Basic tuning overview

[mtxcontourSVT]

I noticed a lack of information in the tuning forum and decided to post my notes. I hope this creates some more in depth discussion. Thanks to Demon and Warmonger as almost all my notes are taken from their posts. Please post any corrections/additions.

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Hardware:
-SCT xcal2 Pro Racer Package (PRP)
-wideband 02 (2 most popular described below)

Innovate Gauge is really nice and ties right up to the LC1.
The LC1 has more outputs than AEM. You can plug right into the jack if you want to datalog with their software or an xcal2 even while you have it running the gauge.

AEM works and costs a bit less but I think the innovate offers more features.
You just buy a 1/8" phono jack and wire it to the analog#1 or #2 inputs on the xcal2 cable. The xcal2 should come with the cable you can cut the end off or buy a male/female adapter for the cable. The cable is a 9pin DIN input

LC-1/LM-1 Integration into SCT’s Xcal 2
http://www.innovatemotorsports.com/resources/Xcal2_tutorial.php


Books:
SCT Pro Racer Edition Manual - The Basics of Tuning
CarTech/S-A design will be publishing "Engine Management: Advanced Tuning"

Forums:
http://www.sctflash.com/forum/forumdisplay.php?f=72
http://www.innovatemotorsports.com/forums/

SCT has a PRP forum with all the value files and info you could hope for. You just need to have your PRP serial number (whatever the number is that you unlock the software, that is) and PM the Mod for that forum and it will become unlocked for you to use. The additional manual is well worth the added $ and is a must have IMHO

Other resources:
xcal2 prp video cd
http://www.lasotaracing.com/

alex pepper OBDII
http://www.obd-2.com


Definitions:
stoichometric - The ratio at which all available fuel is combined with oxygen during the combustion process. This theoretically ideal ratio produces minimum emissions, however maximum power is achieved at an AFR 10-15% richer than stoichiometric, while maximum efficiency is achieved at an AFR 3-5% leaner than stoichiometric

Air-fuel ratio (AFR) - the mass ratio of air to fuel present during combustion. When all the fuel is combined with all the free oxygen, typically within a vehicle's a combustion chamber, the mixture is chemically balanced and this AFR is called the stoichiometric mixture (often abbreviated to stoich). AFR is an important measure for anti-pollution and performance tuning reasons. Lambda is an alternative way to represent AFR

Lambda – the ratio between actual air/fuel ratio and stoichiometric ratio. Lambda of less than 1 is rich, and greater than 1 is lean.

wideband o2- will give a linear output for the entire range of A/F ratios that you can possibly see coming out of the engine

closed loop - refers to those times when an EFI computer is using the feedback on the mixture provided by the oxygen sensor to effectively control the injected amounts.

Duty Cycle (DC)– A number indicating the amount of time that some signal is at full power. In the context of an ECU, duty cycle is used to describe the amount of time that the injectors are on, and to describe the “hold” part of the peak and hold injector drivers


Datalogging:

This is probably the basic list and covers most requests
-throttle position absolute
-rpm
-maf AD counts
-airflow in #/min
-load
-open loop flag
-imrc state (if imrc involved)
-Long term fuel trim bank 1
-long term fuel trim bank 2
-Short term fuel trim bank 1
-short term fuel trim bank 2
-O2 sensor bank 1 forward (or upstream)
-O2 sensor bank 2 upstream
-coolant temp
-intake charge temp
-spark timing
-knock sensor retard

You need to do both (steady throttle and WOT). At idle, at light cruise in 3rd gear, and then a 3rd gear pull from a lower rpm.

During your light cruise datalog runs, pick rpms that are easy, such as 2000, 2500, 3000, 4000 rpm so that you have several runs that represent different airflows and throttle positions.

Then the full throttle run from say 1500 all the way to redline in 3rd gear will show how the fuel system is metering in WOT mode.
The cruise runs will show how your O2 sensors are working along with your MAF and of course the fuel trims will help determine how closely the tune is matched.

Find an out of the way street. Sit in neutral turn on the datalogger and rev the engine up in about 750 rpm increments. Should be about 6 reference points. This will show how to tune your idle and cruise. Then do a quick run through 1st and 2nd up to about 5k. If you have room get third. Turn off datalogger. You will be stunned how fast it will ramp up to 5k.

For the full throttle runs, data log the following:
injector duty cycle/pulsewidth, load, tps, rpm, IAT, o2 sensor voltage just in case on both banks, fuel pressure, maf flow (#/min would be nice), maf volts, degrees advance on timing


Throttle position:
60% positive TPS movement from base.
Base is set when the PCM powers up. (Normally around 18-20% but it's all calculated from TPS voltage)
Now that DOES NOT mean 60% movement of the accelerator pedal.
Base is 18-20%
Max is 92-94%
So the range is ~74%
Therefore that would be about 81% depression of the accelerator pedal to engage WOT


Intake Manifold Runner Control:
The IMRC adds 10-14 degrees above the base timing curve.
Without it you can probably add at least 5% top the base timing below IMRC and smoothly transitioning to upwards of 15% increase as you go above 4000rpm. That would be my guess for a car with no secondaries, NA on 10:1 compression. You of course have to adjust that based on your own compression ratio and/or boost/nitrous if applicable.

There is NO IMRC adder when not at WOT.
The IMRC adder does not apply if the IMRC is closed.
The IMRC is closed below 4100rpm unless at WOT. Above 4100rpm then the IMRC adder still only is added when the IMRC is open.

You will not get any Timing or Fuel bump before the IMRC point programming in the PCM. (SVT is 3400rpm & stock is 3800rpm at WOT - other times both vary but by 4100rpm they are always open)

Stock setting is, when above 4100rpm no IMRC unless +45% from neutral throttle position. It does not scale the timing!
The IMRC adder is a set number (dependant on other variables) as set in the IMRC_spark_add_base_spark table.
The adder however is always 100% of what is set in that table.

You can datalog this all day long. As soon as that IMRC opens you get a "set" spike in timing. There is no "partial" IMRC opening or timing scaling for partial IMRC opening.

So in conclusion, Timing advance is scaled slightly per RPM, jumps up +10 degrees at 3400 to +11 around 3900 and stays there.
IMRC opening is scaled from 3400 rpm with activation at WOT at 3400 to down to open at any throttle position by 4100 rpm.
So at half throttle they won't open until 3600rpm at 1/4 throttle probably won't open until 3700. ETC

Your statement that if the RPM and TP reach the levels set in the code the timing adder will be added is correct. However they are added because the IMRC actuates. If the IMRC trigger switch does not tell the PCM the IMRC plates are open then the spark advance never happens. Also the timing advance is delayed by the actual opening time. Once it receives that signal then it adds the 11 degrees or 10 degrees of timing. I usually just skip the 11 degrees part because it only applies from 3400-4100rpm.
Either way it's an all or nothing timing boost. Nothing is scaled. That was my point of contention with what you seemed to be stating

With the correct tuning you can completely remove the IMRC.
However "correct tuning" means the tuner has to know how to do it.
The PCM goes into limp mode otherwise.
Also it's not just telling the PCM to work without the IMRC connected but also knowing how to tune the low rpm range without the IMRC adder. The PCM has a timing limiter in it when it doesn't see the IMRC.


knock sensor:
Don't worry so much about the knock sensor. Leave all the settings on it stock until you get the tuning close to done. If you find that you are loosing too much power during the dyno tune due to the knock sensor retarding the timing, THEN would be the time to adjust sensitivity. you will want it to work at the level that the OEM tuners felt was safe.
The sensor has nothing to due with the amount on timing that is removed. That is preset into the PCM programming, it's more like 3-5 degrees off the top and gets worse from there "knock" dependant


Oxygen sensor:
A properly functioning oxygen sensor in a properly running engine should be rapidly switching from .1 volts to .9 volts.
Also, the sensors should bounce from rich to lean and back and if you graph the signal it will look like a sine wave.
If your O2 sensor voltage is .2v and staying close to it, it would be signifying a lean condition.

Also use as diagnostic tools to compare upstream/downstream performance and bank to bank performance


Intake Air Temp sensor:
The IAT has to read over ~150d before it pulls 40% timing. (and it sure better for the engine's sake)

The 4 points are: 0, 76, 140, 160

76 degrees (default) and the PCM call for a +20% timing increase (based on the base spark tables - figure a 2-4 degree increase (which is miniscule really) for the SVT program - less for your's since your base tables are likely half of a stock SVT

IAT does not affect fuel trim. Only spark advance


Engine Coolant Temp sensor:
in the typical driving operation range the ECT affects timing more than the IAT (hot air) does.
ECT timing pull is
-10 at 200
-20 at 220
-40 at 230
-60 at 254
-80 (i.e. default for bad sensor or maxed reading)

The primary fans don't kick on until 216d
The secondary fans come on at 224d
or -18% timing & - 22% timing respectively.

That's just the straight timing pull. There are many multipliers based on temp via load & rpm as well.
That's probably 10 to maybe 20 HP & TQ lost. Hard to quantify since I've never dyno'd the power loss from losing the majority of your spark advance

The PCM clears OL at 120 degrees ECT.
The PCM enters adaptive fuel control at 140 degrees ECT


PCM behavior:

When your throttle position goes less than full throttle the PCM will attempt to advance the timing to clean up the fuel after a full throttle run.
Timing will always spike when the pcm sees a deceleration. Spiking the timing under decel is emissions programming to clear the cylinders.
So you get spikes like that if you press the thottle and let off.
When you go full throttle your timing will drop down and then slowly climb as rpm climbs. If you mash the throttle and then let off a little bit, you will get a quick drop and then a spike before the timing will drop again and level out.

lean spikes at shifts are normal for a manual trans. When you're coming out of the throttle, your fuel and spark are effectively shut off so all you'll have will be inlet air moving through. as the engine will go rich then lean after the throttle snaps shut

A MAF voltage of 4.26 volts on a duratec means you're pulling in close to maximum airflow

The main concern for tuning on your OBD-II car is wide open throttle, the computer will compensate for most other adjustments below WOT that you make.


Fuel trim tables:
The PCM has a set of tables and modifiers that uses to determine fuel delivery for any given situation as a baseline. But, the PCM also monitors the air/fuel ratio using the oxygen sensors in the exhaust to verify that the fuel delivery is what it expects. Due to build variation in every component in the engine, and changes in wear and buildup that occur over the life of the engine, the actual fuel requirements for a particular engine are determined by taking the base tables, and then taking what the oxygen sensor says and using it to modify the fuel delivery slightly to optimize emissions. The resulting modifier value is stored as short term fuel trim. Over time, the PCM records trends in the short term fuel trim, and adjusts the long term fuel trim value to accomodate it.
Fuel trims are basically what the PCM uses to adapt fuel delivery to the small differences between engines, and the changes that occur over an engine's lifespan.

A lean code gets tripped when the PCM goes beyond 30% fuel enrichment for 3 straight driving cycles.
The PCM only uses the O2 as an indication of unburnt fuel to alter it's adaptive fuel trim. It does not use it as a individual catalyst to trigger a lean code. they are not accurate enough to work that way. Especially away from stoichometric.
However they are accurate enough to tell the PCM if it is running around stoich (the O2's peak albeit small efficiency range) and therefore is an integral piece in how the PCM's adaptive fuel trim works.
On a properly running engine (I.E. no leaks) both bank's long term fuel trim will be nearly identical.
Notice I stated Long Term fuel trim not Short Term fuel trim. There is a big difference here.

Injectors:
The injector pulsewidth refers to how long each injector is open for each time it delivers fuel. You can take this number and the size of the injector and the number of injectors and determine the total amount of fuel flow for a given number of engine revolutions. injector duty cycle refers to the relative difference between the injector pulsewidth and the amount of time the engine takes to complete its cycle (the full 4-stroke cycle). Exceeding 80% duty cycle is not generally a good idea

Also it is a good thing I could easily change the high & low slope in the PCM when I changed to the 24lb injectors. (Using a MAF to change injector size by "fooling" the PCM is not the proper way to do it at all!)
I increased the low slope setting in comparison to the high slope setting to help shorten the low rpm, light load, and idle pulse width and keep excellent drivability.
Though if I needed to I could just have shortened the minimum pulse width limit in the PCM calibration too I suppose.
However the way I did it actually improved my fuel mileage in cruising and light load situations.


Air fuel ratio:
Whenever your car goes into closed-loop your AF should bounce between richer/leaner. In open loop the computer relies on the narrow band O2 and it will try to maintain a certain AF

Also, just because it runs leaner that stoich under cruise is not necessarily a problem. It is fine to see 14-16:1 under light cruise.
expect to see 14-15 at idle. When you go full throttle you should see it settle down and stop bouncing. Expect anywhere from 11:1 to 13:1 under full throttle

The A/F ratio is in a constant state of change. That's why it's called adaptive fuel control.
The target number for normal load (40-60%) is stoich. 14.7
No load/engine braking has no fuel trim. You can see 20.9% oxygen (open air)
Low load is leaner then stoich. (15-16)
Moderate load is slightly richer. (13.5-14.5)
WOT is richer still. (12.8-13.3)
Boosted WOT is even richer. (12-12.5)


Wide open throttle:

The PCM at WOT runs more timing and fuel, any trickery to de done here in terms of telling the PCM to run at WOT before the approx 81% movement of the accelerator pedal? Say at about 55-65% accelerator pedal movement.

Yes and no. Mainly NO.

Timing is based on engine load.
Fuel is based on engine load.

WOT multipliers for both are set at 1 so that really does nothing.

That means without the load above a specific limit you are not using the maximum tables anyway. (actually load is broken down into 8 levels even)

Even if you do get a small fuel increase for passing the WOT point. (think of it like an accelerator pump on a carburetor - it's not sustained)

So there is no bonus to getting to WOT faster without actually having the load tables on the maximum level which of course is only achieved with "more" airflow across the MAF.

 

[mtxcontourSVT]

Timing:
There are many things that can affect timing, poor fuel quality, combustion temps, etc. You have to realize also that back-to-back runs heat up the combustion chamber a lot and where a car was running fine on a certain type of fuel and tune in the beginning, it could later be susceptible to ping/knock once conditions in the block/heads heat up.
Also you can have changes in intake air temp that can be just enough to put the intake charge a bit too hot and more susceptible.

The maximum stock advance is 32-36 degrees. (at redline)
Even a "hard core" tune will not push more then maybe 45 degrees.
A typical pump gas tune is ~40 degrees maximum.

You can "actually" run more timing but it's only hurting your cause above that point.

at 100 F IAT you would NOT be adding timing. 100 F is dead on the Zero point for IAT timing changing as is 200 F for ECT.

Another thing to look at is the timing will never ramp higher then the LOWEST of the base timing tables. (plus IMRC adder of course) Well I guess except in very cold weather where the IAT and even ECT adds timing to promote more efficient fuel burn. The lowest of the 4 stock tables is 21 degrees advance at 6750rpm. The base table is 26 degrees. The IMRC adder is 10 degrees.
The "lowest" table is the borderline detonation table. This table comes into play if you run lower then the best octane premium and/or have detonation during a normal driving cycle. Some people say they can't feel a power loss running "regular" but the timing loss is huge so their butt dyno is off by a mile. PERIOD. (it's 5-15 degrees of timing pull all the time! )

This type of thinking rules the tuner world. They try to do timing changes without datalogging if any changes are really happening. MOST of the time they are not changing the timing at all or very little if they are because they forget a table or 3 or had timing changers pulling out significant timing. Tuning without datalogging is only doing half the job.

Oh you can command more timing in the PCM but it NEVER actually happens. Tuning without datalogging is pretty worthless!!!
There is a couple other issues as well
Also you should do some datalogging. You may be quite surprised to see what the timing actually is verses what it is suppose to be.
You can not just change the timing tables and expect it to work right


Calculating spark:

The SCT advantage software has all the tables in it and it has extensive dialogue that tells you how the spark is added/subtracted to the base spark and under what conditions. It is pretty good because it tries to explain how all the parameters interact so you can make good decisions on your tune. With a little practice you can sit down and calculate what your spark should be for any scenario by reading the table values at appropriate points

Here is the math from my spark tables with the best possible conditions:
Max possible spark
__________________
Highest base spark -- 41 degrees above 6100 rpm
ECT spark add/subt -- (100x0.015)=1.5 deg added for cold temps
ACT sparl add/subt -- (100x00.03)=3 deg added for cold intake temps
Spark added when going commanded open loop -- 3 degrees

IMRC adder above 6100 rpm -- 10 degrees

Total is 58.5 degrees

Of course this is max possible spark from my factory base tune under light load conditions (NOT Decel, decel is actually higher)
But, it isn't likely to be that high so, Here's the realistic one:

At .89 load;
_______________
base spark -- 26 deg
ECT add/sub (normal temps 200F-75F; factor 0 to 20 degrees , I'll go with 8 for this example) up to 8 x .05 -- .4 deg
ACT add/sub (cool intake air of 55F) = 55 x .05 -- 2.75 deg
Spark added whend going commanded open loop -- 3 deg
IMRC above 6100 -- 11 deg

Total spark at full throttle -- 43.2 degrees


Adding a larger TB:
Tuning your A/F is unnecessary just because you add a larger or smaller TB. It doesn't make your car leaner or richer.
The MAF is what reads the airflow. If airflow increases then the computer adds more fuel. Period. A larger TB is not going to change that. It may allow more air in the engine at WOT and high rpm but NOTHING that is outside the MAF's range. The only time you have an issue is if the airflow is out of the range that the maf is capable of reading. Though using the stock MAF is a good choice for the power levels any NA engine is capable of.
As long as you have retained your secondaries then running a large TB is not a problem. I ran a 70mm TB on my NA 3L and it worked pretty well. In actuality it made little difference in power above the 60mm TB. Now for a turbo it is a good idea on my car.
Now the reason we use an SAFC to tune with is to adjust what the COMPUTER THINKS that the optimum AF ratio should be to what YOU THINK the optimum AF ratio should be. On the SVT's the computer tunes for about 12.5 :1 in the midrange and then as rich as 11.8:1 on some cars at or near redline.
We have found through many tests that 13:1 gives great power on a naturally aspirated SVT. Even 13.5:1 will net you a few more horsepower but as the rpms approach 6000+ you will want to richen it back up to around 12.75-13:1 so that it doesn't ping under hot weather conditions.
That is the only reason we use an SAFC.

Best practices:
Tuning with the MAF function is absolutely the worst way you can do it. It's no better then hack tuning with a MAF voltage device. (i.e. screws up the load calculations!)
The MAF function should be a direct function based off the MAF electronics and the intake/setup. All your fuel tuning should be done with the fuel tables.

What does the PCM use as a basis to calculate load? It uses the corresponding KG/HR correlation to the supplied MAF Voltage. IF YOU ALTER THE MAF FUNCTION IN THE CODE IT WILL THINK IT IS GETTING MORE AIR THEN IT ACTUALLY IS. That means an inflated load reading. EVERYTHING is calculated using load.
You can not seriously alter the PCM's MAF function (verses the meter's electronics) without seriously corrupting the load calculations. PERIOD.
This is a plain and simple idea to understand.
There is a huge difference between minute changes to fine tune the MAF function to the intake and stupidly tuning WOT fuel trim with it.

Tuning with the MAF function is IMO a cut rate hack job to make a quick & dirty tune. (i.e. it saves their time) It is not an overly stable tune nor an ideal one in the least.
My fuel tables are 12.5-13.3 at WOT and my AFR is ~13 to 1. My PCM MAF function is within 3% of the electronics. The only changes were some fine tuning in the low rpm/low voltage range. Though you must realize that my setup is far from the stock intake setup. That is a properly tuned setup.

IF you set your lambda to 1 and you don't get a corresponding fuel ratio of close to 14.7:1, then your MAF transfer function is obviously not accurately reflecting the the MAF and the airflow.

The MAF is just a sensor to measure airflow. If you enter in the correct function, then the the base table will be the only proper way to tune. The PCM will know the amount of air and add the correct amount of fuel to hit the target lambda.

In reality, the MAF transfer functions aren't all that close sometimes and you need to tune with the function to get the maf to read the correct amount of airflow as possible. THEN you again tune with the base tables until you achieve the desired A/F ratio.

With small adjustments there is no problem adjusting the MAF transfer function.

I am talking about the actual fuel base tables. The basis for all fuel calculations for all times under closed loop. (there is also a separate open loop table) However these tables work the best and are the ones that should be used for making a properly designed program.



Creating a base tune:
the max allowed table is kind of the central table that all the spark timing hovers around.
All of the other tables (except for a one or two) are used in conjunction with the max allowed table. ACT and ECT tables are just multipliers of the max allowed spark value in a particular cell.
So if at 0.50 load and 3000 rpm you have a value of about 20* max allowed advance, the ACT at loads similar to that may introduce an 10% increase in spark at that point based on cool temps, or th ECT may also do the same. Then there is the IMRC which will add more spark at certain loads above the opening point. It ALSO works in conjuction with the max spark allowed table as a base table.

When I was planning out my Max allowed table, I started with stock, increased the load range on the Axes since I was forced induction to about .99 and then put limitations that I felt would be safe in the loads above 0.6 to 0.7 Then I let the computer actually add any timing to those maximum values based on ACT ECT and as long as it didn't go above my maximum desired timing. For example, I didin't want to go above 23* on a cool day boosting 7-8psi, so I did a rough calculation on the timing advance for cells above 0.85 at the appropriate RPM to determine the maximum it could hit, then adjusted the max allowed table accordingly.

As far as the MBT spark tables, they do absolutely NOTHING for advance but after I worked out the timing tables to my liking I adjusted them downward by about the same percentages to keep the computers torque calculations in-line.

Most importantly, I used a OBD II scanner, AND The XCAL2 to datalog while driving around to see what the values and loads were at cruise, idle, and full throttle. After about 5 days I had a good tune and felt comfortable to raise the boost after confirming with the wideband that the AFR was as expected.

Don't rely on the knock sensor tables to appropriately pull back timing as protection. They don't work all that good and you will be losing power in some cases before you actually experience predetonation.

Leave the stock settings mostly alone until you get it driving fine with no codes, doing only what is necessary to correct for intake system changes and other mods. Then change only one major variable at a time, such as increasing the maximum timing at max load, all by 10%, or changing only the last 1000 rpm by some amount. Address specific problems first. Have an overall plan of attack on what you want out of your car.or change the priority order once you know what you want.

I have found that a timing change of just 2* made the difference between a rough sounding engine at high rpm windout to a smooth sounding engine. I mean at 6000 rpm and spinning toward 7000 rpm, you can hear little things that are hard to describe. If you go slowly and increase till you get these audible changes, then pull back a little, you can get a 90% solution before you ever hit the dyno.
You can see, I was able to roll into the dyno in Montgomery and with NO required tuning changes after the first run. I was able to raise the power to the wheels from about 310 up to 355 in 3 or 4 dyno runs just by turning up the boost....at least until the soft wastegate spring began opening on its own. This is the power of the EEC-V adjustable PCM, getting the settings basically right and letting the computer adjust as it needs to, to meet those settings.

 

[warmonger]

Holy shyt! I recognize a bunch of my comments, some of demons and others. I can' believe you saved all of that!

I think I just put myself out of a job for those that understand it...

And man I read all of that....I thought about taking a break or checking on my Social Security check it was taking me so long. lol

 

[BrApple]

I think I just put myself out of a job for those that understand it...

don't worry I am sure I could pick it up but I rather have someone with the experience do it for me, at least in this area ... and that reminds me I need to get back to you about what I want done in my tune so you can get me a price .... also I wasn't able to go out sunday to do any logging, to cold and windy and I got to other things I have been working on ... maybe this weekend

 

[Yawak]

when's the book signing, i'd like to come? :crazy: :laugh:

 

[mtxcontourSVT]

when's the book signing, i'd like to come? :crazy: :laugh:

you should see my 3L notes :laugh:

 

[morbid]

good god! I gave up reading it while at work, I'll have to complete it at home. Thanks for summarizing all the good forum info!

And thanks to the people who supplied the info (warmonger, Demon, etc...)

 

[Barge]

Just to add a couple things.... Injectors and MAF/Intake changes at the same time can cause all sorts of fun. Luckily the Ford Injectors numbers are pretty well known.

First thing I would do with tuning is to set your injectors (or leave the stockers in) and calibrate you MAF using your final air intake setup. You'd be surprised how much a MAF calibration can change just going from the stock intake to a K&N cone filter.

And don't do this...

I would recommend most people that are going to self tune their cars to get 1 step colder plugs.

If you then decide that the plugs are too "cold" you can always go back to the stock heat range.

 

[warmonger]

Just to add a couple things.... Injectors and MAF/Intake changes at the same time can cause all sorts of fun. Luckily the Ford Injectors numbers are pretty well known.

First thing I would do with tuning is to set your injectors (or leave the stockers in) and calibrate you MAF using your final air intake setup. You'd be surprised how much a MAF calibration can change just going from the stock intake to a K&N cone filter.

And don't do this...



I would recommend most people that are going to self tune their cars to get 1 step colder plugs.

If you then decide that the plugs are too "cold" you can always go back to the stock heat range.

What happened....those come out of your car?

 

[Barge]

Out of my CSVT... yeah. Amazing no real dmg came out of that.... ran like a top after I replaced the plugs... in fact my 183hp dyno run was after that.

It kept on getting slower and slower and I couldn't figure out why. I pulled a couple of the plugs (of course I pulled out the good ones) then proceeded to pull the fuel pump and clean it. I then pulled out all the plugs and went "whoops".

Fun stuff.

 

[pierceME311]

Was that as good for you as it was for me? I need a cigarette after that, then lets go some more!!

 

[Redlineracer12]

Can we sticky this? It was getting old enough that it didn't show up in the last 30 days worth of posts...

 

[warmonger]

Okay it's stuck. Just so long as people don't post a lot of BS in a stuck thread.
I'll leave it open until I see that stuff happening.

 

[Kinyoto]

you should see my 3L notes :laugh:

And where would these be???
I'm interested now!

Thanks,
Mike

 

[Dredd]

I want the 3L notes. That was great!