Those that have made the switch how much have you changed converters and what converter are you running?
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Depending gear you run now, might need work there.
It's easy to figure exactly what all it'll need.
Need the current gear, tire dia, mph & rpm at stripe.
Need the 250 baby blower estimated mph, tolerated engine rpm red line / limit.
Boosted bracket racing, you'll want the converter slipping 15-20% 1/8 mile.
Blake, talk to Chase Huffman this weekend at Tulsa, I am sure he could give to some insight since they added a 250 blower to Rick's car in the off season. I know he has run some high 4.3x in the 1/8th and 8.90 @ 190 in SC trim on the stop
First passes in my dragster with new 250 on my 582.
On Oakley's dyno 1335 Hp at 1095 Tq.
Car weighs 2140 with driver
4.61 - off trailer
4.59 - 2nd pass
4.57 - 3rd pass
Air at 205 to 410 Adjusted
Only change was air pressure on my little buba's
started at 6.5 (old N/A setting) and went up 1/2 pound each pass. It was obvious the little's were going to go bad quickly with the 1.04's short times. Switching to big's this week end.
Oakley recomended a converter that went 6200, I was at 6000. I'm happy with the coverter as long as the air is good, but this summer may need to change back to my old converter that went 6400 when my 582 was N/A at 1100 hp.
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That 6400 converter will be 7000 stall, if the baby blower engine can only muster 1250hp, in the middle of the summer.
It may interest you to know beforehand.
Ya, I was hoping I could use the same old converter, but that was wishful thinking. It's difficult racing mostly in Michigan to get an ideal year round converter. Think I'll give it a try this summer then I have actual data to go by.
Still have some tuning to do on motor, definitely on the fat side, but wanted to make just one change at a time.
I can till put the smaller top pully on top and and increase boost some. The timing is 24 and Oakley recommended no more than 26. Trying to sneak up on things.
1300 plus HP would put your car solidly in the 4.40's and 157 MPH at that weight. Your missing some HP... which could explain the low stall on the converter.
Yup, no doubt, it was pretty fat, but wanted to do the one change at a time thing, and the goal was to find out if the littles were going to hold up to 4.5xx. Didn't take long to get the answer.
Will be leaning it out little by little this weekend to see what happens. May find some of that missing HP. I know it's there somewhere :>)
The 3190's will work but the Big's will be more consistent and last longer. I use the 97's on my RED, it's been .965 in 60' and they have well over 200 passes on them and still going strong!
Blake don't mean to hi-jack your thread, but hope you got some information on converters that will help.
I'll start a new thread if this is the wrong place for this question.
The Oakley 250 combo, wether it a 632 or 582 they but the APD 1600 cfm alcohol carb on. Mine I believe is a 3 circuit and I'm told the APD air bleeds configuration is totally different than anybody's else. Can some tell me which position the Idle, Midrange and Hi-Speed air bleeds are on this carb.
Keep in mind I have the lower HP pully on, so in reality the motor is only making about 1230 right now. I'll be changing to the 1300+ hp pully sometime in the near future and I'm confident the time will pick up closer to the 4:4xx you mentioned.
Jims engine does make that kind of power with a 31 pulley he is running a 35 pulley and makes in the 1220 range just to clarify.
We put a TBS 250 on my dads 598. We are running the same converter with the blower that we had in the car when it was NA. The converter is a Transmission Specialties Super 8 that would flash 5800 and fall back to 6000 on the shift NA. Now it will flash 6400 and fall back to 6600 on the shift. This is in a 2740 pound door car.
That’s a lot of air psi in those tires...heck I’ve been 6.15 in the 1/4 on them
""Fathom the hypocrisy of a Government that requires every citizen to prove they are insured ..but not everyone must prove they are a citizen."
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That’s a lot of air psi in those tires...heck I’ve been 6.15 in the 1/4 on them[/QUOTE]
I was thinking the same thing, I ran 5.4 in my Little Bubbas going low 4.40's and 6.95
I've tried a Transmission Specialties 10" and a 9.5" Abruzzi.
The TS 10" locks up right at 6200 with all the timing in it and a 4.11 gear (crossed 1/8 mile at 6800) and with a 4.30 gear (i never put all the timing in at the hit) flashed to 6000 pulling 8 degrees and crossed 1/8 mile at 7200/7300 with the 4.30. Pulling 10 to 13 degrees at the hit it flashed to 5800 or so. DA was 3-400'.
On the 9.5" Abruzzi, i was pulling 10 degrees, flashed to 6750 with a 4.11 crossed 1/8 mile at 7300 rpm, only have 4 passes on the Abruzzi but i'm thinking it needs to be tightened up about 400 RPMs. More to come on this one soon as the weather and work allow me to race again. DA was 800 to 1000'.
Car weighed 2000 lbs even with me in it before the blower, shipping weight was 125 lbs on the blower plus an additional few lbs on the converter (was an 8") and blower nick nacks, so my best guess is somewhere around 2120 to 2150 race weight. Motor is a 598 with Dart Pro 2 380's,13.5:1 compression, 850 lift, made 1025 and 850 NA. No changes just bolted the blower on top, MFI injected, Bird Catcher both NA and with blower.
It's been 4.45 at 155 with the 10" converter, pulling 10 degrees at 0.100 and all back in by 0.600, but seems to be a little happier around 4.48 to 4.50 range to keep the front end low enough to be consistent (pulling 10-13 degrees from 0.100 till 0.600) DA was 3-400'.
With the 9.5" and 4.11's it ran 4.56 at 149. The weather was a little worse 800 to 1000 feet, and track wasn't very good at all. Plus I swapped in a bigger fuel pump and still working through the tune up a tad. Was pulling 10 degrees from 0.1 to 0.600.
Nickel...what base timing are you running with this setup?
What pulley (Boost?)?
I hate dragsters.... 30 degrees base timing, the timing mark on the plug looks really close to the center of the bend, but is a tad closer to the electrode than the attached end of the ground strap. This implies i could run a little more timing if i wanted to but no need right now.
Blake 4128, its got the 67 pulley on the bottom and the 33 pulley on the top. Alkydigger didn't really advertise the 67 bottom but when i was ordering i asked what was the largest bottom pulley i could buy he told me they only offer 2, 64 and 67 so i ordered with the 67 figuring if i ever really wanted to turn it up i had the pulley to do it, slowing it down is simple as going bigger on the top so, mine is a little higher OD than most i've heard as the standard setup is 64/33.
I've seen anywhere from 6 to 9.5 PSI on this combination depending on the weather with about 40 or 50 total runs to date.
Still figuring mine out. 33 top pulley. runs low 4.50s shifting at 7200 and will dip into the .40s shifting at 7400. 30 degrees timing. 80 degrees 45% 2900 DA. 565 dart 355s. No buffco top. 4.30 gear 3183 tire. converter flashes to 68-6900. falls to 7000 at shift 7600@154-155
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