Z0HS1CK

Damn there are soo many mixed feedback!! lol

So will the green filter cause MAF issues???

On the green filter site, it says the oil is spread evenly throughout the filter media whereas other oiled filters some spots might have more saturated areas which is what might cause MAF issues.

Not sure how true it is. I have a green filter sitting in my house and i'm looking at it and it doesn't even looked oiled lol

I wanna install it but i don't want problems

BMadden

Z0Sick6, anxious to hear what your findings are regarding the culprit being the ported TB or the x-pipe.

0Chuck CoW

Good point, but realize that ANY change in shape or diameter can effect hoe the pcm "sees" the airflow.

I agree that the same cross section diameter @ the meter is important, but there are so many other attributes and if you recall the C6 ZR1 and C6Z....

Guys were using that "seemingly identical" replacement filter which was just a change in pletes or material...and it goofed up airflow good enough to mess up the tune.

As the other fella showed above.... The airflow can change at different rpms and load as well... Looking at the previously posted AFR chart above...

The AFR on the dyno was good to a point, and then it suddenly flipped in the higher rpms. It's not ever as predictable as one my think.

The mad scientists that helped me understand it better were Greg Banish and Patrick from VARARAM....

I'v been working with Vararam from the very early days and help test and tune many of his products and even participated in developing the C6Z/LS3 MAF housing they use today

that so many have copied..... I learned a lot from Patrick and had it not been for my relationship with him, I'd have a tough job tuning some of these cars.

Doing it intuitively, without his explanation, I'd be hard pressed to understand it better than I do now.... I's been soo easy to navigate the tuning world having worked with Patrick.

The tiniest changes in shape, diameter, and surface and have huge impacts on airflow.... Hard to understand cause you can't see it....

BTW, Patrick sent me some photos of the new C7 VARARAM the other night..... It's READY!

Honestly, I see things very differently than I did when I first got into the tuning business....

Chuck CoW

fleming23

Interesting info in this thread. I guess I need to schedule some more dyno time with mine. Maybe I should give in and set the tuner loose on the computer..... Decisions....

C7/Z06 Man

Hey Chuck, I'm aware of most of the stuff you have mentioned and thought about diving into the weeds some but changed my mind.

I have a question for you. If you have a straight round run, say 10 ft. then add a 90 degree bend what is the percent of reduction of flow.

Here is one that some on here are well aware of, if you have a exhaust tube with exhaust pressure going through it and cut in another smaller tube at a 45 degree angle in the direction of flow, then that tube will blow and if it is cut in the opposite direction then it will suck like a vacuum.

One more, back in the late 60's and early 70's the mopars running on the high speed race tracks would go a few mph faster when running a vinyl top because of the voids (low spots) in the vinyl; the passing air produced less friction on the roof to slow the car down.

1QUICK Z

Thanks Andy. This is great info. To be clear, these "lean" AFR readings with the PTB and x-pipe are using the tail pipe sensor, correct? I thought you said you installed a pre-cat bung and sensor? If we agree that the tailpipe sensor reads between .2-.5 leaner, than you might not be as bad as it looks. 12.5-12.8 AFR on our cars is where we want to be at WOT. Did you data log to see if there was any KR? What about timing? That will tell the whole picture. I'm also very curious if the PTB will actually help 60' times at the drag strip. I just took mine back out of storage and to be honest, I can't really feel any difference with my new PTB. It only spins the tires on the street. Not convinced yet if it's really doing anything on the stock tune.

ACS55

I did install the bung for the wide band, (in the LH side lead pipe pre-cat), but the gauge was not installed and operatonal until last night. I spent all afternoon yesterday making a custom mount bracket and running all of the wiring, etc and getting the gauge programmed and set up how I wanted it.. wiring and programming is not my strong point. I asked the dyno operator is they could use the pigtail off of the O2 sensor for the AFR reading, but he said he couldn't because the sensor was a different brand than they use.
Yes, we have the mysterious 0.2-0.5 point difference to consider... (tailpipe sensor is always leaner than wideband pre-cat sensor) that's a great point and maybe I didn't enunciate that properly in my previous post.

Here is a representation of my AFR tailpipe sensor readings from yesterday:
13.4 at 3500,
13.2 at 4500,
13.0 at 5000,
12.7 at 5500,
12.4 at 6000,

I hate to even do this exercise, but... if we were to "add back in" The 0.2 - 0.5 AFR (diff between tailpipe reading and pre-cat lead pipe reading), then the numbers would look more like this:

12.9-13.2 at 3500,
12.8-13.1 at 4500,
12.5-12.8 at 5000,
12.2-12.5 at 5500,
11.9-12.2 at 6000,

BTW, I got my AFR gauge working last night, but I have no HPT or anything else to "log with" as of yet.

ACS55

My car had a noticeable lag/delay off idle when stabbing the gas before, that's 90% gone with the mamo PTB.
When in gear and stabbing momentarily, the car actually "lunges"... to clarify, even after your foot comes off of the accelerator (after a momentary stab) the car continues a lunge for a .5-1.0 second.. really strange.. is this a forced induction thing?

Mad Dog 24

Me to on the dyno, now as we just installed a Borla X pipe and with our now 2 year old Halltech CAI. Questioning now if the PTB combo is worth the better off idle and on the other end possible causing a lean condition at 6.5k which the car sees a lot of! Boy do the road track guys VS. drag stripers have different wants and needs.

Great thread Gene.....

No tuner for me until the warranty is out, period.

BMadden

That last part about the car lunging even after you take your foot off the accelerator has me a little worried. My Tony Mamo Ported TB is scheduled to be here this week just in time for when I get my new Z, but I'm a little hesitant about putting it on after reading that.

0Chuck CoW

That's one of the reasons why we don't use them....

They are CHEAP so it's a popular mod. They (can) cause idle problems and other unpredictability when tuning

or modding.... There are other mods better deserving of the money you spend and there are also other ways to

get much better throttle response.

Chuck CoW

BMadden

ACS55 is the first person I've heard report that problem and I know for a fact Tony Mamo has hundreds of clients that attest to the improvement in their car's throttle response after using his ported TB so I'm just wondering if ACS55's "lunging" is an isolated incident or if others here have encountered that problem.

phantasms

FWIW the car has been known to lunge or overrun in completely stock form. In my experience the Katech PTB got rid of this problem. My Mamo will be arriving today and maybe I'll test it out if I get the time. FWIW I'm totally happy with the Katech but figured why not try the Mamo since he seems like he's an expert on the subject.

Best,
Gene

BMadden

Anxious to hear your findings, Gene. My Mamo TB will be here either today or tomorrow as well, but I need a car to put it on first.

0Chuck CoW

Yes.... The lunging and "overrun" issue was something I noticed (and people created multiple threads about)

and from everything I saw, it was only the STOCK non-tuned vehicles that did it.

After tuning, that issue was gone.

Chuck CoW

BMadden

I will not be tuning a brand new Z06 and risk voiding my warranty so if it does that stock then I'll just deal with it.

Is2scooby

I have a ported Mamo TB and no lunge for me. Great mod for off idle throttle response!

ACS55

Just to be clear this is not a severe problem, and it can only be duplicated with the car in gear, like 5 mph or less...
and then "stab" the throttle (punch it down and back up immediately thereafter).
The Mamo PTB definitely helped my "off idle hesitation". My car may have had the "lunge" prior to the PTB, I just don't recall noticing it before hand.

I've never had a supercharged car before, I was asking if it was related to a SC car.?!?

dar02081961

No its not. My C7 Z51 did as well. It has to do with you quickly closing the throttle and the sudden reduction in TQ demand trying to stabilize.

dar02081961

Folks this is great information. However we have to be careful drawing any conclusions.

As you stated you haven't been able to log data with anything like HP tuners yet. This critical if you want to compare apples with apples and draw conclusions.

I say this because based on the information provided your AFR may be rising because the car is not going into COT. Or it may only be going into one of the lower of the 3 levels of COT.

Contrary to what many folks think the Z doesn't always go into COT at WOT. And even when it does it doesn't always go to the highest (richest) level of COT. COT is activated by exhaust temperature. I have logged 1 WOT run and seen no COT. Come back to log again to see "COT on" which made my AFR inconsistent.

Point is COT being on for your pull is not a given. Especially if you do like most and keep the car fairly cool so you can get a good strong pull before the car pulls timing due to high IATs. Most tuners will tell you when tuning to turn off COT (and possibly other modifiers) so you can get constant AFR results. This step isn't something most tuners would do if you where just making dyno pulls and not actually tuning the car.
In which case a reliable AFR cant be counted on.

Another point to be made is lets say your latest dyno pull (the orange one) didn't go into COT at all. It is within .5-.8 of what a stock Z runs at WOT when COT is not activated. And this is before you account for the after CAT location of the wideband.

So without an actual data log conclusions about why you lost power on this run and why the AFR is higher should be taken with a grain of salt. And as 1Quick-Z stated midish 12s for AFR is exactly where you want to be, therefore timing or torque management become suspect in you losing power on the "orange" pull.

Just food for thought.