Rtek Stumble Elimination Stage 1.x update for S4 TII now Available
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11-05-07, 05:03 PM
#15
DONT FEED THE NOOBS
Join Date: Mar 2001
Location: land of slow hondas .... TULSA, OK
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the car is 98% better to drive but it seems like my stumble moved to 10 inches of vac on my car
. its by no means as bad but its barely barely there.. thanks for the upgrade guys how does the car know the load????
. its by no means as bad but its barely barely there.. thanks for the upgrade guys how does the car know the load????
11-20-07, 10:20 AM
#16
Full Member
Oh damn, and I was wondering where my stumble is coming from.
At the end I amplified the boost sensors signal a little ( about 0.2 - 0.3 V )
and its better now.
Also enriched the mixture a bit at 3400 rpm with my afc.
Im a bit disapointed now, that the rtek chip is the problem
but Im also glad now to know that it isnt the wiring.
I already checked all the ground points, and thought about buying a power cap
but now I know I dont have to
-Patrick
At the end I amplified the boost sensors signal a little ( about 0.2 - 0.3 V )
and its better now.
Also enriched the mixture a bit at 3400 rpm with my afc.
Im a bit disapointed now, that the rtek chip is the problem
but Im also glad now to know that it isnt the wiring.
I already checked all the ground points, and thought about buying a power cap
but now I know I dont have to
-Patrick
01-04-08, 08:23 PM
#19
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Thank You
I been driving on the update chip for a couple weeks now, and its greatness. I've had that stupid stumble since day one. After doing all the recommended grounds, injector cleaning, and adjustments, it improved but never fully went away.
Now all I can say is, greatness. If you have an S4 TII buy this chip.
Well done DTI/Rtek.
Now all I can say is, greatness. If you have an S4 TII buy this chip.
Well done DTI/Rtek.
01-05-08, 12:36 PM
#22
well i suppose it wouldnt be an actual correction %, but heres my take on it:
I believe other ems have option of the running primary injector p/w a few seconds longer after staging. so for example say you are cruising along, seccondaries off, primares at 4ms p/w. then you go wot, and staging turns on. normally, the injector p/w would simply divide into 2, so primaries get 2ms, secondaries get 2ms.
For a brief moment immediately after staging, the ECU is sending 2 ms to both sets of injectors, but due to injector inductance, wire resistance, etc, it takes a few cycles for the secondary injectors to actually start firing for the full 2ms, causing the engine to stumble, since its getting half the fuel it should. I think this is the cause of the staging hesitations everyone is seeing, especially with aftermarket low-imp injectors. By changing the staging to load-based, it improves the hesitation by delaying the staging to later in the map where longer p/w will not be affected as much by the secondary injector turn-on latency
It would be nice if you could add a "# of cycles" adjustment, so have the primaries still fire at 4ms p/w for a set # of cycles after staging (while secondaries are firing 2ms like normal) to make up for the secondary injector latency. This would give it a little extra fuel immediately after staging to eliminate any hesitations. The user could adjust the # of cycles, according to the severity of hesitation, since each setup will probably have different latency, etc
does that make sense and sound possible for rtek? I think it would cure all staging hesitations for good
I believe other ems have option of the running primary injector p/w a few seconds longer after staging. so for example say you are cruising along, seccondaries off, primares at 4ms p/w. then you go wot, and staging turns on. normally, the injector p/w would simply divide into 2, so primaries get 2ms, secondaries get 2ms.
For a brief moment immediately after staging, the ECU is sending 2 ms to both sets of injectors, but due to injector inductance, wire resistance, etc, it takes a few cycles for the secondary injectors to actually start firing for the full 2ms, causing the engine to stumble, since its getting half the fuel it should. I think this is the cause of the staging hesitations everyone is seeing, especially with aftermarket low-imp injectors. By changing the staging to load-based, it improves the hesitation by delaying the staging to later in the map where longer p/w will not be affected as much by the secondary injector turn-on latency
It would be nice if you could add a "# of cycles" adjustment, so have the primaries still fire at 4ms p/w for a set # of cycles after staging (while secondaries are firing 2ms like normal) to make up for the secondary injector latency. This would give it a little extra fuel immediately after staging to eliminate any hesitations. The user could adjust the # of cycles, according to the severity of hesitation, since each setup will probably have different latency, etc
does that make sense and sound possible for rtek? I think it would cure all staging hesitations for good
01-05-08, 03:57 PM
#23
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Megasquirt does it in that exact fasion, I would imagine other standalones work the same. It works very well in both eliminating the stumble and lean/rich fuel mixtures right at transition.
01-09-08, 03:50 PM
#24
Rotary Enthusiast
quick question to everyone who has had the chip change. before the change, did anyone experience the stumble in the 3200ish range while the car was stationary? i.e. at a stop?
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