Well guys I finally was able to get my WBo2 set up.

You may recall I had some less than good times at the track with the setup I am running ~13.8 @103.

As it turns out I had a bad converter stalled at 1100 RPM. That has been swapped out for a Vigilante 3200 RPM. What a world of difference. It doesn't take the car 3 sec to hit 3000RPM. Anyways that will improve the ETs significantly.

Now are the results of the WBO2. At idle and cruising until PE is invoked the A/F is right around 14.7 +/- .2 That is what I would expect it to be since the ECM/O2 sensor are doing there jobs. Just some peace of mind to know they are.

At WOT or as soon as PE is invoked the A/F goes to 10.1! As low as the meter will read. Sometimes a 10.3 will pop up. WOW am I rich. I suspected that I was from plug readings, but I did not want to mess with the fuel until I was sure. All indicators were pointing this direction, but as stated I did not want to trust a stock O2 or my lack of experience with plug reading, to govern a lean out change. Now I am more comfortable with making the change.

My question is what other items should I be watching out for or trying to optimize with this WBO2?

I was going to get the A/F around mid 12s and try to zone in on a best performance A/F. Sound reasonable. Any advice on balancing Spark advance, A/F at the same time?

Before I was getting knock counts all through first and second. I knew I had an exhaust leak at the collector. That has since been taken care of and I did not have a chance hook the computer up to see where it is at now. Hopefully it took care of some of the counts.

I look forward to hearing from some of you more seasoned WB users and the tircks and techniques used to optimize the potential of the car.

Thanks a million!

 

50 some views and no comments? Come on fella throw me a bone.:hail:

 

Watch for knock. If you are FAT @ 10:1 & you start pulling Fuel out I think that you are going to find that your knock is going to shoot through the roof.

a lot of fuel ahead of knock will supress it but once it happens about the only cure is to pull timing. that is to say, that having the car fat will mask or reduce the knock & now that you start taking fuel out you might find that it knocks like mad.

if you find that to be the case, take a bunch of timing out, then start pulling the fuel out until you get it where you want it. THEN start putting timing back in, knowing that putting timing back in can cause it to go a bit leaner, so again watch for knock.

thats my2c.
BW

 

as a side note, this is a GREAT time to start doing some plug cuts. You can watch what happens on both of your O2's & Knock sensor, as well as start reading the plugs & I would imagine that you are going to have a great idea of what is happening in that beast.

BW

 

Guys,

Thanks for the advice. But more specifically I just burned an ARAP base chip and even with that I am running PIG rich? I thought that would be on the lean side.

I am running the 165 MAF. With the original post's chip I have almost all the BLMs at 128 except idle. I should also add that the knock counts are down considerably with the exhaust leak fixed What tables would you guys recommend changing to get the A/F to ~12.5? And how much off the stock ARAP would you reduce it?

If you could just give me an educated guess from your own experience on these two items I will probably be able to get it pretty close. Then hone in on were it needs to be.

Just thought it was fishy with the stock ARAP chip being that rich.

I have my bachelor party this weekend and Sunday I doubt I will be in any shape to tune. The next week will have to be the week. For I have a local drag racing event here in my hometown I would like to be ready for.

Thanks for your help.

 

I don't know what editor you are using but I think what you want might be referred to as "Power Enrichment vs. RPM". It is expressed as some percent change in AFR so it's kinda tricky. I'm sure there is some good stuff in the archives about this. There is also a PE vs Coolant Temp.

Now I have a question: is there a difference with knock when it's under power or when it's under cruise? I know this is not directly related to the question but I noticed that when the mixture gets leaner, i.e., EGR dilution or Highway Mode Fuel, you try to add timing to ignite the less volatile, leaner mixture. However, when the question turns to WOT, people will always say you are running lean if you have knock counts. What gives?

Now more on point, if you still have knock you might want to check the PE Mode Spark Advance. Looking at ARAP with winbin it says it adds 9* at 3200 RPM. That might be a reason for knock while at WOT.

 

Hectorsn,

Thanks that is what I though and I just got back in from testing two more chips. I have it reading 12.5 with a -6.5% in the upper RPM ranges, but still the knock is present.

I thought it was gone earlier in the day, but the road I was on, I really couldn't open it up.

The Knock begins as soon as I punch the throttle from a dead stop. Timing is set at 6* with the distributer. And WOT spark advance is set at zero. I have a steady average of 8* retard from 1800-3900 RPM and then again from 4500-5550. With an indicated Total Spark Adv. of 31.3*

This seems fishy to me, but I ran two logs at different times and they both follow each other almost identically. The trend is definately there. Now my question is: Is it true or false knock? I will make a new chip with less timing in those areas, but I will only have ~23* of total advance.

Everything I have read, is these AFRs should be able to run way more timing than the stock heads.

Guess I am breaking the cardinal rule and thinking about it. Rather than just doing it. But sometimes I like to error on the side of caution.

Is it possible for false knock to follow this true of a trend?

The car did pick up ~.3-4 tenths by raising the A/F ratio. I'm sure there is a lot of performance being taken my the knock counts.

I'm sorry this is sooooo long, but there is one other thing I thought I should mention.

When I do stab the gas, the A/F goes lean then shoots to 12.5. It gets as lean as 18.5 for a second then quickly transitions to 12.5. Could this be part of the problem. Also my takouts feel a bit sluggish again, little wheel spin.

Thanks and I hope I spelled out the problem enough for someone to help. I will start on the next chip to rid the knock.

I can't wait to hear the advice! Thanks.

 

False or true knock?.

What do the plugs look like?. If no detonation there, then it's something falsely triggering the sensor.

31d might be too much, all depends on your combo.

You have to first get rid of the knock whatever form it is before tuning.

Then you need an repeatable baseline, so you know if you're going faster.

PE and cruise, idle are all different modes.

Your starting to just see the bennies of using it. Tuning transitions are MUCH MUCH MUCH easier with a WB.

 

Now you have to try playing with the Accel Enrich. It can add fuel as quickly as the first DRP so it should cut down on the lean stint you're seeing.

Do like Grumpy says and cut back on the timing. A more efficient head needs less timing, not more.

 

Would it be safe to say, if I pull the 8* of timing out of the chip and and try again with much of the knock disappearing, that it was true knock and not false?

This seems like a logical way to tell. Perhaps I am out in left field. Please advise.

Is the lean condition on initial acceleration due to lack of *pump shot*? Should I increase the multiplier factor in the Accelerated enrichment vs Lv8?

I am keeping notes on changes, but don't want to change the world all at once. Just want to pick my way through.

Seems like since I changed my knock sensor, it has become more sensitive.

Just another side thought, perhaps I don;t need to pull out 8*, does the ECM pull way more than needed. Perhaps I am just missing and only need to take out a little. Say 28-29* total.

Thoughts?

Thanks

 

Good idea not to make too many changes at once. But yeah, try the Pump Shot and try taking just a couple of degrees first and then a couple more in the range before the knock happens. ANd I would guess that if you took out 8* and still had knock it would be false but that is just a guess.

 

How much of a pump shot do you recommend starting with. As stated before I have never messed with fuel curves before and until I get the feel I would appreciate any suggestions you guys might have.


What I am thinking, and it may not be logical, but I would like to add the pump shot first and perhaps that will take care of some of the knock at the initial start I am seeing.

I hate to pull timing if the pump shot is the problem, which it definately looks like it could be.


Thanks.

 

I just recently had a bout with my knock sensor after the new motor has gone in. When you changed the knock sensor, did you torque it in with a torque wrench or by hand? You shouldn't put it in with any more than 14lbs of torque. I had my in EXTREMELY tight, to the point you could take a hammer and hit the accessory bracket on the AC slightly and set the thing off at idle. Maybe try backing the KS off and retorque'ing it with a torque wrench.

Brendan

 

I just recently changed it and I put it in by hand with a wrench. No torque wrench,(don't see how you could get in there with one), but I did not really reef on it. Just tight? Probably more than 14 lbs. I even wrapped it with teflon tape to try to deaden it? I am 1/2 temped to just disable it. And see if I get audible knock. I find it hard to believe that I pulled 5* out of the area I was getting knock and I just had it out again and the knock is still there. Sounds to me like its false.

One other thing, why would the knock be more prevelant at lower speeds than at high for the same lv8 and spark advance? For instance. When I first take out, there is a lv8 of 167 and spark advance of say 28.5* further along in the run at much higher speeds the same combination may occure and there is no knock.

Seems like once I get above say 60-70 MPH it all goes away?

How bad of an idea is it to disconnect the knock sensor? I mean the chevelle has nothing like that and I have messed with the timing on that with no problems. I realize it is a good idea to have it but I think its hurting performance big time.

Guess I will do some more searching tonight. Thanks.

 

a sure fire way to tell if you are knocking or not is to pull the plugs. Youll see little specs of crap on the porcelain like little carbon specs. If its really bad youll see little grey specs thatspart of your combustion chamber melting off. Just get it in high gear and run it at the rpm where you think its knocking and cut the ignition and throw it in neutral, coast to the side and pull the plugs heck its a vette that should be easy for you.
beyond that, i would tune the spark advance for best performance dont worry about the numbers.

 

There is no need to do a plug cut when just looking for traces of detonation. The lil specs will still be there if you drive to a stop.

And yes, you do have to pay some attention to the advance numbers.

 

How much of a pump shot should I add? I made a 10% change and it did not make much of a difference.

Please let me know I would like to try it out tonight. Thanks!

 

In one application I did, I had to add 5x the AE of what the original calibration was.

There are no quick and easy answers.

Doing it correctly means pains takingly time consuming at times.

 

That all I needed to hear. I just did not want to add a ton without really realizing how high I could go. I will double it and see if it helps. If it does then I will back it down till performance drops off.

I just like to error on the side of caution.

Thanks.