OK...I'm not sure if this belongs in the tuning section, Drag section or Tech....its all bunched together.........

I have been struggling with my combination since I got it going. Finally after getting the vigilante in the car I got to go to the track...

The results were better than the first time with the stock (bad) converter but still less than expected out of the combo....

13.2 sec at 104.55 MPH

I posted to other runs with more information in the Drag section, but also mislead some information which I hope to clear up here and find the reason for.

I posted that the best run of the night was done after turning the distributer back (retarding) the base timing from the set 6*. In fact I advanced it, but this is the weird part. When I went out today to check what the timing was at and realized what we had done it really shocked me that no knock counts were seen on any of the runs with the base timing advanced and here is why.

I have been posting and wondering why when I set my base timing at 6* and burn my chips for an advance of around 30-35* in the main spark table I get all kinds of knock counts. With the stock ARAP timing which is pretty high the knock counts are everywere! So I pulled timing out of the chip until I got to 25.3* and the knock counts went away. Up to that point I thought the counts were false, but they disapeared at 25.3*. I should also add that I zeroed out the WOT spark advance tables, so that is not causing the problem.

Well here is why I am confused. When at the track the other night, it was suggested that maybe the timing was still not retarded enough and I should retard it some more. So I figured it was worth a try. That is when we thought we had retarded it, but in our haste getting flagged to the track actually advanced it. Added ~8* more! So with the spark table at 25.3*+8* that is a total of 33.3*

After that... I ran the above time with NO knock and picked up nearly .2sec and 1mph.

Today at my dads we advanced it some more and took a ride...WOW! Its even stronger yet. I can be going 30MPH and break the tire loose with no problem. Still no knock counts at WOT! I figure I am about 36* now at WOT.

Why is my question...would the knock sensor not pick up any counts when the timing is added at the distributer, but go crazy when I add the timing in the spark advance tables.

Everything about the car is better now....idle is tons smoother, throttle response is unbelievable, top end pulls extremely hard, takeouts are silly...I just can't come up with an answer.

The only thing I can think of, is the harmonic balancer has spun and the base timing is much less than more/less than I think it is, but that doesn't make sense because I am advancing the timing and not retarding it.

Perhaps someone has experienced this before.....Its freakin driving me nuts...What is anything can you guys think of.

Sorry for asking so many questions about this car, but its driving me bonkers, yet its a great challange to get right.

I should also add, because others were suggesting that I may be running to rich, that my WB02 is running right at 12.6-12.7. Fuel pressure also holds steady through the entire run.

Hope someone can shed some light!

Thanks everyone! :cheers:

 

I've been wanting to do the same to my chip for a while but have no burner.

I think your answer is the fact the ECM pulls timing at low RPM...and according to the chevy power book...the SBC likes up to 19º at 900 RPM...and max of 36º at 3500-4000 RPM. My 383 loved this exact timing combo.

I think the stock ECM gets confused at low speeds...it lowers idle and low RPM timing to get better emmissions, and then really cranks timing at RPM. By lowering the total ECM timing, and making it up on the distributor, the ecm does not 'over-correct' for adding timing at RPM.

At least thats my theory.

BTW: What would it take for you to send me a chip burned like that? I'd be happy to provide some spare EEPROMS.

 

That is one therory.......

I'm not too sure if you want one of my chips! :lol:

Sure I'll help you out, or make your car run like a turd......like mine.... I'm cracking up here :lol:

PM some of you information and perhaps we can work something out....

Thanks for the comment...........Keep them coming guys....someone has to have the experience to answer this..

Thanks

:cheers:

 

Let me once again suggest that you book some time on a chassis dyno and do some timing and fuel pressure experiments that not only get feedback from your WBO2, but also the validation of dyno results. I think you are probably close to the answer and that you will soon have a breakthrough. Also, have you verified that fuel pressure holds steady during your runs and does not start dropping off part way down the track?

Thomas

 

I wish I could offer you some help. I should be hitting the track Wednesday night. Maybe we'll see how close we are to each other. I'll be on street tires I think, so I'll only be looking for a strong MPH.

 

Guys,

Yeah I will have to call around to see if the one in State College, PA (home of Penn State where I went to college has their Dyno up yet).

As for the FP. It stays dead steady all through the runs. I have the FP guage strapped to the window. That was the first thing that I suspected might be the problem.

I guess perhaps I was not clear on my dilema. So I will state it again:

Why when I add timing via the chip do I get knock counts, but when I add timing at the distributer (global change), there are no counts?

Something does not seem right. Regardless of were I add the timing it should be the same. But I can bet if I would add 36* of advance in the spark tables, where I now have 36* by fooling the computer with the base timing, I would have all kinds of knock.

I think this is what is holding me back. I'm half tempted to disable the knock sensor. But due to the fact that the knock goes away, leads me to beleive that its real, when the timing is added through the chip.

 

Are you seeing actual knock sensor activity, or are you just seeing ignition retard and presuming the knock sensor caused this? I'm pretty sure that I shared with you that I had 6 degrees ignition retard upon WOT at low rpm that was MAF related, there was no knock sensor activity, just ignition retard upon initial tip in to WOT. In that case I change the low rpm WOT advance down from 34 degrees to 31 degrees and the problem went away.

Thomas

 

Hmmmmm, well, no answer here, but I do have a question that popped up in my head. :lol:
Your scan software-Diacom? Or Craigs? Anyway, does it show advance/total advance? With diacom at least, it'll show advance in the tables and then advance in the tables plus base-does it show +true base? (at the dist.) or + "initial spark advance" in the ecm constants?
Do you have an advance timing light?
I know this is just more questions-but yea, thinking about this is driving me crazy now.
What about checking the timing with the "dial back" advance timing light and at the same time check the timing and timing plus base with diacom etc. to see what/if there are any discrepancies that jump out at you then.
Hope this makes sense what I'm getting at! :)

 

Drive it...

Thanks for the comments.

I have Craigs software, which shows the ECMs timing +base on the screen.

Yes I have the dial type light and have checked it against the displayed timing. Its is the same.

My question is still why can the timing be advanced via the distributer to achieve greater spark advance without knock than via the ECM for the same timing?

For example:

The most I have been able to advance the timing at WOT with the ECM is 25.3*. Anything more gives knock counts.

With that same chip in the computer I can take the distributer and move it from the base timing of 6* and move it all the way to 14* without knock! So in essence I am adding 8* more timing to every part of the timing table. At WOT I would now have 25.3*+8*=33.3* with NO KNOCK!

If someone can answer the above scenerio I think that will also answer were my power is at too.

This is the untimate brain teaser! Good luck...I will be forever greatful to the one that answers it. :cheers:

 

i got more questions for ya :crazy:

as i understand, you got knock counts with the 33* chip. you then programmed a ~23* chip and got zero knock counts. then you advanced base timing with the ~23* chip to get timing up to the 33* chip level.

how much time was between testing of the chips? could you have had a tank of bad gasoline that was giving you knock counts? do you still have the 33* chip? if so, you can reinstall it and verify you still get knock counts.

 

Hey someone understands what I am talking about! Congrats.

No on the gas. I have been going round and round with this car for the past few months. It gets better but still missing quite a bit of power.

And now this really has me confused...

 

Can we name your car rubik's cube??? :D
Have you changed the knock sensor module with the "upgraded" one?
I know that probably isn't related but just trying to rule out any weird possibilties....

 

Drive it....

Good name. I would change it but right now its named a few 4 letter words! If I share them your will see my % in my avatar drop dramatically. :lol:

I thought of this after posting all the replies to you that are trying to help and yes I should have mentioned that I have upgraded to the ECS module mentioned in the tech section. I also have a new knock sensor, wrapped with teflon tape to boot.

I was just explaining to my electrician that perhaps the noise from the headers when the cumbustion is correct is setting off the knock sensor. But that still does not explain the reason why I can get 30 some degrees of timing from the distributer and not the timing map.

My plans are tonight to take disconnect the knock sensor and apply Ralphs timing map again. Record a few runs and see if it helps with the MPH.

I am also going to check on the DYNO in state college and also on the possibility of renting the Beaver Springs Track for a day. Somehow, someway I have to figure this critter out.

I think these guys are right about the knock sensor, I was just a bit concerned about taking the safe guards out, but hell I have messed with the chevelles timing and had no problems.

I know what pinging is so if I hear it I will just let off. hopefully soon enough.

Keep the ideas coming and I will keep you all posted.

 

I'm about at the point of removing my knock sensor as well, and I decided a long time ago I did not trust the ECM timing capability either, and always wanted to pull it from the ECM and add distributor advance instead. The only downside I know of is added emmissions at low rpm's. As for pinging...I've dealt with it in non-computerized cars as well, so like you say, no big deal, just let off.

BTW: What gets hurt during ping is mostly connecting rod bearings over time, but in severe ping conditions, pistons can be damaged as well, with cast pistons being the most susceptible, then hypereutectic then forged.

 

what a coincidence Jesse. I read your entire thread called "the project" last night in the archives. It stops at page 5 and is dated like way back in Feb? I didn't recall seeing anymore of that famous thread and was wondering what ever happened and searched for it. I see today's (yesterdays) post. I thought: "he must've figured it out and I missed the post saying it was all fixed".
See, I was looking in the archives on how to install the Superram runners to the lower base and then the upper plennum to the runners. Like what kind of fasteners to use on the lower bolt holes. What to use to turn those fasteners? Allen bolts? Allen wobble wrench? I am not familiar with that one. I must have spent a good hour standing there trying to figure something out. I got frustrated and gave up, called it a night. I will try to go back with a fresh relaxed mind/attitude. Sorry to sidetrack your original question.
**Ahem....attention readers, attention :lol: ** please focus on Jesse's question and not mine. Sometimes I inadvertantly(sp?) sidetrack peoples' posts.
:conehead Sorry 'bout that. In case some one can help me, I can gratefully receive suggestions in an IM.




[Modified by 89 Paul in Cal, 1:57 PM 5/28/2002]

 

I just sent you a IM, Paul.