Boost Control
05-04-05, 08:36 AM
#1
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Boost Control
If i pruchase the Greddy profec b 2 boost controller will this be able to limit the boost to 10psi and keep my standard ecu, it is over boosting since minor mods,(exhaust,decat,induction kit,).
Any help would be great!
Cheers
Funster.
Any help would be great!
Cheers
Funster.
05-04-05, 08:53 AM
#3
What's your point ?
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So if I understand you have a DP, MP, and catback, as well as the CAI. ? ? ? ? What's the 10 psi got to do with the fact you've considerably changed the air flow through the motor ? ? ? You should be looking for an ECU any way's even if you stay at the stock levels.
05-04-05, 10:40 AM
#4
Originally Posted by CantGoStraight
So if I understand you have a DP, MP, and catback, as well as the CAI. ? ? ? ? What's the 10 psi got to do with the fact you've considerably changed the air flow through the motor ? ? ? You should be looking for an ECU any way's even if you stay at the stock levels.
As long as he stays bolw 10 psi he will be fine. And I mean below 10 psi no spikes no creep nothing past 10 psi.
I am currently running:
Mild Streetport
DP
MP
M2 CAI
PFS SMIC
on a stock ECU
Boost is set at 9.5 psi ( i get a spike of 10.2 at transition which is normal when running sequential)
I WOT that baby & take it 7.9k RPM's and I have no worries, never hit fuel cut due to boosting higher levels. Now fuel cut because I went past 8k well that's another story.
I really need a PFC because my baby is just itching to run at it's potential
05-04-05, 10:44 AM
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Originally Posted by montego
Sorry dude but that is not correct.
As long as he stays bolw 10 psi he will be fine.
As long as he stays bolw 10 psi he will be fine.
05-04-05, 11:38 AM
#7
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Cool, thanks guy's. I have been torn between which way to go next with the car lately. My feelings were at this stage it wasnt worth going for the new ecu as my mods are quite minor really and i just want the car to run nicely with the exhaust/airfilters etc. Then obviously i will be going on to the next level, and the next and the next..........
Cheers
Funster.
Cheers
Funster.
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05-04-05, 12:49 PM
#11
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Originally Posted by quicksilver_rx7
Even below 10psi you can still run lean, which is the whole point for an aftermarket.
Put up the wideband data proving your statement. I guarantee you won't find any. On the other hand, there is a lot of wideband data showing you are wrong.
05-04-05, 12:55 PM
#12
Originally Posted by rynberg
NO YOU WILL NOT, not on stock twins.
Put up the wideband data proving your statement. I guarantee you won't find any. On the other hand, there is a lot of wideband data showing you are wrong.
Put up the wideband data proving your statement. I guarantee you won't find any. On the other hand, there is a lot of wideband data showing you are wrong.
05-04-05, 02:44 PM
#13
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Originally Posted by montego
That is so 3 years ago...
No the whole point of an aftermarket ECU is to run higher boost levels safely.
No the whole point of an aftermarket ECU is to run higher boost levels safely.
05-04-05, 02:55 PM
#14
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Originally Posted by rynberg
NO YOU WILL NOT, not on stock twins.
Put up the wideband data proving your statement. I guarantee you won't find any. On the other hand, there is a lot of wideband data showing you are wrong.
Put up the wideband data proving your statement. I guarantee you won't find any. On the other hand, there is a lot of wideband data showing you are wrong.
One common question is "How many mods can I do before I need to upgrade the computer?". The question has to do with what you can do to the car before it starts to run lean and experiences detonation, which will kill a rotary. Mods that improve airflow start to become dangerous if they let it flow too freely, and the stock computer does not provide enough fuel to go along with the extra air. Since the stock computer uses static maps, it either needs to be reprogrammed (see M2 Performance, Pettit, XS). See below for more info --Editor
I'm going to throw some numbers out on to this thread. I know its been cover MANY times, but I have never seen numbers other than my own readings so here goes.
My mods probably wont directly relate to anyone else since everyone does the catback before a midpipe, but I figure the midpipe will make a bigger deference than the catback, & considering I was only running about 8-8.5PSI on the secondary turbo the "intake, DP, CB" configuration at 10 PSI will probably be equal if not worse than my config.
Disclaimer: These are rough measurements taken with a very high quality Fluke 87 volt meter on a very low quality Bosch O2 sensor, & an Autometer boost gauge.
OK, Once I had the intake + DP config I came real close to overboosting one cold morning so I installed a needle valve into the wastegate actuator pressure line. This left me with 10PSI pri, & 8-8.5PSI sec. (don't ask me why, but the Profec B seems to have fixed it)
My maincat clogged so I installed a midpipe, & figure that with only 8PSI on the second turbo that I'd be pretty safe,
Well I did runs with the intake + DP, & measured around .97x, but as the RPM rised above 6K the O2 voltage would drop down to about .927ish I figured that to be plenty safe.
After installing the midpipe, I was measureing the .97v. (around 3K on the tach) but at 5K with 8PSI the voltage would drop down under .9v. With it going as low as .81-.80v. by 6.5K.
That is when I decided that I wouldn't run over 4-4.5K until my Power FC arrives, in fact I rarely drive the car right now. So that is proof (kinda) that 3 mods with no fuel mods other then a K&N fuel filter, & no stock filter make the FD R-REX run lean.
I'm going to throw some numbers out on to this thread. I know its been cover MANY times, but I have never seen numbers other than my own readings so here goes.
My mods probably wont directly relate to anyone else since everyone does the catback before a midpipe, but I figure the midpipe will make a bigger deference than the catback, & considering I was only running about 8-8.5PSI on the secondary turbo the "intake, DP, CB" configuration at 10 PSI will probably be equal if not worse than my config.
Disclaimer: These are rough measurements taken with a very high quality Fluke 87 volt meter on a very low quality Bosch O2 sensor, & an Autometer boost gauge.
OK, Once I had the intake + DP config I came real close to overboosting one cold morning so I installed a needle valve into the wastegate actuator pressure line. This left me with 10PSI pri, & 8-8.5PSI sec. (don't ask me why, but the Profec B seems to have fixed it)
My maincat clogged so I installed a midpipe, & figure that with only 8PSI on the second turbo that I'd be pretty safe,
Well I did runs with the intake + DP, & measured around .97x, but as the RPM rised above 6K the O2 voltage would drop down to about .927ish I figured that to be plenty safe.
After installing the midpipe, I was measureing the .97v. (around 3K on the tach) but at 5K with 8PSI the voltage would drop down under .9v. With it going as low as .81-.80v. by 6.5K.
That is when I decided that I wouldn't run over 4-4.5K until my Power FC arrives, in fact I rarely drive the car right now. So that is proof (kinda) that 3 mods with no fuel mods other then a K&N fuel filter, & no stock filter make the FD R-REX run lean.
05-04-05, 03:00 PM
#15
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Originally Posted by quicksilver_rx7
Disclaimer: These are rough measurements taken with a very high quality Fluke 87 volt meter on a very low quality Bosch O2 sensor, & an Autometer boost gauge.
Those measurements mean nothing. There are several of us with actual WIDEBAND data that show the stock ecu is below 11:1 AFR, even with several mods.
05-04-05, 03:12 PM
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Originally Posted by quicksilver_rx7
No problem. I was hoping you would actually post the data so I could learn something on here.
You can also do a search using my username and "dyno results" or "mod rule". You should come up with my stock ecu dyno sheet showing below 10:1 with downpipe and cat-back. I can't find a later stock ecu dyno sheet I had with intake, SMIC, dp, and cb, but the AFRs were still WELL below 11:1 on that setup. Several other people have similar sheets too, although I don't immediately have any to show. A search would probably find them.
Sorry to snap at you but this thread is at least the 4th or 5th one of these lately, including one from yesterday! I just get sick of people defending the 3-mod rule when they've never even seen a frigging wideband AFR plot of a stock ecu car.
05-04-05, 03:21 PM
#19
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Not a problem. I just know for me personally, I'm not rich like some of the guys on here, so I prefer to play safe. PowerFC was the first mod I did. It probably wasn't necessary at the time, but I've got it now and anything else I do I can adjust for.
Also, thanks for the info and the link.
Also, thanks for the info and the link.
05-04-05, 04:55 PM
#21
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Originally Posted by quicksilver_rx7
Not a problem. I just know for me personally, I'm not rich like some of the guys on here, so I prefer to play safe. PowerFC was the first mod I did. It probably wasn't necessary at the time, but I've got it now and anything else I do I can adjust for.
Also, thanks for the info and the link.
Also, thanks for the info and the link.
Also, Gadd's car is the leanest stock ecu AFR I've ever seen with only a few mods, probably just the difference in widebands.
05-05-05, 10:36 AM
#22
Warming the planet.
Originally Posted by rynberg
Ironically, you have to be more careful with the PFC as the default map is LEANER than the stock ecu! Many people don't believe this but it's true.
Also, Gadd's car is the leanest stock ecu AFR I've ever seen with only a few mods, probably just the difference in widebands.
Also, Gadd's car is the leanest stock ecu AFR I've ever seen with only a few mods, probably just the difference in widebands.
Also, these are logs from street runs not a dyno. And from what I understand, street runs tend to be slightly leaner than a dyno run.
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