From knowing nothing to having a Thunderbird supercharger on an m20b27i

[Ether-D]

Yep got a lc-2.

[george graves]

What are you measuring AFR' on? When tuning, richer is better. Unless your soooo rich that you have gas going into your oil, but I doubt that you have that going on - BMW piston rings are much better then most. So not at lot of blowby. Did you get a wideband?

[Ether-D]

When stone cold, it starts out idling at 10.9 then you can watch it step up as it warms up. 11.2, 11.4-5, 11.7-9, 12.2-3, then leveled out at 12.6ish.

Now, I did tell the megasquirt that it has 33# injectors instead of 36# which is what these are called. I can see that making it run a bit rich as the ecu tells them to pulse a bit longer than they should because it thinks they are smaller than they (maybe) are. But that's no big deal. A little rich is fine for now. I also heard a small amount of pinging going uphill at low rpm a couple times, but that could partly be the regular gas that's still in it. So any real world experience and/or tips for getting her dialed in are very appreciated. Even little things. Thanks fellers.

Anyone know how to get my idle to go down a bit? How to mess with the idle PWM settings or what those numbers mean?

[ak-]

Cold start, the car should idle a little rich around 11 to 12.
Once getting up to proper temps it should bounce from 14 to 15 and back.

[Victell]

Awesome. Congrats on the progress so far.

[Ether-D]

Also, it's idling at about 1400rpm. I looked at the idle window in tuner studio but I couldn't make heads or tails of the numbers to enter. Just sitting there idling at 1400 and warmed up, it is at 12.5 AFR. Is that in the ballpark? I really have no practical experience with AFRs and such.

[ak-]

If you're cruising without load, hitting 16 won't damage anything.
12-13 on mild boost is alright, but obviously nothing is ideal yet.

[Ether-D]

It was super brief, but I saw it a couple of times. Not under a load, I feel like it was part throttle 2000ish rpm. Most of the time it was in the 12-13ish range.

[LJ851]

That is WAY lean, do not drive it like that !

I would want to be under 13 when you are boosting, at least.

[Ether-D]

So I took her for a short spin. Feels right peppy, but I was pretty easy on it. I saw AFRs in the upper 16s a couple times. What amount of swing is normal on AFRs? I also saw 7psi on the little vac/psi gauge I had on the manifold. So kinda right where I wanted it at first. I'm stoked. Thankyou R3V!!!!

[LJ851]

I'll just put this here.

https://www.facebook.com/photo.php?v...type=2&theater

Oh yes.

[Ether-D]

I'll just put this here.

https://www.facebook.com/photo.php?v=752225021457166&set=vb.100000090243381&type=2&theater

[Ether-D]

It's alive again. Only this time it revs and makes really sweet sounds. I'll elaborate more when I get back home.

[The Dark Side of Will]

That's what I'm talking bout LJ. Aaaaaand I got a set of 33lbers at the yard today for $8. Hells yes! For anyone who wants to know, all of those late 90's supercharged 3800 gm motors have 33lbers in em. I've read that they are 36# and I've read that they are 33# so I'm going with the lower number to be safe.

Be careful with those... modern ethanol gas is a lot more likely to cause injectors to stick as it evaporates than older non-ethanol gas.

Also, you can have those injectors cleaned and flow tested for $15-20 each if you look around. That will give you the exact flow constant to use in MS and make tuning a bit easier. It still won't give you dead time, but I bet there are MS guys who've used those injectors and may be able to help you out with their deadtime numbers.

[LJ851]

Keep an eye on your wideband AFRs. With a conservative timing map and AFRs that stay on the rich side you should be good. Avoid the temptation to apply large throttle openings with lean AFRs no matter how good it feels !