TurboBitten

You mention that there is a separate A/C pulley that can bolt up to the six holes in the solid pulley that you have. I'm not sure yet whether I'll keep my A/C, but I was wondering if you knew the part number, as I haven't been able to find it. Thanks TurboBitten

shift - I agree that nothing can be done by boost to overcome valve timing/size and exhaust/turbine restriction to let the exhaust out. But a lot of the negatives of valve timing/size and intake ports can be over come by simply pushing the air with more force. If the hole is small and only open for a brief moment, all you have to do is push harder to get more fuel/air through. If nothing else, it will be a fun project and I will have a great deal of flexibility with whatever I make. The only way to find out is to try it. Besides, I always enjoy finding new and inovative ways to blow things up. ;D Thanks again for the opinions. TurboBitten

heefner, thanks for the info, I was not aware of the AVCR's ability to handle RPM based mapping of the boost curve. Also, I see what your saying about the MPI however, there are still factors on the intake side which have not changed even after these swaps to MPI, such as the basics of the engine block, head, and valve-train. Even if the problem is on the exhasut side, it may still be possible to overcome some of it with a pragrammable boost curve, as long as it's possible without reaching detonation points. Basically, I think that there are still benefits to be had from a nicely tuned boost curve. Obviously, one boost level is not going to be ideal at all RPM points, but I won't really be sure until I get this thing built and get a turbo big enough to blow cool at high boost levels. Thanks, Turbo Bitten

I've been thinking lately about boost control as well as the 4000rpm cliff that our beloved engines suffer from. Â I'm just throwing this out there to get some opinions. Â My logic goes like this... Torque is directly related to cylinder pressure. Â I believe this is prety much an unarguable fact. Â Following that enters the concept of volumetric efficiency. Â I have read (and it seems reasonable) that the engines VE is directly related to the torque curve. Â Essentially that an engines torque peek will be at the engines VE peek. Assuming that there is some validity to the first set of assumptions... Â here's another... Â VE is essentially the engines ability to move the air efficiently. Â This is affected by both intake efficiency (abilty to completely fill the cylinders with air and fuel) and exhaust efficiency (ability to expel the exhaust). Moving on for any that are still following... Â As I understand it, detonation is most likely to occur at the engines VE/Torque peek when cylinder pressures reach there highest point. So here's my theory. Â If intake efficiency is a contributing factor to the torque fall-off @ 4000rpm because the cylinders are unable to fill effectively, then increasing boost after this point would allow increased VE past this point. Â Of course, if the major problem is on the exhaust/turbine side of the engine, my idea obviously won't help. My vision of how this could be achieved is through a "smart" boost controler. Â I have seen commercial EBCs that adjust the max boost based on vehicle speed, but none that adjust PSI based on RPM. Â It's a relatively simple task to use a microcontroller programmed to operate a solenoid to control the wastegate actuator and also be able to set different boost levels for various RPMs. Â I am going to build one of these to test in the future, but I am curious what others think of the idea. Â I admit, I may be really stretching some of my assumptions here, but I'm going to build one anyway for fun and to test my theory. Â I expect to add knock sensing also to help me avert disaster and possibly make my EBC as smart as modern ECUs and control boost based completely on learned limits. Â It would also not be much of a stretch to incorporate intake temperature or other sensor data into the equation. As I said, I will be building a prototype or at least something like it in the coming months, but I would value any feedback from any here that might have some sound ideas, even if they're critical. Thanks and sorry for the long post By the way, there is no plan to produce this as a commercial item, so I'm not looking to make money from anybody's input here, just test some new ideas. Â However if it proves to be effective, I will certainly share the design plans. Â I expect that the parts will be ~$100 to ~$150 for a prototype, but if it works, a more economical unit could likely be produced for $100 or less. TurboBitten