Voodoo 268 Cam - Help
Thread Starter
Pro
Joined: Sep 2004
Posts: 579
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From: North Texas
Voodoo 268 Cam - Help
Thanks for any help guys. Here is my setup and problem:
355 cid, vortec heads, ~9.75 cr, performer intake, holley 650dp, 1.5 rr, 1 5/8" hookers, 2 1/2" dual chambered, voodoo 268 (60103), stock stall/TH350 , 3.70 posi.
Problem: I tuned using a vacuum gage and ended up with 17" at idle. Park/neutral idle is 1200rpm, drive is 700rpm. Any changes I made to carb or timing decreased rpm and vacuum so I thought I was good.
The vette is an absolute dog until ~2800rpm then it feels like a turbo kicks in and it takes off - a huge difference. *Also, it shifts at 3500 now instead of 5500.
Do I have a timing problem? Could the carb need different jets? Is this just the cams power band - I would say it feels like only ~100tq until ~2800rpm then ~300+tq.
355 cid, vortec heads, ~9.75 cr, performer intake, holley 650dp, 1.5 rr, 1 5/8" hookers, 2 1/2" dual chambered, voodoo 268 (60103), stock stall/TH350 , 3.70 posi.
Problem: I tuned using a vacuum gage and ended up with 17" at idle. Park/neutral idle is 1200rpm, drive is 700rpm. Any changes I made to carb or timing decreased rpm and vacuum so I thought I was good.
The vette is an absolute dog until ~2800rpm then it feels like a turbo kicks in and it takes off - a huge difference. *Also, it shifts at 3500 now instead of 5500.
Do I have a timing problem? Could the carb need different jets? Is this just the cams power band - I would say it feels like only ~100tq until ~2800rpm then ~300+tq.
Last edited by Nate 76x; May 17, 2005 at 11:20 AM.
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
My setup is a little like yours (see sig) so this might help:
First - what is your total advance set at? My car runs best at 36 degrees total.
Second - you need to change the shift point on the trans. My trans is not stock, but I can change my shift point by turning a small screw inside the modulator on the side of the trans.
Take care of those items and report back, maybe we can come up with more help.
First - what is your total advance set at? My car runs best at 36 degrees total.
Second - you need to change the shift point on the trans. My trans is not stock, but I can change my shift point by turning a small screw inside the modulator on the side of the trans.
Take care of those items and report back, maybe we can come up with more help.
Instructor
Joined: Nov 2004
Posts: 194
Likes: 0
From: Appleton Wi.
I have an engine package similar to yours, and I had a terrible flat spot from idle to about 1500. Than took off like a raped ape. No amount of tuning helped. I have a Demon 650 dp. Air gap manifold. My problem was that the gasket under the carb was incorrect, even though it was the one Demon suggests. Turns out I needed the 4-hole design. There was a bit of reverberation between sides of the manifold. That may not help, but it sure did the trick for me. Good luck.
TJ
TJ
Burning Brakes
Joined: Aug 2001
Posts: 947
Likes: 0
From: I can explain it to you, but I can't comprehend it for ya.
some timing advice that I've heard from many Vortec head users and have proven myself at the track is; No more than 32 degrees total timing in by 3000 with the Vortec heads. Thats where they perform the best.
Which Voodoo cam are you runnin? The 262/268 or the 268/276?
Which Voodoo cam are you runnin? The 262/268 or the 268/276?
Last edited by Dwaynes69BB; May 17, 2005 at 02:56 PM.
