[s-cars] Re: Rs2 MAF and FI swap

[Pram]

Another observation Bob wrt the RS2 MAF and RS2 FI swap

Before the swap my S4 tend to take 1-1.5 sec of cranking before the
engine run.  Now (5-6 start) my S4 engine turns on almost instantly.  It
is like the MAF is responding much faster than before.

The other thing is that,  with the stock MAF and FI (w/Hoppen 3Bar PT,
RS2 turbo, RS2 IM and RS2 ex cam), there is a more off and on feel
during boost.  After the swap, the power delivery is more linear.   One
other noticeable observation is also the boost (from the stock digital
boost gauge) definitely rise faster.

I am starting to think that a lot of them are probably because my stock
MAF is starting to go to the parts "heaven".

FYI, I am using 93.5 octane gas (mix of 91 octane  CA gas and 100 octane
76 race gas)

Pram



On Friday, October 11, 2002, at 08:25 AM, Robert Pastore wrote:

> Pram:
>
> Give the ECU some time to adjust, & keep me posted!
> Bob
>
>
> -----Original Message-----
> From: Pram [mailto:pramtt at pacbell.net]
> Sent: Friday, October 11, 2002 11:23 AM
> To: Robert Pastore
> Subject: Rs2 MAF and FI
>
>
> Bob:
>
> Installed and tried the new set-up last night and this morning going to
> work.  Just like you said, the install was a breeze.
>
> The (+):  Better off boost drivability (slightly better).  No pinging at
> full boost and car seem to pull stronger.
>
> The (-):  Some hesitation at WOT before clearing up to full boost.  Also
> after going on boost then off boost and on boost again, there seem to be
> some hesitation.
>
> I might check my BPV tonite.
>
> Otherwise, I might have to go to the full Monty (with RS2 FPR and RS2
> Map)
>
> Cheers,
> Pram
>
>
>
> Just like you said, the install was a breeze.
>
> On Thursday, October 10, 2002, at 02:37 PM, Robert Pastore wrote:
>
>> Pram:
>> I only have a few minutes....
>>
>> It is easy to think of the MAF and injectors as a matched set but it is
>> technically incorrect.
>>
>> The chipset in the ecu is written for a specific hardware set.  The MAF
>> output is between o and 5.o volts, and is interpreted as a certain air
>> mass
>> by the ECU.   The rs2 MAF and the stock MAF use a different scale.
>>
>> The ECU outputs an injector duration based on the amount of air that
>> has
>> been measured.   The assumption is the FI installed and the FP
>> installed.
>> If teh MAF, FI, & FPR match the hardware set the chip was written for,
>> your
>> A/F ratio will be on the money and all will be good in the world.
>> IF you start swapping things around, only good luck will keep the car
>> running well.   That being said, the swap of the maf and FI do work in
>> opposite directions, so from my experience, you won't run terribly if
>> you
>> swap them together.
>>
>> Bob
>>
>>
>> -----Original Message-----
>> From: Pram [mailto:pramtt at pacbell.net]
>> Sent: Thursday, October 10, 2002 4:51 PM
>> To: Robert Pastore
>> Subject: Got the UPS shipment
>>
>>
>> Bob:
>>
>> Just to let you know that I received the UPS package from Northside
>> today.  Man, If I am able to get home a little earlier than usual I
>> might be able to install them tonight.
>>
>> Bob, going back to our conversation regarding my two ECUs (both for the
>> RS2 turbo, one with 2.5PT the other with 3.0PT), you mentioned that the
>> 2.5Bar PT ECU will not be ideal for the new set-up.  What I do not
>> understand is that, since both ECUs work fine at this time in my S4
>> with
>> stock injectors and stock MAF.  Why if I just changed to RS2 MAF and
>> FIs, only the ECU w/3.0PT will work while the ECU with the 2.5PT will
>> not?
>>
>> To me if the RS2MAF output match the RS2 injectors for the ECU  w/3.0PT
>> then technically it should also match my other ECU w/2.5PT or maybe my
>> theory is screwed up.
>>
>> Pram
>>
>