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I recently bought a '69 GT coupe that has been restomodded somewhat. It has a 351W with a weiand supercharger with a Demon carb on top. The gentleman that built it had passed away a couple years ago so his family decided to sell it. They weren't really car people so they couldn't tell me too much about what exactly was on/in the engine. I've called several shops here on the island and the few that can tune carburetors won't do it with a supercharger. I've tried to educate myself on how to do it but feel like I'm not doing it any favors. Anyone know of any good resources I can use to help me get this thing tuned right?
 

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Maybe you could contact the manufacturer of the blower? You may be able to get some pointers from them.
 

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Does it drive like the tune is off?
 

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I will ask a friend of mine that is still on Oahu if he has anyone he can recommend on the island. I grew up there but haven't been back since 89. All the places I would want to go back to are all gone now.

One thing I would do if it were mine would be to install an AFR gauge so you can at least make sure you don't end up going way too lean. That's what I worry about with forced induction.
 

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Discussion Starter #6
Does it drive like the tune is off?
Somewhat. I replaced all the spark plugs, have messed with the carb, and played with the timing a very small bit but back at the exhaust it still feels like it's missing. I'm not sure what the cam is so maybe that's it just feels off in my.gur if that makes sense
 

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Hey Nagini - just saw the picture of your car on another thread....that is a serious blower on there. I have a little experience with whipple style blowers. What is your car doing? it should be a beast from idle to whenever it quits pulling. Is it stalling at low RPM? Does it run like a beast once it is wound up?

the car may have never been dialed in after being built. Check the timing. A SC engine should be dialed back from an NA car a bit. Maybe 30° to start. Also check all the vacuum lines on the carb. There is a big PCV line at the back of the carb and a full manifold vacuum line on the front that is hidden under the front fuel bowl that should be plugged or hooked up and of course the vaccum advance on the side of the carb. Holley has some great tuning videos on youtube and the idle circuit is pretty easy to get right. Watch the videos from Holley, Summit or something like that rather than the dude that is in his moms garage.....you will get it dialed in quick!!

beautiful car by the way!
 

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Discussion Starter #15
Hey Nagini - just saw the picture of your car on another thread....that is a serious blower on there. I have a little experience with whipple style blowers. What is your car doing? it should be a beast from idle to whenever it quits pulling. Is it stalling at low RPM? Does it run like a beast once it is wound up?

the car may have never been dialed in after being built. Check the timing. A SC engine should be dialed back from an NA car a bit. Maybe 30° to start. Also check all the vacuum lines on the carb. There is a big PCV line at the back of the carb and a full manifold vacuum line on the front that is hidden under the front fuel bowl that should be plugged or hooked up and of course the vaccum advance on the side of the carb. Holley has some great tuning videos on youtube and the idle circuit is pretty easy to get right. Watch the videos from Holley, Summit or something like that rather than the dude that is in his moms garage.....you will get it dialed in quick!!

beautiful car by the way!
Thanks! So she was idling about 600rpm when I first got it. I have it up to about 850 now which has helped somewhat with when she first starts up. I still have to keep my foot on the gas for about 3 or 4 minutes. It feels like it shakes more than it should and really it feels like it doesn't have as much power as it should. It might be my vast inexperience with old cars. It has a C6 tranny and I've read those are solid but the tradeoff is you lose some power so maybe that's it. Back at the exhaust about every 2 - 4 seconds it feels like a large puff of air rather than the steady, constant exhaust flow. I have no idea what kind of cam is in this thing so maybe it should do that? Part of it might be me coming from a C6 Corvette to this but I would've thought a blown 351 would at least give me somewhat of that oomph.
 
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