tune, but why would someone settle for this?

 

I would never try using a VAFC for an FI application, but I know S2000Junky did it. Maybe you should sent him a PM.

My concern would be that you can't use the VAFC to add fuel, but you really shouldn't use it to remove fuel either, since that will advance ignition timing. Baiscally, you'll just be able to use it for lowering VTEC engagement IMHO.