Help - More Nitrous, no change in ET
#859276
11/21/10 01:50 PM
11/21/10 01:50 PM
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Joined: Jul 2004
Posts: 1,145 Arizona, USA
gsmopar
OP
super stock
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OP
super stock
Joined: Jul 2004
Posts: 1,145
Arizona, USA
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Hey guys, I ran the car at PINKs this weekend and am fighting some gremlins. Some basic symptoms: The car is hard to start, no change in ET after adding about 30hp additional nitrous. 1st run: Friday. Hit the rev limiter in both shifts(driver error). Car popped and sputtered in all gears, most noticeable in the top of 3rd. Plugs look clean, no smell of fuel, not hot, just normal. 65n52f 27TDC 1.579 4.576 7.099 97.2 9.285 11.15 2nd run: Saturday morning, better air. The tank was full of 110 Hot Rod fuel, and the engine is only 10.5:1 compression so I decided to add some timing. All of the popping and sputtering was gone. The car ran smooth through all gears, but ran slower. Plugs still look perfect. 65n52f 34TDC 1.598 4.623 7.166 96.46 9.370 11.256 119.57 Final Run: I have to check the notes that I left in the trailer, but I'm pretty sure I bumped the Nitous jets to 71n59F. Changed to a fresh bottle. The car still ran smooth, no wierd sounds, plugs look good, no real change in ET. 71n59f 34TDC 1.63 4.619 7.135 97.33 9.337 11.241 118.17 440, Eddy performers, .590, bla bla bla I've posted the combo before and I think it's pretty common with a lot of you guys. I'm questioning the timing mark on my timing chain cover because of the hard starts and popping on the first run. I'm pretty sure I checked it when I degreed the cam, but that was a long time ago. Possibly the old Mallory Uni-light distributor, nitrous solenoid, pinched nitrous line, etc...??? Had a blast! It's good to finally move from spectator to participant. My wife and I got the hang of setting up the pits, parking a trailer, etc... Everyone at the track that we met was really nice and helpful. In general it was an awesome weekend, but I just really wanted to run a 10. Thanks again!!!
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Re: Help - More Nitrous, no change in ET
[Re: gsmopar]
#859277
11/21/10 03:04 PM
11/21/10 03:04 PM
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Joined: Dec 2008
Posts: 1,200 UK
602heavy
pro stock
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pro stock
Joined: Dec 2008
Posts: 1,200
UK
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IF my memory serves me correct 71n/59f jetting is around 200 hp , what is the total timing on motor? , 34 degrees total spark lead @ 10.1 cr seems a hell of a lot of advance when on the bottle , maybe post a pic of those plugs , did you drive back to the pits with those plugs? , heat range? what fuel pressure/bottle pressure are you running? , without this info it's a crap shoot , i'd say the motor slowed down due to detonation. About the only other answer you'll get here will be give Monte Smith a call.
Last edited by 602heavy; 11/21/10 03:08 PM.
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Re: Help - More Nitrous, no change in ET
[Re: 602heavy]
#859278
11/21/10 03:26 PM
11/21/10 03:26 PM
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Joined: Jul 2010
Posts: 791 Bama
Randy..
super stock
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super stock
Joined: Jul 2010
Posts: 791
Bama
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Quote:
, 34 degrees total spark lead @ 10.1 cr seems a hell of a lot of advance when on the bottle ,
Xs 2... i was only running 26 deg with just a 150 shot, what fuel are you running?
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Re: Help - More Nitrous, no change in ET
[Re: 602heavy]
#859280
11/21/10 03:48 PM
11/21/10 03:48 PM
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Joined: Jul 2004
Posts: 1,145 Arizona, USA
gsmopar
OP
super stock
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OP
super stock
Joined: Jul 2004
Posts: 1,145
Arizona, USA
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fuel is 110 octane. I drove back to the pits, but we pitted right by the return road. I'll pull the plugs and post some pics. Fuel pressure is 7.0 psi on a dedicated system; dead head holley regulator and Edelbrock pump. 73n is 180hp according to the manual for my Cheater kit. Monte posted the 65n52f as a 125 shot, which made me think that the book is a little optimistic.
Last edited by gsmopar; 11/21/10 03:52 PM.
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Re: Help - More Nitrous, no change in ET
[Re: gsmopar]
#859281
11/21/10 03:52 PM
11/21/10 03:52 PM
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Joined: Dec 2008
Posts: 1,200 UK
602heavy
pro stock
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pro stock
Joined: Dec 2008
Posts: 1,200
UK
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Just remember to cut the threads off those plugs so these guys can see the fuel ring. Who's plate is this?......i just set fuel pressure @ 5.5psi & tweek jet spread/timing till plugs look good , don't be too concerned if the jetting ends up squared , unlikely although some motors just want what they want.
Last edited by 602heavy; 11/21/10 04:26 PM.
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Re: Help - More Nitrous, no change in ET
[Re: 602heavy]
#859282
11/21/10 05:47 PM
11/21/10 05:47 PM
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Joined: Jul 2004
Posts: 1,145 Arizona, USA
gsmopar
OP
super stock
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OP
super stock
Joined: Jul 2004
Posts: 1,145
Arizona, USA
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Quote:
Just remember to cut the threads off those plugs so these guys can see the fuel ring.
Who's plate is this?......i just set fuel pressure @ 5.5psi & tweek jet spread/timing till plugs look good , don't be too concerned if the jetting ends up squared , unlikely although some motors just want what they want.
It's a NOS Cheater Plate 4500 carb flange.
I found a pretty bad kink in the line, I must have smashed it at some point??? The last pass I increased both fuel and nitrous jets. If the Nitrous flow was limited by the kink, I should have dropped the power when I increased the fuel. I'm going to pick up a new line, back the jets back down and start over. Pics to follow, but probably not for a few days (family coming to town).
Thanks,
Greg
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Re: Help - More Nitrous, no change in ET
[Re: 71cudaddict]
#859285
11/22/10 02:32 PM
11/22/10 02:32 PM
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Joined: Nov 2004
Posts: 6,890 North Alabama
Monte_Smith
master
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master
Joined: Nov 2004
Posts: 6,890
North Alabama
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Looking at the 1/8 mph numbers, they were all virtually the same, so the power level never increased. The 330 numbers were all over the place and this is where the differences in ET likely showed up.
Usually when you make a change and the mph does not increase, you are not getting the extra nitrous, or you are blowing through the converter.
It would seem you found the issue, with a kinked line. Going back to square one, is a good idea. When you make timing changes, I suggest a little more discretion. A 5-6 degree move is a ton. You need to be moving in the 1-2 degree range at the most.
Keep an eye on the bottle and keep it in the 950psi range. Also be a good idea to weigh it after every run and see how much you use. After it gets half empty, performance will fall off, due to dropping bottle pressure. Better to have 2 or 3 bottles with you for a track day.
Monte
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Re: Help - More Nitrous, no change in ET
[Re: gsmopar]
#859286
11/22/10 10:08 PM
11/22/10 10:08 PM
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Joined: Feb 2004
Posts: 1,093 Long Beach, CA
Mike Swann
super stock
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super stock
Joined: Feb 2004
Posts: 1,093
Long Beach, CA
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Waht kind of balancer do you have? If you detonate it with a pressed ring type (stock or a P type), the outer ring will move relative to the hub in a heartbeat.
8.30's @3400 lbs
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Re: Help - More Nitrous, no change in ET
[Re: Biginchmopar]
#859288
11/23/10 03:12 AM
11/23/10 03:12 AM
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Joined: Jul 2004
Posts: 1,145 Arizona, USA
gsmopar
OP
super stock
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OP
super stock
Joined: Jul 2004
Posts: 1,145
Arizona, USA
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Balancer is an SFI Summit type. It doesn't appear that there was much if any denotation. The plugs look clean and I'm very familiar with what this engine sounds like with denotation (don't ask). Plans so far: Change N2O line. Inspect N2O screen at the solenoid. Inspect the N2O solenoid plunger. Attempt to fab up a piston stop and verify the timing mark on the balancer and timing chain cover. Set the timing back to 27. Set the tune back to the 65n52F shot. Go back to the track and give it hell!
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