Originally Posted by Reverant (Post 861464)

Post a log of enrichment problems. Its ok if it goes lean for less than 0.1s, as long as the engine doesn't bog down and accelerates as intended.

Originally Posted by hustler (Post 861282)

It will live on as a boat anchor or something. Actually, I'm giving it to RHarris.

Originally Posted by rharris19 (Post 861470)

Where it will live out the rest of its life in style, in a LeMons car.

Our last motor took a solid 60+ hours of racing before it spun a bearing, but really that was because it consumed WAY more oil than we thought and ran low. LeMons doesn't allow you to check those things in hot pits. It also had 270,000 miles on it when we put it in.

This motor should be pretty on par by the sound of it.

Originally Posted by hustler (Post 861282)

Talk to me about this.

Also remember the engine in my car currently is hurt and sad. It detonates on 25* of spark at 4000rpm on 93-octane and I checked timing calibration. It will live on as a boat anchor or something. Actually, I'm giving it to RHarris.

Originally Posted by Wikipedia

EGR in spark-ignited engines

The exhaust gas, added to the fuel, oxygen, and combustion products, increases the specific heat capacity of the cylinder contents, which lowers the adiabatic flame temperature.

In a typical automotive spark-ignited (SI) engine, 5 to 15 percent of the exhaust gas is routed back to the intake as EGR. The maximum quantity is limited by the requirement of the mixture to sustain a contiguous flame front during the combustion event; excessive EGR in poorly set up applications can cause misfires and partial burns. Although EGR does measurably slow combustion, this can largely be compensated for by advancing spark timing. The impact of EGR on engine efficiency largely depends on the specific engine design, and sometimes leads to a compromise between efficiency and NOx emissions. A properly operating EGR can theoretically increase the efficiency of gasoline engines via several mechanisms:

• Reduced throttling losses. The addition of inert exhaust gas into the intake system means that for a given power output, the throttle plate must be opened further, resulting in increased inlet manifold pressure and reduced throttling losses.
• Reduced heat rejection. Lowered peak combustion temperatures not only reduces NOx formation, it also reduces the loss of thermal energy to combustion chamber surfaces, leaving more available for conversion to mechanical work during the expansion stroke.
• Reduced chemical dissociation. The lower peak temperatures result in more of the released energy remaining as sensible energy near TDC, rather than being bound up (early in the expansion stroke) in the dissociation of combustion products. This effect is minor compared to the first two.

It also decreases the efficiency of gasoline engines via at least one more mechanism:

• Reduced specific heat ratio. A lean intake charge has a higher specific heat ratio than an EGR mixture. A reduction of specific heat ratio reduces the amount of energy that can be extracted by the piston.

EGR is typically not employed at high loads because it would reduce peak power output. This is because it reduces the intake charge density. EGR is also omitted at idle (low-speed, zero load) because it would cause unstable combustion, resulting in rough idle. The EGR valve also cools the exhaust valves and makes them last far longer (a very important benefit under light cruise conditions).[citation needed]

Since the EGR system recirculates a portion of exhaust gases, over time the valve can become clogged with carbon deposits that prevent it from operating properly. Clogged EGR valves can sometimes be cleaned, but replacement is necessary if the valve is faulty.

Originally Posted by rharris19 (Post 861470)

Where it will live out the rest of its life in style, in a LeMons car.

Our last motor took a solid 60+ hours of racing before it spun a bearing, but really that was because it consumed WAY more oil than we thought and ran low. LeMons doesn't allow you to check those things in hot pits. It also had 270,000 miles on it when we put it in.

This motor should be pretty on par by the sound of it.

Originally Posted by y8s (Post 861496)

i will just paste from the brain of the internets:

Originally Posted by Bryce (Post 861524)

EGR is for emissions AND fuel economy. The mention of it in this thread has piqued my interest and I'm gonna go unblock mine and wire it up.

Originally Posted by hustler (Post 861536)

I think the EGR solenoid is dead in my car since it no worky. I suspect I can get one on here approaching "free" considering our general disregard for Mother Earth.

Originally Posted by Bryce (Post 861625)

It probably just needs the valve and EGR passage in the intake manifold cleaned out.

I have an extra one somewhere... It just occurred to me that I only have an NB2 EGR pipe, which is apparently somewhat shorter than the NA EGR pipe, and has a different fitting than my NA header. Gonna have to do some welding, I think.

Originally Posted by jacob300zx (Post 861652)

Thoughts on increased gas mileage, HDR apocalypse front lip with birch splitter running all the way back to the trans, wheel spats front and rear /, straight shot intake, light eBay flywheel, with 1.6 6 puck, rear bumper vents, ls1 coils, 100% real gas / no 90/10, do they make 3.30 gears?

Originally Posted by hustler (Post 861636)

The hardware is clean, Johnwag snaked it with his wiener. I have no doubt your plumbing is shorter than mine.

Next time I go to Houston, we should meat up and eat pig guts tacos.

Originally Posted by jacob300zx (Post 861652)

Thoughts on increased gas mileage, HDR apocalypse front lip with birch splitter running all the way back to the trans, wheel spats front and rear /, straight shot intake, light eBay flywheel, with 1.6 6 puck, rear bumper vents, ls1 coils, 100% real gas / no 90/10, do they make 3.30 gears?

Originally Posted by Reverant (Post 861850)

Make sure your <1500rpm high-load cells are properly tuned, otherwise your are band-aiding the actual problem. 1st/2nd gear in an empty log and use the brake to simulate the load.