See version 1 for my Profec-B installation.

As for the pills, I used two silicone hoses between the Profec-B and the wastegate and the right little neck beside the turbo so I suppose at least one pill removed, unless the pills are integrated somewhere because I have new JDM 1999 RX-7 turbos ?

Could it be my problem ?
If it's the case how do I removed integrated pills ?

Thanks again !

 

You still have precontrol enabled as with stock. You will need a pill in this line.

One cause of spiking at transition is pre-spooling turbo 2 too much.

I believe you have to drill out the orifice. I imagine a wastegate pill + Profec B could cause the wastegate to open too late as the actuator doesn't see the pressure it needs to open the wastegate quickly.

As an aside, I've always thought the proper way to design a boost controller would be to eliminate the wastegate pill and control the wastegate solenoid...

 

Obviously not in first gear because the RPMS will climb very quickly. Just flooring the throttle at a relatively low RPM gives a wide throttle opening, allows the engine to ingest lots of compressed air and it inefficiently turns that into an overboost situation. The problem is that there isn't enough RPM (immediately) to properly evacuate the engine.

There are many ways to describe it, but even in naturally aspirated engines it is always bad to call upon horsepower at too low of an engine RPM. It is always a good idea to get near an engine's power band prior to any wide throttle openings.

Quote:

Whataya mean by exhaust velocity being great enough to counter boost being produced by turbos? Turbo rpm is directly related to exhaust flow, which is again directly related to engine speed. How can this balance be off sometimes, and on others?

I'm not trying to critique you here, I just don't understand what you are saying.

I hope I answered that sufficiently above. It is just incorrect driving to not downshift or already be in the productive RPM range before you call upon boost.

The exhaust at low RPM isn't moved through the turbos and the wastegate fast enough to properly actuate everything. Boost pressure is allowed to skyrocket and the engine injests it because of the wide throttle opening. Plain and simple it is asking it to function outside of its design parameters.

When you are in an automatic and you floor it, the engine has the sense to downshift. People should to.

 

yeah, that's right, you have integrated boost pills, you'll have to drill one

 

WVRx7,
Help me out... the ECU calls a lookup table(fuel map) that is based on mass air flow and mass fuel flow... so whatever the air flow is, the proper fuel is injected... Having said that, how can you boost spike at low rpms if the exhaust flowrate is low and the spike is produced by turbos being "over-spun" which cannot happen when you dont have the propellent exhaust energy?

Unrelated to the above, I do agree that WOT at low rpms is not the best for the vehicle as a whole considering the high loads placed on the powertrain. Similarly, the same concerns as well as others exist with overrevving.

 

Nope. The FD is a pressure-based system, not an airflow-based system (which presents the difficulty in modding them). The ecu reads engine speed and air pressure and looks up a fuel value to inject.

 

p=m(RT/V) where R,T, & V are constant. So I don't understand the objection nor how it relates to the original question...

 

Your assumptions are wrong regarding the ideal gas equation, which doesn't really apply here. I was merely correcting your comments above.

I agree with your points about boosting. WVrx7's comments do not make sense to me, so he either a) has no idea what he's talking about or b) is not wording it very well.

I have been hitting 10 psi below 3k rpm for the last 19 months with no problems with spiking or anything else as far as I can tell....

 

I'm sure the fuel maps have an injector duty cycle for 3000 rpm @ 10psi, since this is something your car should have done from the factory...

Of course, in practice, I'm not sure why a downshift wouldn't be in order!

 

Sounds good. I don't understand how you could spike below 2 or 3k rpm. Maybe Im just not seeing something.