Pettit Racing’s Forced Induction System
I've always been on board. My posts are by far the most abused, misunderstood, despised, misinterpreted and maligned of any substantiative observations made.
More effort is put in effect to malign me personally over what I post than to refute the actual data.
Fact is, people don't like being called out for being ignorant, parochial, dogmatic or just plain stupid - so it is apparently easier to simply attack my character than deal with reality. Especially when the subject is the title of this thread.
You, of all the people living in glass houses around here, should know to withhold stones.
More effort is put in effect to malign me personally over what I post than to refute the actual data.
Fact is, people don't like being called out for being ignorant, parochial, dogmatic or just plain stupid - so it is apparently easier to simply attack my character than deal with reality. Especially when the subject is the title of this thread.
You, of all the people living in glass houses around here, should know to withhold stones.
It's like Atilla the Hun questioning your character for fighting back against the Mongol hordes.
Now that I got the use of that "ignor" thing I can come back to these threads with out having my blood boil.
If I understand previous postings correctly you are telling me that I need to get new injectors in order to make my objective hp? Ok, not really a big problem (if such a thing is available) but what will be the side effects? What else do I need to consider? Keep in mind that mine is a 4port.
If I understand previous postings correctly you are telling me that I need to get new injectors in order to make my objective hp? Ok, not really a big problem (if such a thing is available) but what will be the side effects? What else do I need to consider? Keep in mind that mine is a 4port.
), if thats the case I think Pettit needs to be spending more time developing the flash. The fuel trims should be helping you acheive your desired fuel trim and not working against you.... 
"He had alot to say.
He had alot of nothing to say.
We'll miss him.
So long.
We wish you well.
You told us how you weren't afraid to die.
Well then, so long.
Don't cry.
Or feel too down.
Not all martyrs see divinity.
But at least you tried.
Standing above the crowd,
He had a voice that was strong and loud.
We'll miss him.
Ranting and pointing his finger
At everything but his heart.
We'll miss him.
No way to recall
What it was that you had said to me,
Like I care at all. "
Gotta love Tool.
He had alot of nothing to say.
We'll miss him.
So long.
We wish you well.
You told us how you weren't afraid to die.
Well then, so long.
Don't cry.
Or feel too down.
Not all martyrs see divinity.
But at least you tried.
Standing above the crowd,
He had a voice that was strong and loud.
We'll miss him.
Ranting and pointing his finger
At everything but his heart.
We'll miss him.
No way to recall
What it was that you had said to me,
Like I care at all. "
Gotta love Tool.
they mention small LTFT's fuel trims building.
If they have the correct fuel tables and lambda targets loaded, building small LTFT's should be celebrated and not continually cleared as they should be helping you meet your lambda targets - they are a results of countless things changing like fuel injector cleanliness, maf cleanliness, fuel quality, intake and exhaust conditions, hell battery voltage can even effect the fuel injection.
it seems odd to me that there is a need to get rid of the fuel trims
If they have the correct fuel tables and lambda targets loaded, building small LTFT's should be celebrated and not continually cleared as they should be helping you meet your lambda targets - they are a results of countless things changing like fuel injector cleanliness, maf cleanliness, fuel quality, intake and exhaust conditions, hell battery voltage can even effect the fuel injection.
it seems odd to me that there is a need to get rid of the fuel trims
Our pcm/maf/wideband is too dang smart and is a ganging up on us. This tuning is progressing---it aint easy.
Someone shared and idea with me. Just hook a switch up to the room fuse connector and whenever you go to start the car -push the button 1st-wait just a second then start. Sweet!
I am about ready to say --chunkit! Put a cable TB on , a haltech and a straight pipe! JK.
oscd
Someone shared and idea with me. Just hook a switch up to the room fuse connector and whenever you go to start the car -push the button 1st-wait just a second then start. Sweet!
I am about ready to say --chunkit! Put a cable TB on , a haltech and a straight pipe! JK.
oscd
Administrator
Joined: Jul 2002
Posts: 21,958
Likes: 115
From: portland oregon
i said this in the other thread but ill repeat it. i believe what you have here is an incorrect understanding of what is written on the RB site. That whole paragraph is talking about the process of creating their tune. the mention of clearing the trims for track use is about the stock untuned car. ill post the response from JM when i get it.
If I understand previous postings correctly you are telling me that I need to get new injectors in order to make my objective hp? Ok, not really a big problem (if such a thing is available) but what will be the side effects? What else do I need to consider? Keep in mind that mine is a 4port.
So, if you are looking to put down more than 220 or so at the wheels, you will need to upgrade.
The actual upgrade is relatively easy and cheap and fairly easy to tune on the Int-X or the EMU. I don't know what the Pettit flash can accommodate.
+1
My intuition tells me that the RB flash does NOT address the lambda tables. It merely changes the injector targets or, even worse, the airflow targets.
It LTFT is fighting the flash, than, as I stated elsewhere, its merely an AFM modifier like the S-AFC.
That's kinda like saying your eyes and ears communicate with each other. The PCM "sees" varying voltage values from all the sensors independently(like our brains). The rest is explined quite well on RB's website. I think they recently update it a bit because JM defined what "hysteresis" means and he didn't do that before.
I'll have to go look at RB's WEB site. I haven't been there in a while.
Registered User
Joined: Jun 2002
Posts: 3,086
Likes: 1
From: Misinformation Director - Evolv Chicago
...that's just twisted and funny.
i prefer alpaca's over goats... much more upscale and they make a nice woorbaling sound
I wonder if the placement of the MAF sensor is causing some problems. MAFs need a constant velocity profile (so it either needs to be laminar or completely turbulent... turbulent is actually perferred). The placement a few inches behind the filter would be in a transitional flow which is rather unpredictable.
Do they use any flow straightener screens like the OEM intake has?
The position would make me worry with no flow straightener, ideally you would want to be a good 3-5 pipe diameters upstream and downstream of anything funky without a flow modifier.
The diameter changing steps may or may not be acceptable depending on the application as sometimes it can force a nice looking turbulent flow pattern (but is very tricky to accomplish). For the record, a nice turbulent pattern has a velocity profile that looks like "]" while a laminar flow pattern looks like ")". Flow nozzles in flow measuring instruments for instance are commonly used to do this very thing - some are ramped in shape and some are square... however, to rely on that for profile adjustment i'd wager it needs to be 2-3x the length.
i'd say the setup could be suspect... at least some screens should be there to help average the flow velocities (probably before and after actually) if a maf problem is suspected.
I have been thinking about the need for a screen also.
The maf pipe does not have diameter changing steps at the ends as far as i know. Actually i am using the RB Revi maf pipe which is fine per Pettit.
Now before I had a car that ran well with no maf pipe screens. I have not thought about screens until it was mentioned now. Food for thought.
The system is intra dependent, skilled at multidisciplinary tasking but possibly schizophrenic. No anhedonia as i really thinks it enjoys all of this.
Maybe I need a trim
oscd
The maf pipe does not have diameter changing steps at the ends as far as i know. Actually i am using the RB Revi maf pipe which is fine per Pettit.
Now before I had a car that ran well with no maf pipe screens. I have not thought about screens until it was mentioned now. Food for thought.
The system is intra dependent, skilled at multidisciplinary tasking but possibly schizophrenic. No anhedonia as i really thinks it enjoys all of this.
Maybe I need a trim
oscd
Pettit fangurl <3
Joined: Mar 2005
Posts: 5,386
Likes: 0
From: Aston, PA
ok...here comes the dumb broad remark...
i do have a screen....hopefully its the one that everyone is referring to..
it fits over the MAF tube between the end of the MAF tube and the filter...
is that the one?
i do have a screen....hopefully its the one that everyone is referring to..
it fits over the MAF tube between the end of the MAF tube and the filter...
is that the one?
Pettit fangurl <3
Joined: Mar 2005
Posts: 5,386
Likes: 0
From: Aston, PA
Pettit fangurl <3
Joined: Mar 2005
Posts: 5,386
Likes: 0
From: Aston, PA
here is a pic of what mine looks like at the present...
we fabricated this one from the factory box...
you can actually see where the screen is and the tube doesnt really have diameter changes per se...
we fabricated this one from the factory box...
you can actually see where the screen is and the tube doesnt really have diameter changes per se...
It only dynos less than a corrected DynoJet. (Which is something FI people do to inflate their numbers.)
True, uncorrected numbers from a DynoJet look just like the ones from a DynaPack and a Mustang give or take 2% or so.
I did my runs on a DynaPack - which is also reported to deliver numbers that are significantly lower than a DynoJet. I don't think anyone believes my numbers are low.
Twice its diameter its diameter is optimal. 1.5 times its diameter is really the minimum for an accurate reading.
Last edited by MazdaManiac; Jan 23, 2008 at 10:57 PM.
Mu ha.. ha...
Joined: Aug 2004
Posts: 14,361
Likes: 3
From: Cali
Charlie, I have re-read RB's info on that and I don't think I am misunderstanding what they are saying at all. I am looking at option 1 wherein JM talks about disconnecting the O2 sensor, pulling the room fuse, and reconnecting the fuse. In that example, he never mentions re-connecting the O2 sensor but does mention that the trim tables will never build and you'll get a CEL. In option 2, he mentions warming up the engine and resetting the PCM by pulling the fuse, then heading to the track. My understanding there is that in open-loop mode, such as in a racing context, the trims won't have time to build(theoretically, anyway), and afterward one can drive their car home and the tables will build at that time.
I wonder what his response will be and I look forward to reading it.
I wonder what his response will be and I look forward to reading it.
Funny you should mention that. I am presently turning over in my little brain a way to incorparate the RB filter/horn/1 screen and the maf pipe onto my set up. Lets see if wide band readings change. (shouldnt) but hey no harm in looking.
ray sending you a PM.
OSCD
ray sending you a PM.
OSCD
Jeff - when you're talking length, is it overall length of the housing or the distance from the mouth of the housing to the MAF sensor, or does this make a difference?