replicaracer43
Grumpy Old Man
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My 71 dart has a bone stock 5.2 magnum with a m1 dual plane and a sharply tuned thermoquad, 3:23 gears and a 904 and will get 20 on the highway steady driving.
Are you driving it like a granny, or are you driving it like you should drive a mopar? (I love stoplights)I just attended the 16 chryslers at carlisle and finally after 8k miles after beING restored I calculated mileage! First off I have a 69 dart with the numbers driveline. 340 stock 727 and 3.23 suregrip. I'm running a 255/60/15. I'm only averaging 10mpg running at 60mph. I feel that's poor mileage and was wondering what yall are getting. The car runs great but is there something going on with me achieving these numbers. I'm running 93 octane also. Thanks in advance
Yeah your tuning has to be off. My duster has a 1990 360 with 9.7 compression, an air-gap manifold (not a mileage booster), Lunati Voodoo 270/279 hyd. roller cam, roller valvetrain on stock 308 heads, topped with a Eddy AVS 650 carb.
I also have an A999 (with lockup function fully removed), an 8.25 with 3.21 gears and a 27 inch tire.
I tuned my carb with an AFR gauge, I'm actually running a tad on the rich side.
I get anywhere from about 16.5 to 17.5mpg freeway mileage at around 70 mph
I also get about 10 to 14 around town (depending how froggy I get with the throttle).
Any suggestions
What carburetor? Your metering rods or power valve may be too weak and pulling closed...Not to highjack the thread, but I'm hoping this question will help the OP in regards to tuning.
Here are my specs as stated earlier.
My timing is set around 14 degrees adv. initial. And it seems to run the best.
I do have vacuum advance hooked up.
Low and Mid RPM response is phenomenal. I do have a audible ping at High RPM (around 4500+) even with 91 octane. I live at 4500 ft above sea level. I'm running a stock VA distributor. I'm thinking the total advance is within range. My fuel pump is a Carter performance one [120 gph, 6.9-8.1 psi]. So I know its not that.
So I'm thinking I should put the initial back down to 10 degrees. Any suggestions? Or should I invest in a performance distributor?
My duster has a 1990 360 with 9.7 compression, an air-gap manifold (not a mileage booster), Lunati Voodoo 270/279 hyd. roller cam, roller valvetrain on stock 308 heads, topped with a Eddy AVS 650 carb.
I also have an A999 (with lockup function fully removed), an 8.25 with 3.21 gears and a 27 inch tire.
I tuned my carb with an AFR gauge, I'm actually running a tad on the rich side.
I get anywhere from about 16.5 to 17.5mpg freeway mileage at around 70 mph
I also get about 10 to 14 around town (depending how froggy I get with the throttle).
I tuned the carb with an AFR gauge. My jets and rods have already been set. The only thing I haven't looked at yet is the distributor. I'll do what rmchgr suggested its running so good other than the WOT ping I would hate to retard the timing less than what it is now.What carburetor? Your metering rods or power valve may be too weak and pulling closed...
I tuned the carb with an AFR gauge. My jets and rods have already been set. The only thing I haven't looked at yet is the distributor. I'll do what rmchgr suggested its running so good other than the WOT ping I would hate to retard the timing less than what it is now.
I just attended the 16 chryslers at carlisle and finally after 8k miles after beING restored I calculated mileage! First off I have a 69 dart with the numbers driveline. 340 stock 727 and 3.23 suregrip. I'm running a 255/60/15. I'm only averaging 10mpg running at 60mph. I feel that's poor mileage and was wondering what yall are getting. The car runs great but is there something going on with me achieving these numbers. I'm running 93 octane also. Thanks in advance
check your ignition timing, is your vaccum advance hose connected? were the jets rods and spring changed? low pressure on tires could cause a little bad mileage too but not too much
Lack of vacuum advance. It's ping is probably related to a fuel curve issue. Getting control of the advance curve for a street car is also different than a race car or car with a high stall converter. All in at 2500 is not a good thing with a tight converter and slightly lean mixture. Slow the mechanical advance curve and or shorten it and make sure total timing with vacuum in not going over 45 degrees. You may need stiffer metering rod springs and or smaller rods too.
My truck does not like vacuum advance at all. I have a lot of initial advance because of the cam and used the FBO limiter plate to limit the mechanical. I don't remember what it's set at exactly but with V.A. hooked up it sputters bad. I adjusted the canister to where it was not as prevalent and maybe I can tweak it a little more but the symptoms still persisted so I capped it off. I gained mileage with my last round of tuning but I am not sure if I left anything on the table without the V.A. This is possibly due to a problem in rotor phasing
In theory as long as you keep it clean yes. They are still a problem on many new models, especially diesels.The best thing about an EGR valve is that it closes at a lack of vacuum, AKA, wide open throttle. During normal operation, part throttle, the valve is open recycling exhaust gas from one exhaust port only. (Small block at least.)
Since at the cruise stage and modest acceleration, the performance factor is not missed.
@ AJ/Form /S
I have 3.23 gears... 26.5 tires and Iron Heads ( x Heads ) and as soon as I hook up the VC ..the engine makes this strange sound at 50- 60 mph.. exact the range when I need the VC.... When I accelerate hard... there is no pingnig...
Greetings Juergen
@ AJ/Form /S
I have 3.23 gears... 26.5 tires and Iron Heads ( x Heads ) and as soon as I hook up the VC ..the engine makes this strange sound at 50- 60 mph.. exact the range when I need the VC.... When I accelerate hard... there is no pingnig...
Greetings Juergen
got you !
I think now I know where my problem is... first I have too much timing @ idle..( 16 deg ) and the curve is to fast... all in 35 deg @ 3000 prm
So I will keep your advise... go "down to 12-14 deg @ idle...with 20-22 deg advance all in around 3500 rpm....
I have a Vacuum caister from CRANE so I think this canister can be limited ( in case )
Thank you
Juergen