Hi folks,
I have an AE86 with an ae111 blacktop engine in it. I'm looking for an ignition map that someone has had good results with. I won't be able to tune the car for a little while until I square away other things, but I'm driving it daily at the moment.
If you have a map you could post up, or maybe just critique mine, that would be great. Thanks!
(http://i84.photobucket.com/albums/k23/stupidbuthey/sparkmap.jpg)
Hopefully that is legible...
Also, what injector sequence are you guys using? I am currently at 4,1,2,8 on the injector output screen.
Thanks
This is AlphaN BTW.
Those numbers look high for this type of engine ,
compression ratio, 5valves,
I would have guessed at at least 5deg less in the top and scale that down to the peak torque at the bottom.
OK, found someone with an ae101 engine (smaller throttles, slightly less compression ratio) but he's running Speed Density.
Nonetheless, I tried to emulate his spar table.
Any thoughts on this one?
(http://i84.photobucket.com/albums/k23/stupidbuthey/RJinfluencedtiming.jpg)
That looks alot more like it.
Seat of the pants says I lost a fair amount o power :o
I need to re-check my base timing sync with a timing gun. I just got this car running so I might be jumping ahead of my self. Fueling is safe though. :D
Seat of the pants says I lost a fair amount o power :o
I need to re-check my base timing sync with a timing gun. I just got this car running so I might be jumping ahead of my self. Fueling is safe though. :D
Dyno tuning will tell.
And base timing has got to be spot on.
When you check timing make sure that you do it through the rev range - the trigger may retard through belt movement as RPM increases.
What do you guys think about switching to speed density? I'm not really happy with how the car is driving down low. I think the biggest issues is throttle response down low with SD? But I don't really know.
There is no such thing if you tune the accelaration enrichment right.
Connect the MAP sensor to the vacuum port on the 20v's ITBs and see what you think of the signal. If its clean enough at idle and part throttle then use SD, it doesn't tend to be stable until around 3.5K so consider AlphaN Blending.
On the ae111 engine (blacktop) I think they sorta fixed the map sensor signal flakiness. There's a pulsation dampener installed in line, which pulls from the shared mini-plenum. Anyhow, the map signal seemed stable at idle and low rpm, but was at 65kpa at idle (mostly b/c I have a small bleed line to the non-functioning IACV valve which works fine for Alpha-n).
OK, I tried SD today, car barely ran but I don't have a proper map for SD.
Also, tried alpha-n with blending on 1.44alpha....was like a joke. Set alpha-n to 2000 rpm, then SD from 2100 rpm on since the car wouldn't idle with just SD. Car would buck hard during the transition period. I feel like the blending on 1.44alpha is meant only for turbo cars with ITB's....where they would use alphaN up to a point where boost kicks in.
The only way to get proper blending with two maps like the Megasquirt guys do it is to wait for Vemstune to get the bugs ironed out? Thanks for the help so far!
Quote from: Grant on September 22, 2009, 04:10:12 PM
On the ae111 engine (blacktop) I think they sorta fixed the map sensor signal Also, tried alpha-n with blending on 1.44alpha....was like a joke. Set alpha-n to 2000 rpm, then SD from 2100 rpm on since the car wouldn't idle with just SD. Car would buck hard during the transition period. I feel like the blending on 1.44alpha is meant only for turbo cars with ITB's....where they would use alphaN up to a point where boost kicks in.
"Blending" means that you have to put rpm values the other way around. Max alpha-n rpm should be higher and min SD rpm should be lower value, this way the overlapping rpm range is the blending rpm area.
OK that makes sense. But still can't let me use SD for lower RPM and alphaN for higher RPM. This is ultimately what I'm looking for I think.
No ,
why do you think that?
Quote from: Grant on September 23, 2009, 04:53:34 AM
OK that makes sense. But still can't let me use SD for lower RPM and alphaN for higher RPM. This is ultimately what I'm looking for I think.
You want AlphaN down at low RPMs where the MAP signal is noisy, and SD further up once the pulses even out.
That is what the OEM did.(run MAP down low and TPS for the rest) I want to do the same for my alfa too.
For idle the motor has a small log plenum and works like a plenum motor down low and idle.
but as you lift off then the reading can go to hell. On my alfa spider the problem is the vents in to the ITBs from the tiny plenum get venturi like so the MAP numbers get strange depending on how the air flow is going past the vent. one moment it can be blowing in the vent giving more PSI then is, there then the next change to a venturi where the PSI is much lower then real.
I could and did run MAP on the spider. but the maps had a lot of ups and downs. And the EGO worked overtime. I put the vents in the best place I could. I placed notches in line with the shaft of the butterfly. where the air speed is the slowest. The stock ports for idle bypass where the worst as there were right on the out side and had big time venturi affects.
I am guessing the 20V may have the same problems. but getting good MAP on idle is very easy on a ITB car. you just need the idle plenum and take the reading from there. The idle plenum is also what keeps the balance as the butterfly's never seal the same when all the way closed. even the smallest of scratches makes a big difference then.
I hvae run a blacktop on pure map,
And the only problem i had was if was was going to hold a high speed with partial throttle, that was fixed with running a very fast ego corretion, as it had to lean out fast, otherwise it would make a bug as it would run really rich lambda 0.7
The take of was the oe take of to the map sensor ,and the is normal engine vakuum, no problem at all..
/Skassa
AlphaN blending uses TPS at low RPM and MAP at high:
http://www.vems.hu/wiki/index.php?page=GenBoard/UnderDevelopment/AlphaN
When I did the mapping on a 20V I used SD because of the plenum signal - but it was poor in two areas: the difference between 1% and say 5% TPS opening was vast, and the difference between 75% and 100% was a few kpa, but I got it evened out okay using very small steps from 95kpa, fuelling from closed throttle was always a pain though.
The professional calibrator (who works for an OEM) who then mapped the car, put it onto AlphaN blending and got a spot on map that's in use on about 5 different cars used for drift and road driving - which is why I recommended it.
This is the reason that many OEMs use MAFs - they meter the airflow regardless of throttle type, and use the TPS for acceleration enrichment.
They say that we can technically use MAFs on this system by replacing the TPS input with the MAF output - I've never seen it done though.
OK, so the guy you know overcame the issue you had with small throttle openings by using alphaN @ small TPS, and switching to map above there and it seemed to work?
What RPM do you recommend I switchover from AlphaN to SD?
Also,
1. Do you have any idea what I might be having trouble with getting fuel cut to come on full time? Under what seem like the same conditions (similar RPM, CLT temp, MAT, and 0 TPS) fuel cut will happen 1/4 of the time or so, and the rest of the time it will not. I've been fiddling with megatune for a while now and am stumped. Maybe it's a bug from using strictly alpha-n?
2. Any idea why when I sloooowly tip in the throttle at low-load, lower RPM (3% tps, 2500 rpm) I keep getting spikes of extra fuel, before EGO leans out to the desired lambda? MAT % is like 0-1% extra enrichment, Accel enrichment is nearly nothing in the first few default DV/DT bins.
Thanks for any help ;D
The answer for all of this can be found in the maps, PM IrishTwinCam on here, he's got all this info stored away he's a walking reference for all 4A-GE related info.
IIRC the blend point was around 3500rpm for alphaN and 2500rpm for SD.
As for fuelling - what firmware is this on again? I think you'd really benefit from the newer ones with dTPSvsRPM mapping
If you have pulsation in the map signal then you´ll need to dampen that.
Especially if you have good pressure readings at low throttle angle. Then you should have the same at higher throttle angle.
If not then putting in a damper as can be found in most aftermarket boost controllers should dampen the signal.
The place where all the ITB´s connect together and then to the ecu, this is where you can redesign it´s size to create a smoother signal.
I´d rather go Alpha-N with map compensation , and the reading for the map would be infront of the itb´s.
Ok Rob, I'll be sure to PM him.
For blending...I'm a bit confused, since there is only one map to reference from, how do you figure out what values to input if KPA was a reading for TPS position below 2500, but becomes actual vacuum above 3500? How would you map out 3000 rpm if the two load designations are conflicting?
Is there a way to have two separate maps to reference from that I'm not seeing or something?
This is on 1.1.44alpha2, but I'm OK with upgrading to anything that is stable. Daily driver at college ATM.
Gunni,
When you say AlphaN with map compensation, that's what we're talking about as well right? AlphaN below a certain rpm, then SD above it?
PS, map readings are fine on this engine, it's a factory ITB engine so they did their homework. Seems stable at most RPMs. The trouble is, as Rob mentioned, The map readings are usually very high or very low, not linear at all.
No what I´m talking about it using Alpha-N only for all the fuel.
But then adjust for any ram-air effects or different atmospheric pressure by measuring the pressure infront of the ITB´s runner.
If you have a smooth map signal all around , then you can adjust the scaling so that the trouble area has better resolution
say
Kpa axis , 20,40,45,50,55,60,65,70,75,80,90,100
But hybrid alpha-n is probably the best solution though. , Low rpm is alpha-n and low intake pressure, higher rpm´s and higher intake pressures where they are stable you run MAP.