Proform 850 dialing it in closer

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yeah its a thought, but not enough time to do it at a race.
It is something that i need to re due, now that my o2 don't freeze up any more.

I need to find a place that i can make several stomp in a row with out bringing attention from the law.

This last race is a drag slick race, so i will get some full load, thru 3 gears.
 
Agree, wouldn't do it there. Looking forward to hearing how it goes since we are pretty close in the same boat!
 
F,ING Rain
Hoping it will blow over.
Raining and 45 degrees……not much hope. :(
 
So i did get to race but only have one date log, as i Corrupted the card by not stopping the recording.
putting the brass plugs in the metering block helped 60' foot back in the 1.7s(normaly 1.8s.)Et back in the low 7.9x but the mph was down by .5
091821 Run before jet change.JPG

(we had a head wind all day long........but i wasn't think about that when i changed the jets

So out cam the jets and bumped it up 2 jet sizes in the front and back metering block. although i don't have any data on the jetted up runs. IT slowed my 60' a little and mph was slower by .5

left the jet in and finish out the day this way.
It never improve the rest of day. will be putting the prev jets back in.
 
@Demonx2 said VVVVVVVVVVVVVVVV
I looked but didn't see if you posted the intake you're running. I have a Super Victor intake with a Holley 850 DP and am working on a hesitation I get when I open the secondaries. As long as I don't go deep enough to open the secondaries, the response is crisp. Front likes a 31 shooter and standard white pump cam in hole #1. But mashing the pedal all the way down and I get a pretty good hesitation. Been working the game of squirter size and pump cam on the rear. It seems to want even more than a 37 shooter and either the brown or bigger cam. I am getting some larger shooters to try.

Wondering if you would share the shooters/pump cams you are using? Mine is a 408, 251/255@050 SFT cam, mildly ported Eddy RPM heads, 28"W tire, 5000 stall conv, guessing car weight at 3100#'s plus me. Best so far is a 7.11 eighth mile. Has a 4.56 axle so no need to spin it up in the quarter...too much rpm 6700+ and the engine does not make power up there.
Thx for any insight!
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So first off i use to have a 3000 stall and i went back to my LD 340 manifold. this winter it will be getting a single plane back on it.
I went up, down, and sideways in pump shots and pump cams. tried every combo under the sum and didn't fix my problem.

Remember You have a 30 CC pump..........no matter what squirter or pump cam you put it......That's all you get!!!
Now that i have said that, put your pump squirters or pump shot back to what the carb came with
2nt you stumble is NOT because you have to big or to small of a pump cam or squirter Period. Your secondary stumble is that you don't have enough primary pump...... think a bout that for a second......... then watch this video.
About 2:20 in the video i do a slow mo of the carb. this is done in gear with my foot on the brake. Noticed the spray volume from the primary and the secondays.......Both are 30 cc pumps......


The problem is that you are using up some of the 30 cc raising up the rpm to stage the car. whack it to the floor and there is not enough squirter left and leave a hole or lean condition because the fuel thru the Venturi has not started to flow yet.
Make sence?
There was Two thing that help and basically fix my stumble after 2 years Fing with my demon carb and building and F'ing with Proform carb.
#1 throttle fineness......Instead of a wack it to the floor board like you want to push it Thru the floor board.........a vary fast but Rolling the throttle to the floor.
#2 I put the stock squirters back in....think they are 33s and changed to the red or pink pump can and put it in position #2.
This cam has a vary slow starting ramp and don't give much pump movement just off idle so there is more for the launch. So its a bit stumble off idle. But delivers all the fuel needed to get the main booster flowing fuel.

I may have to brake down and buy a 50cc pump on the primary side of the carb. but the secondary stumble at launch is gone.
 
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That's a great video - thx for posting!! It is very helpful to me (and hopefully to others too) and is basically where I'm headed. I noted that when I put a smaller shooter on the front (31), which would have made the pump shot longer, things got better but not great (it has the pink cam for the reasons you state). I think I'll get some videos of mine to help - I wasn't smart enough to think of doing that!

Anyhow, I don't want to hijack your thread so I'll keep watching as you dial yours in and learn from it. Meanwhile, I'll go get back to work on mine. Thx!!
 
Your not.
ask a way.
Happy to help.
If you really feel guilty, you can just post up on my old thread.
Holley/Demon Carb stumble
This thread is all about the stumble from primary to secondary. and has some more videos as well.

My gopro has been a vary valuable tool !!!!
 
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That's a great video - thx for posting!! It is very helpful to me (and hopefully to others too) and is basically where I'm headed. I noted that when I put a smaller shooter on the front (31), which would have made the pump shot longer, things got better but not great (it has the pink cam for the reasons you state). I think I'll get some videos of mine to help - I wasn't smart enough to think of doing that!

Anyhow, I don't want to hijack your thread so I'll keep watching as you dial yours in and learn from it. Meanwhile, I'll go get back to work on mine. Thx!!


Well i finally took your advice!!!
The proform came with 33 squirters, and i went to 35s with little help.
Been racing all this time, having too roll.... into the throttle to keep it from launch... then bog.
Dug up a pair of 28s and threw them in before the race yesterday.
I can now WHACK the throttle and not fall on it face. who new!!!!!!! :thankyou:

Well just thought i would put a Period on this thread.
Always figured it was just to big of a carb and i would just have to feather the throttle out of the hole. or maybe put a 50 cc pump on it but just couldn't make up my mind as to which side needed it(primary or secondary) so i never got one.
NOPE! THE SQUIRTERS WAS TO BIG, "NOT" THE CARB!!!!!:thumbsup:
Final Note: The adjusted altitude was 9400 foot yesterday.(track is a 6600 foot) good air for us is 7500 foot. I tell you this because my 60' time was with in a couple .0x of my best 60' times with this carb!
 
Hmm maybe i haven't finished this thread after all.... reading back threw this thread i realize that i haven't got any data recordings after my change from 3, to 2, E-holes in the metering blocks.
next month is street tire, so it may not be until September.

Holy crap that will have been a year ago, by the time i get a chance to test/data-log it.:lol:
 
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