AUDIOZ A4

Or is the 5bar FPR adequete?

There seems to be an awful lot of conflicting advice on this issue

ModifiedA4

which ever you change the software needs to know.

Audi2ptzero

Some people have tried going to 310cc injectors and used a adjustable fpr to get the pressure correct to make the larger injectors supply the same amount of fuel as the stock/5bar combo. Just go to this page and find out what the fuel rate is at 5 bar for the stock injectors and then do the same for larger injectors to find out what pressure you need.<ul><li><a href="http://www.rbracing-rsr.com/fuelinjectors.htm">click</a></li></ul>

auditunerb5

Or are there other reasons why you would want to change?

AUDIOZ A4

But really, Im just trying to make sure I do it properly first time around

Devious27t

iirc only the J31 sauce for the MY2000 req's change of injectors?

Devious27t

having done logs with it i am pretty sure you will be fine.

AggregatVier

That's a great link! Thanks!

xr4tic

I've heard stories that a 5bar FPR has the same "cap" as a 4-bar FPR, so in theory, at high boost pressures, the 5-bar will have the same fuel pressure as a 4-bar.

If this is really true, then the fact that boost tapers off in upper RPMs is probably the reason why it still works. Plus, if this is the case, then a stock FPR and larger injectors would not work the same as a 5bar FPR and stock injectors, as far as the chip is concerned.

Only a fuel pressure gauge and WB O2 sensor would tell the story for sure.

I thought GIAC had a program for larger injectors, and if it was me, that would be the route I would go as I would think it would lead to longer pump life (less fuel pressures)