Alpha N Kit

[ffonseca]

Hello Jeroen,

Because I'm thinking of giving some vitamins to my 320is, I am thinking of ordering a Alpha N Basic Kit from the E30 Shop in Germany.
Do you Know if the kit setting is a straight forward job?
Is it really worth the price?
Haven't seen anywhere written of how many horse power is it really worth, nor if it's a good torque improvement.

I have read the installation procedure and it seem's easy, what worries me is the tunning afterwords......

Any coments on this will be much apriciated.

Thanks & Regards
Frederico

[france320isco]

I have recently tryed my own 'AFM terminator' kit (100€), with some entusiastic results at high rpms but that suggest a more advanced study at low rpms.

I will take advantages of the alfa N only when my AFM will pass out, in the meantime i'll continue my kit study, just for fun.

I've seen on the web also procedures to 'bypass' the AFM.
I really dont like it for a lot of reasons.

To let more air comes in an engine you have to modify the throttlebodies and what follows.

In my opinion an alfa N kit surely does the job, but the HPgain/(COST+TUNING and POST PROCESSING) ratio is way too low.

For the 'AFM pressure-killer' contest, be aware of the fact that the porsche 944 turbo (2.5-2.7cc) has the same 320is AFM dimentions, with only a different volt output.

[Jeroen]

The AFM is somewhat restictive but I think the data provided by the AFM is the biggest limitation (combined with the Motronic). Alpha-N is more versatile and flexible and can be programmed by yourself to your own wishes and using your own laptop. It should be clear that process will take quite some time.

If you want to do it right, install a lambda probe in the X-flow section of your exhaust and connect an air/fuel ratio meter so you are able to monitor that during driving, and under every possible condition.

Even though I'm not planning to fit Alpha-N in the near future, I'm also thinking about fitting an air/fuel ratio meter.

On some other forums (especially the English ones) you might see some posts by Adwo. He lives not too far from here and he has done a lot of mods to his M3 (camshafts, carbon airbox, Alpha-N to name but a few)... his car performs very good and he has done all the programming himself... he will be the first one to admit it takes time.

[ffonseca]

Thanks a lot for the info!

After reading somewhat about this device, I think i don't have the necessary knowladge to set and tune the alpha n kit properly.

So for now i will stick with a pair of camshafts from www.catcams.be (the less agressive ones in order to keep an sustainable idle) as well as a fuel pressure from the E30 shop and a proper tunning chip to make it all work.

Please tell me if you have any thought on these changes or if there is something of these changes i shouldn't do!

Regards
Frederico

[Jeroen]

Frederico,

Faster cams are ok, but don't expect them to perform miracles. If you really want to make a big jump in power you have to combine that with a carbon airbox and Alpha-N.

I'm not sure about the power boost valve or fuel pressure valve. Haven't seen it in real life too often and I have no experience with it. But I believe air supply is more a problem than fuel supply so again, expect no miracles.

And with different cams and a different fuel supply you gotta have a custom made chip... so have one designed on a dyno, specifically for your cars' setup.

All together I expect a very expensive gain of max 15-20 horses.

I'd rather go for a kit from KK (see www.kk-automobile.de ) consisting of two 290 degree cams, adjustable cam gear, Alpha N, carbon airbox & adjustments. That 3.500 EUR will give you an extra 35 HP and a considerable amount of extra torque as well. It's simple... extra horses don't come cheap.

[niall]

i dont usually stray into the s14 stuff
i just thought id comment on the
power boost valve/ fuel pressure regulator
i have heard alot of stories from my
friends who have bought these and ended up going back to
the standard pressure regulator, dont confuse
fuel pressure with fuel volume , even with
the modifications you have listed you may not need
any fuel changes except for the chip of course

[hardtailer]

the adjustable fuel pressure regulator is of no benefit compared to the stock one as the stock one already adjusts for intake air pressure (that's what the thin hose is for).

running your injectors at a higher pressure just messes up your fuel mixture. You'll be too rich at wide open throttle, as the motronic is fuelling to achieve maximum power anyway and it does so thinking the fuel pressure is 3 bar over intake air pressure.

tha fact that it adjust for increases in intake air pressure 1.7 times quicker is not worth the money IMO.
Let's say teh stock fuel pressure regulator takes 0.5 of a second to react when throttle goes from idle to wide open (and it will be way quicker than that) than the adjustable FRP will take 0.5s/1.7=0.3 s. Wow 0.2 of a second quicker! Doing the same calculation and taking a more realistic (estimated guess) 0.1 of a second for the stock FRP gives you a difference of 0.04 seconds...
It would spend that money on having the fuel pressure checked (best during a test drive where woWOT and high revs are reached) and the injectors cleaned and checked.

[france320isco]

does someone here has some dyno tests for comparison before/after A-N or similar kits?

[france320isco]

My engine was replaced on 3-1-2006 after a major damage caused by a throttle valve screw sucked in the CC while driving.
The new engine has less kmters than the older one.

Now i have tested an alpha n system based on an M3 e46 potentiometer and a 320i Air Temperature Sensor plus an eprom of mine that i specifically tuned to make the engine goes.
After the street tuning operations i finally had a dyno test on friday.

They have mistaken the wheel profile while tuning the test bench so the max HP is 150cv, but don't worry my car is OK.

Here is the car with the standard AFM and the stock FPR:



And here is the car with the alpha N, adjustable FPR set to 5 bar



The wave effect at low RPM in the stock configuration is caused by the AFM rotating blade, swinging accordingly to the air intake variations and giving a fluctuating injection signal to the ECU.
On the contrary, with the potentiometer (alpha n system) the signal is very smoothed and so the injection.

[Jeroen]

That was a case of very bad luck Francesco! I'm glad things are working fine now. Even though I'm absolutely sure the less restrictive and more advance Alpha-N system works better, the readings you got with stock AFM are not ok. Maybe AFM spring tension was not right. I definitely have to do a dyno test myself!

[france320isco]

That was a case of very bad luck Francesco! I'm glad things are working fine now. Even though I'm absolutely sure the less restrictive and more advance Alpha-N system works better, the readings you got with stock AFM are not ok. Maybe AFM spring tension was not right. I definitely have to do a dyno test myself!

Maybe you are talking about the M.A. alpha n kit with the programmable module.
They talk about dyno tests on s14. net that prove +5cv on M3 b23 engine with the M.A. kit.
I dont believe others saying +20cv gain only with an alpha N system without heavy engine works.

I dont like that M.A. kit cause you can't work on the ignition advance via laptop but only on the injection timing.
And more air = quicker combustion = less advance.

You're absolutely right about the possible spring issue, but the AFM used in the test was a sealed brand new AFM taken out my friend's car.

Waiting very badly your dyno test but i'm almost sure that you will see fluctuating torque/power cause you can't phisycally get a spring to stuck inside an airflow .
It will be interesting to compare the fluctuation path.

byebye

[hardtailer]

"The wave effect at low RPM in the stock configuration is caused by the AFM rotating blade, swinging accordingly to the air intake variations and giving a fluctuating injection signal to the ECU. "

This wave effect is there all the way through the entire rev band, not only at low revs, but that aside, the cause is not the air intake variations that would cause the flap to swing.
With every revolution of the crank shaft there's one (and only one) cylinder sucking in fresh air. That means that the lowest frequency at which this happens is (idle rpm)/60 (sec/min) to get frequency in Hz: 880/60=15Hz and the highest 8000/60=133Hz. Since the AFM can only follow alterations in air flow up to a frequency of ~10 Hz (BOSCH literature) there is just no way that those waves are caused by the flap and spring in the AFM. Not in a correclty working AFM anyway. On a side note the AFm has a dampening chamber as well to reduce overswing.

I did some logging of the AFM-signal and it does indeed vary a little at idle (you can see the wiper oscilate a idle if you tkae the black cap off the AFM) but as soon as you step on it and have WOT the signal steadily increases to something like 4.8V.

THere must be a different reason for this behaviour.

[france320isco]

Thank you for your comment.

In point of fact AFTER having got a better look to the chart i realized that it couldn't be some air pulse (the frequency is way too low).

I'd rather think to the AFM failure like jeroen said.

The spring-flap system is a 2° order system so the response to a rising input is obviously a rising oscillation.
But again those swings should die proportionally to the system time constant that i don't know (also i don't think that the stifness of the spring is costant).

In other words the effect should be over due to the fact that the more you open the flap the more force you have to apply to open it and the more the spring action keeps it steady.

[france320isco]

It is common that they say that to run some kind of alpha n system you have to increase to 5 bar the fuel pressure.

I was also sure about that.

But now i realized that the 5 bar issue is because their map is all wrong. It is possible to tune the map to go with the stock fuel pressure and the engine sounds real better. That's what i have done in the past few days.

No discoloration due to excessive leaning of the mixture can be observed on the spark plugs.