Preyupy

I'm sorry to hear of Bill's passing. I talked to him last fall and got a chance to catch up. He has always been a source of information and help anytime we were at Sears Point racing. I have a couple of cars that I now take care of that used to hang out at his shop and we always got to have long CSL conversations. We were at HIstoric LeMans in 2012 paddocked next to each other and helped each other get through the weekend. Bill will be greatly missed.

I have taken BMW m10 based race engines that made 225 hp @8000 rpm on a DTS engine dyno and put them in race cars and run them on our Dynojet drum dyno. In a standard 2002 with a 5 speed transmission (running in the 1:1 gear) and 4.11 final drive with just enough air in the tires to keep traction throughout the run we saw 185-192 hp (tire pressure and engine oil temp seem to make the most difference ). The same engine in a sports racer using a Hewland transaxle at somewhere close to the same overall gear ratio ( tire size and gears = roughly the same speed/rpm) the numbers were slightly higher 188-196hp. Obviously these tests we not done on the same day so weather conditions did change but this is what I usually use to compare OUR Dynojet to the DTS dyno I usually use. I never split hairs on HP/Torque numbers between different dyno, I have seen some dynos that are obviously calibrated in Clydesdales and others in Shetland Ponies.

I haven't seen anyone forget the Pressure Plate, but I have seen a BMW master tech forget to put the clutch disc in. I was helping him put the exhaust system back on a 635CSI when he noticed the new disc sitting on the work bench. I LMAO.

If that is a picture of the throw out bearing arm with the bearing just touching the pressure plate and not compressing it. You have the wrong throw out bearing or something else is wrong. The arm is going to hit the bell housing before it can push the pressure plate far enough to disengage the clutch. Do you have a picture of the TOB mounted on the arm before you installed the transmission on the engine?

With the 232 transmission you should be using the original style clutch slave cylinder (mounted low on the bellhousing with the end of the throw out bearing arm coming out of the bell housing. Using Zinz's picture above its the cylinder on the left. With everything assembled push the rod coming out of the slave cylinder in as far as it will go. How much gap between the throw out bearing arm (with the bearing touching but not depressing the pressure plate) and the end of the push rod do you have? It sounds like you have the wrong push rod in the cylinder, and you are running the piston in the cylinder all the way to the stop before you move the arm far enough to release the clutch.

I just bought some for a 235/5 rebuild and the only place I could find them was the BMW dealer. I did wind up with a problem as the new synchro rings were 0.96mm too wide. I have never had this problem before with rings I have purchased from BMW. I was able to put them on the surface grinder and get them down to the proper measurement. I thought about sending them back and trying again but it took over a month to get these and I just needed to get the gearbox done.

The L-jet system is airflow based so the theoretically it should compensate for the increased displacement at the lower engine speeds and throttle settings. You should install a wide band O2 sensor and monitor it. My main concern would be full throttle higher RPM as you might run into max fuel delivery and go lean. My recommendation is staying richer than 13:1 under load ( you will see much leaner than that under very light loads and decel). You can affect mixture by adjusting the clock spring inside the Air Flow Meter. The 6mm mixture adjustment screw will only change the idle mixture with very little change in off idle mixture.

Glad you found one.

It would be good information if you taped the fuel pressure gauge to the windshield and went for a drive. If the pressure is steady at your 22.5 psi when you have the engine under load at 3500+ rpm you probably have a bad fuel pressure regulator valve, not a clogged intake screen or air leak on the inlet side of the pump. If it was a clogged fuel filter the fuel pressure would be closer to the 29 psi they normally run if you turn on the pump without starting the engine. That pump should be capable of supplying at least 3x the volume that engine needs and well over 80psi if it is healthy. But again if the pressure does not fall off under load it’s probably NOT a fuel pump or pickup problem.

Mine was the 1st ever in Western Washington. I am a long time '02 owner so the basics were there. I learned a lot putting mine together. Who would have guessed that I would wind up working on 7 different Turbos over the last few years.

Thank you. I lusted for a 2002 Turbo ever since I got a ride around the Nurburgring in July 1974 in one. Until I got this one running Rudy's was the only Turbo I had ever even sat in. Only took me 36 years.

Left the factory on March 13 1974 headed to England. Moved to the US in 2001

If you look at the actual primary tube diameter and length the headers used on the mid engined sports cars and formula cars are the same as the sedans. The difference is the packaging of the entire engine bay. There are often frame tubes, suspension pieces and even bodywork that dictates that the exhaust has to run much higher and straight out the back of the car compared to in a front engine sedan. All other things being equal straighter pipes flow better.

I have a decent 4/70 dated 118 head if that will help. I know you are looking for the correct date but if this would help you are welcome to it.

Your picture shows it as a LEFT HAND DRIVE car. The header was designed for a Right hand drive car with the steering box and shaft on the exhaust side of the engine bay. Seems like a lot of extra bends and heat issues that are not needed in your car.

It's not that bad actually, your mind is so numb from the noise you don't notice the heat.

Changing the #4 spark plug on a hot engine is not going to be fun.

Looks like a large tube race header designed for a Right Hand Drive car. The headers we usually see for Left Hand Drive don't leave any room for the steering box or shaft. This is not a performance improvement over the left hand drive headers it is just necessary for the RHD cars

And occasionally someone has tried to get really creative with air boxes and completely forgotten to put this hole in the backing plate. They quickly discover the engine won't do anything but idle.

It was a non sound controlled event (pre historics weekend) and I saw there were people in the sound booth. I knocked on the door and asked if they were taking readings? She said yes but only because they were training new people, "we aren't busting anyone this weekend". I asked if they had readings just so I could see what I might need to do if we came back on a sound controlled weekend. She did have some and I gave her the group number and car number, when she found it she just smiled and said "YOU WIN" I think it was 128db actually. We were louder than the CanAM cars mostly because their pipes aim straight back and the Microphone isn't looking straight into the pipes.

We saw over 125dB at Laguna with this one. The two 4" pipes coming out of the right side, aimed right at the microphone didn't help. An M49 at 8000 rpm WOT is REALLY LOUD

WOW peak torque at 7500! And you still have 160 lb/ft at 5800. I'm impressed. Engine development is so much fun. You can wear an engine out trying all of the different things and seeing what they do to the Torque/HP curves. The simple ones are mixture and ignition timing. Then you try different cam timings (being a twin cam you have the chance to change overlap between the intake and exhaust) I noticed you are at 102/106 deg how did you come up with that combination? You can also play with intake runner length by changing velocity stack length. Then the time consuming and costly trial of different header designs, runner tube diameter and length, collector size, exhaust system diameter and length, even mufflers. And every time you change one thing you need to try all of the others again to see what is needed to optimize that configuration. Then you get to figure out how to make it fit in the car. Now that you have it all figured out pull the engine apart and freshen it up because you have just used up 50-60% of its life.

Just be careful about dumping the exhaust under the car (even behind the driver) it helps with sound levels but you stand a chance of Carbon Monoxide poisoning (happened to me at an endurance race in Portland years ago) and the other big problem is trying to keep the Differential cool, at least dump it behind the Diff.

I am not a big fan of the supertrap plate mufflers. By the time you put enough plates on the end of the pipe so they don't eat up 30% of your HP you haven't lowered the noise level enough. The big problem with the original exhaust on this car is the pipe is sticking straight out the right side of the car. If the noise nazi is on the right side of the track you are going to have a huge problem. I would not use those Abarth mufflers, they are exceedingly heavy and huge. Try one of the Magnaflow mufflers. Figure out what space you have and go looking for a muffler that fits. Maybe even round resonator type muffler up under the car along with a muffler out back. It really depends on how quiet you need to be. You might consider an OVAL tube to run over (or under) the rear crossmember. I have built a number of 2.5" systems for 2002's over the years and it can be done fairly easily.

After years of racing everything from 1920's Bentleys to late 90's F1 cars meeting sound limits is a tricky problem. The biggest thing is to know WHERE they are measuring the sound? Which side of the track are they on? You can lower your "measured dB" by making sure the microphone can't SEE the end of the exhaust pipe. If the Mic is on the right side of the track run the pipe out the left side etc. Side exit exhausts are the hardest to get within limits. If you run it out the back you can put a tip on it that you can aim to the left or right depending on the track and where the sound control station is located. This alone can cut 2-4db off the top. There are a lot of good mufflers out there now that do a good job of sound control without making a big dent in your HP. There is also the change in sound pressure levels depending on weather so the fact you were at 102 dB one day does not mean you won't be over the 103 dB limit the next day. Also know that it isn't just EXHAUST noise you need to pay attention to. If you are running an air box on the intake and have it ducted to the front of the car the intake noise can sometimes be 98+ dB the sound control people don't care where the sound is coming from just that you are too loud. A few years ago, at Laguna Seca the B Sedan group was running and there were a number of Alfas that were getting busted for noise (I think they needed to be under 100db that day) and they kept working on the exhaust systems and could not get under the limit. One of them finally took the hose off the airbox that was running to the headlight bucket and suddenly they were legal. Sometimes you just need to DRIVE the car differently as well. Once you know where sound control is located you may just have to "pedal it" as you go by. I raced a big block Corvette with side pipes at Laguna Seca once when there was a 103db limit. The 427 Cobra that I was racing was also running side pipes. We both had as much muffler on the cars as we could fit, with shields, tips turned down etc. The sound control shed is on the hill between Turns 5 and 6 before the bridge. It is on the Right side of the track about 70' feet from the edge of the track. Mac and I would come out of turn 5, short shift to 3rd gear, dive to the left side of the track and go to 1/2 throttle until we went under the bridge and out of range. They kept telling us we were "getting close" at 101.5-102 db all weekend. On the last lap of the last race of the weekend we both lit up the tires coming out of 5 and laid 4 black tire marks all the way up the right side of the track to the bridge. If we had not gotten the checkered flag that lap we would have been BLACK FLAGGED for noise! My recommendation is run the exhaust all the way to the back of the car, Fit in as much muffler as you can fit. Design it with an adjustable tip that you can AIM away from the Sound Nazi. Be prepared to modify your cold air box if needed. Also be prepared to "pedal it" if you have to.