Will the Audi TT225 injectors work on a VW 337 1.8t?

[ZGSON]

Anyone?

[manguyen]

I sold a set to a guy in chile for his vw 1.8t

[OneBadAudi]

dont see why not, there both 1.8's, i would call giac or someone like that just to make sure they do in fact work....
Good luck

[ZGSON]

I sold a set to a guy in chile for his vw 1.8t

And you sold the ones I have to me too.

[risc427]

This is something I've been wondering for a while. I don't understand why APR/GIAC don't have a 1+ files for the VWs. If you find out for sure please post up the info.

[OneBadAudi]

From what i have heard, audi puts in smaller injectors for the 1.8's...i was wondering the same thing as well and even there stage 1 is our 1+ becuase we need bigger injectors

[old guy]

This is something I've been wondering for a while. I don't understand why APR/GIAC don't have a 1+ files for the VWs. If you find out for sure please post up the info.

The VW 1.8T is a totally different animal. Instead of the returnless fuel system as used in the B6, the VW 1.8T uses a pressure regulated return system. Consequently you can increase the amount of fuel by turning up the fuel pressure. Because it is regulated the absolute fuel pressure can be maintained. In other words, as boost increases the fuel pressure differential can be maintained by increasing the fuel pressure an equal amount thus eliminating the need to replace the fuel injectors as in the B6. In the B6 the fuel delivery is constant and does not adjust for the boost pressure differential and consequently has to be increased by a combination of changing the injectors and modifying the duty cycle of the injectors.

[ZGSON]

The VW 1.8T is a totally different animal. Instead of the returnless fuel system as used in the B6, the VW 1.8T uses a pressure regulated return system. Consequently you can increase the amount of fuel by turning up the fuel pressure. Because it is regulated the absolute fuel pressure can be maintained. In other words, as boost increases the fuel pressure differential can be maintained by increasing the fuel pressure an equal amount thus eliminating the need to replace the fuel injectors as in the B6. In the B6 the fuel delivery is constant and does not adjust for the boost pressure differential and consequently has to be increased by a combination of changing the injectors and modifying the duty cycle of the injectors.

wat

[dougyfresh]

wat

He is referring to the fact that the B6 is the only vehicle (I think) with a 1.8T in it (Audi and VW) that uses a returnless fuel system.

The VWs use a system similar to the B5 A4 and thus for simple software flashes you do not have to change fuel injectors. He just went into considerable detail as to what a return-style fuel system is and what it does.. This is the 'tech talk' forum

[old guy]

wat

I'll word it a little different and give you an example. The VW 1.8T's have a 4-bar fuel pressure regulator with intake manifold pressure feedback. The manifold feedback adds the amount of manifold pressure to the system pressure. This means that the pressure drop across the fuel injectors is always 4-bar (although the system pressure will go up with boost.) The B6 A4 has no intake manifold pressure feedback. The fuel pressure is controlled by a flapper valve located in the fuel filter so the fuel system pressure in the rail is always at 4-bar.

For example:

VW 1.8T running 17psi: Pressure drop across injectors remains at 4bar. Actually it will remain at 4 bar regardless of the amount of boost.

B6 A4 running 17psi: Pressure drop across injectors is equal to system pressure minus intake manifold pressure. 4-bar - 17psi = ~ 2.84 bar. Consequently you need larger injectors to get more fuel as you increase boost. Then the tuners can further adjust by altering the duty cycle (on/off time) of the injectors.

Hope that makes a little more sense.

Cheers!

[ZGSON]

I'll word it a little different and give you an example. The VW 1.8T's have a 4-bar fuel pressure regulator with intake manifold pressure feedback. The manifold feedback adds the amount of manifold pressure to the system pressure. This means that the pressure drop across the fuel injectors is always 4-bar (although the system pressure will go up with boost.) The B6 A4 has no intake manifold pressure feedback. The fuel pressure is controlled by a flapper valve located in the fuel filter so the fuel system pressure in the rail is always at 4-bar.

For example:

VW 1.8T running 17psi: Pressure drop across injectors remains at 4bar. Actually it will remain at 4 bar regardless of the amount of boost.

B6 A4 running 17psi: Pressure drop across injectors is equal to system pressure minus intake manifold pressure. 4-bar - 17psi = ~ 2.84 bar. Consequently you need larger injectors to get more fuel as you increase boost. Then the tuners can further adjust by altering the duty cycle (on/off time) of the injectors.

Hope that makes a little more sense.

Cheers!

So the injectors won't work then?

[old guy]

So the injectors won't work then?

You may be able to get them to work by reducing the fuel pressure. I'm not sure why you would want to though. It would probably take a lot of logging and trial and error to get them to work properly. Not a job I would recommend for the average Joe wrench turner.

[ZGSON]

You may be able to get them to work by reducing the fuel pressure. I'm not sure why you would want to though. It would probably take a lot of logging and trial and error to get them to work properly. Not a job I would recommend for the average Joe wrench turner.

Thanks.

[jbrown7815]

wat

This made me LOL

[JebusA4]

Sorry for bringing this back from the dead, but this helped me out. Thanks

PS. Every since I strayed away from Audi to VW (Had a B6 A4), I always wondered why the Audi guys never bought AFPR's instead of buying overpriced injectors, now I know.

Thanks again!