Tuning 750 BLP carbs on a 511 with Indy t ram
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Re: Tuning 750 BLP carbs on a 511 with Indy t ram
Trying to tune this thing while the pink cams are still in place is going to be like trying to spin-balance a flat tire. You may have other issues that need to be addressed but you'll never know for sure until it has the right cams on it.
DON'T PANIC
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Re: Tuning 750 BLP carbs on a 511 with Indy t ram
Take your idle air bleeds to .060, and retune the mixture screws.
Mark Whitener
www.racingfuelsystems.com
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Good work isn't cheap and cheap work can't be good.
www.racingfuelsystems.com
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Good work isn't cheap and cheap work can't be good.
Re: Tuning 750 BLP carbs on a 511 with Indy t ram
I tune mostly by ear and use the gauge as a reference. Mine idles the smoothest high 13's, 14.0. Anyone tuning a carb should have an AF gauge as a tuning tool. It's a great reference tool. I use PV front and rear, so 4 pv's with .055pvcr's. While tuning on these 750's(1.325 venturi) i have noticed that all changes made have to be half of what they were tuning my 1100 Dominator. Every little change on these carbs is huge, thats why i only went up 1 size on the main jet. Normally would be 2 sizes on my Dominator. The Dominator did every thing right on this combo and never fell on it's face with 35 squirter. In fact 1' wheelies off the line and a 10 O 1/4. I will try more IFR today as well, .032 and may drop the IB down 2 to .068. If that doesn't fix it i will try the 74 main jets, but i feel that will drowned it, thats about an 82 jet without pv's. Thanks
Re: Tuning 750 BLP carbs on a 511 with Indy t ram
Mark, i will give that a try, but i think with that small of an IB the mix screws will be less than 1 turn out. I have some blue pump cams ordered, but will not be here til next week.
Re: Tuning 750 BLP carbs on a 511 with Indy t ram
Here's what worked the best so far. Put a .032 IFR in and a .066IB (because it was the smallest i had) and that flat spot was almost gone, so then put a .028HB in and sometimes the issue would be there and sometimes not, but not bad. Next i raised the float levels 3 flats and the stumbling issue is almost just about not even noticeable. No issue at all in launching in first gear now. Raising the float levels and the .066IB made the biggest improvements. Gonna try turning the tunnel ram around to see if the carbs set level, i think they will. Mix screws are at 1.25 turns out. Thanks guys
Re: Tuning 750 BLP carbs on a 511 with Indy t ram
From the research and feed back i have done i'm very confident that the issue is the power valves late opening. I have some 8.5's and 10.5's ordered. My cruising vac is in the 14-15" area. The tune is coming around real nice as the last test drive showed 4.5 seconds from 60 to 110mph and very responsive. I have changed the IB to a .070 the HB to .030 and added straight 4 hole spacers. The 4 holes seem to really pull on the carb at idle and wot. Think i will replace the ifr with a .031 to lean it out a bit when i get it apart to install the pv's.
Re: Tuning 750 BLP carbs on a 511 with Indy t ram
I’ve had good luck using larger 50cc pumps on primary side when using tunnel ram. I think the long runners need the extra volume, especially when the walls are somewhat cold on intake.