Clemson Sports Car Club

Bill has brought us his Ford Focus for a tune on SCT. This is Bill's Autocross car and he is looking to just get the most out of his bolt-on setup and cleaning up some drive ability issues from his mail order tune.

Setup:
Header
Exhaust
Intake
Cosworth Intake Manifold

Tuned on SCT.

Some of the symptoms that were addressed in this tune:
- Rev hang up after shifting
- Idle stayed at 1800 rpms
- not as responsive after shifting

In addition to addressing those symptoms, we also disabled the air pump through the tune, along with disabling the EGR system and a number of miscellaneous options. We also moved the a/f ratios from the 12:1 range to the 13.5 range for better performance and cooler under-hood temps.

This setup was tuned entirely with the fan off with more pronounced heat soaked conditions. This is usually how we tune autocross vehicles for those who are not aware.

couldn't rev any higher?

nice flat tq curve.

Wish I could see the pictures here at work, would love to see what it made and the powerband. I am guessing you fixed the sarting issues as well?

I don't know Focus's that well. Is his a 2L or the 2.3L? I am guessing a 2.3 from the dyno.

How did leaning out the airfuels that much decrease underhood temps? I was under the assumption that less fuel would create hotter conditions in the cylinder and therefore in the engine, is that incorrect?

~curious.

Scorke

It's a 2.3 Duratec.

Running 12's with stock ignition values will cause some of the fuel to burn in the exhaust thus raising underhood temps. It's more pronounced in forced induction applications. This only applies in this situation. Different levels of ignition values will have different effects on temps depending on the a/f ratios as well, and this is also influenced by the overlap of the cam(s).

A/F ratios of 13.5 is usually where you want to be for maximum efficiency on n/a applications. There is a .3 wiggle room in short spurts but it should be kept as close to 13.5 as possible throughout the rev range for the most part when dealing with stock or relatively stock cams. While we are on the subject, "Wild" cams will usually call for leaner a/f ratios on the low end and migrate closer to 13.5 in the mid to upper rpm range.

Car could rev higher but I belive there is some sort of issue with the oil pump (possible cavitation or something) according to the owner and he did not want to go any higher.

(05-18-2010 06:27 AM)zps2004 Wrote: [ -> ]I don't know Focus's that well. Is his a 2L or the 2.3L? I am guessing a 2.3 from the dyno.

i would have guessed 2.0, my neon motor makes 130 ft-lbs at the wheels.


that sucks he can't rev higher, almost defeats the point of the intake manifold.

kind of crappy tq for a 2.3 motor,
i guess the runners are fairly short, and a big plenum.
makes sense why the powerband is so high.

i see the manifold has velocity stacks, nice setup, overkill if it can't rev higher.

Hey everyone, it seems that the bug I had in trying to register for the site is fixed, and I can comment back about my car.

Overall, I've been satisfied with the tune, and I was able to drive the car to CMP for the memorial day autox without issue. Car pulls much stronger, and the revs don't hang between shifts like they did before. This was really the primary goal, get the car to a easier to drive state and fix the underlying idle issues I was having.

Regarding the redline, I understand the car continues to make good power past where I have the redline now. There are a couple of reasons why I'm limiting it to this level for now, the biggest one is this: I bought the car with 90,000 miles on it, with the intake manifold already on it. I don't have a good handle on the car's/engine's history, and I don't have ready access to a tow vehicle, so I'm not looking to push the reliabilty of the engine for a few hp at the top end. The car needs to carry me + gear to autox's up to three hours away, and bring me back.

This summer, I'm hoping to finally get a LSD/Clutch/Flywheel installed. After getting some more seattime, and more tire up front, we can revisit the engine with some cam adjustment and other "street prepared" tweaks to get the last bit of power out of it.