It is very hard to tell the difference between the 87-88 roller cam designed for the square tooth timing belt pulley and the 89-up(?) roller cam designed for the round tooth timing belt pulley. For people who run a stock cam without the use of a degree wheel to get correct centerline who may have trouble with lost horsepower and uncontrollable part throttle detonation this maybe an overlooked issue.
After 3 years of ecu tuning on the daily driver 89 Daytona for someone else and 4 years of tuning since I've owned it, I have battled to find any power this engine should be producing while running upwards of 16-18 psi boost and trying to get rid of a large amount of detonation at part throttle.
Last week I finally coughed up $100 bucks and installed an adjustable cam gear with the a theory that someone had installed an 88 cam instead of an 89 which would put the 88 cam roughly a few deg advanced. When the 89 cam gets installed into an 88 non common block you get visa versa as the 89 cam needs to be a few deg advance.
Since I didn't build this engine I have had no clue what parts are installed, also I have no clue of compression ratio until I tear this engine down to measure the volume of the chambers and piston dish.
The belief with the 88 cam theory in my 89 common block seems to have been proven as I picked a substantial amount of power from 3000-6000 with only 3 deg cam retard where as before the engine wouldn't get out of its own way at any RPM and knocked like a mad man at the slightest boost at part throttle even with ignition timing retarded to a factor that doesn't make sense.
I have noticed a power trend between running the 88 and 89 turbo cams. My 87 2.2 CSX started with the 88 cam years ago. The 88 cam seems to be slower to reach power in the lower RPM and produces a sudden rush of power once it reaches the mid RPMs which is the performance on the Daytona at this point.
When the 89 cam was installed in the CSX the power transition was a bit more linear as there was a bit more power in the low RPMs and the transition into the upper RPMs was not as harsh, but still carries power well to redline. Like most people have stated, it is hard for the "butt dyno" to tell power increases in revs when the cam is adjusted, but this was an incredible amount of power gained with 3 deg difference.
I still believe there is a small compression ratio issue or needed chamber rework with this engine due to the amount of ignition retard I have to run, but part throttle detonation became less of an issue after retarding the cam. Just for numbers sake, there is roughly 13-15 psi (static) difference between zero deg on cam gear (135 psi my results) and 3 deg retard on cam gear (120-122psi my results) which can be a cause for the part throttle detonation at very low boost pressures (1-5 psi).
Most of us love the stock turbo cams as I have been a full second faster in the 1/8 and a little less than a second in the 1/4 with my A-413 CSX with a stock turbo cam.
If anyone finds any misinformation with this post please add corrections.
Chris
TurboFreak.com
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12.57@104 :O) 
Originally Posted by turbovanman
Perfect. Thanks for adding the link Simon. I guess a good case in point is who knows what in the world we have after years of repairs and modification.
