OK, sorry about the long delay between posts, it would have been even longer if I didn’t add the post about my trip to the local car museum. Life and car problems got in the way of my plans to race the first part of the season in the V Tech club. In February I was scheduled to race at the Willow Springs race track. However on the day of the event just as I was turning on the highway to make my 3 hour drive to the track, the check engine light came on in the dash. I found oil leaking underneath the car and returned home. After pulling the codes for the check engine light from the car’s computer I discovered that it was a faulty O2 sensor that triggered the light, and that the oil was coming from my oil cooler thermostat at the back of the engine. The solution to both of these problems turned out to be bigger and much more expensive than I originally thought it would be. Couple that with some family events and I have missed most of the first half of the season.
The picture above is the thermostat for the oil cooler, seen under the coolant cross pipe when the intake manifold is removed. I previously had a stacked arrangement so I could mount temperature and pressure sensors. You can look back at the install here https://noxqcsmotorsports.wordpress.com/2013/02/ The two stacked blocks never quite sealed correctly against the block and leaked a little oil now and then. To fix this I removed the block for the temp and pressure sensors and had to rotate the thermostat more towards the left which caused me to have to purchase new 90 degree fittings to clear the water pipe running across the back of the block.
Before I show all of the solutions let me present how I got there. Taking the throttle body and intake manifold off are simple enough, just make sure to cap all the hoses and fuel lines so as not to make a mess in your engine bay. I found that a latex glove and some duct tape make great corks on all the hoses. I didn’t see the need to drain the radiator and only a little coolant leaked out. Once the manifold is out of the way I was free to work out the best way to fix the leaking oil problem.
Removing the second block on the back of the engine necessitated the relocating of the oil and temperature sensors. The oil pressure sensor is too heavy to just mount directly to the back of the block. Many racers remotely mount it using a tee fitting on the factory pressure sensor. This allows the heavy pressure sensor to be mounted on the firewall and isolated from engine movement so as not to break fittings or lines. The other end of the tee fitting is the factory sensor which will keep the ECU happy, and won’t set any warning lights off.
Here is the Tee fitting installed in the factory pressure sensor location. You can see how cramped underneath the intake manifold will be. The temperature sensor will be mounted in the new oil pan in a future installment of this blog.
While I had the intake manifold off I decided to upgrade a few items to increase power, something I have been wanting for awhile now. First is a 70MM throttle body from Skunk2. The difference is obvious, the larger mouth on the new throttle body will allow more air and when added with fuel will create the increase in power. My factory throttle body was caked with depositS, and no matter which grade of gas I used or additives I put in the tank none of them cleaned it. Another benefit of the larger throttle body is better throttle response and a smooth transition from the already installed air intake tube.
Though the Skunk2 Throttle body will bolt right up to the factory intake manifold, the air flow would hit a wall unless I opened up the intake to match the hole in the Throttle body. You can see above the marked area that would need to be cut out then smoothed down to make a good transition for the air coming into the engine. I stuffed a towel inside to keep as much of the metal chips out of the intake runners, and taped all the holes closed. One piece of metal shavings could do lots of damage if it got inside of the engine.
To get the desired opening in the throttle body I used a few different bits on my die grinder. The first one in the upper left corner was used to get a rough opening and remove large bits of the aluminum intake. The one in the middle was used to to shape the opening to smooth away the gauge marks the metal bit makes. The bottom right bit was used to polish the intake, and give it it’s final finish.
The final result. You can see the tapered opening makes a smooth transition to the outside edge where it will mate up to the larger throttle body. It worked so well that in the future, I would like to port and polish the whole intake including the runners into the engine to see if I could get a better flow of air into it. Once I was done I cleaned the intake with degreaser to remove the gas deposits.
Before reinstalling the manifold I had to remove the old gasket, it did not want to come off. For 15 years it kept a good seal and fought til the end but eventually a lot of adhesive remover and a pack of razor blades proved to be too much and bit by bit it surrendered until the head was clean again.
To replace the gasket I used a Hondata heatshield gasket. This is should provide a thermal barrier between the head and intake, and not let the intake become heat soaked causing a loss of power.
To control the spark and fuel, a Hondata ecu was installed in place of the factory one. This is a reprogramed Honda Civic ECU that has been rechiped to accept the changes the tuner adds to it. The Hondata S300 is a plug and play ecu that will allow a whole world of options to the car. I will have the ability to datalog engine dynamics and make changes to the tune if needed. The ECU will also allow me to monitor a lot more of the car vitals once more sensors are installed.
To extract all this power and make sure the car was healthy doing it, I took it to a local tuner here in Vegas. I don’t have access to a dyno, and his pre programed tunes saved me hours of trying to tune on the street. 3 hours later I had this….
The final result 154.9 hp @6336 RPM and 134 tq@5027 RPM. The torque curve(Blue line) is nice and flat, and it makes steady power all the way up to redline. This is at the wheels on a Mustang brand of dyno, the stock car made 140hp and 110tq at the crank from the factory. I will be testing this all out on my local track very soon. I hope to see the new power making for much faster speeds.