I did three a-tap runs(really quick one's). The first two were in second gear and about 3500rpm then punch it. I take threw 2nd into the top of third. Everything is cool, no KR, timing is at 21* right where I set it.

The third run is from a stop(mind you I have really crappy traction), so I ease off then I punch it. This time I have 8.5 deg of KR(so now my timing is at 18.5)my rpm is 1300, I am going 10 mph at this point. Then I shift into 2nd now at 4000rpm I have 3.3 Deg of KR(my timing at this point is 17.5) and I am going 31mph. Then still in 2nd gear I take it to 6100rpm and no KR.

Anyone know what gives??

 

It just sounds like you're getting false knock retard due to when you shift and/or when the tires are spinning..mine does it when I shift hard and cause the tires to spin cause of all the banging but you should be ok as long as that's the only time that it does it..

 

You are actually loading your engine too much which is causing the KR.

Try this. Put your car in 4rth at 25 mph and mash the throttle. I bet your KR will jump up to something like 8.5. It is the same thing when you are stabbing the throttle at 1500 rpm.

If you have a car that does not generate much torque down low, then you are going to run into this. The same thing would happen on a stock car.

To avoid this, don't mash it in such a low gear. Instead of 3rd, use 2nd. Instead of 2nd, use first.

Good Luck,
Kevin

 

oops, NoGo is right..I didn't see where you posted the rpm's you were at when you were stomping it but I have the problem that I posted when I check mine..my bad <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by NoGo:
<strong>You are actually loading your engine too much which is causing the KR.

Try this. Put your car in 4rth at 25 mph and mash the throttle. I bet your KR will jump up to something like 8.5. It is the same thing when you are stabbing the throttle at 1500 rpm.

If you have a car that does not generate much torque down low, then you are going to run into this. The same thing would happen on a stock car.

To avoid this, don't mash it in such a low gear. Instead of 3rd, use 2nd. Instead of 2nd, use first.

Good Luck,
Kevin</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Is that normal?

If I am racing at a light or better yet at the track, how do I avoid that problem? I have never had this happen before? I also though I might have heard some pinging. Not a 100% sure though. I am looking at the file now and my TPS is only at 42% and my O2's are .735 and .675 when the 8.5 degrees of KR happened.

At 4100 rpm my MAF is at 56.20lb/min, ,my O2's are at .935 and .940, 3.3 degrees of KR.

As I keep looking at the file 4900 rpm 1.8 deg KR, MAF 52.76 lb/min, O2's .935 and .945 TPS is 100%.

People on the other board are telling me to raise my MAF table and raise my PE vs RPM down low by 110%. I am Not messing with my MAF table anymore. ABout the PE table, what does anyone think about messing with that?

Thanks for the help.

Jason <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

There are a couple ways to avoid this problem.

It sounds like you have two problem at play here.
1) You are detonating at high loads. This is fairly normal but not good. Keep reading if you want to know how to fix it.
2) You are too lean up top. A high load detonation should spike and then die out over the next couple cells. ie, it spike to 8 then quickly dies out.

To take car of your low RPM high load detonation, you can run low initial timing. If you look at your High Octane Advance table in the lower left you will note that for the high g/cyl and low RPM timing is very low. This is because high g/cyl low RPM is a heavy load condition, and you have to pull timing to avoid KR. People who make a step adjustment to their timing table (ie adding 4 deg to the entire thing) can encounter this problem because it raises the timing for these high load conditions too high. To drop timing in this area select all cells above .56 g/cyl and left of 1800 rpm. Subtract 4 deg from all cells. See if this helps.

To take car of your lean condition, you will need to make adjustments to your P.E. table. On a forced induction vehicle, a 3-5% change of the P.E. table equals 1 a/f point. I would multiply your entire P.E. table by 5% and see if that takes care of your problem. I would not go more than 10%.

Good Luck,
Kevin

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by NoGo:
<strong>There are a couple ways to avoid this problem.

It sounds like you have two problem at play here.
1) You are detonating at high loads. This is fairly normal but not good. Keep reading if you want to know how to fix it.
2) You are too lean up top. A high load detonation should spike and then die out over the next couple cells. ie, it spike to 8 then quickly dies out.

To take car of your low RPM high load detonation, you can run low initial timing. If you look at your High Octane Advance table in the lower left you will note that for the high g/cyl and low RPM timing is very low. This is because high g/cyl low RPM is a heavy load condition, and you have to pull timing to avoid KR. People who make a step adjustment to their timing table (ie adding 4 deg to the entire thing) can encounter this problem because it raises the timing for these high load conditions too high. To drop timing in this area select all cells above .56 g/cyl and left of 1800 rpm. Subtract 4 deg from all cells. See if this helps.

To take car of your lean condition, you will need to make adjustments to your P.E. table. On a forced induction vehicle, a 3-5% change of the P.E. table equals 1 a/f point. I would multiply your entire P.E. table by 5% and see if that takes care of your problem. I would not go more than 10%.

Good Luck,
Kevin</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Thanks Kevin,

But my a/f dyno shows an a/f ratio of 10.6:1 at 2600 rpms. and doesn't go above 12.3:1 until 6100 rpm's. So, if I multiply the PE table I will be runninng super rich. The timing thing you described makes sense and I will try that, do you think I should raise my PE from 0 to 2600 rpm's?

Looking at my edit file, Ed does have the timing kinda on the high side, for example from 1200 rpm to 2400 rpm and .08 to .16 the timing is in the high 30's to low 40's.

Thanks Jason

Thanks Jason

 

The timing you mentioned is normal. It is low g/cyl and low RPM. You can get away with, and acutally want alot of timing in this situation.

The problem that you are facing is HIGH g/cyl and low RPM timing and is located in the lower left of your timing table as I indicated earlier.

In regards to your dyno: 12.6 is too lean for a supercharged car. If you are tuning on a dynojet you want 11.4 across the board. I would take some fuel out down low, and add some fuel up top to maintain 11.4. This ensures a safe, powerful setup.

Before you start tackling your WOT detonation (after the initial hit) you need to get your a/f right. There is no way around it. You can't play with timing if your a/f is all gummed up.

Once your WOT a/f is correct then you can start adjusting your timing.
Try removing some WOT timing and see if your KR disappears. I know that you have the upgraded intercooler and the lot, but timing, especially for FI is setup specific. Some setups, despite what the manufacturers say, just don't take well to timing.
If that doesn't get rid of your timing, then try upgraded fuel. If you still have detonation, then you need to start looking farther into your setup or explore the possibility of false KR.

Good Luck,
Kevin

 

I would not make any changes to the P.E. table unless you are at the dyno.

Makeing changes to your P.E. in the lower RPM to compensate for a lean condition when you punch it is going to do nothing. Unless your fuel system absolutely kicks *** (90 psi, front mounted regulator, dual intank Walbro's).

As long as you are using the stock regulator (or a regulator in the same place as the stock one) to maintain 58 psi you are going to have a lean spike when you first climb on the throttle. There is about 20 ft of fuel line from the injector to the regulator and it takes some time for your fuel system to pick up the slack when you jump your honking injectors from 2 ms to 8 ms.

Increasing your P.E. table in the lower RPMs is only going to generate a rich dip in the a/f once the fuel system catches up (right around 2500 rpm on most cars).

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by NoGo:
<strong>I would not make any changes to the P.E. table unless you are at the dyno.

Makeing changes to your P.E. in the lower RPM to compensate for a lean condition when you punch it is going to do nothing. Unless your fuel system absolutely kicks *** (90 psi, front mounted regulator, dual intank Walbro's).

As long as you are using the stock regulator (or a regulator in the same place as the stock one) to maintain 58 psi you are going to have a lean spike when you first climb on the throttle. There is about 20 ft of fuel line from the injector to the regulator and it takes some time for your fuel system to pick up the slack when you jump your honking injectors from 2 ms to 8 ms.

Increasing your P.E. table in the lower RPMs is only going to generate a rich dip in the a/f once the fuel system catches up (right around 2500 rpm on most cars).</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Ok, sounds good.

The intake fuel pump is stock, I have an inline fuel pump that came with Vortech's kit, along with 38lb injectors. I am thinking about getting a new intake fuel pump.(Walboro 340) I was told was a good chioce.

 

Bigger fuel systems are always a good choice <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

I did excatly what you said, but I have not had a chance to make it back to the dyno. My car made the most power with a a/f ratio of 11.5:1. So, I guess I need to make it back to the dyno.

So, should I leave the PE table down low alone?

So, for now I changed my timing where you told me too. If that works, can I leave it there?

Thanks Jason