LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Heads/cam done now issues

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Old Sep 28, 2004 | 08:17 AM
  #16  
gearneck's Avatar
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From: Kansas City
Re: Heads/cam done now issues

Hope it dosent show a red X but here is the dyno sheet with the first tune.http://img.photobucket.com/albums/v3...e/100_3848.jpg
Old Sep 28, 2004 | 08:19 AM
  #17  
1982z28with18s's Avatar
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From: Mission, Kansas
Re: Heads/cam done now issues

Post the graph dude, I heard it was choppy as hell, which means something isn't right. I don't think you need injectors yet, the stock ones aren't hurting you. Stall/gears aren't hurting your dyno #'s either. Look into the rocker adjustment, fuel pressure, vacuum leaks, get long tubes and a cai and then go from there. But Joe, please do post that graph, it'll help us decide what your problems could be.
Old Sep 28, 2004 | 09:25 AM
  #18  
WS Sick's Avatar
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From: Oklahoma where trees are made of wood.
Re: Heads/cam done now issues

Adjust your rockers. verify fuel pressure through the full run, then get some gears.

Your car is falling on its face because when you shift to third it drops so much in RPM with a 2.73 that you fell right out of your power. I would go no smaller than a 3.73, heck your power is still climbing when the graph of the dyno stopped, nice flat torque curve too. The wavyness of your curve could be the lifter preload, or ign trouble, have any weak wires etc?

You can verify your FP by getting a shraeder valve mounted fuel gauge with about 2 feet of line , tape the gauge to the windsheild in your line of sight and take it out and drive it ard through the gears. it should stay pretty constant and initially rise, but should not drop more than 3 to 5 PSI at the top of your gears, if it is your pump may be weak.
Old Sep 28, 2004 | 10:38 AM
  #19  
turbo_Z's Avatar
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From: Kansas
Re: Heads/cam done now issues

50+ rwhp arent hiding in your exhaust and people have made 400 rwhp with mac shorties.

It looks like you might be running too much timing. The choppy look is caused from detonation.. at least thats what I was told last time I dynoed my car. Had the same problem up high so I added a little fuel and fixed the problem. Wonder if you are just down on a cylindar... next time you go to start you car just let it run for 5 seconds or so and then touch each header primary to see if they are all equally warm. A cold primary would indicate a misfire.
Old Sep 28, 2004 | 07:24 PM
  #20  
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Joined: Sep 2002
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From: South Shore MA
Re: Heads/cam done now issues

I'm was pretty much in the same boat as you! I went to the track with Hotcam, decent heads, longtubes, cutout, 2.73's and 1.5 rockers and went 13.6 @ 103 with a 2.2 60. I was kinda pizzed but thought about it for a while. It was humid, rockers weren't adjusted very well and my 2.73's are holding me back. It pulls hard up until it hits 3rd gear then It falls on it's face in since I have teeny teeny gears.
.
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