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| Timing | Login/Join |
DRR Pro |
I have a 598 BBC 12* profiler heads on alky injection. With the timing at 30* the timing make on the plug is at the end of the strap. With 32* of timing the timing mark on the strap is 1/2 way from the end of the strap to the middle of the curve. Looks like it will like more timing or??? Any ideas on timing. TDC was verified and is correct. Any ideas would be appreciated. Should I keep going up? Until the timing mark is on the curve of the strap I put new plug in in the staging lanes, shut it off at finish line. Get off track and pull out Thanks Brian Mollison 2013 American Dragster 2020 Sumerduck Dragway VA Top ET Champion 2017 Sumerduck Top ET & SSS Track Champion 2017 MAC Top ET Track Champion 2009 Sumerduck Dragway Va Top ET & IHRA SSS Track Champion 2008 IHRA Division 1 Top ET Bracket Final Runner-up 2007 Colonial Beach Dragway Top ET Track Champion | ||
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DRR Pro |
I like the mark even with the center electrode tip. "Despite the high cost of living, it remains popular." Dave Cook N375 | |||
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DRR Top Comp |
I would just go off et and mph. I do read plugs most every run,but the proof is in the time slip and/or the data logger. As for question. I like just short of full strap so as to error on safe side. America home of free. Brought to you by 2nd amendment. | |||
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| DRR Pro |
? Will adding or removing fuel change where the mark lands on the plug strap? Agree with w231, read the time slip. I prefer my methanol tune up slightly fat. | |||
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DRR Trophy |
I didn’t think 12 degree cylinder heads responded well to methanol without some special considerations. | |||
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| DRR Pro |
We shoot for the heat mark on the bend of the strap, but tune the timing for max mph. Then back off the timing slightly for a safer tuning window. Since building the ProCharged motor & switching to EFI. Last fall we had no heat on the ground strap. I decided to add 1.5 degrees to the boost side of the timing table. The car responded with a 3 mph gain in the 1/8 mile & turned it into a wheelie monster. We use a 1.5 degree launch retard now, along with suspension changes to help control the wheelies. We still have no heat mark on the ground strap & need more timing. I have a revised timing table saved to try eventually with 1 degree of timing added from about 7 lbs. of boost & above. When I get back to racing 1/8 mile, I'll probably load the tune/table in. 2BKING  1980 Camaro Taking the Best Working Small Tire Shyt Box & making it Greater Than Before! 3000 lbs. Pump Gas 436 | |||
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| DRR Pro |
My 598 @ 2020 lbs has been 4.548. That’s in my 2013 American 250” TD dragster. I think that’s not bad at all. Brian Mollison 2013 American Dragster 2020 Sumerduck Dragway VA Top ET Champion 2017 Sumerduck Top ET & SSS Track Champion 2017 MAC Top ET Track Champion 2009 Sumerduck Dragway Va Top ET & IHRA SSS Track Champion 2008 IHRA Division 1 Top ET Bracket Final Runner-up 2007 Colonial Beach Dragway Top ET Track Champion | |||
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DRR Pro |
Not shaby at all "Just Shut Up and Race" Brian Martin Martin Racing 5.50 126 | |||
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| DRR Top Comp |
In lieu of a dyno I always jet by the time slip.... . Dave F J B | |||
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| DRR S/Pro |
I know it's old school, but I have always been a plug reader, all 8 of them. Bob | |||
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| DRR S/Pro |
Hands down the B E S T way! California Screaming! Raceless in California! | |||
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| DRR Trophy |
It seems like you’re asking for tuning advice to pick up an engine that you think is already performing well based on your expectations. These kind of engines usually run best on gasoline. I would think a 598 spreadport engine would be quicker than 4.548 in a dragster. | |||
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| DRR Top Comp |
I trust dyno and/or time slip more that myself lol. I mean faster/quicker is max power right? . Dave F J B | |||
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| DRR Pro |
My comment isn't directly related to Mr. Pryor. It's more about similar fragile ego post(s) like this one. I understand the concept of having the quicker/faster race vehicle. But there are plenty of competitive slower/slow vehicles out there going rounds & winning. It sounds like DEAD ON has some room for timing & possible pick up a little performance. What does it really matter, this is a bracket racing forum. Not a Wanna-Be heads up forum.  2BKING 1980 Camaro Taking the Best Working Small Tire Shyt Box & making it Greater Than Before! 3000 lbs. Pump Gas 436 | |||
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DRR Top Comp |
You are doing the right thing adding timing and checking plugs and MPH / ET. If you are too fat you can run a little more timing but it is not best tune up. I think when you get fuel and timing right it will not swing as much in weather changes and be more predictable with those weather changes. https://postimg.cc/gallery/np3zpruo/ "Dunning-Kruger Effect" -a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge. Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue. 4X NE2 CHAMPION. 2020 TDRA NE2 Champion | |||
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| DRR Sportsman |
Curly1's comments are consistent with what i've seen. For the OP's question, my advice is go up 1 degree at a time monitor the timing mark on the plug, verify what you are seeing with performance, once it gets to the mid-point in the ground strap curve stop, I haven't seen any benefit going further than that. The performance demonstrated by the combo isn't bad considering the weight of the car. At 2020lbs in a dragster it takes a good amount of HP to get it moving and get it to run sub 4.50. I fought the same issue with a 20 degree 615 combo, everyone will tell you it won't run on alcohol till the cows come home. I have dyno sheets showing it made 30 HP and 50 tq better with more area under the curve on injection/methanol than 1400 cfm gas carb from 6000 RPM to 7200 RPM. That's tunnel ram injection vs. MerlinIV and 1400CFM Gas on 116. IMO Area under the HP curve = ET but you gotta match the converter to the power regardless of which combo you pick. I did notice that peak tq on gas in my application was 6200 (860 ft-lbs) vs. injection was 5850 (905 ft-lbs), which leads to earlier peak HP numbers injected vs. gas and less usable RPM overall. Methanol fall off seemed worse after peak HP gas vs. injection. Good luck on the combo. If the OP is searching for ET, i'd focus on the converter next. I highly doubt an optimized converter from a gas combo will outperform one optimized for the injected/methanol combo. Most guys i talked to with 20 degree gas combos were flashing the gas carb conv. to 7000 and shifting at 7400/7500 and crossing north of 7400/7500 1/8 mile. I found injection was difficult (not impossible) to manage that high in the RPM range. | |||
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| DRR Top Comp |
I have been told by many that the SB2 combination will not work on alcohol, going to test and find out. The motor I am working on now when I dyno it I will be taking 3 sets of headers and several different gas carbs and an alcohol carb. If I have to I will set up and run Enderle hat injection on alcohol. Several different race gas and alcohol so I will probably be on the dyno for 2 maybe 3 days. I also run 8 O2 sensors on the dyno and my data logger and I think that helps with the tune up. Have another larger SB2 I will be building after this one I get done with this one. What I learn on this will help with the decisions on the next one. https://postimg.cc/gallery/np3zpruo/ "Dunning-Kruger Effect" -a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge. Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue. 4X NE2 CHAMPION. 2020 TDRA NE2 Champion | |||
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DRR Pro |
I disagree. I ran those same heads on my last combo. Best I could do on gas at Bandimere speedway with dual fours, very well tuned, was a 7.56. At the same track, worse DA, injected on alky, 7.32. Only change was ditched carbs for mfi and alky...oh, and timing. It wanted more on alky than it did on gas...... Mark Goulette Owner/Driver of the Livin' The Dream Racing dragster www.livinthedreamracing.com "Speed kills but it's better than going slow!" Authorized Amsoil Retailer | |||
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| DRR Top Comp |
I am in a similar situation. Find it strange that most combinations work well on alcohol but this certain one will not..... On SB2 I am building was told alcohol will never work so I am going to do most of my dyno testing with gas carbs but going to try a alcohol carb also and if I have to will try MFI. Depends on how it goes on dyno. https://postimg.cc/gallery/np3zpruo/ "Dunning-Kruger Effect" -a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge. Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue. 4X NE2 CHAMPION. 2020 TDRA NE2 Champion | |||
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| DRR Top Comp |
While no real dog in this fight. I have never understood why this combo will not run on alky. Like Curly said every other combo seems fine b ut this one combo has been said to n ot work with alky. Would love to hear explanation as to why not. What makes it hate running on alcohol? America home of free. Brought to you by 2nd amendment. | |||
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