Logged performance of additional RS4 fuel pressure regulator valve

[muckipup]

My car is Revo stage3 and one week ago I wanted to play around with the Select Plus to see if I can get better power output. And moreover, I have the feeling that some time to time in 3rd gear at full throttle there is a little hesitation at about 5000rpm.

Any way, I just get a Ross tech cable so I went for some logs.

And then I found out that Actual Rail pressure was quiet low compare to requested one.

I Emailed Revo And Carl comfirmed me that it should come from a failing fuel pressure relief valve.
So I decided to fit a rs4 fuel pressure regulator valve.

It's a pain to remove and a nightmare to fit.

I have to run more test but the fuel pressure looks much better and the car seems to be a little bit more responsive and to pull more smoothly and strongly.

Four logs with Difference between request and Actual Rail Pressure.

Positive number means Actual is below requested.



Here requested vs OEM VS RS4




If somebody can tell me how to properly display an Excel Graphe on the Forum he will be welcome...

That looks like a good example of a car where the benefit of the RS4 valve can be easily predicted by logging rail pressure ahead of making the swap.

It is a personal thing, but I wouldn't do it myself unless I logged rail pressure first and found that actual rail pressure was tracking notably behind requested rail pressure - I'm sure a few psi could still be gleaned from the RS4 valve, I don't think it would translate into a noticeable difference on the road. However, it looks like the OEM valve can vary in spec and a 10 psi shortfall across most of the rev range as can be seen above would be a different story!

[Poverty]

it aids the HPFP further.  there were plenty of stage 2+ guys with the hesitation at 5200rpm who used his valve to get rid of it iirc

i remember when all you guys where saying that me and wayne where making this up and that there must be a problem with our cars 

[muckipup]

Yeah, humble pie time....I'm going to get one too 

[Janner_Sy]

it aids the HPFP further.  there were plenty of stage 2+ guys with the hesitation at 5200rpm who used his valve to get rid of it iirc

i remember when all you guys where saying that me and wayne where making this up and that there must be a problem with our cars 

i think your making it up.....

[robdf2]

it aids the HPFP further.  there were plenty of stage 2+ guys with the hesitation at 5200rpm who used his valve to get rid of it iirc

i remember when all you guys where saying that me and wayne where making this up and that there must be a problem with our cars  

yes but you also did say that your car was the fastest on the road iirc and oh would beat the milenium falcon ?  
good to see you still around mate  

[Poverty]

it aids the HPFP further.  there were plenty of stage 2+ guys with the hesitation at 5200rpm who used his valve to get rid of it iirc

i remember when all you guys where saying that me and wayne where making this up and that there must be a problem with our cars  

yes but you also did say that your car was the fastest on the road iirc and oh would beat the milenium falcon ?  
good to see you still around mate  

You guys will never get rid of me 

[Janner_Sy]

damn

[muckipup]

I've got an RS4 valve and took a quick look at the weekend to remind myself what it would take to fit it and experiment with a few spanners and tools.

Even with loosening the clamps holding fuel lines to the intake manifold, removing PCV or, in my case, loosening the relocated DV, I still struggle to see how this could be done without some very weird shaped spanners. I saw another post on the use of crow foot spanners ( http://www.mk5golfgti.co.uk/forum/index.php/topic,9196.msg198941.html#msg198941 ) but even then, I can't see how a crow foot spanner would get in a the correct angle or give enough purchase to fully loosen and tighten.

I think I'll try doing some 'Uri Geller' spanner bending on an old set of spanners before going at this or maybe just forget about it 

[vRSAlex]

I dont use any bent spanners for this job.  Use the closed end of a 17mm spanner 

[muckipup]

I dont use any bent spanners for this job.  Use the closed end of a 17mm spanner 

Thanks again Alex - it was more about loosening the 14mm connection to the fuel line before the 17mm valve could be got to that had me scratching my head.

[Janner_Sy]

[muckipup]

Ahh yes, a well used tool in my garage for a bit of 'percussion adjustment'   

[Janner_Sy]

i know it as the persuader

[vRS Carl]

To me it's known as Jim.

As like in the 90's Jim fixed everything and so does a Hammer

[muckipup]

i know it as the persuader

I'm sure the hookers would get in the car if you just asked them nicely