Re: drilling TQ throttle plates?
[Re: kilroy]
#1256786
06/26/12 01:49 PM
06/26/12 01:49 PM
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Joined: Jan 2003
Posts: 1,793 Windsor, ON, Canada
Diplomat360
top fuel
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top fuel
Joined: Jan 2003
Posts: 1,793
Windsor, ON, Canada
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Hmm...good to know what sizing worked for you. I haven't gone quite that big...was a little worried.
I wish there was a way to run a channel into to secondaries base plate. Sort of a controlled air leak, say, adjustable with a air-bleed type jet. The other approach would be to crack the secondary throttle plates just a tiny wee amount to let some air in, but not initiate any of the secondary fuel system....easy to say, quite a bit more difficult to actually implement.
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Re: drilling TQ throttle plates?
[Re: Diplomat360]
#1256787
06/26/12 02:24 PM
06/26/12 02:24 PM
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Joined: Sep 2004
Posts: 2,094 oberlin, Ohio
Rapid340
top fuel
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top fuel
Joined: Sep 2004
Posts: 2,094
oberlin, Ohio
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I played around with this problem in the past on a stroker motor with a bigger cam. 1) Drilling throttle plates may lead to booster fuel dribble. 2) Cracking open secondaries could be difficult for a number of reasons but mainly because they are so big and it would need to be done almost to perfection. What I did was take a tee off of the PCV hose and used different orifice sizes, it seemed to work well but I did not mess with it very long. You would want to have this extra orifice take in filtered air. I tried many orifice sizes and dont remeber what I ended up with but it was not small, (I think around 3/16 inch) You would want to use a wideband A/F device to iron out your system.
1971 Factory Appearing Duster 340 11.000 @ 122 mph
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Re: drilling TQ throttle plates? ***UPDATE***
[Re: kilroy]
#1256795
07/01/12 08:30 PM
07/01/12 08:30 PM
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Joined: Mar 2005
Posts: 862 Iowa State fan
kilroy
OP
super stock
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OP
super stock
Joined: Mar 2005
Posts: 862
Iowa State fan
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Ok, did some serious driving today. Im not advocating drilling blades for everyone, but as a last ditch, this worked excellent for me. Settled on 9/64 holes drilled in both front plates on the away side of the throttle shaft from the transfer slots. The idle is outstanding. 850rpms just over square on the transfer slots and excellent off idle movement no stumble bumble of farts while driving at any engine speed or driving attitudes and Im a stickler for stuff running without a hitch. After hot driving (its 95* and high high humidity) I was able to lean the mixture screws down to 2.5 turns, maybe able to get another 1/8 to 1/4 turn after driving some more. I have notice I think that overall Im slightly more rich (Im attributing this to the extra turn on the mixture screw) but I really dont know because I dont have an A/F meter (yet). Could just be the heat. I plan on leaning the system by a 1/4 turn on the metering rod tree and see what happens. I will let yall know more in a day or so.
1973 Charger, former SE, former auto
I'm not trying to be difficult, it comes naturally....
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Re: drilling TQ throttle plates?
[Re: kilroy]
#1256798
07/01/12 11:24 PM
07/01/12 11:24 PM
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Joined: Mar 2005
Posts: 862 Iowa State fan
kilroy
OP
super stock
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OP
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Joined: Mar 2005
Posts: 862
Iowa State fan
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I also forgot to mention on my earlier that I have looked at my carb during idle and have seen no booster puller over since drilling my blades.
Last edited by kilroy; 07/01/12 11:25 PM.
1973 Charger, former SE, former auto
I'm not trying to be difficult, it comes naturally....
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Re: drilling TQ throttle plates?
[Re: 440newport]
#1256800
08/01/12 11:59 PM
08/01/12 11:59 PM
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Joined: Mar 2005
Posts: 862 Iowa State fan
kilroy
OP
super stock
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OP
super stock
Joined: Mar 2005
Posts: 862
Iowa State fan
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Just thought I d update some more. Im having no drivability issues with my car after doing this. Ive leaned my carb up with the metering tree as I said a little bit and I need to mess with my vacuum adv just a bit but my carb is great idles smells cleaner now that that Im off the transfer slots so much. NO intermittent drivability issue, or top end issues. Next step getting a/f meter to get killer tune on.
Again this is not fix all, it was just my last resort to get the idle slots down to "correct" after having a very aggressive tune on the distributor and a "big" @.050 street cam.
1973 Charger, former SE, former auto
I'm not trying to be difficult, it comes naturally....
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