[s-cars] Spreadsheet data needed - Fuel pressure, Air:Fuel, Boost etc.
benswann at verizon.net
Tue Aug 31 12:36:42 PDT 2010
FWIW, I have been mapping out fuel pressure settings as combined with various injectors
as used by various chipsets - mostly mine, but some others as well.
I'd be interested in collecting additional data to include in a spreadsheet. I intend to
post these online once I have enough emperical results.
Typical data would be gathered using an Air/Fuel meter with data-logging preferable, but
A/F without logging or even narrow band works - just that results can get misread, out
of range or out of mind sometimes. Having assistant/co-pilot take readings would be a
good safe way to do this if no data-logging is set-up.
Manifold Pressure - vacuum and Boost readings from accurate guage preferred in PSI, but
Bar is OK -just ususally not as accurate. If using non-stock MAP sensor(insede ECU),
don't use or trust digital dash guage unless re-programmed to match the pressure
transducer. At least tell me about the mis-match so I can recalculate offset. For
example, you might have 3 Bar MAP Sensor in the ECU, but the dash is calibrated to use
output of the 2.5 bar MAP sensor.\
Please include RPM or RPM range at each data point.
Any comments on performance, drivability, exceptions, etc. would be good and might even
have me identify a problem you may have or that improvements can be made. If you have
good record of fuel economy over typical driveabiliy, that won't hurt.
Results would likely include:
Car, engine, any modifications.
Type/brand/rating of fuel injector installed: OCTANE, ambient conditions (Cold, Hot,
Rainy, etc.) Air:Fuel Readings (and driveability comments) at:
Moderate load/accel (under 1 Bar atmospheric) around .7-.8 no boost. Mid RPM
Cruise (low load/not decel.) .3-.6 Bar Mid RPM 3700-4000
Decel - Downshifting decelerataion readings
Accel. Load range from .9 to 1.2 bar boost
Higher boost vs. Air Fuel reading - can have range of measures, since some are running
to 2.5 bar, some with 2.5 overboosting, and some over 3 Bar.
Each collection of data can have many many lines, since load(boost) and RPM are two
variables and A/F adds another.
For Example, someone with mostly stock vehicle running some 2.5 bar chipset they got off
eBay might give the following results...
Stock S4, OEM K24 turbo, Stage 1, 2.5 bar chipset (undisclosed chip), WBO2 sensor, Adj.
Fuel pressure set to 45 PSI on Stock injectors: It was a Hot Sunny day in the high 80's
and filled up on 91 octane..
Idle Startup - 13:1
Warm Idle: 14:1 varying
Moderate load .7 bar 14:1 Occilating 13.8-14.7:1 A/F
Cruise 3400RPM .6 BAR 14.5:1 - just loafing along on the highway in 5'Th gear 66 MPH
Decel .2 Bar - 16:1 "exhaust popping" noted
Accel .8 bar 13.7:1
Low Boost 1.3 bar 13:1 A/F
Mid Boost 1.8 Bar 12.8:1 A/F (accelerating in 3'rd gear from 3400-4300 RPM)
High Boost/WOT 2.2 Bar (maxed out on boost) A/F is 14:1 (punching it in 3'rd gear at
and engine starting to hesitate a bit.
High Boost and RPM accelerating - 20 PSI on guage and 5000+ RPM A/F 14:1 - engine
revvin mean (and lean)!
BTW - if you see anything like the last couple of lines of results, you are running lean
and will probably be replacing the engine soon.
I will be happy to post the results compiled in a spreadsheet once I have enough data.
[Date: Tue, 31 Aug 2010 12:13:28 -0400
From: LL - NY <larrycleung at gmail.com>
Subject: Re: [s-cars] Mileage with MTM 1+.
To: chris chambers <fastscirocco_2000 at yahoo.com>
Cc: "Bogach, Konstantine" <konstantine.bogach at credit-suisse.com>, Scar
<s-car-list at audifans.com>
I get in real "town" type driving and mixed driving what Chris gets. I "only" ever get
about 25-26 in open highway cruising, although around here, it's all hilly open highway
cruising, so I imagine that matters.
LL - NY - MRC Stg 2 if that matters, but as I recall, way back when it was stock, it did
about the same.
On Tue, Aug 31, 2010 at 11:53 AM, chris chambers < fastscirocco_2000 at yahoo.com> wrote:
> Based on my experience I'd say that's about right, alot of it depends
> on your right foot; the heavier it gets the faster you go through the
> I can get 27-28 MPG on the highway cruising at ~78mph, 3200 RPM, city
> driving it's closer to 16-18 MPG with an overall average of 23 MPG per
> tank (more highway driving than city)
> Garret 3071
> RS2 fuel injectors
> RS2 MAF
> Pastore "rs2 mix"
> 6 speed edu
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