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Discussion Starter #1
Just got my build from Steve (GMR) and had the first 20-30 miles on it. Just breaking in. The engine is rather hot (as expected?) and runs quickly to 140-150C (with outisde temperature of 40C). I expect it to cool down once the engine breaks in.

However, as I was riding at some 2500-3000 RPM I heard what I think could be pinging.

How can I verify that? Can I do that somehow by looking through the log data in DTT TCFI log? How to eliminate it? What timing / slope can anyone recommend to make sure it won't happen?

Thanks.
NM
 

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Premium Member
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373 Posts
"Usually" pinging results from one of two (or a combination) things.
1) Too much timing advance
2) Not enough fuel - too lean

There are other possibilites, like excessive quench, poor head design, mismatched components, etc. Being that you have a package from GMR, it is not likely that any of these will have anything to do with it.

I have a TFCI-IID as well & really like it. The main shortcoming it has, when comared to a SERT (espically w/TwinScan II+) is that the DTT unit does not expose knock detection (ion sensing) data that clearly pinpoints detination and helps one tune it out.

If you feel confident in your AFR values and that it is tuning in relatively well, I'd look at gradually reducing timing in the effected area.

Or... like Bob said... holler @ Steve.
 

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nmandic said:
Just got my build from Steve (GMR) and had the first 20-30 miles on it. Just breaking in. The engine is rather hot (as expected?) and runs quickly to 140-150C (with outisde temperature of 40C). I expect it to cool down once the engine breaks in.

However, as I was riding at some 2500-3000 RPM I heard what I think could be pinging.

How can I verify that? Can I do that somehow by looking through the log data in DTT TCFI log? How to eliminate it? What timing / slope can anyone recommend to make sure it won't happen?

Thanks.
NM

Here is my take for what its worth. I had Steve build me a GMR - pwr pack 2 with DTT and WEGO. I road out to AZ from the West Coast. Needless to say GMR did flawless work. Then I rode it home. After I got back, I noticed the dreaded ping followed. We can only get 91 octane fuel out here. Originally I put in some octane HD booster and the ping almost went away.

After a while, I started to learn how to work with the DTT program and began to retard the timing profile. From what I have found, the DTT software timing profiles are way, way too agressive. And not to mention, I don't think that Steve gives himself enough credit for machining and building very efficient cylinder heads. With this being the case, I was able to significantly retard the timing and richen up the Air to Fuel Ratio a couple of tenths (12.5:1 at idle and 13.5:1 at cruise) slightly richer at WOT. Its pretty funny, but some folks think that they really need a lot of advance to get performance, when its actually not really the case. But you will have to find what profile will work correctly with your setup, especially when it comes to your choice in exhaust pipes and airfilters.

Now my bike doesn't ping and it runs significantly cooler, not to mention has incredible power. I am not able to measure the cyulinder head or oil temps with an infrared gun or a gauge as you are, but its easy to tell by the amount of heat that isn't generated any more.

Also, you may want to check out your plugs and carefully read them under a magnifying glass to see if you are in fact operating too lean. Do yourself a favor and search the web on how to read spark plugs. I believe there is an article entitled Spark Plug Reading 101 that offers some great info.

Provided you are using a similar build as I am, along with a DTT, go ahead and pm me with an email address and I'll zip up my current settings and email them to you. All you would have to do is unzip the file and upload it back into the DTT in your bike. I'll bet it will get you into the ball park. Your choice.

the bottom line to me was not enough octane, and too much timing advance-2$en#e-

here is the build in my 2005 FLTRI:

98 inch GMR power pack two
high compression heads
DTT and WEGO
615/585 gear drive cams
fueling oil pump
heavyduty clutch spring
V&H Tru Duals w/modofied Kerker Slip-ons
Stage one air cleaner..
blah, blah, blah..
 

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IronButt
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6,364 Posts
I did send you a e-mail back but it is good info for others to read.

The DTT system is a rather agressive ign curve. If you look at a high compression engine you need to back the timing down to prevent early ign of the mixture. As well with increased comrpression you have more push on the piston over tdc. So you do not need the heavy advance. back the timing down and you will find the bike runs cooler, and will make more power.

Start with the advance table at 0 and remove 5-7 degress of timing across the board as a base for that engine, then work from there. It is not going to like a bunch of timing. A 131 is a monster and will run very well with a mild ign curve.

When you get the engine to detonate it can be for several reasons but what is going on is that the piston is trying to go up and it fires long before the piston tdc, thus you are in effect hitting the piston with a hammer and trying to stop it's upward movement hence the noise you hear.

When tuning I do not care what timing ends up at as long as you have first have a correct afr then you start to add more timing until you either make no more power or it pings. Then back it down some to be safe.

There is no reason to run a street engine on the ragged edge, better safe than sorry. For those that have been to my shop and seen the glass cabinet full of broken parts. Almost all where on the quest to make that last little bit of power. Drag engines are a completely different animal.

Think not so much if they are going to break but when they will break. That is just the nature of the beast. Hard to beat a safe tune on a street bike.
 
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