[s-cars] Relayed FP

Tue Nov 15 08:55:18 PST 2011

Thanks Scott.  If you have any photos, I could add them to the relay DIY along with your suggestions
regarding fixed mounts for the relay, and fuse blocks, etc.  In the meantime, I think I have "tied" things
 down pretty well (been fine for 7+ yrs so far), as shown in this photo from the DIY:
http://12v.org/urs/almost_done.jpg

PM me with any photos.  In the mean time, I will check out rallylights and your suggested Hella PNs.

Dave F

----- Original Message -----
From: Scott Justusson <qshipq at aol.com>
Date: Tuesday, November 15, 2011 8:32 am
Subject: Re: [s-cars] Relayed FP
To: forgied at shaw.ca
Cc: s-car-list at audifans.com

> My concern with inline fuses are the common associated, nothing 
> to do with the actual fuse, but it's installed environment... 
> The ATC inline fuse holders vary in quality, their mounting 
> should be mechanical (not dangling inline with the wire) to 
> eliminate vibration, and they trap heat that can reduce the 
> overall rating/life of the fuse.  I'm not a fan of 99 cent 
> electrical protection of a critical electrical component 
> counting on 100% duty cycle.  Hella makes a single 'open'-
> rigid mounted ATC inline fuse holder (Hella PN:  87134) 
> that would be a 'minimum' for this FPR mod IMO.  On all FPR 
> relays I like to use a minimum 2 gang aux fuse block, and I also 
> like to use a rigid mounted relay holder (so the relay can be 
> replaced easily).   The four gang block I commonly use 
> is Hella 62935 mounted under the back seat.  The rigid 
> mount Relay Holder is Hella PN: 87123 and comes with the proper 
> stress relieved terminals that Audi uses (2 crimps - one on wire 
> jacket and one on wire)
>  
> A good source for individual Hella components is www.rallylights.com
> 
> Cheers and HTH
> 
> Scott J
> 92 v8 ABT Chipped
> 95 C4 Avant FWD
> 2 x urq
> 2 x CGT
> 
>  
> 
> -----Original Message-----
> From: David Forgie <forgied at shaw.ca>
> To: Scott Justusson <qshipq at aol.com>
> Cc: s-car-list <s-car-list at audifans.com>
> Sent: Mon, Nov 14, 2011 12:48 pm
> Subject: Re: [s-cars] Relayed FP
> 
> 
> Scott: Thanks, I appreciate your comments about use of the 
> larger gauge wire.  I was going to do that
> but at the time, I couldn't find wire with insulation that 
> wouldn't get eaten by the gasoline.  I did eventually
> get some teflon-coated wire but I have yet to install it.
>  
> One comment that I have to argue is the use of a spade-type 
> inline fuse.  That is exactly the same fuse
>  type as the OE fuses in the fuse panel.  I have not 
> had any fuse failures in 13+ years of UrS ownership so
>  I am  not concerned about that fuse failing (hasn't 
> in 7+ years so far).  I presume that you have different 
> experiences with these fuses.
>  
> Dave F.
> 
> ----- Original Message -----
> From: Scott Justusson <qshipq at aol.com>
> Date: Monday, November 14, 2011 10:21 am
> Subject: Re: [s-cars] Relayed FP
> To: forgied at shaw.ca, s-car-list at audifans.com
> 
> > 
> >  Good information, but also know that there are several
> > 300+ATWHP cars running no relay mod, hence my suggestion it may
> > not 'solve' anything.  To your writeup itself, when I did 
> > one of these mods to a 400ATWHP S car, I also replaced the 
> stock 
> > 14guage wire to the actual pump in the tank, with 10 guage 
> wire 
> > from the aux relay pin 87 feed, and added a redundant ground 
> of 
> > 10guage wire to the pump as well.  Likely massive 
> overkill, 
> > but I also do this routinely on the urq external pumps.  
> > Also, I don't use a crappy failure-prone 'inline' fuse for 
> this 
> > mod, I usually mount a aux fuse block under the rear seat, 
> which 
> > also gives a couple slots to add 12v feed to the headlights, 
> > which can also suffer light output from lower than battery voltage.
> > 
> > Cheers and HTH
> > 
> > Scott J
> > Relay mods aplenty
> > 
> > 
> > 
> >  
> > 
> >  
> > 
> > -----Original Message-----
> > From: David Forgie <forgied at shaw.ca>
> > To: s-car-list <s-car-list at audifans.com>
> > Cc: qshipq <qshipq at aol.com>
> > Sent: Thu, Nov 10, 2011 8:52 pm
> > Subject: [s-cars] Relayed FP
> > 
> > 
> > Scott:  As detailed in the link to one of my DIYs that 
> JaMu 
> > provided(http://forums.quattroworld.com/s4s6/msgs/24327.phtml) 
> > there was a significant improvement in the
> > voltage at the fuel pump when the OE fuel pump relay was 
> simply 
> > used to trigger another relay sitting
> >  beside the battery and 4 ft from the fuel pump instead 
> of 
> > allowing current to flow forward from the
> >  battery, through the fuel pump relay and all the way 
> back 
> > to the fuel pump.  This was done to help
> >  eliminate significant pinging on certain unnamed (okay, 
> > Pastore) "RS2" software that Sean D. and I were
> >  experiencing on Chevron 94 shortly after we RS2's our 
> AANs 
> > back in 2004.  The new relay definitely
> >  helped to decrease the occurence and severity of the 
> > pinging.  The real solution for us was better
> >  software  (MRC Stage 3 in my case and Dahlback MTM 
> in 
> > Sean D's case). 
> >  
> > It must have been a good idea if 034 commercialized it.  ;>)
> >  
> > Dave F.
> >  
> > Scott J expounded:
> >  
> >  >The urq pump is also relayed from the factory, and this 
> > is a standard issue mod, not based on theory,
> >  >it's a known practical application of voltage at the 
> pump 
> > vs pump output.  The main reason to do this
> >  >relay mod is 17 feet of wiring between the factory FPR 
> > and the fuel pump can create quite a voltage
> >  >drop.  Easy to test this improvement, if battery 
> > voltage = voltage at the fuel pump = no improvement. 
> >  >IME with Audis, rarely does the battery voltage = 
> voltage 
> > at the fuel pump.  And the difference in fuel 
> > >pump output is quite significant when voltage drops:
> > >http://performancefuelsystems.com/images/clip_image004_001.jpg
> > >
> > >I won't go so far as to say it will *solve* anything, but low 
> > voltage at the fuel pump can create running
> >  >problems under boost.  The good news is with many 
> > Audi batteries mounted under the seat, this is a
> >  >simple and effective mod.
> > >
> > >HTH and my .02
> > >
> > >Scott J
> > >Relayed fuel pumps aplenty
> > 
> >  
> > 
>  
> 