To remain consistent with my “mod baseline” research; I patterned this thread title after SL55 Setup Fact, Fiction or Matter of Opinion?. Pulley/ gauge were installed yesterday and weather permitting, I will hit the track today making three passes to obtain numbers. I put about 50 miles on it last night driving normal (daily), moderately (quick acceleration), and hard (WOT). The car was already fast so my butt dyno has not changed and I need numbers to tell the story.

Side note:
My gauge is a combo that reads boost and A/F, let me know what you think about my readings.

• On start up the boost gauge reads –8 to -7 and the A/F starts out optimal, then begins bouncing throughout the lean/ optimal/ rich ranges.

• Under normal driving, boost level ranges from –6 to –4. While A/F readings bounces throughout the three ranges, never holding in any range.
• During moderate driving, boost levels range from –0 to 8 and A/F readings hold slightly in the rich stage, then begins bouncing.
• When at WOT, boost levels range from 13 to 15 and A/F reading becomes a permit fixture in the rich stage.
• Any time I remove my foot from the accelerator boost reads –8 and A/F becomes a permit fixture in the lean stage. Once accelerator is reengaged boost level returns to “normal” and A/F starts bouncing throughout the ranges.

 

Sounds to me like tuning would be in order. Question is, would the "tune"
being offered by various vendors resolve this fluctuation? Also, did you
happen to notice these fluctuations in the stock config?

Coyote

 

When you are taking your a/f ratio reading directly off the factory o2 this is normal. The factory oxygen sensor constantly looks at the rich/lean condition and tries to keep it in a range that optimizes fuel economy. and detect any abnormalities( switching as much as 100 times a minute from rich to lean). The only way to solve the problem is to get a seperate wideband o2/ Or consider it normal during daily use. It only matters under sustained wide open throttle periods, as this is the only time that power is made anyway and engine parts can get hurt. Running lean at idle and cruise is just conserving gasoline. The object is to make precise power under WOT only and conserve fuel otherwise. And a custom tune would take care of the problem of running too rich under WOT. Hope this helps.

 

Wideband looks like its reading fine to me.

Lower boost than I would have expected from a 181, though.

 

Throw that narrowband AFR gauge in the trash................Wideband is the only AFR gauge anybody should buy.


As far as your vacuum/boost readings go it looks like you might have a small boost leak. Did you remove the intake manifolds ever? Most cars(all that I've owned) read around -16 to -18 at idle and during cruising.....................and the MOST boost I have ever seen with my 185 pulley is 18.9psi(which happened only once) to date.

 

He doesn't have a wideband, he is using the factory sensor! And yes boost is low should be above 18.5 or so.

 

Ah, I didn't look at the Vac. Most cars are -20 to -18 idle, from my experience. I didn't realize he was using a narrowband either. Oops.

 

Intake, Pulley, Tune, Cooling

This is the mod path we all seem to be going - and then asking the question in between mods - does it really work?

Mod #1 - Should be cooling the IAT's to the MAX before anything else (bigger HE, pump, separate coolant sources, heat wrap, etc..)

Mod #2 - Preparing the engine to flow more boost (Intake & perhaps headers?)

Mod #3 - Adding more boost (Pulley)

Mod # 4 - Tuning this combination up (ECU)

I didn't follow this route - I went 2,3,4,1

I truly feel that once you tame the IAT's - the performance gains from the other 3 mods (all which will increase the IAT's and will affect your timing) will not be lost on you......

The bigger you do each one, the bigger the performance gains you will see.....

But if you don't address the IAT first...

I feel an IAT gauge is more important then an A/F ratio gauge - unless you are going to tweak the ECU settings continually. You can actually do something about the IAT's.....if you have the right setup.

 

[quote]When you are taking your a/f ratio reading directly off the factory o2 this is normal. The factory oxygen sensor constantly looks at the rich/lean condition and tries to keep it in a range that optimizes fuel economy. and detect any abnormalities( switching as much as 100 times a minute from rich to lean). The only way to solve the problem is to get a seperate wideband o2/ Or consider it normal during daily use. It only matters under sustained wide open throttle periods, as this is the only time that power is made anyway and engine parts can get hurt. Running lean at idle and cruise is just conserving gasoline. The object is to make precise power under WOT only and conserve fuel otherwise. And a custom tune would take care of the problem of running too rich under WOT. Hope this helps. [quote]
MD SRT6,
You are 100 % correct Sir! I sought some feedback about those readings yesterday and was provided information echoing your comments. Everything is operating as it should and I am considering it normal until deciding on a WB O2.

[quote]As far as your vacuum/boost readings go it looks like you might have a small boost leak. Did you remove the intake manifolds ever? Most cars(all that I've owned) read around -16 to -18 at idle and during cruising.....................and the MOST boost I have ever seen with my 185 pulley is 18.9psi(which happened only once) to date.[quote]
Moparrbust,
The driverside mainfold was removed and tapped. I will go back and verify everything is sealed, as it should be. Is this the only place a boost leak could occur?

Any one really know the stock boost level? If I should be seeing a boost level of 18 psi, then would Moparrbust have a leak if he were producing 18.9 with a 185 pulley


[quote]
Intake, Pulley, Tune, Cooling

This is the mod path we all seem to be going - and then asking the question in between mods - does it really work?

Mod #1 - Should be cooling the IAT's to the MAX before anything else (bigger HE, pump, separate coolant sources, heat wrap, etc..)

Mod #2 - Preparing the engine to flow more boost (Intake & perhaps headers?)

Mod #3 - Adding more boost (Pulley)

Mod # 4 - Tuning this combination up (ECU)

I didn't follow this route - I went 2,3,4,1

I truly feel that once you tame the IAT's - the performance gains from the other 3 mods (all which will increase the IAT's and will affect your timing) will not be lost on you......

The bigger you do each one, the bigger the performance gains you will see.....

But if you don't address the IAT first...

I feel an IAT gauge is more important then an A/F ratio gauge - unless you are going to tweak the ECU settings continually. You can actually do something about the IAT's.....if you have the right setup. [qoute]
BB
Being new to the moding scene and I know I’m not only new member upgrading. You guys have knowledge that this newbie and other newbies are seeking, which is the reason for my threads . I’m getting baseline numbers and information for each mod, to better understand cause and affect. Completely maximizing performance is not my intent because track visits and dyno runs will stop after the ECU tune. I understand heat soak/ IAT temps are performance killers but under daily driving conditions they mean nothing.

 

I drove the car all day, on those days I went to the track for my first set of runs with the intake and pulley. Yes, the car was suffering from heat soak/ high IAT temps after running it all day and then trying to get baseline track numbers. That’s why my best runs have come on my second track visits, after I leave the car in the garage and only drive it to the track and back home.

With that said, the first visit showed a slight improvement compared to the intake mod.

1st Best Run
R/T- .586
60’- 2.074
330- 5.606
MPH- 65.52
1/8- 8.506
MPH- 83.48

2nd
R/T- .752
60’- 1.992
330- 5.609
MPH- 62.54
1/8- 8.571
MPH- 81.21

3rd
R/T- .520
60’- 2.290
330- 6.314
MPH- 60.58
1/8- 9.306
MPH- 81.12

Traction on stock PS was a problem.

 

Wow, that is almost a pointless improvement over just the intake by itself. If my car puts down numbers only slightly better than what I did with just my NW intake I'm going to be pissed.

 

Don't worry, that wont happen! Honestly though, Everyone running these SL55 setups and "home made" CAI are not touching the numbers(1/4mile wise) that the NW intake has produced IMO. I could be wrong, but NW seems superior to the rest.

 

Yeah, I know but we will see if my second visit theory holds water.

 

Sorry but have you looked at my SL55 FFO thread? Dyno numbers say different, if that’s our gauge .

 

More then likely that's exactly what will happen. Look at the numbers the folks at the Midwest drag shootout laid down. they all saw around 12.5sec runs and then heat would catch up them. Heat kills your peformance. (but this should be nothing new - everyone who's been to the drags has said mentioned this)

I saw this happen to my SRT after 20 dyno runs on a 90deg day. No intake, No pulley, No air cleaner is going to save you from the heat.

IAT cooling mods are should be your first mod....

 

I ran 12.84 @ 109 with SL55 complete intake on stock tires at 2200ft. above sea level. A bunch of people on here claiming SL55 intakes just by the "y" tube and modify it to fit on the stock airbox............which is pointless and won't see the gains. A correclty installed complete SL55 setup will make just as much(if not more) power than any other setup..........the only difference is you don't have the LOUD s/c whine.

 

I will agree with you that we get plenty of air. I hear the SC whine briefly when I first stomp on the gas sometimes and then all I hear is the roarof the engine and air being sucked in. Things start going past the window very quickly.

MikeR

 

Have problems with my SLK32 when i put Kleemann-pulley (178)l, sometimes i only have 0,9 bar (should be 1,28).

Yesterday i intall Let-wheel 185 and get same problem, its load only 1,33 (should be 1,55)

I change my sparkpluggs and my problems are gone.

now its load 1,55 bar (22,5 psi) all time!

Sorry my bad lang....Swedish....

 

Don't worry , I was born in the US and still can't speak proper English. Good find with the spark plugs. What was wrong with the previous plugs or better about the new ones?

 

x2............I was considering pulling mine and gapping them down a little to see what happens. I have 1 step colder NGK's at factory gap currently.