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I sort of had that problem with mechanical tripower that would let the engine see all 1125 cfm at once if you went WOT. Velocity stayed up if you tipped it in and not flipped it WOT. If fact, it would respond best just as you felt the 2 secondary carbs open up. ???? Dont know how an 1125cfm tripower setup compares to what you have tho.
 

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Best $1,000 I spent, was having a pro put my car on a chassis dyno and tune it. I can only get it so close, even with help. There is always something, idle, or part throttle- always something.

The shop nailed it. It never drove so good. No flat spots, no stumbles, etc... The Chassis dyno doesn't lie.

It was well worth the money. That was 5-6 years ago, lots of miles and smiles ago.
 

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TBI EFI's act the same way as a carb would since the fuel comes above the butterflies. Also I recall it feeling the same way with the carb too.

When it warms up I'll do some testing/data logs and see if there is anything noticeable going on.
Also a 4-7 cam profile might help as cyl 5 always wants to rob cyl 7. If you could could see each EGT of each cyl that would tell you by temp if your lean or rich like I see on the dyno.
 

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Can you change the linkage to progressive opening of the secondaries?
Have you confirmed that the throttle blades are 90 degrees to the throttle bores at full throttle and not over center?
 

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Discussion Starter #25
Can you change the linkage to progressive opening of the secondaries?
Have you confirmed that the throttle blades are 90 degrees to the throttle bores at full throttle and not over center?
You can't make them progressive. To get all the throttle blades to open to 90 degrees, they have to be set to open at the same time. I have confirmed 90 degrees at WOT.
 

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Anyone else ever feel like your car pulls harder at part throttle than full throttle? Mine sure does, at least the initial hit when it puts you back in the seat. Perhaps it's just too much air for the load/speed im going, but it's almost always felt like this.

Of course I am not talking smashing the gas and roasting the tires.
Probably AFR . Carb might not be tuned in quite right . Whats the motor and cam ?
 

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You can't make them progressive. To get all the throttle blades to open to 90 degrees, they have to be set to open at the same time. I have confirmed 90 degrees at WOT.
You actually can make it progressive.
Holley sells a kit for that. I've got one .
You can set it up 3 different ways.
1 to 1 and then 2 other settings that do slow the secondary from opening some but who knows he might just be goin real fat up high because of jetting and or bleeds
 

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Discussion Starter #28
You actually can make it progressive.
Holley sells a kit for that. I've got one .
You can set it up 3 different ways.
1 to 1 and then 2 other settings that do slow the secondary from opening some but who knows he might just be goin real fat up high because of jetting and or bleeds
I don't have a carb. I have a Fitech EFI which uses their own linkage.
 

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Best $1,000 I spent, was having a pro put my car on a chassis dyno and tune it. I can only get it so close, even with help. There is always something, idle, or part throttle- always something.

The shop nailed it. It never drove so good. No flat spots, no stumbles, etc... The Chassis dyno doesn't lie.

It was well worth the money. That was 5-6 years ago, lots of miles and smiles ago.




This is true to an extent. IE, I was at the track yesterday with my boys and was speaking to a guy that has a mutual engine builder with me and he was doing shakedown passes N/A on his mid 8sec gbody (drag week) street car.
We were talking about his new Holley FI he recently switched to and said he recently was on a chassis dyno and made 570 at the wheel.
On his 1st pass of the day it nosed over at a smidge passed the 1/8.
Chassis dyno's don't, can't account for gravity of your fuel system under load as he found out the areo 340 was good on the dyno but not on the track.
Not saying nor was he that dyno's are ng, just doesn't account for actually going down the track.

BTW, the 340 was for street driving in the GN tank. 5gal cell for spray is in the trunk.
 

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I noticed this on a dead stock or 4 barrel/header 72 350 Malibu. I can’t remember which it was, but the car would only chirp the tires from a standstill at half throttle. Mashing the gas all the way down couldn’t produce a chirp.
 
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