Returnless Fuel System FMU

[Nemasys]

Im starting to build my turbo project for my Aveo and im trying to find a cost effective solution to increasing my fuel delivery without using complicated engine management units and such.

Since the cars use a returnless fuel system, i started doing some research and i found 2 ways of increasing the flow.

Either modify the current system to a return system, using a old fashioned boost controlled FMU or i found this thing, a digital FMU specifically made for returnless systems, used in conjunction with a 2nd fuel pump, it controls that pump based on your boost levels and you can build your own fuel curve relative to your boost curve.

What do you guys think? Heres a link to the Digital FMU:

http://www.cimotorsports.net/motor-spor ... l-fmu.html

[PrecisionBoost]

The fuel pressure issue with returnless can be a pain, aeromotive is a good brand and should help out but they are expensive.

Honestly for $480 plus the cost of an inline fuel pump ( $150 ) you would be far better off going with a different setup.

The aeromotive system will give you a "rough" tune just like a rising rate fuel pressure regulator.

You will still ideally need an aftermarket air/fuel controller to fine tune the required adjustments.


Personally I think you would be far better off looking at something along the lines of adding another injector up near the throttle body.

There are tons of supplementary injector controllers on the market around the $250 to $300 range.

Here is an example.... http://www.034motorsport.com/product_in ... ucts_id=71

A number of these injector controllers are very simple.... you just adjust the amount of fuel based upon a couple of parameters such as boost and RPM.... the install is not that complicated and it gives you full control of your additional injectors.

If you increase boost and you run your injector at too high of a duty cycle you simply replace it with a larger one.

Here is an example of a weld on adapter for adding another injector.... http://www.urdusa.com/product_info.php? ... 1260518943

You can also get versions with a throttle body spacer, but in your case that would probably have to be machined or adapted from another vehicle with the same TB mount pattern.

[Nemasys]

Yeah i know those fmu's are a bit expensive, after a little thinking i came to the conclusion that there should be something less costly.

I liked the idea of adding an extra injector, but unlike Jason's Optra, i dont have access to a good shop, most of the work will be done by myself so im relying on alot of things that hes done to his car.

I do have a good knowledge in mecanics and stuff but i might need a little help with the fine things like adding this fuel injector. How would i feed fuel to this extra injector, i know i could use a fitting at the end of the fuel rail, but do those boss adapters come with something to accept the fuel delivery to the injector or i need to fabricate something?

Maybe i should mention i have a 2.0L swapped into this car (U20SED).

Thanks for the help btw Chris!

[gse_turbo]

since you have the 2.0, why not find a fuel rail, return line and fuel pump assembly from the from Nubira or Leganza?