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Performance, Brainstorming & Tuning Talk about modifications, or anything else associated with performance enhancements. Have a new idea for performance/reliability? Post it here. No idea is stupid! (please use Detailing and Appearance for cosmetic ideas)

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Old 09-29-2004, 02:21 PM   #1
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I see that some here have an Intense PCM, or such, installed. I had considered this as a mod, but was worried that it would cause my shifting to be harder and be rough on my tranny. Since I am just a street driving man(albiet spirited) with a very rare trip to the track, I don't want to beat up my car since it'* a daily driver.

Outside of possibly doing a little on my exhaust, I was not planning on doing anything else as far as mods. However, if the PCM makes my car more efficient, wakes it up a bit, and tunes it up without causing excessive wear and a lot of loss in gas effeciency, then it is an option to consider.
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Old 09-29-2004, 02:36 PM   #2
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The pcm really does not add that much power but it does raise the shift points, not as much as a shift kit but you do feel it. I would think the quicker shifts would help perserve the tranny though, as the clutches are slipping a lot less with the quicker shifts?
In order to take advantage of the higher shift points though you need to beef up the valve train or else you may get valve float and a drop in performance.
Most consider this mod to come last as it does more with raising limiters and shift points than a performance mod?
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Old 09-29-2004, 03:06 PM   #3
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A lot of people get the PCM when they change to a smaller pulley, which is totally fine.

But personally, I think if you are going to get the PCM, then upgrade the valvetrain a bit, with better springs and pushrods, and maybe even a nice set of rockers. That way you can be sure that you can handle the higher shifting. Just a thought.
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Old 09-29-2004, 04:26 PM   #4
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Quote:
Originally Posted by Sol
A lot of people get the PCM when they change to a smaller pulley, which is totally fine.

But personally, I think if you are going to get the PCM, then upgrade the valvetrain a bit, with better springs and pushrods, and maybe even a nice set of rockers. That way you can be sure that you can handle the higher shifting. Just a thought.
Since I don't plan on doing all those things, it is probably best I don't get the PCM. Thanks for the info.
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Old 09-29-2004, 04:54 PM   #5
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What is valve float and why is it bad?
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Old 09-29-2004, 05:04 PM   #6
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Definition: A high-rpm engine condition in which the valve lifters lose contact with the cam lobes because the valve springs are not strong enough to overcome the momentum of the various valve train components. The onset of valve float prevents higher-rpm operation. Extended periods of valve float will damage the valve train.

I googled it...
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Old 09-29-2004, 06:23 PM   #7
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Quote:
Originally Posted by Twister97
What is valve float and why is it bad?
Good question.... I was wondering as well.
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Old 09-30-2004, 09:19 AM   #8
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basically what that means is ... the valves are trying to move so fast the springs can't keep up and the valves can't actually close.... how is this bad?... well it'* bad on many many levels

1) if your valves aren't closing EVER .. your not getting full compression and your kicking fuel and air down your exhaust and exhaust up your intake (think NASTY valve overlap)

2) if you've got a very tight valve to piston tolerance .. and your valves aren't closing all the way... piston + valve = BAD

3) this is the most usual thing that happens... you've created a gap in your valve train from the cam allll the way to the valve... so now allllll the other stuff is slapping and bouncing to make up for that gap... it'* a really good way to mushroom lifters and bend rods amoung other things
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Old 09-30-2004, 10:36 AM   #9
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But what are some effects to the car, like how is it noticeable?
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Old 09-30-2004, 03:54 PM   #10
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Go up to one of your friends, and give them a really hard slap. If you did it right, that is what you would hear with "piston slap." That was just an example, and a poor one at that. Trust me, if your piston was hitting the valves.. you WOULD hear it.


-justin
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