This is Bill with the Valvoline car. I think you guys have both been following the progress of the car up to the AudiWorld article on the Hershey Hill Climb. The car ran pretty well at Hershey, but it has always been a little inconsistent on power and boost. It seems that the more improvement that is made to the efficiency of the motor the more the top end suffers.
Here is a time line as best as I can remember. Bought the car...very sluggish...no power but smooth...found the throttle linkage was hitting a hose clamp and not opening all the way. Also the exhaust manifold was leaking. Changed fuel filters, installed new plugs, checked and adjusted all the pressures, used a innovate A/F data logger...much better but still runs lean on the top and does not pull hard over 5,000. Ran Hershey Hill Climb ran 15lbs Sat. ran fairly well but started to lose boost on Sunday, which sucked, because I was really starting to figure the car out and we only had to competitors ahead of us. Came home and had Dwight Foster of Foster's Automotive install an adjustable warm up regulator, a new high volume fuel pump and is it "Franko" adjusting cam gear. He had used the regulator and cam gear on his 10V Ur with great success, until he installed stand alone and later started a 20v project. It has an allen set screw in the bottom of the regulator that he can use to change the pressure. He uses a gauge to set it to the parameters that you guys discuss and it works really well.
Here is the problem and the questions that I have. Every time we increase the performance of the car (low end) it becomes leaner on the top. Remember this is a eurospec 2.6, piper cam, dialynx manifold, k26, full 3inch exhaust (no cat, one scorpion muffler), large "Ford" intercooler probably off of a 2.3 Mustang or T-bird. By the way have you heard of that setup? Should I keep it? Dwight and I are assuming that we are just trying to push too much air through the motor at 15lbs and 5,000 rpm for the CIS to handle. Is this a good assumption? Right around 4,500 the A/f starts to move toward 15:1 and the car just doesn't pull and light detonation starts.
I have spent about 10 hours or more researching all of your posts, among a few others and I have gone through the first steps that you list. The only exception is to flow the injectors into glass cylinders to check the rate. This is something that Mike Hoppen told me they used to do for these cars back in the day. He said that Audi would just send them boxes of CIS units and they would test and adjust them all to find the ones with the highest flow rates and the most consistency. Dwight is ordering some glasses today and we will probably test them the beginning of next week. NOW HERE IS MY BIGGEST QUESTION...WHAT IN THE CIS SYSTEM IS THE RESTRICTION TO THE FLOW? Can you enlarge some of the passages in the metering unit? Or is it the injectors that cause the restriction? We have taken another unit apart to study it and after some time I still cannot fully understand all of the aspects of it. What exactly does the plunger in the center of the unit control? I understand how it moves I just can't figure out what it changes and why. What are the larger holes for in the cylinder that hold the plunger and what is the tiny hole towards the bottom for? Below are a few pics that refer to what I'm talking about.
I guess what I am getting at, is between Dwight and I we have paid some dues, so can we get the real story of how to create a 400whp CIS Audi. I promise I will make you guys proud, if you can led me to the DARK SIDE.
Bill III
Here is a time line as best as I can remember. Bought the car...very sluggish...no power but smooth...found the throttle linkage was hitting a hose clamp and not opening all the way. Also the exhaust manifold was leaking. Changed fuel filters, installed new plugs, checked and adjusted all the pressures, used a innovate A/F data logger...much better but still runs lean on the top and does not pull hard over 5,000. Ran Hershey Hill Climb ran 15lbs Sat. ran fairly well but started to lose boost on Sunday, which sucked, because I was really starting to figure the car out and we only had to competitors ahead of us. Came home and had Dwight Foster of Foster's Automotive install an adjustable warm up regulator, a new high volume fuel pump and is it "Franko" adjusting cam gear. He had used the regulator and cam gear on his 10V Ur with great success, until he installed stand alone and later started a 20v project. It has an allen set screw in the bottom of the regulator that he can use to change the pressure. He uses a gauge to set it to the parameters that you guys discuss and it works really well.
Here is the problem and the questions that I have. Every time we increase the performance of the car (low end) it becomes leaner on the top. Remember this is a eurospec 2.6, piper cam, dialynx manifold, k26, full 3inch exhaust (no cat, one scorpion muffler), large "Ford" intercooler probably off of a 2.3 Mustang or T-bird. By the way have you heard of that setup? Should I keep it? Dwight and I are assuming that we are just trying to push too much air through the motor at 15lbs and 5,000 rpm for the CIS to handle. Is this a good assumption? Right around 4,500 the A/f starts to move toward 15:1 and the car just doesn't pull and light detonation starts.
I have spent about 10 hours or more researching all of your posts, among a few others and I have gone through the first steps that you list. The only exception is to flow the injectors into glass cylinders to check the rate. This is something that Mike Hoppen told me they used to do for these cars back in the day. He said that Audi would just send them boxes of CIS units and they would test and adjust them all to find the ones with the highest flow rates and the most consistency. Dwight is ordering some glasses today and we will probably test them the beginning of next week. NOW HERE IS MY BIGGEST QUESTION...WHAT IN THE CIS SYSTEM IS THE RESTRICTION TO THE FLOW? Can you enlarge some of the passages in the metering unit? Or is it the injectors that cause the restriction? We have taken another unit apart to study it and after some time I still cannot fully understand all of the aspects of it. What exactly does the plunger in the center of the unit control? I understand how it moves I just can't figure out what it changes and why. What are the larger holes for in the cylinder that hold the plunger and what is the tiny hole towards the bottom for? Below are a few pics that refer to what I'm talking about.
I guess what I am getting at, is between Dwight and I we have paid some dues, so can we get the real story of how to create a 400whp CIS Audi. I promise I will make you guys proud, if you can led me to the DARK SIDE.
Bill III
