Progress continues with the Evo 9. We took a weekend to install cams, the new intercooler and the exhaust system.
The cams are GSC Stage 1 cams designed specifically for the Evolution IX’s MIVEC engine. For the 2006 model (no Evolutions were built in 2007) the 4G63 engine received a new head design that included variable valve timing for the intake. This provided a boost in power as well as better mileage.
I had used GSC Stage 1 cams on the Evo 8 and liked the performance boost very much. They provided plenty of mid and top range power while maintaining drivability. On the track as well as the street drivability is important. It is no fun trying to fight with a narrow power band while negotiating challenging corners.
For the cam project I enlisted the aid of Doug since he always does a fantastic job of installing cams and timing belts on the 4G63. While he worked on the cams I would find times to install the Greddy titanium exhaust and Tanabe downpipe.
The first part of installing the cams is getting everything out of the way so you can get to the old cams as well as keep the timing intact. A lot of fasteners and parts have to come off so being methodical and keeping the parts organized is key. We made certain that we had a good sized work surface to keep parts on and magnetic trays to store fasteners on.
Doug spent a lot of time making sure that the timing was right by marking the timing belt and the gears and crank pulley. That meant we didn’t have to guess as we put things back together. The 4G63 takes a couple of special tools in order to do the job and one of them is a long bolt-like device that is threaded into a hole in the block designed to release the tesioner. With the tensioner retracted a pin can be inserted to hold it in place, then the tensioner is unbolted from the block.
Each of the cam gears had to be unbolted from the cams and this had to be done with care. The cams come with flats that you can use to hold them in place while a breaker bar is used on the cam gear bolts. Keeping everything clean is paramount. Paper towels are better than rags for wiping parts and protecting things from dirt. The rags will leave strings of cotton that can get into places and oil galleries and stick there. The paper towels may shed a bit of paper fibers, but they won’t clog any oil passages.
We had to be sure to keep the cam bearing journal caps that were removed in the proper order. They must be kept in the same order they were taken off and in the right orientation. There are dowels that keep them from moving around, but they also make them difficult to remove. We used a large channel lock pliers with a towel to cushion the jaws.
The exhaust cam was done first and the old one was removed and set aside. The new cam journals were coated with engine assembly lube and set carefully in the head. Then each of the cam journal caps were put in place and lightly tightened down. Doug used a Snap-On digital quarter inch torque wrench to carefully tighten the cam journals. He used a three stage tightening and the factory torque sequence. That ensured that the journals did not get stressed and the cam was seated properly.
Both cams have cam sensors in this last version of the 4G63. That meant unbolting a cam sensor target from each cam and making certain that is was oriented on the new cam properly. This is especially difficult on the exhaust cam since the target is not keyed to go on. We had to be sure to mark the shield and its orientation to the cam’s dowel pin on the opposite end of the cam shaft. The cam sensor target also had to be installed after the cam sensor housing was slipped on the cam.
New cam seals were used at the gear ends of the cams but the sensor o-rings and gaskets were re-usable.
The intake cam was much the same. The only difference was the cam gear was quite different so that oil pressure could advance the timing. That meant that there were two different torque specs on the connecting bolt and the cap bolt that covered the outside of the gear pulley.
Doug ensured that the timing belt went back on properly and that the engine stayed in time while a new tensioner was installed. He rotated the engine crank to be sure everything was as it should be and that the timing was intact.
Then the valve cover was installed and all the fasteners and sensors were installed. Doug took particular care in using the right torque when installing the valve cover. They are cast and can easily crack if over tightened.
I repainted my valve cover in wrinkle black a while back. Wrinkle black valve covers have become sort of a trade mark of mine ever since my air-cooled VW days.
During the cam install process Doug had to take a few minutes away to work on another car so I took advantage of the break to remove the “stock” exhaust system and install the system that had been on my older Evolution. The system that was on this car had been thrown on to bring the car back to stock or something close. The piping and muffler was certainly stock, but the catalytic converter was all wrong. I was glad to get the old system off. The Greddy titanium system is so light that it was easy for me to put on by myself. It weighs less than ten pounds.
I had the Tanabe downpipe bolted to the high flow cat and had put fresh exhaust wrap on the downpipe. It was a simple matter of bolting the downpipe up and then lining the cat up with the Greddy system. I had a fresh 3” exhaust gasket to install and use stainless steel bolts with double nuts, just to be sure that vibration doesn’t loosen up anything. The downpipe and cat assembly weighs more that the rest of the system. I also installed a brace that I had used with my old car. It replaced the two cross bars that the factory installs with a triangulated set of braces made from stainless steel tubing. This ensures that the lower suspension flex is minimized.
I needed to add some spacers to this bracing so that it would not come in contact with the downpipe. It had been a problem that I had not addressed with my old car, but this time I paid attention to it. I had a machine shop make five half inch thick spacers out of stainless steel for me and they were bolted in place giving enough clearance for the downpipe. Next I had them MIG welded to the brace.
Doug returned and we finished up the chore of putting all the pieces back on the engine. Since the exhaust was installed we could fire the engine up and see how the cams sounded. The engine fired up nicely and we waited for things to warm up. The engine was rev’ed for a few minutes to break in the cams and then it was allowed to settle down so we could hear the idle. With my previous car the GSC cams gave it a bit of a lumpy idle. Nothing radical, but you could tell that something was different about the cams. With this engine’s MIVEC the idle was as if it were stock. No lumpy idle at all. When I took it out for a test drive you could feel the cams come in nicely. Plenty of mid-range and sufficient top end to make it all worth while, and no ECU tuning had been done yet to capitalize on the change.
The next day I brought the car back to the garage so that I could install the new Greddy intercooler. It was the same model I had used on my Evo 8 and I liked it because it fit without having to cut the bumper cover or any of the bumper, yet it provided a lot more capacity of the generously sized factory intercooler. Some after market intercoolers won’t allow the installation of the factory under pan, but this one does.
The Greddy intercooler comes in aluminum that is a lot shinier than the factory intercooler, and while that was OK for the Evo 8, I thought I would try for a stealthier look with the Evo 9 front end. So I found a shop in the Raleigh area that would black anodize the intercooler and piping for me. I also found a supplier that had black transition hose to replace the Greddy blue hoses. The Greddy couplers came with worm gear hose clamps that I replaced with T-bolt hose clamps. I’ve had experience with hoses blowing off during boost and I would rather use T-bolt clamps.
While I put on the intercooler and piping Rodney installed the front sensors for my Escort Radar/Lidar detector. Rather than having a detector that is on the windshield for all to see I find the Escort SRX remote a nice way to be alerted and yet keep the profile basically invisible. The Lidar detectors fit in the factory bumper slots perfectly and we fashioned a mount for the radar antenna just above the intercooler.
It cost a little more to get the intercooler black, but I like the look and it should also transfer heat better.
We are still waiting for the Tamei ARMS turbo. When that comes in we will swap out the radiator for a nice Mishimoto unit with Samco silicon hoses. Then some tuning of the ECU to capitalize on all the goodies. Stay tuned.