Getting the most out of your Apexi S-AFC= Stock MAF honeycomb removal

[Innovator]

Originally posted by SpyderVR4
For some reason the honeycombs are lightly glued on on some MAF. I've got 2 MAFs, one of them you can clearly feel and see the glue, and the other no glue what so ever. Any case, you can still push them out without damaging them even when they are glued on.

I took some folded tissue paper (cloth would work just as well) and a pen. Put the paper in first, and then push all around the edges gently with the pen. After you feel the honeycomb start to move, exert more force and it'll pop out.

BTW, my SAFC is also at somewhere around -15 right now with 550cc, O2 at WOT is around .94 to .96. Good to see we are all close.

So what are your impressions of the gutted MAF? Also, are you -15 on the high settings? If so, you need to be leaner .

-15 works well on the low setting across the board, except for idle 100 rpm setting) where + 4 to +8 seems to work best.

[Eric_VR-4]

Originally posted by Innovator
Don't tune the car so it has no knock. That will make your car slow, and it won't last any longer, providing the knock is light.

what is a little versus too much?.. right now I run between 2 and 6 but I haven't finished fine tuning (still rich).. and now I'll have to start over anyhow when I gut the honey's ....( hmmm that pun sounds a little scary)

[BlackStealth]

I made a mistake in my earlier post. Somehow I managed to look at my MAFT+LS6 log instead of the gutted MAF. My O2 readings were .94 and .92 at 5000 rpms. Updated signature is done. The AFC settings will surely change as I've only spent 30 mins tuning and an hour of driving/testing. So far the car seems to respond really well.

[Innovator]

Originally posted by Eric_VR-4


what is a little versus too much?.. right now I run between 2 and 6 but I haven't finished fine tuning (still rich).. and now I'll have to start over anyhow when I gut the honey's ....( hmmm that pun sounds a little scary)

I don't hold much faith in the knock sum numbers. The sampling rate on the logger is too slow to really tell you much IMO. I think these Knock sums may be giving people the ‘Chicken Little’ complex. After all, the ECU knows how to deal with these sums to a large extent.


It takes a lot more than a little knock to be of any harm. Many car manufactures write in the user manual that *audible* knock is normal. While I wouldn't want to give that advice to anyone, I still think that the knock counts tell you very little.

Better to use a WB02 and an EGT gauge. This is just my opinion though.. Don't blame me if your engine blows, but if it does, it will most likely be a rod bearing that goes from making to much power or low oil pressure, and not a piston from detonation unless you are very lean or running too much boost. I really don't think knock is as big an issue on second gen cars. First gens are a little more prone to it, so I'd just reduce the base timing a few degrees to be safe. You can't adjust the base timing on a second gen. From what I can tell, the second gen ECU does a very good job of suppressing knock by dumping fuel when required. If you have an EGT gauge, you'd see a sharp spike in the temp, and it would not climb smoothly to 900c as it should. Knocking usually will result in high fast climbing EGTs.

Keep in mind that on my 95 VR4, I can't really monitor knock, and I've put 28,000 hard ass miles on it running it leaner than most guys would. I've had many online arguments with peeps on this forum about it. The fact is my car runs better than ever, and burns not a drop of oil, nor does it blow any out of the crankcase, so the rings are perfect.

Here is my advice. USE A WIDEBAND TO TUNE A/F


Run no more than 16 psi to redline, use premium gas, use OE laser platinum plugs(yea, the stock heat range) , and always keep the air fuel ratio at 11.5:1 at WOT over 4500 rpm's, and your engine will be happy as mine is. There is no reason why knock should be an issue.

If you run race fuel, you can raise the boost, and at that point a colder plug wouldn't hurt. The Laser Plat plugs are FLAT OUT the best plug on the market. I find the stock plugs work best for me, but that me.....

Other add on knock suppressants, like WI can only help, and you can get away with running a tad leaner with it, which will give you a little more HP and a little less knock at the same time.

[Bluv69k]

Originally posted by Innovator


They aren't glued in any MAF. Some are just stuck in mopre than others with residue.

Use some denatured alcohol to soften the deposits, and tap them out with a smooth blunt object. The back of a screw driver works for me

Dude, the inside corners are glued. Mine where. Trim 1/4 in from the lenghth of a credit card and push it in along the inside edge. When it's out bend the fins back

[Innovator]

Well, I could be wrong about that then...doood

[boostedVR4]

My combs were glued very slightly. Nothing a little alchy and the back of a screw driver didn't take care of.

I have Denso 550cc injectors, Supra pump (hotwired) and the IPO dual feed fuel system. Right now, my AFC is set to around the -36 to the -37 range.

I have looked back on quite a few logs, and noticed one major detail about my knock. It ALWAYS, (and I mean always) starts at 33 degrees TA. I'de never really paid alot of attention to my timing before, now I am. Every single run, 02's are at .94 -.96, duel, all the way up to about 5k. My timing starts at about 18, then goes up. When it hits 33, (and this is each and every time) I get knock. Then down comes the timing. I'm talking knock over 10. You can see my log up a few posts. The only way I can stop the knock is to add fuel, which runs it rich.

So how can I stop the ECU from advancing the timing so much?? My base timing is right where it should be. I'm going to try this gutted MAF trick, mainly for the added flow/spool up. But if it lowers my timing enough to get it to stay below 33, that would be perfect.

I still don't see how this is going to effect the timing at all, but I'll try anything for fun.

[TurboBob]

If your trims wind up at the same value, your timing will be the same.

The ECU does not know how many screens are in the MAF or how the AFC is configured, it just takes airflow and turns it into injector pulsewidth based on its programming and calibration.

That said, my testing has indicated that the High trim is included in the WOT injector pulsewidth calculation, but not the timing calculation. So, tune the AFC or Translator so your High trim is on the high side (110-120), and then re-tune your WOT fuel. This will reduce your WOT timing somewhat. Although I don't know how much.

That said, tuning the trims high like this makes my car run a bit funky. The ECU will set the O2 trim to 79 at times. I believe this is some kind of diagnostic function. Tuning the trims low (80's) makes this less noticable.

Bob

How do you like those Denso's?

[John Monnin]

Has anyone considered a Greddy E-manage,

For about $150 more than a SAFC you can adjust your timing too. The problem is I do not know of any 3S owner using the timing feature yet, and its the reason I am considering a E-manage.

[boostedVR4]

I've also been thinking about using the Haltech standalone, simply because its cheaper than the EMS. But, I don't know of any other 3S using it. I DO know that its been on several 8,9 and 10 second cars.