FMU vs. FPR on a D16Z6 with IHI RHB5
 

Hey Guys...

I'm about to put a IHI RHB5 into my '95 Civic Si, and I have a question about an FMU. I have recently bought a B&M FPR for my setup, but a mechanic from a local turbo/performance install shop told me that an FMU would be much better for my application. What should I do? Should I return my brand new B&M Command Flo FPR and get the FMU from him? What's the difference between the two? Which one is better for my setup?

Thanks in advance,

P.

Re:FMU vs. FPR on a D16Z6 with IHI RHB5
 

fmu raises the fuel pressure according to boost...thats what you want

Re:FMU vs. FPR on a D16Z6 with IHI RHB5
 

ghettot is right a fpr is really useless on a boosted car compared to an fmu. get the fmu or you will have problems with leaning out if thats it for your fuel mang.

Re:FMU vs. FPR on a D16Z6 with IHI RHB5
 

So it's definitely better to get an FMU, right?
What will happen if I just use the FPR?
Will it screw up my engine?
Also how should I go about adjusting the FMU if I do get it?

Re:FMU vs. FPR on a D16Z6 with IHI RHB5
 

AbaZ or Shortyz, would you mind answering this one?

Re:FMU vs. FPR on a D16Z6 with IHI RHB5
 

the FPR will just adjust your static fuel pressure. you shouldn't have any reason to toy with that unless you check it and find out you arent running ~38psi at idle. if you use the FPR....well, you wont notice dick because it wont really do a damn thing. just sell the FPR and get the FMU.

Re:FMU vs. FPR on a D16Z6 with IHI RHB5
 

You can also keep the B&M and get a FMU.

The FMU actually works in conjunction with your stock fpr, weather it is stock or modified for adjustability with the B&M. If you ever get you car tuned, you can make some adjustments.

The only thing is you might not need the B&M 'cause it only increases pressure. If you get/have a high pressue fuel pump, you might find you self wanting to decrease the pressure a bit.

Re:FMU vs. FPR on a D16Z6 with IHI RHB5
 

I think everything said in this thread is about what I would say.. ;)

FMU's are a cheap way to add fuel... they add more pressure as the boost rises. (how much is determined by what size disc is in the FMU) a Adj FPR, can only change your base fuel pressure, nothing will change under boost.

Jeff

Re:FMU vs. FPR on a D16Z6 with IHI RHB5
 

why not use both? you can adjust the fpr to match additional modification you have when driving normal , then the fmu will take over for boosted situation, or to better explain say you turn your boost down low, but you also have a built engine, slightly modified, you will need aditional fuel, right? fmu only adjust when sees boost. wrong or right?

Re:FMU vs. FPR on a D16Z6 with IHI RHB5
 

Thanks for all of the informative replies to this topic. You guys really healped me understand the diff btw the FMU & FPR.
Now I'm convinced that I'll want to sell the FPR, and get an FMU.

Is anybody interested in my D16Z6 IHI Turbo Install?
I have a lot of pics of the engine rebuild/mods, and I'll have all of the Turbo install pics this Friday.
Let me know :)