Projects #003 & #004

I ran the truck (P-002) on the wide band O2 sensor. In a nutshell the only immediate adjustment made was the fuel pressure. I'll write more on it later.

Now I want to talk about the new projects. These are daily drivers.

P-003 - 1995 Acura Integra RS Hatchback
P-004 - 1994 Honda Civic DX 2 Door Coupe

I'll start with P-004 first.

P-004 is my wife's car. It is a zippy little runner. While more zip is always welcome my primary focus with this vehicle will be economy. There are a number of modifications that could improve either zip or economy but right now I'm going to write about a mod that will do both. The clutch is dying so while I'm in there I'm replacing the stock flywheel with a light aluminum flywheel from Fidanza. The flywheel looks like a good unit. This will reduce the overall weight of the car by about 7-10 lbs. That is not a lot but every bit helps. The real benefit comes from it lightening rotational weight. The less rotational weight the easier it is for the engine to rev-up. The easier it is to rev up the engine the less energy required to accelerate. One of the reasons vehicles get better mileage on the freeway is that they aren't spending energy (burning fuel) to accellerate the car. It requires far less fuel to maitain speed than to build it.

P-003 is my daily driver. It has 200k+ miles on it and presently gets about 30 mpg and accelerates well. I would love to build this car up into a fire breathing road warrior but the fact is that I will only be able to get so much from it. If the Integra were a rear or all wheel drive car I would be more inclined to build a serious mill for it but since it is front wheel drive I can only get so much. A car has four tires doing three things - accelerating, braking, and turning. Both front a rear wheels experience side loads durring a turn but the front tires much more of the load than the rear. When you add the force of acceleration you quickly approach the limits of the friction the tires can supply.

A simple way of increasing friction is to make the tires wider (don't give my any of that crap physics teachers pull about the weight being spread over a wider area so the friction is the same with a narrow tire as with a wide tire. The coeffiecent of friction of a tire is not linear. As long as the traction is not compromised (rain, gravel, etc.) the wider tire of the same compound has more grip). I plan on getting wider tires but there is still a relatively low practical limit on the power you can use from a front wheel drive car. There are people who drag race front wheel drive cars. Some people find drag racing to be stupid. I don't. However, I also don't find drag racing compelling. I love seeing the cars run a greatly appreciate the work a research that goes in to the cars but I don't want to do it. I like curves and most of the things you do to a car to make it a good drag car make it hadle curves poorly.

My original plan had been to modify the cylinder head and the cam to get some significant flow improvement. I quickly found in my research that this was not a viable option because everything was pretty well optimized already. So then I was thinking about a super charger. but the output on superchargers tend to drop off with RPMs. Turbos, however, do not. However, turbos (good ones) are not cheap nor are the bits that go with it. Additionally, how much power will I be able to use from a turbo? This will also hurt the gas mileage some. Today I came to the realization that nitrous oxide injection just might be the ticket. I was going to install it on the turbo version to eliminate turbo lag but now I think it might just do it on its own. N2O can be set up in stages to give pretty specific levels of output. Right now that is where I think I will focus on the big power. However, there are other areas.

• Get the propper alignment angles. The car was lowered by the previous owner so the caster is out of spec.
• Cold air intake.
• Free flowing exhaust. I'll start with the muffler.
• New suspension bushings.
• Water injection. I'm thinking about setting this up for daily driving to I can run more spark advance. I need to read up on the car's ignition system.
• MSD type ignition? With all the complimentary upgrades. I'm not sure if it would help much. The car is definitely of the open chamber design but the combustion chamber may be small enough that it doesn't really matter. If/when I install N2O I will have to upgrade to something to make ignition absolutely certain.
• N2O
• Wide low profile tires. How wide? I don't know. I need to talk to some tire shops about what will fit. I also need to find some rims that I think are worth spending money on. I am one of the biggest rim snobs and there are very few truly good looking rims out there. I'm looking for a clean, simple, open, 5-spoke wheel.
  
  
  Something like that. Unfortunately that is a Porsche wheel and I haven't seen anything like it for an Integra.
  
• New clutch.
• Aluminum flywheel.

I'm sure more ideas will come but that is what I have for now.

The owner of P-001 is back in town so I may be doing some work on that too.
Builder

Project #002 Phases 1, 2, & 3

Phase 1 - Exhaust Leaks
Exhaust leaks are eliminated. Replaced both donuts on the manifolds and installed one of the Remflex gaskets on the passenger side manifold. This was a piece of cake until I got to the top rear bolt on the manifold. I am very grateful this is not a modern vehicle, otherwise the bolt would almost certainly have broken off. In the end it came out and it all went back together just fine.

The other gasket will need to be replaced but it is fine for now.

Phase 2 - Reliable Ignition System
The ignition system is not quite as reliable as I would like but I think it is good enough for the initial tuning I will be doing. I have a nice set of Accel spiral core wires for the truck. If these wires are treated right they should last for nearly the life of the rig so I want to do a nice job routing them. When I bought the wires I also bought a plug wire stripper and crimper tool. This turned out to be a total wast of money. First, the plug wires came with a set of vice mounted crimpers. Second, the wire strippers suck. It is important that I get nice clean stripped ends to get a clean wire install. So I ordered another tool that I think will be just the thing. Unfortunately it is a special order item and hasn't arrived yet. This puts the whole ignition system upgrade on hold. I can't install the new ignition box and coil until I install the new plug wires and I can't install them until I get the wire stripper. I'm using this time to get the wire routing sorted. I will be ordering some wire routing accessories this week. They'll probably get here before the wire stripper. The present ignition system will be good enough for our purposes we just won't know how lean we can go in a few driving circumstances.

Phase 3 - Carburetor Tuning
This is the one I really wanted to write about. The carburetor is a Carter AFB competition series. This will be the routine we follow:

1. Tune primary barrels at low manifold vacuum (high load) and WOT (Wide Open Throttle). Lock out the secondaries so we are just measuring the primaries. This will establish the jet size. There is no point in adjusting the metering rods if the primary jets won't flow enough fuel. I will be using the metering rods with the narrowest enrichment diameter (They will flow the most fuel).
   
2. Test A/F ratio with primaries at WOT over varying load conditions. I will want to see when the metering rods are moving and how the air/fuel ratio looks.
   
3. Tune/observe primary part throttle A/F ratio over various manifold vacuum readings. I am not sure how well I will be able to tune this because of the metering rods I have. This is where the metering rod tuning will commence. There are three tuning areas. The metering rod's enrichment diameter, the metering rod's economy diameter, and the spring that determines when the metering rods move (i.e. when the two metering rod diameters are inserted into the jet). This is where I will be making adjustments in these three areas.
4. Tune idle and off idle circuits. This carb does not permit easy adjustment of the mixture of these circuits. The idle adjustment screws only adjust idle mixture VOLUME. It looks like the fuel restriction for the idle circuits is hard to get to but I may be able to do the adjusting I need by varying the size of the idle air bleed. I will have to check in to this before I start drilling. These are serious modifications.
5. Now with these circuits in order I will unlock the secondaries and test the overall fuel mixture at WOT. Since the other circuits should be in order any variance from the ideal (or at least the best achieved at the other load conditions) will be corrected by changes to the secondary jets.

That sounds pretty straight forward. We'll see what the results are.

Builder

Project #002

Vehicle: 1975 Ford F-250 Camper special
Engine: 390

Objective: Improve/maximize efficiency

It has been over a year since I last posted. Many things did not go to plan. But now I have a new project.

The truck tows a fair sized boat and is presently getting 4 MPG. I think that can be improved to at least 8 or 12 while it is towing and perhaps even twenty when it is empty. The issue is efficiency. This means that a properly metered mixture is well atomized and evenly distributed to the cylinders in a way that keeps the fuel in suspension and is then introduced into a well designed combustion chamber with enough swirl to completely burn the air fuel mixture when it is ignited by a very reliable ignition system with a well chosen advance curve and the exhaust leaves through a nearly zero back pressure exhaust system.



I see this job having many phases. There are a few that may overlap.

Phase 1
Eliminate all exhaust leaks.

The Ford 390 is notorious for its manifold gaskets failing. I've throw down the gauntlet and bought some Remflex exhaust manifold gaskets. I have not installed them yet but I have heard a bunch of good things from various people in various fields. I personally had a very good experience with the company. They are located in Washington state where they make the gaskets. I called them up and spoke to a human being who actually cared whether I got what I needed. I really hope their gaskets are as good as their service.

When I do this I will need to replace the manifold bolts. The gaskets are a lot thicker and the bolts are 33 years old.

The reason this is important (besides the exhaust leak) is that I don't want to get a reading on my wide band O2 sensor that is falsely lean. This will lead me to make the mixture richer than it should be and that will hurt the MPG.

Phase 2
Make the ignition system reliable.

There are two parts to this.

First I will replace the spark plugs, plug wires, and cap and rotor. This will make that side of the ignition system solid. I will be using spiral core wires instead of the usual carbon filament type. They cost about two or three times as much but almost last forever.

Second, I am in the middle of researching ignition enhancements. Specifically the multiple spark discharge type of ignition. David Vizard says in his book "Performance With Economy" that they virtually eliminate misfires and greatly reduce the time the choke needs to spend on. This is an obvious potential economy improvement. The question is how much will it cost. This may be a later addition.

Phase 3
Tune carburetor.

I have purchased a Zeitronix wide band O2 sensor. This was not cheap but considering the features you get it's a great value (It plug into your computer and gives you simultaneous data-logging of RPM, A/F ratio, manifold pressure (vacuum in this case), exhaust gas temperature, throttle position, and a user determined input of 0 to 5 volts. I bought the additional MAP (Manifold Absolute Pressure) sensor so I can look at the screen and get a pretty good idea of what is going on. I have attempted multiple times to dive into this carb using a single wire lambda sensor but it only got me close. This setup gives me an actual air/fuel ratio. With a real A/F ratio there is no guessing. . .as long as there isn't any air getting into the exhaust system up stream and there aren't misfires sending cylinder fulls of air and unburned fuel into the exhaust (hence phases 1 and 2). I did a quick check and I found the A/F ratio was around 11:1 full throttle/full load (It shouldn't be any lower than 12:1 and in this case I'm shooting for 13:1 or 13.5:1) and it got as lean as 15:1 only for brief moments. So it looks like there are some sizable improvements to be made.

That covers the immediate future. At some later date I will delve into the following

Phase 4
Design and install new exhaust system.

Phase 5
Major work
- Port heads (for efficiency - see here)
- Enlarge exhaust valve (perhaps)
- Address any valve shrouding
- CC Heads
- Intake with good flow and mixture distribution (Stock, modified stock, or aftermarket. Whichever looks to be the best)
- Wide LCA (Lobe Center line Angle) cam.

Phase 6
- IR intake system.

Builder