Tuning issues

[gt90stang]

Hi all,

Been busy but finally got a little time to tune. I’ve been fighting a over 4500 RPM detonation problem at full throttle in 1st gear only. I tried TTNOV pulling timing and it worked but performance really suffered so it wasn’t acceptable. The most timing I could run in the WOT spark advance vs RPM function was 21*, but I still got detonation over 4500 RPM in first gear.

I got to thinking about what was going on, looking over the datalogs and nothing made much sense (looked ok). So I decided to back up a bit and remove the tweak I did to the spark advance rate vs RPM function. When I originally did this my thinking was to allow the PCM to remove timing faster.

The spark advance rate vs RPM function settings I was using:
0, 0.5 992, 0.5 3008, 0.375 4000, 0.125 8160, 0.125

Versus the original of:
0, 2 0, 2 992, 2 3008, 1.5 4000, 1 8160, 1

So basically 4 to 8 times faster advance rate than stock. So when I went back to the original spark advance rate vs RPM function I am now able to run 23* in the WOT spark advance vs RPM function with no detonation. All I can think of is that the PCM can’t deal with the higher slew rates of the modified spark advance rate vs RPM function. Datalogs before and after these changes are virtually identical. Anybody have any insight here?

Gt90stang, Don

Engine: 306 ci w/ timing at 10*, Sterling pistons H273CP w/8.9:1 compression, FMS Harmonic balancer, Edelbrock 6037 heads w/2.02" intake valves, Explorer lower intake manifold (GT-40), FMS 1.6 roller rockers, Crane 444221 (2030) 216/220 @ 0.05" with 112 lobe separation 0.533"/0.544" lift, Ron Davis aluminum radiator, Lincoln Mark VIII electric fan, 130G alternator Tweecer RT, Performance Distributor TFI module & Scream’n Demon Coil, Denso Iridium Spark Plugs IK-20, FMS oil cooler.

Fuel and Air: KenneBell Blowzilla @ 8psi with a 10# pulley, 42# FMS injectors, Edelbrock 70mm TB, C&L 76mm MAF, Stock fuel pressure regulator, 190 lph fuel pump, Stock airbox w/ K&N filter (silencer removed), 91 Octane Fuel.

Exhaust: 1 5/8" JBA Titanium ceramic coated shorty headers, MagnaFlow SS 2 1/2” catback and X-pipe w/Cats.

Drive Train: D&P Products 2500 RPM stall 9 1/2” torque converter w/damper, AOD w/ TransGo HP shiftkit, Earl’s 19 row transmission cooler, FMS 3.73 gears.

Wheels and Tires: 17” x 9” Replica Cobra R, 555 Nitto Drag Radials 275/40ZR17 rear & 555 Nitto 255/40ZR17 front.

Brakes: Front 73mm calipers from 1991 Lincoln Mark VII, Sn95 MC w/3-2 port conversion & Russell SS hoses, adj. Proportioning Valve in series with the stock Combo Valve.

Chassis: FMS Subframe connectors, Energy Suspension engine, transmission and front sway bar mounts.

[QWKSNKE]

21-23 degrees of timing is kind of high with your current compression ratio being that you are blown. I realize that you are running low boost but any boost will generate heat (without an intercooler) and limit your timing that you can safely run.

In my opinion you should tune no higher than 19 degrees total timing from about 4k rpm and up at WOT. If you go to a higher boost pulley down the road you will need to cut the timing back more.
Aside from that, your C&L meter is not doing you any favors either

[Cougar5.0]

Aside from that, your C&L meter is not doing you any favors either

Please explain...

[Cougar5.0]

I’ve been fighting a over 4500 RPM detonation problem at full throttle in 1st gear only. I tried TTNOV pulling timing and it worked but performance really suffered so it wasn’t acceptable. The most timing I could run in the WOT spark advance vs RPM function was 21*, but I still got detonation over 4500 RPM in first gear.

I got to thinking about what was going on, looking over the datalogs and nothing made much sense (looked ok). So I decided to back up a bit and remove the tweak I did to the spark advance rate vs RPM function. When I originally did this my thinking was to allow the PCM to remove timing faster.

The spark advance rate vs RPM function settings I was using:
0, 0.5 992, 0.5 3008, 0.375 4000, 0.125 8160, 0.125

Versus the original of:
0, 2 0, 2 992, 2 3008, 1.5 4000, 1 8160, 1

So basically 4 to 8 times faster advance rate than stock. So when I went back to the original spark advance rate vs RPM function I am now able to run 23* in the WOT spark advance vs RPM function with no detonation. All I can think of is that the PCM can’t deal with the higher slew rates of the modified spark advance rate vs RPM function. Datalogs before and after these changes are virtually identical. Anybody have any insight here?

Gt90stang, Don



Wow, you run more timing than I do and I have Meth/H2O injection. You do have lower compression and boost though. Good you were able to fix it, though I never messed with that function so I can't help you. I am seeing about 20.5 degrees max above 4500 RPM. I do pull timing via TTNOV to keep tire spin away at launch, but I pull most of it (6 degrees) @ 3000 RPM and am only pulling 2 @ 5k & none @ 6k, so I don't think it hurt performance that much. Did you use the same amount of timing pull in all cells? I pull more if the load goes down because that means the tires spun. Anyway, that's the way I use TTNOV. it may be that the datalog does not catch the timing changes due to how fast you rev out in first. It is known that the TwEECer does not log a lot of data at fast rates of change (like in 1st gear in a blown car). Anyway, sometimes success is the best explanation and the only one you need :banana:

[QWKSNKE]

Please explain...

They suck :P

I have seen a few members on this site (including myself) have nothing but trouble with these meters. We use to be a dealer for them but after seeing many problems with them I made the call to quit carrying them within about 8 months and I do not recommend their meters whatsoever on any car.

[Cougar5.0]

I have had nothing but luck with them.

C&L 76mm w/ 24's N/A

C&L 76mm w/36's S/C - 8 psi

C&L 80mm w/36's S/C - 8 psi

C&L 80mm w/42's S/C - 11 psi

Each time I simply changed the sample tube and adjusted the MAF curve accordingly. I am now running the 80mm with the "Tuner Tube" and it provides a super clean signal from idle to over 3000 kg/hr if needed. There aren't many meters that can do that.

I would use a C&L w/Tuner Tube over any meter on the market & I love the flexibility it offered me over the years. A new injector or max. flow rate was just a sample tube away. I did a survey on a huge Mustang hop-up site a while back and a huge majority of the complaints were about ProM/PMAS meters. People can believe the bashers if they want, but all meters have issues when people who refuse to get a tuning device think they can just throw on a new meter and larger injectors and go. Then they blame the meter - unbelievable!! :devileek:

[gt90stang]

Hi all,

Thanks for the replies. Yeah, I have both Spark advance vs ACT functions pulling 10* at 254*F, so it really only sees about 21* max and less as it heats up.

Both C&Ls that I have used (73mm & 76mm) required tweeking the MAF curve with a WB02 and I now am seeing some strange pull back areas (not huge) that are noticable in the MAF, MPH and RPM plots at WOT. These are probably due to the C&L MAF. Anybody else try the tuner tube in the 76mm C&L MAF with 42# injectors?

Don

[Cougar5.0]

Hi all,

Thanks for the replies. Yeah, I have both Spark advance vs ACT functions pulling 10* at 254*F, so it really only sees about 21* max and less as it heats up.

Both C&Ls that I have used (73mm & 76mm) required tweeking the MAF curve with a WB02 and I now am seeing some strange pull back areas (not huge) that are noticable in the MAF, MPH and RPM plots at WOT. These are probably due to the C&L MAF. Anybody else try the tuner tube in the 76mm C&L MAF with 42# injectors?

Don


I'm using it with the 80mm MAF - don't see why it would work differently with a 76mm. A lot of people don't even know about the tube yet. It pulls air from the bottom of the tube near the middle of the meter so it is more resistant to back-pulses and bends in the piping before and after the meter (the main problem people have with meters is they've changed the intake tubing). Even the STOCK A9L programming has several places where AFR was modified @ WOT (OL), so since even Ford with their little 60mm meter couldn't get it perfect, the idea that any meter could be perfect is some bizarre internet fantasy. If you were a mechanical engineer or had read about meters as much as I have you would realize that 99.99% of the people on the internet haven't the foggiest notion about airflow meters.

[QWKSNKE]

but all meters have issues when people who refuse to get a tuning device think they can just throw on a new meter and larger injectors and go. Then they blame the meter - unbelievable!! :devileek:

I agree. That was the problem with the C&L on Italian's car. It couldn't be cleaned up with a tuner

[Cougar5.0]

If it can't be cleaned up with a tuner, then the electronics are bad/got damaged/are dirty. I have two sets of electronics so I was able to verify that one set was indeed bad. Having used two different diameter tubes (76 & 80mm) and 5 different sample tubes (clear, black, red, blue, and Tuner), S/C & N/A, I can verify that the meters have no inherent issues with being tuned. If the meter has a bend immediately before or after it, then all bets are off - but this is common sense stuff. Here is a post that discusses all this stuff. I love his description of a ProM Bullet meter:

The Bullet is for all intents and purposes is a ****ing fluted exhaust pipe with a molded plastic "sampling tube" with a draw-through slot cut in the back of it shoved into the pipe.

Read the whole post here -->http://forums.corner-carvers.com/showthread.php?t=8535

I could point to a dozen folks who have cursed to high heaven using a ProM or PMAS meter, so examples of people who can't or refuse to tune properly or give up after 2 days are a dime a dozen...

[gt90stang]

Cougar5.0,

Do you have a pic of the tuner tube either in the MAF or out doesn't matter. I tried to check it out on the C&L website and the pic they show has it picking up air near the edge of the MAF tube (same place as my green tube does)?

My car runs pretty good now with the original 76mm C&L with green tube. I'm running the stock airbox and plumbing with a K&N and the silencer removed. The Blowzilla uses the MAF as a draw through, I only get a few small wiggles in the RPM, MAF and MPH curves on WOT acceleration. I think due to noise in the MAF signal from the C&L, but nothing major. AFRs, spark and boost look good.

GT90Stang, Don

[Cougar5.0]

If you are using the TwEECer to log, the wiggles in the plots are more than likely due to sampling errors - the TwEECer just misses points or grabs a noisy one or duplicates instead. I have logged the C&L MAF & other parameters using my LM-1 which logs the voltage directly and the curves are smooth and consistent.

With the tuner tube, when I say it samples closer to the middle, I am describing the bend down at the back of the sample tube where is "draws" air in from near the middle of the meter. This "venturi" type pickup makes it more immune to back pulses and it compensates for pressure differentials between the middle and outer perimeter of the meter - making it more immune to irregularities in airflow caused by bends etc in the intake piping.

http://www.cnlperformance.com/images/2Tuner85mmComp.jpg

[gt90stang]

Cougar5.0,

Cool, Thanks

So can I just buy a Tuner tube for my 76mm and put in the new transfer function? That would be cool and lower cost, I don't think I need a bigger MAF due to my Blowzilla with standard input plenum and 70mm TB.

Near the 1st gear shift I can feel it pull back a little and it shows up on the datalogs also. Maybe it is the AOD shifting...1st goes pretty quick!

GT90Stang, Don

[Cougar5.0]

Cougar5.0,

Cool, Thanks

So can I just buy a Tuner tube for my 76mm and put in the new transfer function? That would be cool and lower cost, I don't think I need a bigger MAF due to my Blowzilla with standard input plenum and 70mm TB.

Near the 1st gear shift I can feel it pull back a little and it shows up on the datalogs also. Maybe it is the AOD shifting...1st goes pretty quick!

GT90Stang, Don


I bought the Tuner Tube for my 80mm and input the new curve. I was pegging the other tubes and just wanted to run more in the linear range of the meter. I have had pullback in 1st due to running into the rev-limiter, blowing out spark, uncovering the sock in the gas tank & pegging the MAF! Everything does happen fast & it's not always easy to figure out what is causing the pullback since the TwEECer misses a lot of data up top.

[86GT]

I have to agree with Cougar50. I used the C&L 73 with the tuner tube and a set of 42s. It made a hugh difference. I have a picture of it if you would like to see it Send me an email.

I will never use another C&L without the tuner tube. I was able to use the straight tubes but once I saw the difference the tuner tube made I was convienced the straight tubes were not as good.

[QWKSNKE]

I have to agree with Cougar50. I used the C&L 73 with the tuner tube and a set of 42s. It made a hugh difference. I have a picture of it if you would like to see it Send me an email.

I will never use another C&L without the tuner tube. I was able to use the straight tubes but once I saw the difference the tuner tube made I was convienced the straight tubes were not as good.

hmm. to bad they didn't have these tuner tubes a couple of years ago

[86GT]

hmm. to bad they didn't have these tuner tubes a couple of years ago

I think they did, they just were not advertised. I have had mine about a year and a half. I only found out because when I called I was able to talk directley to Lee.

[Italian LX]

I think they did, they just were not advertised.
Bad marketing mistake on their part. Their crappy meters with the straight tube design left a bad taste in my mouth after I work with it for over a year trying to give them the benefit of the doubt. I have since gone with a PMAS meter and had excellent results and now I advise poeple to steer clear of C&L.

[Cougar5.0]

Yep, even though I had no major issues with all the combinations of straight-tubes that I used previously, I was immediately impressed with the lower voltage noise after switching to the Tuner Tube. This is most noticable when I am lugging up a hill in 5th gear at 1100 RPM or so on the back roads around here. I hadn't previously thought this was possible with a slightly lopey cam that wants to idle at ~800 RPM. That and the fact that it can flow to over 3000 kg/hr using the 85 mm tube and it's an all-round winner for me.