How rich it too rich?
 

First off I'm sorry but I have no idea how to post up data logs but I'll be very specific. Starting at 3843 rpm, 226 load I am getting 2 counts of knock. Knock persists to 5093 rpm at 216 load, at least one count but mostly two. Timing is 3 to 4 degrees during the entire knock so I don't suspect too much timing. AFR is 11 - 11.2 the whole way which I know is too rich(12.5 during spool up mid eleven during peak tapering to 11 at red line, right?) but could this be causing the knock? Mods are in the sig, 91 octane, 5800 ft. elevation at 21 - 21.7 psi. I know the fuel is crap but it is all I can get on a daily basis. Any help, input or suggestions would be great, thanks guys.:beer:

It's a bit rich, but I don't think enough so to be causing knock. Would be easier to diagnose if you could upload the whole log, or at least an image of the problem area.

There are a couple of ways you can post up your log.

Firstly, take a screenshot of the area you want to upload with the printscreen key on your keyboard. Open up MS Paint and hit ctrl + v to paste the image on your canvas. Crop out whatever you don't want to include in your image, and save it (as a .png, not .bmp or .jpg). Then go to http://imageshack.us/ and upload your image. Paste in the code it gives you for forums, and your image will appear here. This works well for posting small areas of a log that can fit in one screenshot.

if you want to upload the whole log, put the file(s) you want to uplaod in a .zip archive scroll down to the "Attach Files" section when you're replying to a post or starting a thread. Browse to the archive you want to upload, select it and it will be attached with your post. Other members will then be able to view it.

I don't think this is too rich. Are you knocking every pull at the same RPMs ?

Also you can run rich and don't knock. Just pull 1 degree and see what happens. My car was tuned with incorrect Injectors settings, and Im very rich on spool up mid 10s, and I don't knock.

Thank you sir, ill try to get the log up, I'm perplexed timing isn't causing it, afr isnt then what? Just the low octane fuel?

Not every pull, am I being too careful? I just want to up the boost to around 23psi but make sure im not gonna blow anything up, its my dd.

Get the log uploaded and I'm almost certain someone will be able to find what is causing your knock :)

If your car is normally aspirated then it is too rich but for a turbo car on pump that is not too rich.

What is your timing at peak torque? If it is 3, it could be too much.

really? the screenname and avatar didn't give it away that he was turbo'd?lol Just playin'.

I've tuned anywhere from 10.8 to 11.5 with almost no real variation in knock generally. There is usually slightly more power to be had with the leaner mix but never enough for me to consider it worth it. If you are within that window of AFR, try reducing timing a few degrees to see if it consistently goes away, otherwise it may be phantom knock.

11 afr is not to rich especially for 91octane. i wouldnt go past 11.2 myself.

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No offense but thats plain retarded. you're lucky you didnt melt anything. you arent even going to gain anything from 11 to 11.8 on 91octane hardly cept for a lot more heat. 11.8 is what i use on E85....

I should have edited it, I just looked at an old log and it was between 11.2-11.6. It was originally a tune by a certain person that said 12.0 with no knock was good and I backed it down a lot. So ignore that post...

Damn dude. 12 AFR lol. don't let that person tune you again. you most likely got away with it becuase you never road coursed the car or beat on it long periods of time.

now if its 12 afr on a sniffer at the end of the pipe on a dyno its fine, but not a true wideband output reading.. thats just dangerously lean.

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Theres a lot of ****ty tuners that should not be allowed to tune cars. The only respectable email tuner I like is Mellon.

I dont have firsthand experience with 91 octane and some of its "habits" so I cant comment one way or the other. I have tried mixing 89 and 92 for guys that are going to CA (should be 90.5) and other than it doesnt like timing it seems to be the same as any fuel I have encountered.

Per 12:1 and road racing. Works great for 15 minutes and then the heatsoak and mildly increased EGTS seem to start knock issues on straight pumpgas. You might get one 20 min session and then its gonna happen on the next one (based on our resident course guy). He adds a pint of Torco and gets the octane to mid 90s (from 92) and is good for a few more sessions before it becomes needed again and he has to add some more race gas concentrate (the torco).

I didnt get the full rundown from Tahoe55 after the last track day when we tuned him for 11.0 as far as knock but the car was still plenty hot on the EGT front and was loosening turbo bolts and ate a gasket. Gas in general seems to run so hot its amazing that cars can go so long in endurance races without turbo or engine failure. I am thinking of cars like the Audi 4.0 FSi motors running 12.2:1 and 20psi on 100 octane ELF. I know they tune the decel fuel and use it to keep the turbos cooler. We can do the same thing and get the best of both worlds, well on the IX anyway. Besides everybody loves flamethrowers right?

Thanks for the feedback guys, sorry I can't figure out how to get my logs up, I know that's sad. Now I took a look at my low octane map and is is anywhere from 0.2 - 1.1 leaner than the high octane map....uh okay, this is why I am learing to tune my baby. I thought that there was no way 3* was causing the knock but I guess I'll back it down a degree and see what happens. As far as correcting the low octane map half and afr point richer should be safe, correct?? Oh man now I don't know if I should just put the stock maps back on, and start all over, or keep going on the ones I have, any more thoughts would be great...I need a beer.

thanks bud {thumbup}

*tip toes in to hijack a little* Can anyone comment on the ARF (93 and E85) for a Road Race tune and the timing as well? Thank you.

EGTS are so low on E85 in general I tune it like we do for drag racing. High 11s and 2* back from MBT (typically 16-17*) to account for heatsoak. Alot depends on overall combination but JID2's car is a good example of what I mean. He had mostly street tuned it, we threw it on the dyno for a freshen up and giggles. The next day he was racing it on the track at 500whp and more or less what I just outlined.

I normally see EGTs somewhere around 1050-1150 in a pull it seems.

Wow, that is fairly low.

Yeah E85 seems to be alot more akin to diesel for EGT than gasoline. I attribute most of it to the quantity of fuel being consumed and the ability to use great timing at high boost. E85 on a 12.0 gas scale is more likely something like 7:1 or whatever on a true lambda scale.

The hottest I think I have ever seen an E85 car is 1400s....maybe? I have never made a thin wall header glow on E85 so its not too warm. My car for instance can start a pull at 172* and end a pull at 172*....at 600whp. E85 is pretty awesome really.

3 could definitely be too much on crap 91. Im restricted to 91 and Im pretty sure im running close to 0, maybe 1 deg at peak torque (23 psi on the stock '05 turbo and low 11s afr). Every car and gas station are different. If its knocking (real knock, not phantom knock) with a reasonable afr, pull a degree of timing. Ive got my low octane map about a full point richer. But Im still learning as well. good luck.

:beer:

Thank you for the input, I am at a loss. After really looking at my tune it went from a stock, too rich and too aggressive maps to even more rich and aggressive. I thought a good place to start was to lean the stock map but my high octane map is almost a full point richer everywhere than the low octane map which was not touched at all. I think I am going to go back to the stock fuel map and take it from there, anyone else have any ideas?

if you want some assistance getting your afr good just give me a pm, ill get you goin the right direction.

Gettin everything dialed in great, I leaned it out a bit up top to hit 10.9 afr. Honestly I think changing fuel is what caused it. I used to only put chevron but in my area they went under so I had to swith to Phillips 66 and the fuel does behave differently. Thanks again for the help fellas, anyone else notice different brand of fuels being more "high maintenance"?

rich = backfire=flames:D

I prefer my car to have a conservative tune on mediocre 91, rather than a ragged edge tune on the best brand fuel. That way there's always a little bit of safety margin, and I never have to worry about filling up at a particular station, or with a particular brand of fuel.