tonyzS/C03

iTrader: (3)

I thought that this was going to answer all of my questions, but alas it didnt, it did however answer a lot. i think that this threat would also benefit from ppl posting up what timing they are running at a given RPM but also throwing in there what load cells they are in. I am trying to self tune my own car right now, i've had a nightmare thus far with my build but that is a whole different thread haha.

Last night I sat down with a good friend of mine that tunes a lot of EVO's and we talked timing at length. now you Vet's by all means and jump in if i'm wrong, but on my car for instance my high load cells (13psi is my peek boost right now) leading up to peek boost and TQ are in the neighborhood of 11* to 14* on the way up peeking at 3500 RPM and 13PSI of about 5* or 6* of timing. After that as I continue up through the RPM's load should in theory start to drop off because MBT has been achieved, so my map is now retarding timing back down to about 23* to 24*. Am I understanding this right?

I would love to see this become a sticky as well, and I am more than willing to share my maps with everyone, the only down side is that I'm tuning with Hydra, not the most popular of tuning solutions lol.

rcdash

iTrader: (18)

5 to 6 degrees is retarded, not advanced. You will go up to about 17 degrees at redline if you are around 11 to 14 at peak tq for MBT. The higher the #, the more spark advance (the earlier before top dead center the plug fires). Retarded timing is later (fewer degrees before TDC).

tonyzS/C03

iTrader: (3)

ok this makes more sense, thanks for setting me straight

bealljk

iTrader: (13)

I'll start by saying I have zero experience dyno tuning (looking to dyno tune this late winter/early spring) and some street fuel tuning and no street ign timing tuning ... how I understand ignition timing in a nut-shell ... you increase timing until your torque output (from the dyno) peaks. after it peaks back it off a degree or two and move on to the next cell(MBT limited). Or if you are seeing knock, stop there and back it off a few degrees(knock limited) and move to the next cell.

I think it's a common practice to gently increase timing until you pickup knock/ping on the engine - what if youre picking up knock after MBT - you've past your max output and you're putting your engine in jeopardy? I think it's true that each cylinders knock point is slightly different than the others (but, yeah, find knock and back it off a few degrees to account for those inconsistencies).

if you're getting knock while shifting (on the street) wouldnt that be an indication of a lean condition or too much timing? wouldnt that indicate a bad value in accel/decell ignition adjust (or applicable compensation table)?

Probably wouldnt show up on a dyno, but if you're adjusting your main ignition table to account for this decel (and not in a compensation table) are you shooting yourself in the foot but curing the symptom and not the root?

Indeed, a dyno cant replicate every single real-world condition ... a good tuner will dyno tune you and then verify their work on the street.

Many people drag-strip tune their cars. (Solely in my opinion) a trap speed, ET time, or speed doesnt provide enough resolution or consistency and introduces an uncomfortable (IMO) amount of risk to the engine. Just my opinion ... it looks like it's worked out for you though

binder

iTrader: (8)

As a basic sense if knock is detected definitely reduce. It is fuel dependent. Pump gas will be limited by knock. On boosted applications just the single instance of knock COULD ruin the engine. Built engines less likely, stock highly likely. So it's dangerous just to tune using that. Most of the time per given engine there have been enough ppl tuning to know a ballpark of where to stop and save yourself some grief.

I'm not sure most tuners "tune up to the point of knock" as much as they know what a stock block can handle, built block, etc. If there is any instance of knock a tuner will definitely reduce timing at that point. I would never purposely keep adding power until I get knock on a car I'm tuning.

On any engine decel there won't be knock. When the throttle closes and power shuts down the engine isn't producing power therefore no knock. There often is noise picked up by the knock sensor but that's not knock. There has to be fuel to ignite to cause knock and when you back off throttle the fuel injectors close which means no fuel. Wouldn't show on the dyno because the power/torque curves would be in a straight down line as power drops.

Now, if you are talking about knock that occurs between shifts it most likely is AFTER the shift when power is applied again. As boost comes back in from a shift the rpms are in a lower range of timing cell with still a good amount of boost. If those cells aren't properly tuned you can get knock. No special tables or anything need adjusted. Just the timing cell that gets recorded just post shift. Many dynos can be used to tune this. You just need a load based dyno like dynojet with eddy current rollers, dynodynamics, or a mustang with eddie current. That allows the engine to be loaded and produce boost and hold it at each cell. Much safer than street tuning although logging the streeth then adjusting later works as well.

This could also be the transient lean condition of a shift. The tuner would have to look at everything logged when that condition occurred. If the fuel is lean at that point I would start with adding fuel before pulling timing. If the timing is higher and fuel is still safe range then pull timing in that cell. This can be adjusted as an overall on the transient throttle enrichment (for haltech). If it's only at 1 cell or only on a 2-3 shift verses after every shift then I would just tune the individual cells and leave the transient enrichment alone. Either adjustment would only work if it's a fuel issue causing the knock and not timing issue.

The good dynos can come very close. Usually street driving afterwards is to adjust smooth application verses actual power portion of the map.

bealljk

iTrader: (13)

I appreciate the time spent on the explanation and the nuggets of information

MicVelo

Word.

CK_32

iTrader: (1)

This just sounds like a bad idea. They have things like this on gun forums of people who do the proper work up, and work up their loads of gun powder in safe ranges to not explode your gun and face.

But since they started making "what's your load threads" people come in and copy cat loads with out going to the pursuit safely. Ending in their guns exploding or just gettinglucky and skipping the process because they are lazy and cheap.

I can see the same thing now, especially with all the kids that come in and want power but can't even open google.

It's awesome in theory, but in reality it's going to blow so many motors because people are going to plug in a 600hp power timing map, then wonder why their NA motor gave out.

bealljk

iTrader: (13)

I whole-heartily agree with this ...

I try to stay out of peoples business and if others want to road tune their ignition - more power (ha!!! get it) to them ... to each their own

I have the upmost respect for Oldman and he's doing something right (something tells me he's got a wealth of experience he's leaning on) but when people tell me they (or suggest I) road tune my ignition I smile and keep them at an arms length.

BluestreamDE

Just street tuned today. Now running 19° no knock all the way to 7100rpm from the previous 17°, .75 to .76 lambda.

Definitely smiled today. Car pulls alot harder now than it did before.

If you don't know what you are doing, then yes you deserve to blow up your motor. Copying another person's map to put on your own car is also very idiotic. That's why with street tuning, make small changes to the tune only, and you constantly need to review your data logs and watch for knock. If people are that dumb to not take the proper precautions, not reading up on basic tuning books and just changing what ever the hell they wanted without researching what each part of the map does and it's effects, they deserve what's coming to them. Let nature take its course and weed then out.