http://www.drivendaily.org

There was some data loss, but I hope to be back up to speed soon!

Here’s the link:  http://www.crxmpg.com

I’ve sold Project Anger, and handed it off to a guy who is just barely getting into cars now.  He doesn’t really know what he’s doing, but has a few good mentors.

Darth Z (260z with a 351ci Ford Winsor v8 ready to swap into it) has been sold, along with its donor car.  It is destined to receive a build 383ci Chevy v8.

CRX 2.0

CRX2.0 has gained some paint, knuckles, big brakes, and suspension.  It is still engineless because the wiring harness is pretty much ruined.  I need new ECU connectors off any obd0 Honda.  Anybody have spares?  I need at least one foot of wire on each ECU pin.  Let me know if you have one available, or have a donor car, or anything of the sort that you can ship to me.

I’ve picked up a not-project as well.  It’s a 1976 Toyota Celica fastback.  It’s bone freakin’ stock, and has a few little quirks to work out before I trust it completely.  It was a whole $500, and drove home on its own four wheels.  These little quirks will most likely be the subject of discussion this month.

This car is essentially the epitome of rice racer. It has a massive fart can, is lowered too much, the wheels are too tall and not wide enough for the car, the body kit scrapes the ground on turns, the paint job cost more than the car, and the driver has no idea what he’s doing (throttle control would be a good thing):

Now, I don’t have a problem with making a car look terrible and not gaining performance. What bothers me is the fact that many “rice” modifications are actually dangerous.

My own CRX had clear corners, clear bumper lights, a nasty hairball of stereo wiring, a red-themed engine bay, and cut springs that didn’t fill the strut perches. My big issue is the cut springs. Everything else is physically harmless, but incorrectly cut springs destroy the travel of the car’s suspension, making it skittish and unpredictable. If the car were to go over a bump at a speed high enough to decompress the spring, it could easily wiggle off its perch and suddenly one corner of the car has no suspension. Also, the camber wear on the tires was bordering suicide, especially because the tire would regularly rub against the inner fender well. All around, a horrible idea for any car.

Rice Cop has a wide selection of tickets with the intention that you will print them out and distribute them as needed. Some of the user tickets are especially creative, and you’re encouraged to create and submit your own as well.

Unfortunately, this seems to be an incurable disease. Try not to make fun of them too much, but instead educate them on how cars actually work. If they want a car that looks fast, at least give it the ability to go fast, and don’t endanger everyone else on the road while doing it. Send pictures to Madness Manual and I’ll add them to the gallery for this post.

What’s your definition of rice?

• front crossmember
• DC sport ceramic header
• shift linkage
• new axles
• Si transmission + intermediate shaft
• AEM ram air intake
• motor mounts (with polyurethane inserts)
• virgin pm6 ecu (now I have two, I suppose I could tune one specifically for smogging)
• tuned (fuel map and raised redline) pm6 which probably won’t tune worth dirt

I have an extra set of hands, so I’m going to pull the old d15b2 and figure out what I’m going to do with it.� It might become a parts motor for the d16zc, or it might get traded for something more fun.� I honestly haven’t decided yet.
I have yet to work out what I’m doing to fix the horrible suspension on it, and the damaged front panels.� More updates to come shortly.

The basic rules I have to abide by are:

1. The cost of the car combined with the cost of parts to get the car running and racing cannot exceed $500 (not including safety gear like seats, roll cage, and safety harnesses).  That means getting receipts,
2. The car that “wins” the “People’s Curse” award gets their car crushed halfway through the race.  Congratulations.
3. The car must survive all 13 hours of racing (it’s over a course of 24 hours).  If it doesn’t, you’d better hope that some other kind driver is willing to push you the last few laps.

Now, the search begins for a damaged (salvage, possibly damaged frame) CRX that comes with an engine or two for under $500. Since I can recoup initial costs by selling parts from the car, I’ll probably be selling the fenders and interior.

Primary Concerns

My primary concerns after that are building the suspension and braking systems to handle all the abuse our team will be liberally applying to it.  As far as the engine, as long as it offers 100hp or more, I’m happy.  I want to make sure it’s going to survive the race.  If I can source out all the parts, I’m hoping to slap a turbo on it as well.

Power Adding

Turbos are pretty cheap if they’re out of a junkyard, and it’s becoming common knowledge that the d-series blocks can handle boost.  As long as I get positive results from the leakdown, a turbo won’t be an issue.  I feel secure with using a stock 4-speed or 5-speed transmission, regardless of gearing.

Handling

If the budget allows it, I’ll go with a full coilover setup for the car.  Brakes should be fine with proper pads and decent ventilation.  Wheels and tires aren’t under the $500 maximum so I can get a few decent sets of 205-series radials.

Cooling

A DA radiator will fit nicely in the EF chassis and will provide adequate cooling for long-term racing.  The radiator fan should have two power switches, in case one fails during the race.  I’m also considering dual smaller fans instead of one large fan, but the $500 budget will be the deciding factor.

Conclusion

I have seen several CRX’s at the LeMons, but they never seem to place especially well.  Why do you think that is, and what can be done about it?

Mechanical torque wrenches come in two flavors:

Beam Style torque wrenches use a beam of spring steel that is bent by the force you put on it.  These are accurate enough for most backyard repair and part replacement jobs, and are inexpensive enough that it won’t break your budget.  For a first torque wrench, I highly suggest a Beam-StyleTorque Wrench.

Click Style (pictured) torque wrenches use a clutch-style mechanism.  These are generally more accurate than beam torque wrenches, but are more expensive because of their complexity.  The SK Micrometer Torque Wrench is one of the best feeling torque wrenches I’ve had the privilege of handling.

Photo courtesy of exfordy.

As with any project, the first thing you should do is establish your goals.  This is going to require a bit of math, but we’re going to determine the ideal target crank hp gain for your vehicle.  A good rule of thumb is that every 10hp you make with a gas engine requires a pound of air per minute delievered into the intake manifold. For example, to transform a 100peak horsepower (php) naturally aspirated engine into a 200php turbo engine, you’re going to need a turbocharger capable of flowing 20lbs of air per minute at a realistic boost pressure. You’ll need to compute the basic engine airflow rate in CFM as follows:

Airflow=(cubic inches displacement * rpm * 0.5 * volumetric efficiency(V.E))/1728

The *0.5 is there because a four-stroke engine only breathe every other revolution, while 1728 converts cubic inches to cubic feet per minute

If you were to insert 83 percent for V.E for a typical 2.0L Honda engine’s 122CID * 7000 * 0.5 * .83/1728=247 CFM

At 83 degrees ambient temperature at sea level 247CFM converts to pounds/minute follows: lbs/min=CFM * .07

Therefore 247CFM * .07 = 17.29 lbs of air per minute.

Using this rule of thumb this 2.0l engine should produce approximately 173 NA HP.  Now let’s see what we could do with that number using a compressor.

Verify Target Boost Pressure

On a street car, target boost pressure will be the lesser of the boost needed to make target power or (more likely) the engine’s boost detonation limit. Increase boost enough and A/F mixture in the combustion chambers will begin to explode instead of burning smoothly, which is very bad for the engine. There is no point of having a turbo that can push abnormal amounts of air beyond the point of the engines boost detonation limit if your fuel system cannot deliever the fuel required to safely run your engine at that boost. Additional boost limiting factors include fuel supply constraints and engine calibration limitations. With premium street gas (typically 93 octane for most and 91 for us Cali folk), assume a maximum of 10 psi of boost without an intercooler and 15 psi of boost with an intercooler. Highest boost pressure will be feasible with pent roof combustion chambers, really efficient intercooling, higher octane gas, excellent engine management with a high quality calibration using the best anti-detonation countermeasures.

Convert Target Boost PSI to pressure ratio

You need a pressure ratio to work with compressor maps that plot air flow at various pressure ratios and compressor speeds. If you’re working with target boost pressure, you’ll need to convert boost pressure to a pressure ratio, which is the percentage of one atmosphere above nothing at all delievered at the compressor’s outlet. For example: 10 psi of boost + 14.7(atmospheric pressure)/14.7=1.68 boost pressure ratio. Which means BPR of 1.68 equals 68 percent higher pressure than NA.

Convert Pressure Ratio to Density Ratio

Unfortunately, a turbo engine system will not usually flow as many CFM as you’d predict just by multiplying the pressure ratio by the NA airflow of the engine in CFM.  Bear in mind that density ratios vary because of turbo’s thermal efficiency and efficiency of the intercooling system. Most street turbos operate in the thermal efficiency range of 55-85 percent.

Let’s go back to the 2.0l Honda engine. If we were to boost that engine to 7.5 psi without an intercooler, the pressure ratio for that engine will be (7.5+14.7)/14.7, which yields a pressure ratio of 1.5. Using the stock airflow of that engine of 17.29lb/min(247 CFM), at a BPR of 1.5, you might expect the airflow under boost would increase to roughly 28lb/min. However, if this particular turbo with no IC is just 75% efficient, the density ratio at sea level is really about 1.3 which equates to 24lb/min of airflow. Bottom line: when turbocharging your engine, you’ll need to start with a slightly larger turbo to compensate for turbo inefficiency.

Select the RPM range of your engine for maximum compressor efficiency

Contact various manufacturers for a turbo compressor efficiency map for every turbo you’re interested in. You’ll typically want to match your turbo’s maximum compressor efficiency with your engine’s natural powerband. This will require a lot of knowledge about turbos, so you may want to contact the experts at Garret, Precision Turbo, etc.

Rather than aiming to achieve maximum peak power, think of the areas that will greatly help your vehicle acceleration. 500HP at 10,00rpm is useless compared to a 300hp at 4000-6000rpms in a street application. But if you are trying to maximize your peak power, remember that a forced induction system will always shift peak power to a higher part of the rev range. But with the days of electronic boost controllers, users will be able to pinpoint when the peak boost will be created anywhere on the rev range based on rpm, gear, and other factors. You might place peak boost at lower rev range to amplify torque (helpful with acceleration) but you’ll need to reduce pressure at higher speed to limit peak hp to stay within certain fuel constraints or  to protect your drivetrain. For example, dragsters limit boost at lower gears as a form of traction control.

Select a compressor

You’ll notice that a compressor map will resemble a 3d topgraphical contour map of a hill. This map describes the compressor’s efficiency at various combination of airflow rates and boost pressure. To the left of the map also are danger zones at the east and west of the map. This zones illustrates the surge and choke zones of the compressor. Big turbos tend to surge at lower revs with huge turbo lags and usually no streetable power gains. Hybrid turbo is a solution if you are looking for a big compressor but a quicker spool-up time.  The t3/4 hybrid is a perfect example which utilizes a smaller turbine but with a bigger compressor to virtually eliminate turbo lag.  If your engine has a powerful bottom end, you might choose a big turbo to create big peak power but to accentuate your bottom end as it creates full boost. But with a engine with a weak bottom end and a strong top end (such as a b16 or 13b), you might want a smaller turbo that spools quickly and build boost as soon as possible to maximize bottom end power and let your engine’s top end take the rest of the way. Either way a small turbo will run out of steam at the upper reach of the rev range and a big turbo will spool slowly but their airflow at higher rev range will eclipse the smaller turbo counterparts.

Some engines also incorporate a second turbine.  These can be twin turbos (in which both turbochargers are the same, and increase the gains in their particular rev range) or sequential turbos (in which one turbo is smaller to help the engine wind up, and another to carry it through the upper powerband).  Some smaller engines may actually see performance decrease if a second turbo is added because the engine does not produce enough exhaust gas to spool both turbos.

Photo courtesy of Mingo.nl

The b16a1 is the holy grail of CRX motors.  It boasts true vtec, aggressive dual overhead cams, a high safe redline, a lsd-equipped close-ratio cable-driven transmission, and a very tuneable ecu.  It really is as nice a fit for the CRX as Honda ever made.

All b16 motors are good choices because of the aftermarket available and the near-perfect rod/stroke ratio, but the b16a1 is particularly suited to the ED chassis (88-91 CRX and Civics) because it’s obd0 and uses a cable transmission.  If it came from a CRX SiR, the transmission will be LSD-equipped.  If it’s from an Integra XSi, it will come without an LSD.

However, there are downsides.

Because the b16a1 was only available in Japan, and was only produced in the CRX and Civic SiR, getting one requires contacting an importer (who will generally buy one from a running car because of modern Japanese smog restrictions).  You will not know any of the history of the motor, but if the shop is worth spending time on, they will offer a full test run on the engine (dyno run and leakdown test) to ensure that it’s in working condition.

The other problem that arises is finding replacement parts.  The B family of Honda motors benefits from a large aftermarket parts availability, but stock parts are difficult to find because they need to be imported directly.

Final Thoughts

Overall, the b16a1 is a great choice to put in the CRX.  As long as you find a reputable dealer that offers a “complete swap” (axles, ecu, wiring harness, intake manifold, throttle body, exhaust manifold, etc) and the motor and transmission are both in good repair, expect to spend roughly $3,000 USD on this swap, assuming you will be installing it yourself.

More Info

That’s just the beginning.  There is a wealth of information available for the b16 series.  Here’s a good start for your hunt for more:

• Identify a b16
• Ryans CRX
• B16a1 Nitty Gritty
• Wikipedia B-series