What the topic says.

Are people tuning for partial throttle settings by a/f and butt dyno to make sure they aren't too lean? Partial throttle tuning isn't for whp so much as for good mileage, and safe settings against leanness.... right?

 

im interested in knowing peoples settings for their VAFC's also, even if they dont have the exact mods i do, i just want to make sure im not running lean or too rich. can someone take the time to post their settings and mods?

 

Since a VAFC only adjusts according to engine speed, how are you adjusting partial throttle settings (absent a DFI system)?

 

the VAFC has wide and narrow throttle settings, and has wide and narrow throttle fuel adjustments..it will adjust fuel according to how much throttle you give the car...it does this by reading the throttle ECU wire voltage.

 

I stand corrected.
As so far I'm running just a Mugen ECU (plug an play, but no adjustability other than an AEM FPR).

 

"partial throttle"? What's that?

 

That's the key to making the lumpy joy streetable..............and 34 mpg.....

 

At the speed limit, I suppose.
I've got my trip from Alexandria, VA to Youngstown, OH just about optimized.
But I can still make a lower ET if I stop for gas!

 

however, wont the ecu correct for open loop changes? whereas under WOT, changes can be made in closed loop? I might have mixed them up.

 

You're right, but I believe it will only correct if it detects too lean a condition...

 

Believe what you will but, if I take out my Partial settings, my car drives like crap and smells of raw, unburned fuel. Driveablility was acheived only through the partial settings, a must have for my city driven hatchcrap.

 

I have just changed my signature...

DV- who will be changing his username and avatar upon his arrival home

 

Hmmm, I notice a smell of raw unburnt fuel on my Hondata/P28 ecu set-up (running Toda Spec B's, pistons). I wonder if that's because my tuner hasn't done any proper partial throttle tuning? Jack, how lean are you running your car at partial throttle? My car is running around 12-13 a/f (a touch on the rich side, for safety) at WOT, but I'm not sure how rich it's running at partially throttle. Thanks for any tuning advice...

Dave


[Modified by Ddddave, 1:50 PM 9/4/2001]

 

the ecu will normally adjust only short term trim levels during closed loop operation by utilzing the 02 sensor readings and trimming accordingly...it will however store an average of these trim amounts as long term trim levels which it will also use to adjust open loop operation as well. If you are using a piggyback system like and apexi SFC then it will allow you to adjust part throttle fuel settings by tricking the ecu via false I/O pulses of various sensors (map, o2, TPS, etc) so that the ECU doesn't adjust beyond what you set the AFC to.

to answer your original question: you can tune for part throttle by driving around town (or on a dyno) at part throttle with a decent lambda meter or 4 gas analyzer, etc...so you can see what is going on. otherwise you are just guessing....

hope that helps
dave w

 

Ddddave -

Your IM feature is off, if you wish for an answer, IM me.

 

how do you partial throttle tune? do you just cruise and make adjustments from the RPM's? hmm. when at WOT i know the hondata will run in open loop, what happens when its at partial? does it switched to closed loop? From what i heard the Hondata will run 2 maps, would this be the partial throttle (closed loop) map, and the WOT (open loop) map? or is there even such a thing! haha. i did my research and found nothing.

 

I dont know much about tuning but why cant you just cruise on a dyno and do partial throttle tuning?

 

if you guys are asking this question, seriously i suggest you leave your tuning to the pro's.

playing with timing or fueling maps can be dangerous for your engine

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1SlowSi &raquo;</TD></TR><TR><TD CLASS="quote">I dont know much about tuning but why cant you just cruise on a dyno and do partial throttle tuning?</TD></TR></TABLE>

You need a specific type of dyno.

P73 = can't change partial throttle settings

 

Im not doing any of the tuning.. its just something that i would like to know. You can never know too much! LoL. but yeah ill be running the P28 ecu. What kinda of dyno would you need to use. Does anyone know if Secret Services uses that kind of Dyno?

 

Shawn Church does part throttle tuning on his Dynapack dyno. Correct part throttle tuning makes a huge difference in the drive-ability of a vehicle. One of the major advantages of the Dynapack is the ability to tune the part throttle maps. Another advantage is that the Dynapack is portable.