Running VPC in SD, Should I add a SAFC?

[Nate355RS]

I'm running pretty mild setup on a '92 AWD Talon. It has bolt ons, Evo 8 cams, Evo 8 injectors, 18g turbo, and my FMIC arrives tomorrow.

Right now it's tuned in SD using only the VPC with a 550 chip. The Evo 8 injectors are larger than 550s so idle runs pretty rich. So does most of the RPM/MAP range, verified by a WBO2.

Would the SAFC help with idle and driveability? Does anyone even use this setup anymore? Any other piggy-backs in the same price range that would be more effective?

I know the first reply is probably going to say "Buy Link" but it's not in the cards for me at the moment. And I'm not looking for most of those features. I'm just looking for a fun reliable setup that I can take on trips and will allow me to get decent WOT safety and performance.

 

[Broke4speed]

Evo 8 injectors are 560cc, no? A 10cc difference wouldn't make it overly rich, IMO. The fuel trims would more than compensate for that at idle/cruise. Is everything in working order?

 

[Breezio69]

I have a keydiver chip with an safc on top of that. I've been running fine at 18psi on my 16g for almost a year now.

The reason I have the safc is same as yours, its chipped for xxx injector but I'm running yyy injector. Just use math to decide what you should start the tune at 550/560 (although they do flow more like 580) then minus 1 x 100= only about a 1.7% difference, but if you think of them as 580's instead that's a solid 5% difference. That will make your tune rich for sure.

But, for what its worth. When I get back from my vacation mid november I will be buying link... I've been having phantom knock issues all over the place even at 2.5k, and you can't do anything about it with the chip or safc. So yes, it can be done. But coming from someone in the same boat, I'm going link. I can probably sell my ecu that's socketed and safc for 2/3 of what link costs (used) anyhow, so why not.

 

[Nate355RS]

My old current cold side does have a small boost leak, which doesn't help, but before when it didn't leak it was still a good bit rich.

With the VPC I'm not too sure how it would work. Would I need to tune SAFC to account for the injectors and then use the VPC to dial in the tune or do I have that backwards? Because I'm SD I would think I would need to keep the VPC but that might not be the case.

 

[thomcasey]

Your chip is setup for the RC 550's, and their dead-time. The 560's have 0 deadtime, like the 450's, so you will definitely run different. Why not have the chip changed to the new injectors rather than compensate with the SAFC?

 

[Breezio69]

The easiest would be to zero out the VPC and start the tune over. That way everything with your sd stays the same then you tune solely with the safc. You will need a logger at that point.

You say you are chipped, are you talking about the vpc being the chip, or the vpc and you have a chip in the ecu as well... like my setup.

Also, with safc and now needing a logger do you see how the cost of link is looking nicer, and that's why it gets thrown out so much?

 

[Nate355RS]

For logging, I have an old OBD1 ALDL cable I used to tune a few cars awhile ago. Do you know of any freeware for logging a DSM? If so it's hard for me to justify link when SAFCIIs go for $150 used. I plan to use this car more as a fun commuter so if SAFC will work well for my purposes then the ~$300 it saves can go pretty far in other areas.

The chip I have is within the VPC itself, the ECU isn't socketed. From what I can tell from HKS's site they only sell chips for stock and 550cc injectors. If someone else sells modified VPC chips that would be an option.

 

[Breezio69]

How about a trade to someone in the classifieds for 550cc injectors and just be done with it? Or buy some and sell yours. Always a market for both sizes with hondas and people with minor mods, like you and me.

Seems like the easiest option.

And I was just referring to if you had to buy a logger and cable, plus the safc you'd be at like $300. Link is $400 all day in classifieds. There is two in there right now for that price that even come with the ecu. Not trying to sway you, just showing you that you would probably spend that much anyhow to get this running right.

 

[Nate355RS]

That's true about the injectors, and I messaged both those guys selling link and they were sold within a day. Link goes quick here

 

[Breezio69]

Yeah I think you'll just need to figure out where you want to be, getting the 550's is obviously the least headache route. Thomcasey brings up a good point with the dead times and whatnot between the two injector sizes, allthough its probably not much of a difference.

My best opinion would be injectors. If your dead set on the evos and already have the propper tuning tools, then I guess an safc also makes eense... but if you had to buy them I'd say otherwise