In Reply to: Sounds like you removed ASC T.B, and how about... posted by dk on March 08, 2001 at 13:42:33:
I read your post, and understood your point, but even if you took out ASC, it is still heck smaller than HFM & T.B. right?
What are you saying is a "heck smaller"? The ASC t-body is smaller then the Dinan standard t-body. So I chucked it out and replaced it with the elbow from a car without ASC (thanks Jae).
I guess ASC T.B. only kicks in when you slip, and in normal operation, the ASC T.B.
No, this isn't the case. Even with the ASC switched off the ASC unit has a smaller bore then the standard t-body and has a swivel sitting in the way (which you can see in the pics). At best case the air is hitting the ASC t-body swivel dead-on which means there is a half inch thick swivel running the full diameter of the ASC throttle plate. But it more likely is much worse then that because the plate is sitting at an angle which increases the effective surface area it presents to the airflow path (as shown in the pics).
Even though non ASC T.B. is a bit larger than stock, it is still way smaller than T.B. or HFM.
I really don't understand this one. There are two throttle bodies in the system... the standard one and the ASC one. I completely replaced the second T-body with a rubber elbow. I now only have one throttle body and it is larger then stock because it is modified by Dinan. The elbow I replaced the ASC unit with is larger then the bore of the Dinan unit. So now the smallest airflow path is the throttle body (because the elbow and HFM are now larger then the t-body).
As for performance. I tried to measure the improved airflow at the MAF. Unfortunately I seem to already be maxing out the MAF at 26.9lbs per minute. So I couldn't plot a maximum increase in airflow. So I have been doing the next best thing which is periodically checking my long term (multiplicative) fuel trim. If the car is seeing more air, then the fuel trim shold become relatively richer. That has been the case so far.