JJ

I set the idle on my 650 dp, turned the air/fuel out 1.5 turns . . . that is the extent of my tuning at this point. this is a new carb, it actually runs pretty good, not really any bog as long as the rpms are up a little. what is the first thing I should do mileage wise ?? sorry I am carb challenged, just trying to learn what is going on.

five7kid

iTrader: (14)

A couple of questions first: Did you convert to a mechanical/vacuum distributor as well? (If you've spent any time at all on these boards, you know you have to do that.) 2nd, are you currently experiencing really bad mileage?

Assuming you have the right combination of pieces and everything is in good condition, the three remaining things are tuning, tuning, and tuning. Make sure your ignition system is in tip-top shape. Set the timing at the proper initial and total advance. Make sure your vacuum advance is working properly. Then tune the idle mixture, primary jets, accelerator pump, and power valve to give no more than the leanest mixture possible for good driveabilty.

Then, pump up the Nike on your right foot with helium.

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82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 open. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

JJ

yep, switched to vacuum controlled dist, the one that comes with the zz4. Yesterday I ordered the msd coil, ignition module and wires - they will go on this weekend, I will start trying to check other things as well as it is getting "really" bad mileage right now. I'm sure it is rich, are smaller jets the route to get it leaner on the primaries?

JJ

yep, switched to vacuum controlled dist, the one that comes with the zz4. Yesterday I ordered the msd coil, ignition module and wires - they will go on this weekend, I will start trying to check other things as well as it is getting "really" bad mileage right now. I'm sure it is rich, are smaller jets the route to get it leaner on the primaries?

FastBroker

You gotta get an A/F meter and check the exhaust. Go leaner on cruise/primary settings/jets until you see 14.7, then go back one step richer for driveability. Secondaries are tougher to tune and wide-bad O2 really needed. Or, GTech and/or strip tuning OR dyno time with a handful of jets...

Make sure your HEI is at 33-36 total intial advance and centrifugal advance combined (NO vacuum advance!) This will give best results 90% of the time.

82z

Everyone is right you definately need to tune tune tune. But you must realize the compromises that come with a dp. You are dumping in fuel regardless if the engine needs it or not. 30 mpg is not possible. Anyway I must recomend an intellitronix a/f gauge. I own one and would definately recomend one to all my friends.

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82 z28 350cid, vortec heads, comp 262h cam, Holley 600cfm carb, 2in twice pipes, MSD ignition, turbo 350 trans, 3.73 posi

FastBroker

Hey 82Z, how come you are running a TH350 over the 700? Besides the "not strong enough" reason that is? You could put 5.11 gears in your axles along with a TH700 and you would have LOWER highway RPM than you do with the 3.73/Th350 combo. and your car would be FFAAAAAASSTT and streetable!!!!!!!!!

[This message has been edited by FastBroker (edited November 10, 2000).]

junkyarddog

5.11 gears! where can I find those?