Audi RS6 - Fuel System Upgrade - Assistance Appreciated

[650RS]

Hi Guys,

Ive decided to up the ante on the car power wise so first thing is to upgrade the fuel system to suppourt this.

I have already fitted Siemens 82lbs injectors and the next step is the fuel pumps, I plan to run the standard in-tank as a lift pump feeding a surge tank and two Bosch 044's or single Fuel Lab 41401 but the issue is there is no room under the car for the Surge Tank/Pump(s).

Has anyone else done something similar on the C5 A6 chassis? If so I would appreciate some ideas.

I dont want to mount these inside the boot for obvious reasons.

Thanks in advance

[Shoppinit]

Presumably you've dumped the DRC, so you could remove the central valves and use the space where they were.

[650RS]

Presumably you've dumped the DRC, so you could remove the central valves and use the space where they were.

Yes, DRC is long gone.

I considered this spot and will be measuring up over the weekend...

[snoopra]

Why is a surge tank needed? I've bought the bosch 044 for fueling upgrade, are you saying I need 2 pumps and a surge tank?

[650RS]

Yes, for E85 1x Bosch 044 will not be sufficent as the AFR is much richer with this fuel.

The need for a surge tank is to ensure that if the lift pump (intank) is ever starved of fuel the 2x Bosch 044's have enough fuel (in surge tank) to ensure the engine doesnt go BOOM!

[snoopra]

We don't have E85 fuel in the VI so one 044 should do it, right?:D
Got it on the surge tank:thumb:

[650RS]

Yes, for standard pump fuel 1x Bosch 044 is sufficent assuming you are running standard turbos.

[p3u]

Hi Guys,

Ive decided to up the ante on the car power wise so first thing is to upgrade the fuel system to suppourt this.

I have already fitted Siemens 82lbs injectors and the next step is the fuel pumps, I plan to run the standard in-tank as a lift pump feeding a surge tank and two Bosch 044's or single Fuel Lab 41401 but the issue is there is no room under the car for the Surge Tank/Pump(s).

Has anyone else done something similar on the C5 A6 chassis? If so I would appreciate some ideas.

I dont want to mount these inside the boot for obvious reasons.

Thanks in advance

I don't have any advice, but am very interested in your e85 conversion. Please update us as you figure out the details!

[650RS]

Detaila are as follows:

- Custom tune required (mine will be mafless)
- Larger Injectors ( 820cc in my case)
- Upgrade Fuel Supply (Bosch 044x2 or equivalent in flow)

Thats pretty much it.

[p3u]

Detaila are as follows:

- Custom tune required (mine will be mafless)
- Larger Injectors ( 820cc in my case)
- Upgrade Fuel Supply (Bosch 044x2 or equivalent in flow)

Thats pretty much it.

Thats all you needed to run e85?!

If thats the case I'm in! :jlol:

[650RS]

Yep!

I am considering offering kits if interested PM me

[vangelis]

Thats all you needed to run e85?!

If thats the case I'm in! :jlol:

Please excuse me, but what does it mean e85?

[650RS]

E85 is a alcohol based fuel which is 85% Ethanol 15% fuel.

It has a higher octane rating and good cooling properties which will allow for more timing and hp.

The changes needed are above.

[vangelis]

E85 is a alcohol based fuel which is 85% Ethanol 15% fuel.

It has a higher octane rating and good cooling properties which will allow for more timing and hp.

The changes needed are above.

Thanks for the explanation, so is that setup will make any differnce in HP when normal 98octan fuel used?

[650RS]

Yes, if you google E85 tuning results you will notice a power increase between 10-20% on cars.

If you have the standard stage 1 chip which brings power to 520HPx1.1=572HP.

My personal opinion is that due to the RS6 cooling issues the gain will be closer to 15% but wont know until its done.

It is costing me ~$3000 for the upgrade and custom tune.

[vangelis]

Mine has Stage1 ABT 510BHP, so where did u get the qoute for ECU cat-less remap? any idea how much cat-less DPs?

[650RS]

Vangelis - Catless DP's are available from Miltek or MTM, Miltke is he cheapest around $2000.00.

For ECU program please PM me.

[vangelis]

Vangelis - Catless DP's are available from Miltek or MTM, Miltke is he cheapest around $2000.00.

For ECU program please PM me.

I've seen only high flow cats fom both Miltek and MTM, 100-200 CSPI, but never seen cat-less DPs anywhere. Any link for such DPs with good price? regarding ECU PM sent.

[Shoppinit]

E85 has an octane rating (http://www.rs6.com/wiki/Octane_rating) higher than that of regular gasoline's typical rating of 87, or premium gasoline's 91-93. This allows it to be used in higher compression engines which tend to produce more power per unit of displacement than their gasoline counterparts. http://en.wikipedia.org/wiki/E85#Comparisons_to_regular_gasoline

I did not know that. Interesting.

How do you go MAFless? What meters the air?

[650RS]

MAFLESS requires a custom tune, air isnt metered as such fuelling is via lamdas, throttle position and water temp under cuise.

WOT is under throttle position.

[ttboost]

What is your expected wheel HP, if you have expectations?

[650RS]

custom tune will full exhaust made 540bhp, custom tune will full exhaust mafles made 568hp with much crisper throttle and quicker revving

E85 should make at least 10% more but I am expecting 15%, so ~620hp

These are engine figures.

[ttboost]

custom tune will full exhaust made 540bhp, custom tune will full exhaust mafles made 568hp with much crisper throttle and quicker revving

E85 should make at least 10% more but I am expecting 15%, so ~620hp

These are engine figures.


These cars typically lose 21%-23%? So 620bhp would be 480ish awhp? Have you dyno'd your car stock, to baseline, so you can redyno on the same dyno? or no Dyno.

[650RS]

power loss is correct as you stated.

The car made 435whp with the custom tune prior going mafless, so I guess close to 500whp would be a realistic power figure.

Also with E85 the tuner said that he should make this HP with boost set at 1.0bar from ~3300rpm to 6500rpm as the timming will take of the rest at most boost will hit 1.2bar so the only hardware being stressed is the transmission but I have taken steps to give it the best possible chance of surviving.

[ttboost]

power loss is correct as you stated.

The car made 435whp with the custom tune prior going mafless, so I guess close to 500whp would be a realistic power figure.

Also with E85 the tuner said that he should make this HP with boost set at 1.0bar from ~3300rpm to 6500rpm as the timming will take of the rest at most boost will hit 1.2bar so the only hardware being stressed is the transmission but I have taken steps to give it the best possible chance of surviving.


Is this all on stock turbos, stock wastegates, piping etc...?

[650RS]

Yes, modifcations to the car are:

Turbo back exhaust
K&N Filters
Bosch 044 Fuel Pump (Upgrading to 2x Bosch 044 for E85)
Siemens 820cc Injectors (Needed for E85)
Upgraded Transmission Fluid Cooling System
Upgraded Engine Oil Cooling System

[ttboost]

Yes, modifcations to the car are:

Turbo back exhaust
K&N Filters
Bosch 044 Fuel Pump (Upgrading to 2x Bosch 044 for E85)
Siemens 820cc Injectors (Needed for E85)
Upgraded Transmission Fluid Cooling System
Upgraded Engine Oil Cooling System


Very nice. Thank you.:hihi:

[vangelis]

Upgraded Transmission Fluid Cooling System
Upgraded Engine Oil Cooling System

Would you please give more detail on that 2 actions?

[SIKAudi]

I have LeBree DP's. They are 2 into one with test pipe installed and Miltek cat back. $1500 Stainless steel DP's came with high-flow cats and the test pipes to change it out if you ever have to do an inspection for some reason. You will also need to get a spacer for the 02 sensors but those are cheap Blackforest idustries sells all kinds of them... most companies should load the software for whatever your setup is. I have APR and they upgraded mine for free. I just paid for the shipping and they loaded the upgrade. They will do the TCU as well. Initial software (ECU/TCU) from APR is regularly about $2k. Check thier website they may have a Promo going on.

Hope this helps!
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Mine has Stage1 ABT 510BHP, so where did u get the qoute for ECU cat-less remap? any idea how much cat-less DPs?

[650RS]

APR/GIAC/MTM are what I like to call cookie cutter tune's they are good but nothing beats a custom tune.

[SIKAudi]

I totally agree. However, Location! Location! Location! and being on the mainland and having access to tuners almost everywhere is a luxury some don't have. ex; Hawaii residents...

To benefit from a custom tune you have to have tuners who know what they are doing and have the Dyno to complete the process = time+money. Cookie cutters aren't bad for the guy who wants a base tune and then tweak hear and there! They are Safe and most are Warranted. Building a repore with the cookie cutters you will also find they do a little more outside the box than what they advertise (those are basic tunes) if you give them what your mods are they have special tunes to accommodate although still cookie cutter.

Although cookie cutter I should have some dyno numbers in the next month or so for outside the box, unadvertised tuning. I will post the numbers shame or fame....

APR/GIAC/MTM are what I like to call cookie cutter tune's they are good but nothing beats a custom tune.

[ttrs6]

what are you doing as far as sparkplugs go?

[650RS]

Bosch FD05PR

[ttrs6]

Bosch FD05PR
how much colder are they then stock and how much timing are you looking to run?

[snoopra]

Bosch FD05PR
Can you point me in the right direction for the wiring kit for the bosch 044?

[650RS]

Snoopra - As far as I know there isnt a wirring kit as such, I worked it out myself.

Feel free to shoot me a PM with questions and I will be more than willing to answer/help

[Mr Balsen]

APR/GIAC/MTM are what I like to call cookie cutter tune's they are good but nothing beats a custom tune.

In one way yes, in another way no. And for the no, it is due to the fact a custom tuner will never be able to register / certify / insure the car properly....

Frederic

[MaxRS6]

Hmmm- haven't done this one yet and may consider it