New Guy with some ?'s

Hey guys, Im pretty new to the board here and to be honest I dont even have a busa.

I am however an ex factory superbike and NHRA prostock engine builder. Now I own a custom shop and I am a carbon fiber parts manufacturer as well as a custom leather company owner.

Anyways, on to the good stuff..............

Im completely familiar with turbocharging and how to fab most of it up. My real questions have to do with the fuel injection stuff.

As all of my previous turbo conversions were with carb'd bikes, Im slightly clueless as to how you guys are doing this with the FI.

Yes I understand Motec and Fast and Megasquirt........but thats just controllers and Im pretty positive that most of you dont end up having to use all the stand alone stuff.

Anyways, who here is mature enough to not pretend that this is some kind of speed secret that I may steal and run off to be the newest whore to BUSA turbos and can chat with me about the FI.........

Id appreciate it. I have enough knowledge that I wont be like some squid newb bugging the crap out of ya and really I just want the straight info.

Thanks guys
hey no secrete it is pretty straight forward i would say the vast majority of people use power comanders.plug and play basicly
.if you have turboed a carbed bike you should be able to turbo a busa blindfolded.
Thanks for the link.

Really I wonder how you get around the stock pump? Are the stock pumps in most bikes capable of producing enough pressure?

I mean if you go 15 psi, arent you needing alot more pressure?

I only question as the stock pumps in carb bikes are dead head types and are set for 3psi.

The hardest part of doing a carb'd bike is finding a boost regulated pressure regulator that would dump back at that LOW of a pressure so you wouldnt blow the floats off the seats off boost.

I appreciate all your guys help, really I do. I figured that the busas are the most popular turbo application so you guys would be my best bet in learning what needs to happen.


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99% of the turbo kits come with better fuel pumps, I have a Bosch 044 on my bike, but thats with 460 hp also. Way overkill for a smaller turbo.
(smithabusa @ Sep. 13 2006,16:12) 99% of the turbo kits come with better fuel pumps, I have a Bosch 044 on my bike, but thats with 460 hp also.  Way overkill for a smaller turbo.
Hey by the way...............I almost **** a brick when I saw your curved intercooler.

Tell me thats not an MCexpress piece and you know a place where I can get those cores, please?

I had to convert two bikes to straight radiators to run a bell intercooler blank over the front of them.............Id love to have access to blanks with curving.


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Sorry it is a curved MCXpress, but you can buy them complete. You see them used every once in a while for about a grand. Well worth the money.


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(xcitebike @ Sep. 13 2006,16:15) Thats what Im curious about..................

How does it mount? Im assuming its just a car fuel pump for FI and its adapted for the bike?
On the larger pumps some guys mount them to the 99/00 stock fuel pump mounting brackets. 99/00 had external pumps.

For the smaller pumps most kits have you install it on the frame rail on the right hand side down under the tank.
i am homebuilding my kit and i am going to use a walboro 255 pump, BEGI FMU (to raise fuel pressure with boost), and a PC2. obviously new lines and vac hoses and the sort. you can get fuel rail inserts from the PC2 is a fuel tweeker that you can use a computer to adjust the injector curves. the injectors are pretty noted to max out at 300hp, then people swap out the FMU, and then go to secondaries on a piggyback ecu. many it seems have seen 500+hp on stock fuel setup and then the standalone. i think only the extreme all-out guys use standalones, and it would seem that any streetbike would not really need to.
(reaper0995 @ Sep. 13 2006,20:45) many it seems have seen 500+hp on stock fuel setup and then the standalone. i think only the extreme all-out guys use standalones, and it would seem that any streetbike would not really need to.
there is a fine line between "getting away with" and "playing it safe".

You may be able to tweek a stock system to deal with 500+hp, but I wouldn't call it "safe". FMU's aren't known for their accuracy period, and most people consider them a bandaid (those that tune anyway)

Its a fine line in the life of tuning. You don't want to do things half-assed unless you don't mind rebuilding the engine often. I don't mind rebuilding engines....but I've learned alot rebuild engines so much. One of the things I've learned is, don't cut corners on fuel management. They will bite you in the end, every time.
You can't run 500 on the stock fuel system. With mods to the output of a stock pump and a BEGI reg you get to around 280-290hp pushing it with bigger injectors. Every aftermarket kit out there uses a replacement pump for high HP.

So what the majority of you are saying is that for a real "top grade" turbo kit on anything FI, you should convert the stock fuel pump over to a car pump.

Be it block off plates or conversion plates to the bottom of the tank?

To be honest, Im really thinking of doing a 600cc engine. Im sure the pump in a 600 is the same style or capacity as the 1300 as it would only make sense to use the same stuff to cut costs in manufacturing.

I just wondered how it all really works now.

"X" stock pump pushes "X" amount of fuel at "X"psi.

If you put 8 pounds of boost to it, you do need more than just 8 pounds dont you?

This fuel injection thing bugs me, not quite as simple but I cant keep my head buried in the sand and pretend its going to go away. Its time for me to step up and learn.

Again I thank you guys.


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Most of the stage 1 kits use a FMU rising rate regulator, and on boost you will probably have 100 psi or more fuel pressure. At idle more like 42 psi. Most of the stage 2 kits and standalone guys run a 1:1 regulator with either huge primaries or stock primaries and large secodnary injectors. You would then have 42 psi key on power pressure, plus whatever boost you run. 30 psi of boost would be 72 psi fuel pressure.


Semper Fi !!!!
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I wouldnt make any assumptions when it comes to fuel pumps,go lean for a few seconds and youre finished,go fat and it only cost a few HP.Get yourself some sort of wide band Air/fuel monitor such as an LM-1,that way you know what youre doing.
Actually I have a wideband 02 for fuel injection as the old style wont keep up with FI.........I use them to tune carb's turbo set ups as its really hard to see what your carb is doing with a plenum over it.

My problems really stem into how the fuel injection is part of the turbo system. turbos have been around since what..........the 30's?

Its not rocket science but with my background I tend to overcomplicate things. So Im hoping you guys are able to help me from re-inventing the wheel.


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With a stage 1 most of your fueling needs are taken care of with a rising rate regulator which raises boosted fuel pressure way up, all depends but can easily go over 100 psi on full boost. You get the fueling as close as you can with the FMU and tweak it with a power commander using engine RPM vs throttle percent tables.  Off boost would be more like 42 psi fuel pressure.

With stage 2 kits you run secondary injectors that run off a fuel controller that uses a map sensor.  You only add fuel with the secondaries when the map sensor sees positive boost pressure.  Each boost level is tuneable vs engine RPM.  They use a 1:1 regulator so that fuel still atomizes well etc.  Off boost you basically run like a stock bike, I am not running a power commander off boost right now and bike part throttles pretty damn good.
i may have said it in an odd way, but it looks like smithabusa already beat me too the "better" way of saying it. on 300 hp and lower, you run a PC and an fmu, aftermarket pump and stock injectors. above that, you take out the fmu, and put in a piggyback ecu and take out to PC, then have secondaries (a second row of injectors found in the plenum) and run a 1:1 regulator. then off boost, it is the stock fuel system and then as boost picks up, the secodaries fire AS WELL as the stock fuel system (stock, kinda....the psi is roughly the same, the injectors are the same, and the regulator is about all the injectors see that is any different from stock)

external pump. have a 2000, so it came external. thank goodness too, i like my gas gauge

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