First, I want to start this post by saying my comments in no way are intended to discredit or minimalize Jon and Dave’s work on PSD advancements!! /ubbthreads/images/graemlins/wink.gif I think they have done a great job!! But this topic gives me a chance to try and convey some things I’ve been trying to describe to people for a while now and have seemingly been unable to get across to most. /ubbthreads/images/graemlins/shrug.gif
While I will agree that a stock pump, modified to flow a little more volume, will help those who are loosing pressure at the upper end of the throttle. It will fall well short of the “real” advantages of a twin setup like the BTS though. /ubbthreads/images/graemlins/eek.gif I’ll explain in a bit /ubbthreads/images/graemlins/wink.gif
Also, in most HPOP threads, people start focusing on pressure values and how high this pump or that pump can hold pressure. /ubbthreads/images/graemlins/confused.gif It’s not about how high the pressure can be, but about how well pressure is maintained! Not only at WOT, but at all ranges of rpms, even at idle! /ubbthreads/images/graemlins/eek.gif In fact, higher pressures will actually DECREASE performance!!
Ok, lets talk a little about the how’s and why’s /ubbthreads/images/graemlins/wink.gif
The HPOP provides X amount of oil so Y pressure can be given to the injectors depending on what the PCM asks based on things like throttle position, load, ect. so they can inject the proper amount of fuel for a giving condition. A problem arises when the pump cannot supply enough volume of oil to maintain a desired pressure. This can happen in a few scenarios. First, and the one most people know about, is at WOT with a hot program or larger injectors. The truck just flattens out up top because the pressure cannot be maintained for the amount of pulse width being asked for. Then there are the ones that most people don’t realize are actually HPOP problems! These problems stem from the fact that the HPOP is gear driven and it’s performance is directly affected by RPM. For example, some people’s trucks are a little slow to respond when aggressively pressing the throttle off idle or low rpms, or immediately after a shift when the rpms drop. They usually chalk this up to something like turbo lag or just overall bad performance of a PSD. When in actuality, it’s because the pump is rpm dependent on its volume output and can’t supply enough volume to create the pressure at low rpms with a sudden request for higher pressure. /ubbthreads/images/graemlins/eek.gif
These problems do not occur with the added available volume of a properly setup twin pump system, even at low rpms /ubbthreads/images/graemlins/wink.gif The result is unbelievable throttle response and a tremendous amount of generated torque!!!
I was having one of my typical long conversations with Brian (BTS) the other day about many things and he asked me what people thought about his HPOP. I told him that I truly believe people just flat out don’t comprehend the advantages it creates because they haven’t been able to “feel” it! And that the price scares them. So everyone is out to find a “less expensive” alternative. As I said earlier, there may be some less expensive ways to go about it, but you won’t be able to modify a stock pump to accomplish the same overall effect.
I’ll give you a specific example of how hard it is to actually comprehend what this setup can do. About 6 mos. Ago, I was having a phone conversation with Jeremy (wacker). I was trying to explain to him the advantages and performance characteristics of the BTS pump. He kept saying, “Yeah, I know” and “I know what you mean”. I could tell he really didn’t!! The next day, he took a ride in a truck with a BTS pump. He made it a point to call me back and say “NOW I understand what you were saying!!!” /ubbthreads/images/graemlins/laugh.gif