ghost1000

iTrader: (1)

Using rpm dependent boost controller to fight boost drop off. The Theory, the faster the rotor is spinning the less time air/fuel has to get into the engine resulting in a boost drop off. With a turbo you also have increasing exhaust back pressure as rpms increase but manifold pressure stays the same meaning boost will drop off sooner. To fight this I want to use a rpm dependent boost controller like the gizzmo and raise manifold pressure at higher rpm.

The question is are you getting the most from your rotary.? Shifting before 8000rpm seems like a waste.

How hi does your turbo motor rev?
What's your port, turbo, shift rpm and peak power, peak power rpm.
What type of fuel and boost control are u using?

Evil Aviator

Your boost is dropping off because your turbo system is not sized properly and/or because your wastegate is leaking. A boost controller can't close the wastegate any more than it is already closed, so it will not help your problem. While a boost controller can use rpm as a reference for setting the boost level, it can only adjust the boost level between the boost level of the wastegate spring and the maximum boost level of the turbocharger system. For example, if the wastegate spring is set to 10psi and the turbo starts to run out of steam at 15psi, then the boost controller can only control the boost between 10psi and 15psi.

As for shifting, maximum performance is obtained by using a dyno sheet to determine when to shift based on the torque curve. Shifting too late means that you are on the back side of the torque curve in your current gear, which will reduce acceleration. This is explained fairly well in Auto Math Handbook by John Lawlor, or you can look it up on the internet.

ghost1000

iTrader: (1)

Sense this thread hasn't been getting any comments we've been discussing this topic under a thread called " high rpm modification " I'm very confident there is room for this to work in my setup and the so many cars with over sized turbos bolted up. The theory is big turbos can't move the extra air do to limits detination but after VE starts to fall there should be room to turn up the boost in order to prolong peak VE. It's interesting and should work.

I already have the that exact auto math book and often use it or reference, its a must have book.

ghost1000

iTrader: (1)

I'm very close to having my turbo done and I have already finished the the rx8 6 speed conversion. Sadly I needed to use some of my savings so this could take a few more months if it gets done this year. I have worked with turbos before but this is my first solo build. I have two motors incase something goes wrong and I will be experimenting with rpm based boost control on my car. To me its not about having a fast car but learning how to build a fast car. I like doing the R&D. I often find what others have missed.