Hello, so I had a project in mind for adding a little bit more hp/tq to this fun car and my idea consisted of running a Fmu with bigger injectors and no intercooler and hopefully push 6psi of boost on the stock ecu. Has anybody tried this method? The only source of information I’ve found was off of civics.
hopefully in the months to come I will hopefully have finished everything and hopefully be a stepping stone for anyone looking for a little extra power out of this grocery getter.

 

What is a fmu?

 

Probably means fuel management unit or something similar, like a piggyback ecu to add extra fuel.

OP, look in the GK engine section for homemade turbo, there's pictures from someone who put the turbo from a Civic directly onto the Fit cylinder head and used a Ktuner for fuel mapping. Said he did 7psi on stock injectors, but no dyno sheet.

I wouldn't skip the intercooler, though. Since you're having to run piping for the turbo anyways, it's not a lot of extra work and the lower intake temperature makes detonation less likely.

 

Maybe the OP should state, just for clarity, which generation Fit they have.

The 1st gen had turbos, which are most likely unavailable now. Kraftworks, I believe.

2nd gen had Sprintex superchargers... can probably still find a few here and there.

3rd, I guess are the homemade ones that @hasdrubal mentioned... which you could also do with 1st and 2nd gen.

That said...

None of that actually mentions what will be generating said "boost." Even if "fmu" means a fuel management unit, it doesn't create boost, just controls fuel (as per the name). Bigger injectors similarly only affect fuel. While it can affect HP, that's not "boost" in relation to 6 psi. That's 'a boost' to HP, not simply "boost."

Honestly, to me, 6 psi doesn't sound like a lot. But realistically, I have a supercharger that generates around 7 psi. I doubt very much you can generate 6 psi (over atmosphere) without some physical method of actually compressing air. Last night I saw a video about an electric supercharger, that started at 6 psi in low rpm range and dropped to 2 psi at higher rpm... so again, what is the method you plan on creating "boost?"

 

fosho I would look into that, but I can’t tune it directly with kpro, I have an automatic which I believe isn’t supported

 

with a td3-td4 turbo of course, I have a Gd3 automatic that I’m trying to push to the limits and have fun with while there’s still life left. It won’t be a sloppy setup neither I need a Fmu because I can’t tune my set up to make up for boost pressure, I know there kits out there but I’m not paying +2500$ For a P.o.s supercharger that only adds 10-20 horses lol? But my Ecu and auto transmission should be able to handle 6-8 psi if I’m lucky with the setup I’m sketching out. But I’ve been watching videos and doing tons of research. In the end it should look like HKS’s L15a1 setup with the turbo connected directly to the throttle with no intercooler but with the addition of a ghetto old school setup. So to sum it up I need a Fmu for a TURBO charger and there’s already manifolds for sale or it won’t be hard to fab one up. Also I’ll be adding a boost and AFR gauge as well and I’ll be keeping my stock injectors

 

Fuel Management Unit.
All it does is block fuel return flow so it forces more fuel through fuel injectors when it senses boost, but it’s not 100% reliable but it’ll do if you’re looking for low boost (10 psi and under!)
only videos you’ll really find online is on miatas and Honda Civics but every setup is essentially the same concept except for the “missing link” you might need but I will be trying it without one.

 

Maybe, instead of an FMU, try replacing the fuel pump with a higher flow one.

I had to do that on my setup because otherwise, I would constantly trip limp mode if I held high RPM for too long. While I did that, I ended up not using the piggyback that came with the setup as it fried itself. And I've been piggyback-less since. Also no limp, CEL, etc. that were related to it. The only CEL I got were when the spark plugs started chewing through the threads.

The factory ECU seems to handle the added air and pump quite well.

 

Don't modify the engine of an auto fit.

 

meh it’s getting scraped out later anyways, I just wanna have my fun

 

I’ll definitely get a bigger/better pump but I still believe I’d need an Fmu since I can’t tune it. But a quick question: how will a new pump support boost/ Will it still force more fuel through the injectors?

 

You're going to spend thousands of dollars to have 'fun' in a 120 whp automatic economy car that you yourself have said you're going to scrap?

 

uhhhhhhh this will barely stretch over 500$? And uhhh pretty much yeah I wanna squeeze as much as I can out of it, especially since I cannot afford a swap at the moment. But hey it’s better than spending 2500$ for a supercharger that only adds like 10 hp?

 

You're going to turbocharge it for $500? Do tell.

 

This is gotta see.... and, read.

 

fmu: $100+/-
turbocharger: $100 +\-
gd3 eBay td04 manifold: $100
oil line: $30
custom down pipe: free
charge pipes: 50$ +\-
boost controller:$30 +/-
vacuum lines: $15
waste gate: $50 +\-
No tune support, no intercooler *roughly $475*
....... but on a side note I’ll tally up the total cost when I complete the project, I’m going cheap on parts because I’m not expecting high performance from an automatic L15a1 also I’ll replace all my gaskets if I have too

 

Love it when the peanut gallery chimes in and kills a thread with dumb questions unrelated to the original thread... Did you ever find a budget fuel solution? Currently looking for one myself.

 

bless bro, shoot me a message on Instagram, same name, Hotdogbox. i'd love to chat on greater detail !

 

What gen is your fit…. If it is GK there’s no need for injectors… they are the same as The ones from the 1.5t engines and are capable of producing maybe close to 300 hp….