Whats happening at 5600RPM?

[veltpak6]

i was booting it on the highway the other night and at about 55-5600 i got this kick in the pants torque spike... now apparently thats not a VRIS point and I do know the car is not optimally tuned. The engine is a KL-DE with a ported ZE IM, square ported intake ports, rear cam bank has KL01 cams, front bank has KL31 cams, both 2 sensors are 1-wires, phenolic spacers and a ported out VAF (3 plunger supports removed to reduce the "footprint" in the air flow).

So quite frankly, I dont know what the "big change" is at 55-5600rpm

anyone have ideas?

[El Nacho]

um.....did you just say you have kl01 intake and exhaust cams in the rear bank and kl31 intake and exhaust cams in the front bank?

[pgt95]

i was booting it on the highway the other night and at about 55-5600 i got this kick in the pants torque spike... now apparently thats not a VRIS point and I do know the car is not optimally tuned. The engine is a KL-DE with a ported ZE IM, square ported intake ports, rear cam bank has KL01 cams, front bank has KL31 cams, both 2 sensors are 1-wires, phenolic spacers and a ported out VAF (3 plunger supports removed to reduce the "footprint" in the air flow).

So quite frankly, I dont know what the "big change" is at 55-5600rpm

anyone have ideas?

You have a different IM, with improper VRIS points (not that you COULD get them right) with 2 different cam profiles, and you messed with your VAFs ability ot properly meter out fule, AND your no longer able to keep a stable A/F ration soe your 1 wire conversions are getting different readings...

My guess, you ECU is freaking out cause if poorly metered air, (VAF all messed up) different A/F ratios (different cams), and you did some kinda ports job... my ONLY guess is that prior to 5600 your ECU is cutting timing or fule cause it is seeing this mess you call an engine, at 5600 for some magical reason the signals are close enough for the ECU to get a more even A/F and re advance timing :shrug:

[TRWeiss1]

Did I hear you correctly when you said you had the ZE cams in one bank and the DE cams in the other? Um....someone correct me if I'm wrong here, but you really should be running one set of cams or the other. I'd suggest all ZE cams ;)

[chaos311clarity]

yea thats what he has ... he posted a lil while back with a sound clip...it was interesting sounding

[mimmp]

Don't know if this applies to your mods, but at about 6000 rpm both VRIS close.

[veltpak6]

Don't know if this applies to your mods, but at about 6000 rpm both VRIS close.


Hey thanks for the sensical reply! Well its definately before 6000.

um.....did you just say you have kl01 intake and exhaust cams in the rear bank and kl31 intake and exhaust cams in the front bank?

Yup. The rear ZE cams cracked. To be honest, the mismatch pulls quite nicely! Don't lack low end, midrange kicks ass and top end is ... pretty damn good :) I still have the stock exhaust, and she pulls like a tractor to about 7500 on the tach.


pgt95 - you're an ass, heres why:
I've probably "thought" more about these mods than you have in general for the past year. The VAF works FINE. No no, let me rephrase that, it works better than fine. The ECU is doing the best job it can for a DE unit. I *can* easily get the VRIS points corrected, seeing as how its more manifold dependant than cam profile dependant and a dyno will tell all. As a matter of fact there may be some sort of inertial anomoly at some RPM because of the (everso) marginal differences in intake harmoncs. I'm going to have to wait till the dyno to find out. Mazda implemented TWO oxygen sensors for a REASON, can you guess what it might be? (hint: variations in bank combustion) and it seems to be working. I'v ran my car with a "dummied" knock sensor to keep advanced timing (questions? ask me how before flaming) and don't notice any difference with the stock one plugged in (94octane) In the real world there are no "magical reasons".... but thanks for the F:lame:

Again, the car runs strong... gets good gas mileage, its just I dont know whats happening with the a/f ratio, what my engine (in its "messy" state) needs and how the DE ECU is programmed.... which leads me back to my original question as to what changes at around 55-5600rpm. Someone familiar with the fuel maps of the DE computer might be able to help :???:

Thanks to all who offered genuine assistance. :thup:

[Courtice6er]

Ok dude calm down. You asked a question and he gave an answer.. dont like it.. dont ask.

Ask for the question. I do not know. I too also think it has ot do with your miss matched parts. I could be wrong. but that is how I feel. I am thinking most likly it will be your cams.

But I dont know why this would bug you. If you are getting extra power at anypoint with our engines it is a good thing. And I wouldnt want to do anything to disrupt that power.

[veltpak6]

Ok dude calm down. You asked a question and he gave an answer.. dont like it.. dont ask.

Ask for the question. I do not know. I too also think it has ot do with your miss matched parts. I could be wrong. but that is how I feel. I am thinking most likly it will be your cams.

But I dont know why this would bug you. If you are getting extra power at anypoint with our engines it is a good thing. And I wouldnt want to do anything to disrupt that power.

he didnt give me an answer, he flamed. he should find out who the **** hes talking to before saying' sh!t like that about something i put a lot of work into.
in any case, I already know that cams are not going to magically cause a torque spike at one set RPM. if anything it would be gradual, which its not Thanks though...

I wish I could ask SDS to convert my EM-3 to 6 cyl, that would solve a lot of problems :spin:

[pgt95]

he didnt give me an answer
To which i posted:
My guess, you ECU is freaking out cause of poorly metered air, (VAF all messed up) different A/F ratios (different cams), and you did some kinda ports job... my ONLY guess is that prior to 5600 your ECU is cutting timing or fule cause it is seeing this mess you call an engine, at 5600 for some magical reason the signals are close enough for the ECU to get a more even A/F and re advance timing I didnt say that cams were causing your spike in torque, but your confusing your computer and perhaps, just perhaps the different air flow chericteristics are confusing the ECU. Your getting different air flow so to each bank, thus different VRIS points for each bank, as well as different ingnition curves.

Finally, as to your VAF working BETTER than stock.... by deleting the supports your intention was to allow more air, however as you stated the STOCK DE ECU is running it meaning that your ECU and thus injectors DON'T KNOW THAT EXTRA AIR IS GETTING IN :roll: thus your ecu cannot compensate...

Last thought, the VRIS points arent manifold dependant, they are air flow dependant, and while the manifold effects air flow dramatically, so do your cam proflies, cause the air flow changes the actual ressonance. If you had a motor pulling as much air at 2K as our does at 4300 stock then your VRIS points would change, thus the change in air flow due to cam proflies heavily effect VRIS points.

When you mod a car in new untested/unproven ways and admittedly havent been to a dyno, setp away and see how it looks from an outsider....

[pgt95]

1. I edited my first post in the hopes of appeasing your injured ego.

2. You will still get a realtively larg dip/spike at your VRIS change over. The way isee it on a KLZE with a Aspec ECU there is up to 10lbft changes at VRIS switch over, now you only have 1 set of cams in, but that is still a 5 Lbft change and it will still be a dramatic drop.

Now you are correct that in between VRIS point the change prolly unnoticable because the powre is an average between the two cam profiles power delivery but at VRIS that dramatic dip is still ocuring on one of the banks.
I am still convinced that the spike is ECU related...

[Level 9]

it does make sense about the compensation for the air portions of the a/f mixture. altho you have 2 o2 sensors you only have 1 vaf. if you have an a/f gauge tap into one o2 then go for a spin, then tap into the other and go for a spin and see how they compare. not saying that this is the prob, but saying it may be. altho i'll admit i couldnt say for sure. sounds like an interesting setup tho for the power you say you get throughout low end, mid and high :thup:

[veltpak6]

This time I'll quote you. Because you clearly cleaned up your rudeness on the last one.

To which i posted:
I didnt say that cams were causing your spike in torque, but your confusing your computer and perhaps, just perhaps the different air flow chericteristics are confusing the ECU. Your getting different air flow so to each bank, thus different VRIS points for each bank, as well as different ingnition curves.


With all the high and mighty talk earlier, I naturally assumed that you KNEW VRIS controls the entire intake manifold. Right? That means both banks, bro.

Oh... uhm that ignition advance curve also applies to the entire engine.

Different air flow you say... that wouldnt be a problem if we had individual FUEL control to each bank... :ohyeah: thats right, we do. :P


Finally, as to your VAF working BETTER than stock.... by deleting the supports your intention was to allow more air, however as you stated the STOCK DE ECU is running it meaning that your ECU and thus injectors DON'T KNOW THAT EXTRA AIR IS GETTING IN :roll: thus your ecu cannot compensate...


Oh youre right. But theres more to the story. The benefits of a smaller footprint will only surface at about 6000RPM or higher; as you already know, above something like 4000rpm, the computer is only reading the fuel table, disregarding the VAF. At this point, the VAF is just an obstruction. Deleted supports = good. Theres nothing at all wrong with the VAF-signalled RPM range. The torque is excellent in the low range... Id imagine thats the rear bank doing it job while the front bank winds up, the difference being very minute. I'd asssume they pass a few ft/lbs back and forth through the crank. Whatever it is, it works :) either way, I mean, its ported ZE hardware on a DE computer, so that alone was a good enough argument. :)


Last thought, the VRIS points arent manifold dependant, they are air flow dependant, and while the manifold effects air flow dramatically, so do your cam proflies, cause the air flow changes the actual ressonance. If you had a motor pulling as much air at 2K as our does at 4300 stock then your VRIS points would change, thus the change in air flow due to cam proflies heavily effect VRIS points.


Now youre talking. You (and I coincidentally) have a good point because I know that. I also know that VRIS acts *entirely* on harmonics, not air flow. Vacuum at the port, at any given RPM has an effect on amplitude, which in turn effects the harmonics. But you must already know that the difference between the DE and ZE cams is by no means a drastic one. Most will agree that both cam profiles allow each cylider to fill with roughly 417cc's of intake. Thats roughly 416cc's being pulled through each runner, which varies a few cc's here and there throughout the RPM range, of course because of the different profiles. In reality, its so insignificant to the harmonics that its not even a concern. My VRIS points might deviate slightly from stock (ZE) points, like every flow modded KL out there, but there is no VRIS activity at 5600rpm. So... :???:


When you mod a car in new untested/unproven ways and admittedly havent been to a dyno, setp away and see how it looks from an outsider....

hey man, I getcha. I just got pissed off because of the manner in which you said what you said. geez man.. don't disrespect your peers' work. At least wait a few posts and feel a person out. Then you can avoid them quoting you and returning the favour in a nicer way.

[veltpak6]

u know whats cool, i just thought of it...

if at say 5xxxrpm (DE cam torque peak), where the the DE bank has a nice pull of air through the runners, then the inverse phase (the bounceback) would be a strong one... and guess who's next on the intake queue? yup its the ZE bank.. and at a good time, because its just entering its torque peak. So that ZE cylinder gets a nice inertial charge, which will leave a bigger vacuum, and get more air into the intake manifold so that whole process can happen again... Thats what I meant earlier about the "harmonic anomoly" thing. Kinda cool if thats whats happening and causing the torque spike... :o

[El Nacho]

hell, i'm just surprised it runs. :thup:. I want to see what a dyno graf looks like.

[veltpak6]

hell, i'm just surprised it runs. :thup:. I want to see what a dyno graf looks like.


ppffffff i'm surprised how quickly i go through the gears, myself. i wanna see what it looks like too! hopefully soon we'll find out soon, eh tronco? whats shakin over in Ohio?

[pgt95]

Make up your mind:
above something like 4000rpm, the computer is only reading the fuel table

Or

Different air flow you say... that wouldnt be a problem if we had individual FUEL control to each bank... thats right, we do.

You cannot have the ECU running on a pre set fule table AND adjusting for individual banks, be DEFINITION that is an impossible situation.

As far as different air flow I don't care that VRIS effect both banks, if one cam has a different duration, lift, and lobe separation angle then those cylinders are receiving different amounts of air, its physics...


The benefits of a smaller footprint will only surface at about 6000RPM or higher
Proof or even sound theory this 6K guesstimate is accurate?


I just think your eliminating potential problems cause you *think* it all works fine when your really doing things never done before (or at least not well documented) and have no qantitative data.

As far as cams being felt in the power band, buffalo slipped 1 tooth on 1 intake cam and felt a palpable difference in power deliver, and those were on 4 matched cams :shrug:

[veltpak6]

Make up your mind:

know what block learn is? tell me what block learn is.
o2 sensors do the 'do' when theyre called for. the fuel table was supporting my VAF argument, not "my car is tuned optimally" in which I clearly stated that its not. the VRIS is the first thing i want to correct. one more thing, what are you trying to prove?

As far as different air flow I don't care that VRIS effect both banks, if one cam has a different duration, lift, and lobe separation angle then those cylinders are receiving different amounts of air, its physics...


are you mixing up flow and harmonics again. engines arent taps the flow nice and steady, or that would invalidate the entire harmonics thing
are you even reading my posts? i thought i addressed that issue.


Proof or even sound theory this 6K guesstimate is accurate?


who cares. i dont.
simple logic is this:
-we know the vaf is restrictive
-the supports removed reduces said restriction.

those are facts i care about. do i care what precise RPM the VAF begins to choke the engine at? nope. what will knowing that do for me? oh yeah I'm gonna go rent a flow bench so i can sleep at night knowing exactly what RPM the stock vaf chokes at :ohyeah: heh


I just think your eliminating potential problems cause you *think* it all works fine when your really doing things never done before (or at least not well documented) and have no qantitative data.


whats your deal with "new ideas" seriously. you seem deathly afraid of anything/anyone thats is "new" to you. this isnt even a "new idea". this post wasnt even supposed to be about my setup, its about the phenomenon. :lol: i didnt chose this setup either, it was a matter of circumstance. it was only afterwards that i learned to appreciate it... because it works and seems to work well. i'm not going to argue insignificancies and worthless questions with you :tdown:

[pgtfreak]

Blah. Flames. Should have taken it to PM.


BTW your car would run a lot better with matching intake and exhaust cams :tup:. Run ZE intake cams and DE exhaust, or vise versa, but DE intake and exhaust, and ZE intake and exhaust, you're bottle necking half of your cylinders.
I'm quite suprised your car even runs, in it's state.

Anyway, like I sad, want to bitch, take it to PM. And next time, please remember "problem" topics go in 2.5 maintenance.

Thank you, good day

:ken: