John Burns Posted March 5, 2013 Share Posted March 5, 2013 Holley's Ultra HP 950- true 950 cfm. A very sweet carb! Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted March 5, 2013 Share Posted March 5, 2013 I caramba I like it.. did it put some pep in her step. Quote Link to comment Share on other sites More sharing options...
beater72 Posted March 5, 2013 Share Posted March 5, 2013 Wow!I'm sure it sounds sweet when opened up! Quote Link to comment Share on other sites More sharing options...
John Burns Posted March 5, 2013 Author Share Posted March 5, 2013 It feels awesome- it felt awesome before with the 850, but I think this motor will really enjoy the extra 100cfm. I need a trip to the track! Quote Link to comment Share on other sites More sharing options...
dbreese Posted March 5, 2013 Share Posted March 5, 2013 It feels awesome- it felt awesome before with the 850, but I think this motor will really enjoy the extra 100cfm. I need a trip to the track! Ultra HP's are super nice carbs for sure Let us know about the track results. David Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted March 6, 2013 Share Posted March 6, 2013 a 950 seems small for a 540ci Quote Link to comment Share on other sites More sharing options...
Jared Richey Posted March 6, 2013 Share Posted March 6, 2013 a 950 seems small for a 540ci I have a Pro-systems 950 on my 462ci Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted March 6, 2013 Share Posted March 6, 2013 Originally Posted By: Sam (Bones) a 950 seems small for a 540ci I have a Pro-systems 950 on my 462ci it depends on the rest of the build and the targeted operating range....if it doesn't have some big heads, big cam and get turned over 7200 it may not be small at all... Quote Link to comment Share on other sites More sharing options...
beater72 Posted March 6, 2013 Share Posted March 6, 2013 He wants 'fuel economy'! Quote Link to comment Share on other sites More sharing options...
John Burns Posted March 6, 2013 Author Share Posted March 6, 2013 He wants 'fuel economy'! I'm getting at least 8 gallons to the mile now! And I'm desperately trying to shift the thamn ding at 6500, but it gets to 7000 much faster than I can anticipate yet. Time to touch up the trans probably, but the 850 got me well into the 10's, so this can't hurt! Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted March 6, 2013 Share Posted March 6, 2013 Originally Posted By: beater72 He wants 'fuel economy'! I'm getting at least 8 gallons to the mile now! And I'm desperately trying to shift the thamn ding at 6500, but it gets to 7000 much faster than I can anticipate yet. Time to touch up the trans probably, but the 850 got me well into the 10's, so this can't hurt! you made a great choice...the Ultra's have already gained a good rep for being pretty spot on right out of the box...just get to the track and play with the jetting a bit.... you should be good to go.... Quote Link to comment Share on other sites More sharing options...
John Burns Posted March 7, 2013 Author Share Posted March 7, 2013 you made a great choice...the Ultra's have already gained a good rep for being pretty spot on right out of the box...just get to the track and play with the jetting a bit.... you should be good to go.... Can I send the car to you to dial it in at the track for me? I know, I just need to make the time to do that properly. My biggest concern was that it had to stay fun to drive on the street. I am amazed at how little I needed to do to dial it in for that. But it has always gnawed at me that my Frankenstein 850 was limiting the car at the track. Although I have severely limited the car's potential to put up big numbers in many ways, at least I think I have the right hardware on top of the motor now! Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted March 7, 2013 Share Posted March 7, 2013 Originally Posted By: CrazyDavey you made a great choice...the Ultra's have already gained a good rep for being pretty spot on right out of the box...just get to the track and play with the jetting a bit.... you should be good to go.... Can I send the car to you to dial it in at the track for me? I know, I just need to make the time to do that properly. My biggest concern was that it had to stay fun to drive on the street. I am amazed at how little I needed to do to dial it in for that. But it has always gnawed at me that my Frankenstein 850 was limiting the car at the track. Although I have severely limited the car's potential to put up big numbers in many ways, at least I think I have the right hardware on top of the motor now! yeah I think it's going to like that a bunch John...go have some fun and let us know.... Quote Link to comment Share on other sites More sharing options...
wallaby Posted March 8, 2013 Share Posted March 8, 2013 Slight hijack here, but how DO you figure out what jetting to use? I have an A/F ratio gauge, and my stupid Holley runs fat all the time. I'm lucky if the gauge shows 13.3 at cruise. Mostly it runs 24/7 at 12 something. The plugs look pretty good with a bit of color. Then the question arises: do I lean my primary jets for cruise, and richen the secondaries to compensate for WOT? My Q-jet was a different animal. This Holley starts better, but seems a little less crisp to throttle changes. Quote Link to comment Share on other sites More sharing options...
CrazyDavey Posted March 8, 2013 Share Posted March 8, 2013 what Holley so you have Mark? Each one is going to be a bit different because of the varying signals each motor makes but compared to mine that would be kinda fat. On my dnyo pulls I was just about that same AR read at WOT....what are your readings at WOT? At light cruise you should probably be somewhere in the 14's....put in a fresh set of plugs and move all the jets down 2 steps at a time until you see it closer to that number. Then check the plugs and see how they look. If the color is still good you should be okay and get a little better fuel mileage too... Quote Link to comment Share on other sites More sharing options...
Heckeng Posted March 11, 2013 Share Posted March 11, 2013 Hey Mark, you need to think of your carb as a multi-stage fuel mixing unit. 1: At idle, you are running on idle fuel ports and very slightly on idle mixture slots. 2: cruising, and off idle, say starting around 2000rpm ish, you start getting a good signal to the venturi which pulls gas from your main jets AND you are getting a better signal at the idle transfer slots. 3: If you have a double pumper, eventually the linkage will start to engage the secondaries so those jets will kick in. 4: If you nail the gas and get a large enough drop in vacuum, the power valve channel starts adding fuel too. If you tune your carb in steps, starting with the first step I described, the idle and cruise will be set and good to go, then you tune the next step and you are still good at idle and cruise/off idle, then you tune the secondaries and PV and you are good to go theoretically in all rpm ranges. So, if you are fat at idle/cruise, you will need to adjust the idle fuel port, idle transfer slots, and maybe or maybe not the primary jetting. At cruise on lower rpms, you may not be getting much signal through the venturi which would mean that the main jets aren't doing anything anyway so if you adjust them, it won't matter much. The idle fuel port would be the main one to adjust. This can be adjusted by either adding a restrictor (small jet) or adjusting an existing restrictor if your carb already has them. On top of all of this are the air bleeds which add confusion to things and unless you are doing major changes, I'd not mess with them much if any. I have had great luck starting at step one and adjusting idle and cruise using the idle feed restrictor which can actually restrict both the idle fuel port and the idle transfer slot. This might be a good topic to actually have a phone conversation if you want some time :-) Quote Link to comment Share on other sites More sharing options...
wallaby Posted March 12, 2013 Share Posted March 12, 2013 It looks like this thread is officially hijacked. My engine was delivered with a Holley 770 cfm street avenger. It was chosen because it "leans out at cruise" unlike some other models, I guess. The carb has the factory jetting, as I live at less then 1000 ft above sea level. The idle mixture is also rich, and it seems to like it. I tune by ear, then look at the gauges. I really need to get a good idea of what A/F ratio I run at WOT...for some reason I tend to be focused on looking at the windshield glass under that condition. I really need to spend some time dialing it in. I need to buy some jet sets so I can make changes if needed. Forgive me, I've never dealt with a Holley before. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted March 12, 2013 Share Posted March 12, 2013 my 454 doesn't like to be leaned out with the muther-thumper cam I have Quote Link to comment Share on other sites More sharing options...
John Burns Posted March 12, 2013 Author Share Posted March 12, 2013 It looks like this thread is officially hijacked. Hijacked in the best way! I too have always just dialed a carb in by feel and the rare trip to the track. Are these wideband O2 sensors worth the effort & cost? Is there a sensor set up that anyone would recommend? Quote Link to comment Share on other sites More sharing options...
John Burns Posted March 14, 2013 Author Share Posted March 14, 2013 Dang... these 950HPs have huge jets out of the box: Primary Jet Size: 92 Primary Power Valve: 4.5 Secondary Jet Size: 92 Secondary Power Valve: 4.5 As much fuel here as most of the biggest dominators. Crazy Quote Link to comment Share on other sites More sharing options...
wallaby Posted March 14, 2013 Share Posted March 14, 2013 Are these wideband O2 sensors worth the effort & cost? Is there a sensor set up that anyone would recommend? I have one from Inovate. They seem to really be focused on this technology. The unit I have has a digital number in the center, and a LED sweeping display around the perimiter. I don't know if the analog-looking gauges would provide any real information...you will find that the numbers are constantly changing as you drive, even if you think you are at a steady state. I have not seen the gauges with a needle in operation, I would guess they flutter and require a little thought to average what the gauge is telling you. Don't wast your time/money on a narrow band unit. Those can only tell you when things are perfect, (their idea of perfect) and have no clue or information to give otherwise. Quote Link to comment Share on other sites More sharing options...
wallaby Posted March 14, 2013 Share Posted March 14, 2013 I did my carb test today and found that this carb has no fuel curve...instead it has a straight line running horizontal on the graph. I have 13.2 at idle, cruise, and WOT. Of course it shows richer than that when the choke is on, and leaner for a moment when I decelerate.. I'm not sure if that 13.2 number is correct for any of those conditions. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted March 14, 2013 Share Posted March 14, 2013 12.8 is great for WOT and max power, idle/cruise try for 14.0 or higher, but my 454 doesn't like to be that lean, mines runs about the same as Mark's mid 13's Quote Link to comment Share on other sites More sharing options...
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