DallasN20

99 EX coupe, d16z6 block, stock y8 head, vitara pistons, rc autoworks custom length rods, 75.5 bore, y8 head gasket, arp studs, acl bearings, 255 walbro, 450cc DSM blue tops, t3/t4 57 trim egay turbo, go autoworks ac friendly manifold, go autoworks 2.5" ac friendly downpipe, tial 38mm wg, no exhaust, p28 ecu with ostrich 2.0 and crome tuning software, innovate wideband, 93 octane pump, base timing set to mark on cover.

Yes I am looking for a dyno tuner in my area, I'm not trying to hit the track on a basemap. I am just wanting to learn more and get some feedback from you guys on the map I'm running on until it gets tuned. My main weakness is in the ignition timing. Is there a general rule of thumb on how much timing should be removed per psi given a certain set of parameters? Any input is welcomed. Thanks to all.

LOW CAM FUEL:

HIGH CAM FUEL:

LOW CAM IGNITION:

HIGH CAM IGNITION:

2x0

It's a base map so you shouldn't be in boost.

1 degree retard per psi.

theYBLEGAL

You sound like you are learning well. This should help your quest!

How to listen to your knock sensor to listen for REAL vs FAKE knock - K20A.org .:. The K Series Source . Honda / Acura K20a k24a Engine Forum

I use the microphone input on my laptop to record the knock sensor. And use audacity to play it back slow.

DallasN20

Correct me if I am wrong but is there a knock sensor on OBDI conversion? I'm pretty sure I remember ziptying that thing out of the way..? That is an interesting method though. My biggest confusion is the number in those timing cels. For instance, what is the difference between 42 and -6.5? From the color of the cels and my common sense it appears that the lower the number, the safer ie. the more retarded the timing is? So if a cel says 23 does that mean its 23 degrees of timing so in other words if your base timing is 14 then the actual number is 9?

2x0

The number in the cell is the degree of base timing advance, how many degrees BTDC the spark will ignite. Lower number does mean safer to an extent. There is obviously a limit to how low you can set your timing before there is no usable combustion and it will spit flames out the exhaust.

You need to make sure your base timing is set correctly at the distributor to 16 degrees without the ecu compensation. Use a timing light and the proper procedure, otherwise it will offset your entire timing table.

Then there are all the timing compensation parameters, but usually you don't need to mess with those.

theYBLEGAL

Lower timing is not safer. Richer fueling is not safer. I've learned this after years of tuning now. The spark timing needs to be right on point. There's a couple degrees of leeway both ways but essentially, 5-10 deg too retarded or too advanced will both produce detonation. Being too rich exacerbates the problem by leaving unburned fuel in the cylinder, further causing detonation.

You should shoot to make power at stoich, aka 14.7:1 air fuel ratio. The reason to run a little rich is to remove heat from the cylinder. But you can't leave too much extra fuel in the cylinder.

You need to ignite the mixture in the cylinder at the right time, so the expansion of gases create the forces on the Piston and rod stroke at the right angle for the least amount of rotation resistance, while also burning the entire mixture.

Put your knock sensor back in. It is invaluable to you; albeit not your ECU.

2x0

We're talking about a base map here. Something to make the car driveable to a tuner. The timing does not need to be "spot on".

Just use stock timing in the vacuum table, and in boost retard by 1 degree per psi. Then go get tuned.

DallasN20

Great info guys! To be clear I'm not asking how to make my car make 500 hp on a basemap, I know its purpose is to make the car driveable to get to the tuner. I guess I'm really just looking at it from the dyno tuner's perspective and wondering what is going through his mind while he tunes the car. The theory of it all really. I know basic mechanics and how a piston engine makes power by igniting an air/fuel mixture at the correct time at the correct ratio to produce an efficient explosion. I've just never seen in actually graphed in a numbered format until I started messing around with Crome. I find it fascinating how a piece of software can modify so many characteristics of an engine. I have read every word on Xenocron's site and every post I can locate on Crome software but I wanted to get some input from you guys, the soldiers in the trenches so-to-speak. I'm beginning to discover though that Crome has gone the way of the dinosaurs unfortunately. Every tuner I have emailed or spoken to has decline to tune with it. I bought the Hondata s300 yesterday per their recommendations and have an appointment with the dyno this weekend. Fingers crossed! Off topic a little but what are your guys' thoughts on the head torque at higher boost levels? I have read that anything above ~15 psi its a good idea to torque the head to about 85 lbs/in?

2x0

No. Torque to their specs. If using OEM studs, use OEM torque spec. If using ARP studs, which I would recommend at that level, then torque to the ARP specs.

Here's a thread on head torquing.

HOW TO REALLY TORQUE ARP HEAD STUDS!!! Straight from ARP - D-series.org



As for how the tuner approaches timing on a boosted car, they will probably start with very conservative timing such at 1 degree retard per psi. Then slightly increase with each pull once the AFR is set correctly, until the maximum torque no longer increases. Then they will back the timing down slightly for factor of safety.

This method tells you when you have timing set to the most efficient combustion for the stroke of the cylinder.

However this is only when you want to make maximum power. For budget builds, I've just left it at 0.75 to 1 degree retard per psi and ran cars that way for years with no problems and making plenty of power. Just depends on your power vs. reliability goals.

I used to use Crome and Uberdata probably 10-12 years ago when street tuning on a budget. Unfortunately yeah, you've gotta pay to get any kind of supported software nowadays.