Okay, so I'm thinking of turbo'ing my car and Ive been reading up on some basic turbo stuff and I read up on something called a Boost Indexed Fuel Pressure Riser (searched but found nothing about it) I was wondering if it is possible to use one of these on a Honda.

The reason I ask is because ive read that it only works on vehicles that have high pressure lines going to the engine and low pressure lines that send the unused fuel back.


Picture of one because no one looks at a thread unless u got one...

 

More often called an FMU or Rising Rate Regulator. Yes you can use one on a Honda, but don't forget to tune it. These are usually only desirable for entry level turbo kits, or users who only desire a low boost level, as these things can put your fuel pressure at an incredible height, to the point of diminishing returns where you begin hurting your car.

 

Point of Diminishing Returns - eco major? haha

what does FMU stand for?

Also, where I read it said that it doesnt require tuning. What kind of tuning would you need? (it said it raises fuel pressure by 12psi for every 1psi of boost)

 

Actually I'm an ME major.

Fuel Management Unit

This is where most people go wrong...they think they can just throw an FMU on there and call it a day. Think about it, at 7 psi of boost, your fuel pressure is at 40 + (12*7) = 124 psi! With only the stock 240cc/min injectors, they can hardly push this, even at 100% duty cycle. Also, you have to look at the force that 124 psi puts on the pintle of the injector. To open, the injector must overcome this fuel pressure, and with incredibly high fue pressures, this can become impossible, causing a lean condition and a blown motor.

 

Well, I realize im going to need larger injectors but how do you make it so that the injectors will be able to handle this pressure?

 

They will handle the pressure up to a point...that's what I was trying to say. In my example, you see that at only 7psi of boost, you're already at 125psi of fuel pressure...you can't go much past this.

Do a search on FMU or rising rate regulator...there are plenty of threads. I know Muckman has had luck in the past with an FMU [he's the first person I can think of], but there are MUCH better options out there, like Ubedata that are nearly free, and will allow you much better tuning than an FMU. The true cost of Uberdata is knowledge.

 

I see, thanks.

 

I have one for sale exactly like the one in the pic if you want it.