Didn't want to hijack anyone else's thread....So when you're running the 1/4 mile what would be the result of running lean and running rich? time wise 60 feet and 1/4 ET?

 

Depends on how far in either direction. Too lean and you start melting pistons. To rich and the car will spew smoke and possibly back fire. Not as extreme as mentioned above but outside of ideal would result in about the same thing either way; slower times. Too rich and the combustion is too cool limiting power. A little too lean and knock can start which when the ECU hears it will back off on timing. This also kills power.

But if you had to go to one side of optimal, side with running too rich.

Below is an example of power between a properly tuned car and one which is having fuel issues; turned out to be the FPR. The first plot is from my first dyno with the blower which confirmed there was a problem which I ended up fixing. The second plot is with a properly functioning FPR. That is a significant difference between proper tuning and poor tuning.

 

If you fuel-air is off, you will obviously see bad times. The MPH trap speed is a good indicator of the HP your car is making. If you have good 60-foot times, but abnormally low trap speeds, you might look for power-making problems (as opposed to traction etc.)

To be sure, you would need to pull plugs out during a full power run and cut power instantly to look at the plug color. I don't think that would be too practical as the plugs are not exactly a 2-minute operation to pull (on some cars, it only takes a few seconds to spin a plug out to get a "read of the plug color")

So, you probably want to be near 12.8-13:1 fuel air at full throttle if you’re not using S/C, turbo, NOS (F/I) (I presume your N/A).. If you are using S/C, turbo, NOS, you would want to keep the car rich to protect it.

So, would you be willing to head to a dyno shop for a few pulls (make sure you tell them you want the fuel-air monitored during the pulls -- they will hook up a wideband 02 sensor and you will know what's up.)

An EGT (exhaust gas temp) sensor and/or wideband 02 sensor would keep an eye on your air-fuel and exhaust temps from idle to WOT.

And, don't forget about the actuator.


BTW, I would mention looking at the tail pipe for black smoke (too rich), but you would have to really be burning pretty rich to get that. And, if you are too lean, you are probably going to overheat something and melt a piston. You'll get detonation if you're running too lean at full power.

 

The reason I ask is, when I tracked my TLS I had some controversial yet excellent 60' times, but horrible ET's in relation. My car was stock at the time. Later I got some headers which I removed when I bought my CLS 6MT. A guy at a do it yourself autoshop looked at the headers and said I was running lean. They're kind of purple and goldish in color. So I was wondering if running lean would cause a good start but poor finish? Or could it have been something else, poor driving, or a fat ass!?!?

 

I would definitely do the dyno....when funds are right!

 

Scalbert is that 323 wheel hp???

 

The SS header aging process makes for some interesting colors/hues... And, they don't need to be running lean to get that golden color...

 

Just so I understand correctly, there was some other stuff going on besides just correcting your a/f to get that much increase in power. But the WHP is stunning, more 100 WHP over stock!!!! Before the I/C Manifold!

 

The headers only had about 10k miles, and were about 6 months old.

 

Since (seemingly) it's a dyno, it's gotta be. And (conservatively) that translates to between 360 and 380 crank hp.

Kudos.

 

So, were mine and the others I looked at...

 

Since I got my s/c I noticed I have black carbon build up around my exhaust outlets all the time. I wipe them down every few days but I can't believe how fast it comes back. I wonder if I am running too rich? I know it wasn't like that before the s/c.

 

That is normal and starts occuring imediately after installation. That is not an indication of a lean condition. Since you have just basic mods I would not worry about running lean.

 

Actually, that was before the IC and more boost. Right now it is certainly higher than that; easily over 350 WHP at this time. I am waiting on another pulley before heading back to the dyno for more pulls.

 

Nope, just getting the fuel right allowed for the increase. I did have the e-Manage installed but it had all zeros for values; no change to any factory value. Essentially, the only change was the FPR.

Now with the IC my goal is to make 150 WHP over stock.

 

It does run richer than stock when at or near WOT with the SC. Any time when into boost the car runs much richer than it would have without the SC at the same throttle input. So additional soot on the tail pipes is to be expected.

The additional power is not without some drawbacks.

 

running lean will result in detonation which could result in melting a piston, throwing a rod, and a lot of other baddddd things.

 

Believe me, I'm not complaining