How to deal with boost spikes(creep)
#1
How to deal with boost spikes(creep)
Hi, everyone! I had stock Rx7 FD3S 97 JDM.
Last week, I've installed DP Feed 3", Midpipe 3"(dimensions like Pettit), CB 3"(seems to be Fujitsubo Legalis), Pettit CAI and Power FC with Base Mod Map. Cruised 1 week and yesterday I installed AEM Failsafe Wideband which is capable to log AFR and Boost for 3 hours to check my boost and AFR log.
My logs scary me, cause I see boost spikes(or its boost creep? from 13-to 16.7psi)
Link to Log file: http://www.filedropper.com/1_99 You can open this log with AEMData program - http://www.aemelectronics.com/files/...ta_4.01.01.exe
I also attached a screenshot from log with a most epic part)
I want a reliable daily driven car with 12-14psi(as I learned 14psi is reliable max), what should I do? Or 97 turbos can handle more boost than 93-95?
1) Install Apexi boost kit or Apexi AVC-R?
2) Porting wastegate?
3) Any easier ways like boost setting in FC-Edit?(dont know if it help)
4) Take off pettit CAI or replace MP with stock cat?)
After resolving this boost issue I want to give a car to a tuner, to optimize my map.
Thanks in advance for you input.
Last week, I've installed DP Feed 3", Midpipe 3"(dimensions like Pettit), CB 3"(seems to be Fujitsubo Legalis), Pettit CAI and Power FC with Base Mod Map. Cruised 1 week and yesterday I installed AEM Failsafe Wideband which is capable to log AFR and Boost for 3 hours to check my boost and AFR log.
My logs scary me, cause I see boost spikes(or its boost creep? from 13-to 16.7psi)
Link to Log file: http://www.filedropper.com/1_99 You can open this log with AEMData program - http://www.aemelectronics.com/files/...ta_4.01.01.exe
I also attached a screenshot from log with a most epic part)
I want a reliable daily driven car with 12-14psi(as I learned 14psi is reliable max), what should I do? Or 97 turbos can handle more boost than 93-95?
1) Install Apexi boost kit or Apexi AVC-R?
2) Porting wastegate?
3) Any easier ways like boost setting in FC-Edit?(dont know if it help)
4) Take off pettit CAI or replace MP with stock cat?)
After resolving this boost issue I want to give a car to a tuner, to optimize my map.
Thanks in advance for you input.
Last edited by 24seven_dada; 06-05-15 at 05:19 AM.
#3
Lousy Crew Chief
iTrader: (10)
Porting the wastegate should always go hand in hand with a midpipe. If you don't have the time to port the wastegate, re install the factory cat and that should bring your boost mostly under control. You can use the PFC to adjust precontrol and wastegate duty cycle to raise or lower boost. You might be reaching the limits of your stock fuel system with your mods and added boost. Bigger secondaries and a rewired supra fuel pump wouldn't be a bad next mod coupled with a tune.
Matt
Matt
#4
RX-7 Bad Ass
iTrader: (55)
The big thing you will be having problems with is the factory boost control can't keep up with the extra flow. Even with a ported wastegate, the factory boost controller just runs away with the boost. I had spiking and problems with just a downpipe and a cat-back on my car back in the day.
You can play around with restrictor pill size with the factory solenoids, but it's sloppy and voodoo work. A good electronic boost controller or even a decent manual boost controller will at least get you back in the realm of safety. You will probably need to port the wastegate as well, but good boost control will get your boost down quite a bit.
Right now you're in VERY dangerous "pop your motor" territory. Take it easy until you get something done.
Dale
You can play around with restrictor pill size with the factory solenoids, but it's sloppy and voodoo work. A good electronic boost controller or even a decent manual boost controller will at least get you back in the realm of safety. You will probably need to port the wastegate as well, but good boost control will get your boost down quite a bit.
Right now you're in VERY dangerous "pop your motor" territory. Take it easy until you get something done.
Dale
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#8
Mazzei Formula
iTrader: (6)
Porting the wastegate will help substantially but in the mean time....
You can safely get your boost under control by installed a restrictor plate in the exhaust. No need to reinstall the catalytic converter unless you want too. Back when I was running the 13b with the twins, I used a 2.25 or 2.5" solid metal cut exhaust gasket, almost like a flange, between the downpipe and the midpipe, this cut out all the boost creep issues until I was able to pull the turbo's off the car.
You can safely get your boost under control by installed a restrictor plate in the exhaust. No need to reinstall the catalytic converter unless you want too. Back when I was running the 13b with the twins, I used a 2.25 or 2.5" solid metal cut exhaust gasket, almost like a flange, between the downpipe and the midpipe, this cut out all the boost creep issues until I was able to pull the turbo's off the car.
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