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Straight Pipes? Yes? or No?

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  #21  
Old 01-25-2012, 11:35 PM
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Are you saying because of the increased flow it would run lean? In that case isn't the ECU always trying to maintain stoichiometry and so would increase fueling?
 
  #22  
Old 01-26-2012, 12:45 PM
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not better flow per-se, but different. and while youre right itll likely compensate enough for fuel to bring it within range... you make most of your power with spark timing, and thats unlikely to do enough adapting (as it typically only adapts downward for knock or other environmental effects) to actually make anymore power.
 
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Old 01-26-2012, 01:44 PM
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In theory the ECM should try to optimize the fuel ratio, but I believe it has limits set (programmed into it) for each temperature range... Quite likely the limits are below what's needed though... Really to bad that there isn't a laptop app the tweak the values like there is available for GM, Ford, and other makers ECM's… The cam shaft and it’s timing would likely need tweaking as well (changing the rise, duration, and overlap numbers)…
If it’s noise you want then there is a device you can buy that will create it and play it through your stereo…

Shonky and the SoundRacer V8 - YouTube#!
 
  #24  
Old 01-26-2012, 04:00 PM
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Then am I correct in thinking a pre-96 with a distributor could be timing adjusted manually to take advantage of it?
 
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Old 01-26-2012, 05:10 PM
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maybe. id be curious to see the difference pre/post on a dyno though...

also, keep in mind that distributor adjustments only change the timing curve in a linear fashion (youre adding/subtracting timing throughout the entire range). certain modifications require that timing be added and subtracted in various parts of the speed/load map... and the changes dont end up necesarily being linear.

im not saying that thats the case, but something to keep in mind...
also, were ultimately likely talking about changes in power that would end up within the noise on back to back dyno runs...
 
  #26  
Old 01-26-2012, 07:45 PM
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the timing I was referring to is valve timing and injector pulse timing, not ignition timing...
 
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Old 01-26-2012, 08:48 PM
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If you want to change valve timing you would need a new cam, and for what gain?
Is it going to be worth the time and money? Not to mention putting a brand new came in a worn engine is a big no-no, it just increases cam wear.
These engines can be tweaked to 5.2L and over 300 horse power, but that requires a full rebuild and ECU mapping, there are places that will remap your current ECU.

RPi Engineering - V8 Engine - Carburetion and fuel Injection
 
  #28  
Old 01-27-2012, 01:22 AM
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Oh I agree... Most likely not wortth the investment and time to just change out a cam... If one were to do it right, then it would be a large investment and require many areas to be changed (modified)... There's just so many other things I would invest in first...
 
  #29  
Old 01-27-2012, 01:39 AM
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Originally Posted by Ed Z
the timing I was referring to is valve timing and injector pulse timing, not ignition timing...

yup, i got that. i (and i think eric) were referring to ignition timing.

any power made to be unlocked from your valve timing changes also assume you can change ignition timing in a non-linear fashion
 
  #30  
Old 01-27-2012, 02:26 PM
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For vehicles that don't have distributors the ignition timing can be altered by slotting the mount holes on the timing pickup bracket (usually a cam or crank sensor)... Or if you have the ECM code cracked you can alter it via laptop... But in any case, it appears getting much gain from these small V-8's is not going to prove simple or cheap...
 


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