Help a Honda guy out... question on 450's

[cacasesi]

I did a search before posting this, and I couldn't come up with an answer. I was looking for the idle fuel pressure on a stock turbo DSM running with 450's. I've recently swapped some 450's into my Si, and I'm trying to find out what the DSM baseline fuel pressure is. I'm hoping if I can hit that pressure, I'll get proper atomization with the injectors. Thanks!

 

[2-0turbo]

1G turbo base fuel pressure is 36 PSI. ALL injectors are rated for flow at 43 PSI. If you really want 450 cc injectors, run 43 PSI.

 

[cacasesi]

Hey, thanks for the info. I've been running 48 psi since I installed them the other day. I wasn't too far off. I'll try to lower it down to 43, but I think I may have a problem. I'm using a B&M choptop regulator and a Walbro 255 lph pump. The pump overpowers the regulator's FP lowering ability. I can always drill a hole in the regulator to lower the pressure. What's the maximum fuel pressure that these injectors see in a stock configuration? What's the maximum FP that you DSM guys will put to them? I assume they can handle 60 psi without any trouble. My stock Honda injectors put up with 90 psi for a year and half...

 

[candela]

Dpends on boost as its rising rate/linear. Base is 43psi and say you run 20psi of boost the injectors/rail will see 63 psi blah blah blah...you get the point. You must be running quite rich with that jrsc. How much boost are you running? I just got done ynoing my friends gsr with that jackson sc on it and he made 218 to the wheels at 7psi. The only mods we had for fuel was a 190lph fuel pump and a linear reg w/ a ratio of 8:1 fuel psi/boost. We saw great o2's from the wideband, so I cant imagine how your running with all that fuel. Im not judging or anything just wondering...

 

[NDgsx]

I would not run them at high pressures with a walbro fuel pump. The flow rate for walbro pumps drops off quickly at higher pressures. On cars with walbro pumps I don't run over 45psi base pressure. I recomend denso pumps when running higher pressures.

Why don't you get an aeromotive, SX, or paxton regulator and have a an fitting welded onto your fuel rail?

 

[salTy]

Originally posted by NDgsx
Why don't you get an aeromotive, SX, or paxton regulator and have a an fitting welded onto your fuel rail?

I agree, the B&M reg IMO is garbage.

 

[BatmanGSX]

I hope your car is turbocharged or supercharged. I don't even know if the all motor Honda guys running 12s and 11s use injectors that big.

 

[candela]

He has a supercharger, but only a jackson...they only run 6psi stock. In my experience with these b series w/ JRSC your setup will run your car way too rich. Read my above post... those linear fuel press. regs are the best for Hondas, trust me.
http://www.capa.com.au/vortech_fuel.htm
http://www.vortechsuperchargers.com...n=PROD&Store_Code=VEOS&Product_Code=6Z110-112

 

[BatmanGSX]

Isn't the JRSC set up to be used with stock injectors? I thought it was a complete kit and you didn't need to worry about additional fuel.

The only thing you need to worry about is keeping the pressure ratio across the injector the same as stock. ANY FPR should work, including the stocker, these things work the same regardless of whether the engine was N/A or forced induction. On an N/A engine as you revved it up it would produce vacuum and decrease the pressure above the injector, on a turbo car it would increase the pressure, the device is the same either way. Set it to the stock pressure (or whatever Jackson recommends) at idle and the FPR will take care of the rest.

You may want to consider using the injectors that Jackson recommends be used with the kit. Unless you are increasing the boost with a new pulley there is no reason to think you need more fuel if Jackson says you don't. They are a reputable company, I'm sure they have researched this.

I'm not familiar with your setup or the JRSC beyond that so I can't say for sure. Just do as they say to do and you will be golden.

 

[candela]

Actually they do run a tiny bit lean (dpends though) in most cases at the top end. I was just under the impression that he was to be running more boost from it thats all. The stock fpr's arent very sufficient for raising pressure at all, cause they dont liniearly. Most all boosted hondas have some sort of fmu to regulate and ensure proper (or close to ) fuel mixture. The Jackson kit doesnt come with anything but the SC basically. Its said to be fine with stock fuell system, although I know its recommended to raise fp a bit. These superchargers can make good power if boost is increased just a little bit. My buddys made about 14 more whp with one more psi of boost on his. It just seems to me that cacaesi has way too much for fuel, definetly overkill for a stock motor. Unless your running like higher CR pistons with like 8 or more psi I think that is just too much. You should get it tuned, or checked out with a wideband to see...

 

[cacasesi]

Yes, the car is supercharged with a Jackson Racing blower. I'm not using any FMU right now. The fuel delivery is being controlled by a magic little box call a Super MAP Controller (SMC) that a guy (Zip22) over on ClubSi.com developed. It can control 440 or 450cc injectors at any boost level. I believe it will work on any vehicle with a MAP sensor although you have to upgrade the MAP sensor above 14 psi. I'm only running about 7 psi right now, but with my new setup, I can easily upgrade to 10 psi without worrying about fuel delivery. The car isn't running too rich. I just dyno tuned it yesterday, and fuel delivery was good. I need to do a little tweaking still. I think I had a minor fuel leak at the rail which was causing some erratic A/F readings.

If I use the stock injectors, as someone suggested, I have to use a rising rate FMU and get WOT FP's in the high 90's! This setup is much more adjustable, with low FP's, and cheap to boot. $89 for the SMC from Diablo Autosports + used injectors + dyno time...

I appreciate all of the input from you guys. I didn't think this post would attract much attention.

 

[BatmanGSX]

That being the case, just run 43psi base fuel pressure with no signal going to the FPR. Then hook up the signal and go.

 

[candela]

That sounds like a neat box, I hope it works well coincided with the sc/boost. You said you got dyno time, what did your a/f readings look like across the board, and what numbers did you get. I also own and still love Hondas, and tis why Im interested in this. Most all Honda forums are bunk as hell, and to get another (there are a few) with Hondas on this board I thinks its cool.

 

[cacasesi]

Originally posted by candela
That sounds like a neat box, I hope it works well coincided with the sc/boost. You said you got dyno time, what did your a/f readings look like across the board, and what numbers did you get. I also own and still love Hondas, and tis why Im interested in this. Most all Honda forums are bunk as hell, and to get another (there are a few) with Hondas on this board I thinks its cool.

My A/F was a little inconsistent because I had a slight leak in my fuel rail which was causing fluctuations in my FP. So my dyno results don't look great right now. The SMC works well though. I could easily correct my A/F across three different rpm ranges. ClubSi.com is a pretty good Honda board. Most of the people there are smart, rice is completely made fun of, and a lot of people don't even own Honda's (especially in the Si vs. All forum). You should check it out.