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 Post Posted: Fri Jul 06, 2012 9:18 am 
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carb is a 4500 1050 3 circuit #9375 first dominator i ever ran

car is 86 gt full weight 3.73 gears also have 2 different stall on for nitrous other for all motor and no more than 100 shot. The car is also small tire 28x10.5 slick.

engine is a stock 6.2 ls based with a 235 240 at .050 609 617 lift on 111 lsa

cars best all motor with the loose stall is 6.64 at 104.4 1.44 sixty with a 4150 1050 proform

currently running a tight stall 2800 on the brake no chip im running this stall for now because i have 250 shot in the fogger

best all motor with this stall is 7.01 at 101 with a 4150 1050 proform 80 degree day 1200 da
then i put a dominator on it ran 7.10 at 102.6 100 degree day 3200 da

i love the dominator except for cruise around the pits and going on brake its rich rich

i have read the 2 circuit conversion prolly 30 times at least can you give me a baseline to start with and what stock metering blocks can i us thanks for all the help trent

ran

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 Post Posted: Fri Jul 06, 2012 10:51 am 
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Trent the "Sticky" up the page has a base line tune that should be a little on the lean side at part throttle and on the rich side down track but it should get you close enough to start.

Just remember that EVERY engine will likely want something a little different. What you will need to do is make sure you take notes from the beginning so you can look back to see what does what as sooner or later you're going to have to make some of these tuning decisions on your own when you're at the track.

AFRs? While most racers don't have this capability I will tell you that something as simple as an AFR gauge can help you more than you know. It's not a do all end all but info from that can be invaluable when used with other info as well, ie, time slip and plug reading.

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 Post Posted: Fri Jul 06, 2012 11:36 am 
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just took a look at my proform 4150 and them metering plate e holes and i dont understand why 1 and 3 are wide open no jet and 2 and 4 are plugged no hole in the jet .....i have had this carb since new

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 Post Posted: Fri Jul 06, 2012 12:51 pm 
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If you look in further it likely has a restriction down in it before it hits the mainwell. In the chance it doesn't you should get some restrictors in there, .026 is a good place to start


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 Post Posted: Fri Jul 06, 2012 2:34 pm 
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jmarkaudio wrote:
If you look in further it likely has a restriction down in it before it hits the mainwell. In the chance it doesn't you should get some restrictors in there, .026 is a good place to start



thanks you are correct bottom of all 4 e holes are .028 \:D/

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 Post Posted: Fri Jul 06, 2012 3:22 pm 
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extwinturbo1 wrote:
thanks you are correct bottom of all 4 e holes are .028 \:D/


Which means that if you're going to use those blocks then #2 & #4 meed to be plugged. (#1 is at the top)

You had asked about the factory blocks? The ones I originally used were Holley part number 5271 / 33102. Those blocks only have two E holes and the IJ is already at the bottom. I think they were originally in an early 750 or 780 carb. I did have to drill out the cross wells to .159 cuz they were only .140 to begin with. They also have the mainwell plugs that are about a half inch down the well. There are some blocks out there that have a flat plug in the mainwell that is level with the top of the block and from what I understand, those are NOT the best to use for this conversion.

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 Post Posted: Fri Jul 06, 2012 5:48 pm 
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Ken0069 wrote:
extwinturbo1 wrote:
thanks you are correct bottom of all 4 e holes are .028 \:D/


Which means that if you're going to use those blocks then #2 & #4 meed to be plugged. (#1 is at the top)

You had asked about the factory blocks? The ones I originally used were Holley part number 5271 / 33102. Those blocks only have two E holes and the IJ is already at the bottom. I think they were originally in an early 750 or 780 carb. I did have to drill out the cross wells to .159 cuz they were only .140 to begin with. They also have the mainwell plugs that are about a half inch down the well. There are some blocks out there that have a flat plug in the mainwell that is level with the top of the block and from what I understand, those are NOT the best to use for this conversion.


ok that helps alot i would like to use stock blocks but if i cant find some i gonna use these outta my 4150 proform

now the plugs u talking about are they the ones that would be on the top of the block down in a hole thanks again guys im learning

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 Post Posted: Fri Jul 06, 2012 7:35 pm 
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Yeah, if you look at the top of the metering blocks, you'll see 4 plugs across the top. The two outters are for the idle circuit and the two inner ones are the main wells, which go all the way down to the MJ (main jet).

If the stocker blocks you have use a flat plug in the main wells that is even with the top of that metering block then you need to look for some that have the freeze plug type of plug that is down the main well about a half inch. Some of those will have the IJ in the TOP location and you'll have to tap the lower hole for a set screw which will be the new IJ (idle jet). Then you need to remove that IJ from that top hole and leave the hole open. As a rule of thumb, you NEVER want to have two metering orifices in the same circuit.

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 Post Posted: Fri Jul 06, 2012 8:25 pm 
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thanks guys be back soon ;-)

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 Post Posted: Sat Jul 07, 2012 9:05 pm 
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i have located some blocks not sure if they are ok to use

5271 5275 3

and

8558 8543 5 this one i checked 2 .028 e holes .038 IJ

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 Post Posted: Sat Jul 07, 2012 11:21 pm 
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Would be really good to have a matched pair. 8-[

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 Post Posted: Fri Jul 13, 2012 11:50 pm 
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done some work this is what im startiing with on my 9375 dom

IAB .066
Hab .028
Tsj .055
IJ .039
MG .093

kill bleed .028 2 e holes .028 stock 750 and 850 blocks for now

any input ??

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 Post Posted: Sat Jul 14, 2012 9:17 am 
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It looks fine to start with. ;-)


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 Post Posted: Sat Jul 14, 2012 11:55 pm 
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thanks turned idle screws out 1.5 turns and turned idle blades 1.5 from screw barely touching no tslot showing at that point so put it on fired up got up to 140-150 and idled
got my wide band on today so testing tommorrow at out local track so far this conversion is awesome thanks guys

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 Post Posted: Sun Jul 15, 2012 4:24 am 
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extwinturbo1 wrote:
thanks turned idle screws out 1.5 turns and turned idle blades 1.5 from screw barely touching no tslot showing at that point so put it on fired up got up to 140-150 and idled
got my wide band on today so testing tommorrow at out local track so far this conversion is awesome thanks guys


Once you get the idle where it needs to be, you may have to work the T slots a bit to get the transition to work right but wait until you see the need before you do that as some have worked fine with no slot showing.

Yeah, most of these conversions have been a "walk in the park" and a few seem to be a "never ending story". I guess I'm lucky as I haven't had one of the "never ending story" ones yet.

We've had guys come in here that had done the conversion successfully and didn't even have a membership to ask questions. They read that thread through a few times and had at it with excellent results for the most part.

Ennywho, glad you're a success story to this point and hope testing will go well for you tomorrow.

Oh, and don't forget that the wide band is only a tool to add info to what you are already seeing. So if the WB tells you something, make sure you have something else that verifies what it said. One of the best things for this is MPH on the time slip along with reading plugs. ;-)

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