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Update DA getting better ET's and MPH are not (long)
#1500853
09/13/13 04:39 PM
09/13/13 04:39 PM
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Joined: Apr 2009
Posts: 447
NJ
JCCuda
OP
mopar
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OP
mopar
Joined: Apr 2009
Posts: 447
NJ
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Sorry this is long and I re-capped from the previous post first. But I wanted to let you know what I found. Quote:
Here is the car 70 Duster 3510 with me in it. 360 pocket ported J heads 2.02 valve, Hughes 232/237 hydraulic cam, 9.9 compression, LD340 (divider cut down) Annular 750, (same issue with my vac. 750) 1" 4 hole spacer heddman 1 5/8" headers, 3" exh. to the bumper with ultraflows. Trans is a 727 with a 9.5 Dynamic converter that stalls about 3500. Rear is an 8-3/4 with 3.91 gears and 27" tall tire. The fuel system consist of a stock tank a 3/8" pickup (I made it myself, copied the original but made it go a little deeper in the tank) -6 braided line attaches the pickup to 3/8" aluminum line and from the aluminum line to the fuel pump is -6 braided line. the fuel pump is a holley 120 gph mechanical. From the pump to the carb is 3/8" steel line with a clear plastic 3/8" filter before the carb. I know it's not the best filter to use but I was having a problem in the summer with fuel boiling off. Nothing is near heat. I installed a return line using the factory fuel line and I put an .039 orifice in to restrict the fuel going back to the tank and it worked great for hot weather driving keeping the fuel filter full all the time. In the not so good air 2,100'DA 85-90 degree it was going mid-high 107 mph and low-mid 12.40's In good air last night 200'DA 45-50 degree air it went mid 108 mph and 12.37. I pulled a couple plugs today and they were white with black specs. I have bumped the jet size from the factory jet sizes Sorry I don't recall whats in there right now, but I went up 3 numbers in the front and 5 in the back with no change. I really think the it should have gone in the 12.20's or even the teens and close to 110 last night. I need some suggestions. I am going to try and put a fuel pressure gauge on the car to see whats going on with that. Sorry this is so long.
Quote:
Finally got back to the track Wednesday night. I put in the .120 needle and seats and added a Holley electric fuel pressure gauge, changed the rear float bowl for one with a notched float and jet extensions also raised the rear float level. At idle the fuel press. is 5 psi. Driving through the pits it's 7 psi and on the track it's 3-4 psi so I suspect this is probably the issue. A friend used to work for IROC and he has one of the mechanical Holley pumps they used to run on the Daytona's and Avengers so he's going to give that to me to try. DA was about 2,900' and the temp. was 88 and humid. Best pass was 12.517 @ 106.87 which is right inline with last years numbers. Still no color on the plugs. I will also try plugging the return line for racing.
Since this last post above I changed the Fuel pump again now I have 6-7 psi going through the traps and the car still went a best 12.45 @107 so giving fuel didn't change anything. The next time I take the car out 1st pass is 12.51 normal for the weather then the 2nd pass it goes 12.62 but it spun a tenth. I put a 12.58 on the window I'm .022 he's .277 I win but going by the 1000' I'm only going 12.79. 2nd. rnd. 12.80 on the window I go 12.733 break out was going 12.60 made another time shot It goes 12.703. et's all over the place and feels like I'm towing a boat. Other then when it spun it was 60' 1.679-1.693. It usually goes 1.69somthing all night. The next think I checked was the valve springs Hughes wants 140 on the seat and 360 open I had 120 on the seat and 300 open so I figured this was my problem. I changed the springs I now have 145 on the seat 365 open. I took the car out in decent air it only went 12.82 at 104 on the first pass second pass it slows down will only go 12.87 and only 101 and doesn't want to rev above 5500. So I leak the engine I find 1 cyl. 17% the rest 10-13% (that's when I asked about sealers for head gaskets in another post)I changed the gasket that cyl. now 10 %. I check the timing it's bouncing all over revved above 2000 new FBO dist. the top bushing is junk (Spoke to Don they will repair for free) put my points dist. back it's steady. Go to the Mopars at e-town both days the car the car is only going 12.70's- 12.80's both day's but I can't dial the car cause it's back and forth. 60' was between 1.708-1.731 total 9 passes. So I figured the only thing left is to change converters. It had a 9.5" Dynamic that stalled 3,500. I put in my 8" from my Cuda. It stalls about 4,200 in the Duster. The 1st pass in 3050' DA 85 degree and I think 70% humid. it went 12.373 at 107.62 and after adjusting the launch RPM to 3,200 it went a best of 12.21 on the brakes. 1000' tells me it was going 12.19 and the best MPH was 108.90. the 60's at 3200 RPM were 1.685-1.688 and I lost in the semi's. Now the car goes what I always thought it should go in the junk air now I just need to see if it get's faster accordingly in the good air. my fingers are crossed because I'm tired of working on this thing for a while.
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Re: Update DA getting better ET's and MPH are not (long)
[Re: JCCuda]
#1500856
09/20/13 12:32 PM
09/20/13 12:32 PM
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Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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Quote:
[quote what's the question??? just kidding I wish you luck I went last night, cool good air and... nadda not a bit of improvement, in fact my 60 was off like from my usual terrible 1.65 to 1.82!!!! mph was also off 1mph (maybe due to head wind) down from 119.8 to 118.9 good luck. ]
Go ahead YUCK it up funny guy  The air was pretty good at e-town this past wed. night DA 840'
temp 67* barometer 30.1 humid. 52% the car didn't pick up as much as I would have liked but it did go 12.119 at 110.15 with a 1.658 60' so definitely very happy. Good luck to you any idea why your 60's are all over the place?
yeah I got suspention issues I guess  I would have thought you'd have more mph at 12.11. Does it feel like it's falling off?
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Re: Update DA getting better ET's and MPH are not (long)
[Re: Mr.Yuck]
#1500857
09/20/13 12:42 PM
09/20/13 12:42 PM
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Joined: Jan 2003
Posts: 6,266
Renton Washington
Triple Threat
master
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master
Joined: Jan 2003
Posts: 6,266
Renton Washington
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110 is about right for that ET, so is the 60 foot.
Congrats on the new bests!
-Dustin
67 Dart, 9 second, 392" G3 Hemi
68 Barracuda 340 F/SA
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what's the question??? 
just kidding I wish you luck I went last night, cool good air and... nadda not a bit of improvement, in fact my 60 was off like from my usual terrible 1.65 to 1.82!!!! mph was also off 1mph (maybe due to head wind) down from 119.8 to 118.9 good luck.
