After 2 months of trying to dial in the fast boost control, I finally have some good results to post up. This is on a stage II car that I have been working daily with the owner to get the control in line. We have tried the map boost method and please do not waste your time with this mode of operation. Only the waste gate method is the way to go, using a 0-100 psi sensor. If you do plan to use this method I would prefer a 0-50 psi sensor.We still have some issues with spike at lower boost targets, but the 42mm gate on a stage 2 headed motor is too small in my opinion, so we have ramped up the boost /vs tps slower to compensate The settings used are in the zip file name.
FAST XFI BOOST Control finally some results!!
- Thread starter norbs
- Start date
turbonetics race gate 7 psi spring, we are trying to get a 25 psi target.
Um, NO. You can refer to the boost chart using the 100 psi sensor. It will be wastegate base spring pressure plus the sensor reading, but since the scale is so big for a low pressure range, you really have to guess the boost vs wastgate boost number. Also the sensor I am using was not a fast sensor and not a true 0-100 psi sensor so take it slow until you see the results you want. WE had a target at 24 in the log so 24%=6psi on top of wastegate psi, so we have a 7 psi spring 6+7=13 psi, but we got 18 psi. This is why I am saying you really need a 0-50 psi sensor to get a better accuracy down low. We may not hit the 25 psi target boost with out co2, but I think we can get close to that target from manifold psi. If you see in the log you can see at top end the fast compensating for boost creep, which is neat
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turbobitt
Well-Known Member
- Joined
- Feb 14, 2002
I like the Fast Boost controller. I wouldn't say mine is maximized yet but boost only spike to about 2 PSI over target.
Also, expect the boost to reduce a little at righer RPM due to backpressure pushing the gate open. This will probably happen regardless of how well it maintains pressure on the top of the gate
Allan G..
Also, expect the boost to reduce a little at righer RPM due to backpressure pushing the gate open. This will probably happen regardless of how well it maintains pressure on the top of the gate
Allan G..
The main thing you have to remember your base boost without the boost control hooked up, and that any boost solenoid has a window of control. I would say the window is 20-90% If you can be in that window the control will work. I would expect not much change in boost after 90%
turbobitt
Well-Known Member
- Joined
- Feb 14, 2002
turbobitt
Well-Known Member
- Joined
- Feb 14, 2002
This is a screen shot showing Boost, RPM, and backpressure. Boost starts at 30 and decreases to 28 at the end of the run.
turbobitt
Well-Known Member
- Joined
- Feb 14, 2002
Norbs,
The wastegate PSI is fluctuating because the high logging rate of the Dash is picking up the pressure pulses from the solenoid cycling. When I data logged this on the XFI, the pressure was steady.
Edit: XFI shows wastegate pressure spike to 25 then steadies out to 21-22 for most of the run.
This also brings out a good point. It may be better for the controler to have the pressure dampened by a large amount of rubber line or something. I have the pressure transducer installed on the solenoid and may not be optimal.
Allan G.
2 psi isnt bad at all, mine seems to take a lil bit before peaking but i only ran 20psi this run, im sure id get a bit of a spike once its turned up to the upper 20's. it started at 19.7 psi by the top of first and finished the run at 20.9
For best control, I would strongly recommend putting the sensor as far from the solenoids as you can and as close to the wastegate as you can get it. This is even more critical with an AMS system
