What about boost spiking, does anyone have this problem with any of the kits? I used to have an GS-T and I had to port the wastegate housing to eliminate it. I don't know if it is a problem on Honda turbo kits but just asking. If so, what do you guys run at, what psi does it spike to, and what does it level out at. Thanks in advance. 00 Si

 

Guys is 7 or 8 psi really ok? I asked Ben at Import Parts and he said just to run 6psi. Any suggestions?

 

I boost all the way up to 12 psi sometimes on my totally stock B18C1.

7 or 8 psi... is definately safe.

 

7psi is fine don't worry about it so much. Ben probably said stick with 6 because he is a dealer and in case anything ever went wrong, he wouldn't be for blame or whatever. But 7 is ok.

 

How long will 8 psi be safe though?

 

'00 Si, you've gotta realize that x psi is good for x setup. Guy at NOPI had 14 psi on a stock ITR - higher compression than an Si. I'm gonna run 8 psi in my B18C5 daily. Its all about tuning... with FMU's, check valves, and VAFC's you're relegated to about 6-7 psi tho maybe you could eek a tiny bit more out. With a good tune, I dont see how you couldn't run 12 psi on a stock B-series. Cylinder pressures... gotta keep 'em in check. HTH, EV.

 

I have also added an V-AFC, fuel pump, and NGK spark plugs as well. Did you just tune your Type R yourself or did you go to a dyno. I have never been to a dyno, do I have to tune it or do they do it there?

 

This is going to sound stupid, but I've got a pretty large (about the size of a nickel) boost leak right now (long story; it's deliberate) which leaves me boosting a max of 3.5-4 psi on my '96 GSR. The funny thing is, it's REALLY fun to drive like this... with less boost it's easier to get a smooth fuel curve with simple tuning tools like a VAFC and FMU and 450cc injectors (way overkill at 4 psi of course) so right now it just drives like stock but has a nice extra pull when I'm passing.

I guess my point is if I'm content at 3.5 psi you're sure not going to be too let down at 6 psi. Boost is boost, enjoy what you got!

Of course when I get my IC pipes replaced and fixed up, I'm going to be back up at 7-8 psi ASAP.

 

00 Si, I see you're very preocupied with the thought of damaging your motor, are you SURE you wanna Turbo? Seems like you'd rest alot easier if you stuck with an all-motor setup. Tuning is the key dude. If you supply the needed amount of fuel at the right time, then there's no reason why your motor can't handle a good amount of boost. I mean we've got a bunch of examples on this board alone of people with stock B16/18's pushing doubledigit psi reliably. It's been said before and let me restate it, you'd be supprised how much boost a stock motor can handle with the proper tuning. IMO, a good 255lph pump, 8:1 or 10:1 FMU, 310cc injectors and a V-AFC with some wide-band O2 dyno tuning will be more than enough to let you squeeze 10psi if you wanted to. Me personally, I'd leave it around 8-9psi for daily and leave the extra few psi for track use, but that's just me. Just remember, although you CAN boost pretty high with the right fuel/ignition setup, the farther you go, the smaller your margin of error becomes, this is why I'd stay away from running really close to the edge, but 8-10psi should still give you breathing room on a B16 with the right fuel setup as everybody here already mentioned.

 

I want to go turbo but my point is this. I have asked severl people what set up they have on their VAFC's and no one wants to tell me. It is like it is a big secret. I wanted to know the fuel +/- on the hi and low settings and at what RPM just to get an idea on what to expect to do. I know that each car is different and I don't expect to copy the map into my VAFC, but I just wanted to know what to expect.

 

00 si I noticed that too when I got my VAFC... I'd be perfectly happy to show you my settings but I'm running 450cc injectors so if you used my settings with stock injectors you would be in big trouble. Same applies for different fuel pressures, different pumps, etc.

The more I use the VAFC the more i dislike it, for one major reason... using big injectors you must trim the fuel down with the AFC; this reduces the MAP sensor voltage reaching the ECU; so when you start boosting, the ECU is still "seeing" vacuum, so at 1-2 psi of boost, the ECU is still in closed-loop mode. Presto - you've got a turbo with JRSC-style tip-in detonation! Aside from this, the VAFC is not boost-dependent in any way so you end up chasing your tail trying to match AFC settings to your FMU settings and never get a consistent a/f ratio.

Give me my damn haltech!

 

Yea the combination of FMU/VAFC/Stock ECU is really a sloppy science, but it can be tuned to work reasonably well. Results will never be as good with a standalone but none the less, a good tuner can get you running very well with a couple hours on the dyno playing with the VAFC.

 

Tuning that has to be done on the dyno or what?