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Advanced cam timing?


94GTP

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Anyone experiment with advancing the cam timing? As I understand it, advancing will place the powerband in a lower rpm. I'm getting ready to replace my timing belt and was wondering if I would experinence any benefit from 8 or 10 degrees before TDC on both cams. Or... am I wasting my time?

 

Anyone got desktop dyno and want to see what would be a safe setting?

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Guest Gp crazy

i do not think so do a search on this web site there is alot of info on the dohc 3.4 !

i hope your replace everything when you do this. :bash: if not you will pay in the end !

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It has been over a year now that the 13 degree exhaust retard spread across the internet as an easy way to get power out of this motor. It seems that another person has experimented with the timing o­n a ported engine mated to the automatic trans. It retains the 13 degree aspect but advances the intake cam as well to lower the powerband from what we had already tried. I hope this is right, 7 degrees advanced o­n the intake, 6 degrees retarded o­n the exhaust

anyone know any actual numbers on this? gains?/ loss?

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No one *really* knows anything when it comes to adancing or retarding the cams. I'm leaving mine at zero.

 

well i would consider doing the experiments on a g-tech.. but the results if any would be inconsclusive in the end due to g-techs rounded numbers. i wish my town had a dyno that would be so much nicer.

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No one *really* knows anything when it comes to adancing or retarding the cams. I'm leaving mine at zero.

 

That's the conclusion I came to. There's not any data to support any adjustments, only opinions. Well, there is Michael Smith's page with the fiero, but he has a massive intake and exhaust. Those tend to accentuate adjustments in timing. Too bad we can't get someone to fund a research project on cam timing.

 

I'm already in the middle of replacing my belt. I actually got everything together, but it's making a mild noise that sounds like an exhaust leak. At least that's what I thought it sounded like. Then I realized I have my tensioner too tight.

 

While I was timing the front bank I missed the mark and had to rotate the engine 720* to get the mark back to where it needs to be. While doing this one of the pulleys on that bank accidentally tightened up. This caused the tensioner to tighten up. I didn't think it tightened that much, but when I got everything back together, I realized the sound was coming from the cam carriers and resonating through the intake.

 

I'm hoping that the timing wasn't affect by the over tensioning, but I don't think I will be able to get the right tension without releasing the front cogs. (Since they were adjusted while the belt was already mega-tight) No wonder the dealership charges $500 to $700 to do this!

 

I can reset the front bank and tensioner without taking of the intake, but my question now deals with whether the rear bank is in time. I hate taking that intake off! But, I'm probably better off checking.

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well i would consider doing the experiments on a g-tech.. but the results if any would be inconsclusive in the end due to g-techs rounded numbers. i wish my town had a dyno that would be so much nicer.

 

Wouldn't it be nice if there was a speed shop franchise that offered dyno testing on a drive through basis? I know the money they would make from the general public wouldn't warrant the cost, but it would be awesome.

 

BTW, how many hours did you have in polishing your intake? I've been thinking about doing that, but I'm too anal to make the job quick. Your's looks sweet, but I do like what you did later as well!

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