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Midpipe, Before and After

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Old Dec 10, 2003 | 11:52 AM
  #26  
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From: Buckhead
Originally posted by Zoomspeed
Like I said before, some people get creep and others don't. Why that is I dont know, but that seems ot be the way it is. What I'm saying though is that it doesn't have to be the cat back thats restricted to prevent creep. It could be other restrictosn in there that would precent creep.

For example one could upgrade the CB, then the DP, and then get creep after adding the MP assuming its one of the cars that will get creep. Now if its one of the cars that doesn't get creep then you can go in any order and you still won't get creep.

Sounds like your car is one of the ones that dont' creep (as is mine, lucky for us ). Am I making sense? I havn't slept in a day or 2 and that makes me ramble. lol
I misread your post. The point im making is that the midpipe alone will not give you boost creep. In my world boost creep doesn't exist. I think alot of it is exaggerated, like someone sets the power fc to .80 and they get .84 and call it boost creep.

and yea I have had 2 sets of turbos, 1 straight through exhaust and a semi-restricted exhaust and no boost creep, so I dunno, I guess I got a lemon.
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Old Dec 10, 2003 | 12:04 PM
  #27  
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just to clear a point up, thats a 4th gear pull... in 5th gear on the road i do see alot more boost at redline

edit: not that ive redlined it in 5th
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Old Dec 19, 2003 | 04:11 PM
  #28  
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I believe the exhaust system has the largest portion of the boost creep equation. However, if your intake tract is restricting flow through the motor the exhaust doesn't have the same amount of CFM (cubic feet per minute) of gasses to release. Now if you add a large stock mount intercooler and remove the second set of butterflies in the throttle body with a free flowing exhaust you should be able to flow enough CFM to over power the stock waste gate. Simply because you’re flowing more air.

Steve
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Old Dec 19, 2003 | 05:19 PM
  #29  
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You are so right. It depends mostly on exhuast system. The other stuff like intake has an effect but not as much.

Also, the factory pills can have an effect.

For instance, my buddy installed a full exhuast with a bunch of other mods. He has over 15psi after switchover. I removed his wastegate pill and the reaction time for the gate opening is much faster. It reduced his boost pressure on lower gears to about 11-12 psi.

Since he has a Haltech, his boost setting will react differently than stock ECU boost settings.

-Jeff Ho
93' R1

Originally posted by TireSmokin7
I believe the exhaust system has the largest portion of the boost creep equation. However, if your intake tract is restricting flow through the motor the exhaust doesn't have the same amount of CFM (cubic feet per minute) of gasses to release. Now if you add a large stock mount intercooler and remove the second set of butterflies in the throttle body with a free flowing exhaust you should be able to flow enough CFM to over power the stock waste gate. Simply because you’re flowing more air.

Steve
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Old Dec 19, 2003 | 06:13 PM
  #30  
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Now are all of you running an upgraded ECU?
Or do some of you have like a DP and MP with out one?
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Old Dec 19, 2003 | 06:51 PM
  #31  
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Now that I got my smog issues taken care of. I'm gonna get a mid pipe too..
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Old Dec 19, 2003 | 07:31 PM
  #32  
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Im pretty sure that everyone who modifys their car has an upgraded ecu
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Old Dec 19, 2003 | 07:48 PM
  #33  
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Originally posted by XSTransAm
Im pretty sure that everyone who modifys their car has an upgraded ecu
huh? How do you figure? I disagree. I know TONS of people who have various engine mods without an ECU. Most people start modifying by adding DP, CB, and intake well before they get a new ECU.

However, MPs are typically a later upgrade and most people that switch to a MP already have an upgraded ECU. A good amount of people have trouble with creep using a MP, which is a BAD thing on the stock ECU. But, if you can keep the boost constant and under 10psi, then you'll be fine on the stocker.

Rob
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Old Dec 20, 2003 | 12:53 AM
  #34  
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I think the two mod rule comes into play here... like dp intake, but as soon as you try to make real power you NEED an ecu. but hey if you think otherwise go ahead, its not my engine

I did have my dp, cat back and intake before my ecu... car was fine. would I have gone further without ignition and fuel control? hell no!
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Old Dec 20, 2003 | 08:49 AM
  #35  
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The three mod rule has been totally disproven. As long as you keep the boost below 10psi, the stock ECU can handle all of the bolt-ons. This has been known for years. Take a look at Wade Lanham's site:

Myths: 3 Mod Rule

The three mod rule is a good general guide for newbies who may not know how to control boost. But it is a fallacy as long as you can keep the boost at stock levels.

But again, a MP usually introduces some uncontrollable boost creep, which would be BAD on the stock ECU. I was just addressing your statement that everyone who modifies their car is running an ECU. Which (most people here will agree with me) is not an accurate statement.


Rob
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Old Dec 21, 2003 | 03:05 PM
  #36  
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Can someone exsplain to me what a boost creep is, i've heard of it but I dont understand.
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Old Dec 21, 2003 | 07:34 PM
  #37  
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Originally posted by spoolin1012
Can someone exsplain to me what a boost creep is, i've heard of it but I dont understand.
Its when your waste gate can't vent enough to keep the boost level down. When that happens you get a slow rise in boost at WOT.

This ends up being a problem when people open up there exhaust becasue there is more flow through the turbos hence the wastegate has more it needs to vent.
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Old Dec 21, 2003 | 08:12 PM
  #38  
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Or boost spike is when it just jumps up. Like from 10 to 16. A big *** waste gate can prevent this.
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Old Dec 21, 2003 | 08:42 PM
  #39  
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Re: Midpipe, Before and After

Originally posted by XSTransAm


catless is red, stock cat is purple

You sure the catless isnt purple and the stock cat is red. Cuz if its the way you said it the stack cat is making more boost than the catless.
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