Mine doesn't bobble at all, it's a flat line the whole run. Magna fuel 500, magna fuel dead head regulator and 3.8 psi fuel pressure.

same as both my cars on gas. Firebird...Product Engineering 460 pump and PE dead headed regulator set to 6.5psi. Dragster...Magnafuel 500 and MF dead headed regulator set to 6.5 psi.

Jesse, post photos of your regulator mounted and racepak v net fuel pressure sensor.

This message has been edited. Last edited by: 1320racer,

Vacuum line not connected off regulator since the install of APD carb. Open to atmosphere.

Vnet sensors rubber mounted to firewall on slight side to side angle - vertical otherwise

Regulator is rubber mounted, or hanging from lines as recommended to reduce vibration.

Ed you do realize this is on alcohol. As soon as i called apd and asked what pressure for this carb they asked gas or alky. When i said alky, they said 9psi not any lower. I asked about the .3 it was at from mech have and they said it didn't matter if thatis what it was run at. They went on to say they run 11-13psi on belt systems.

Let me ask a stupid question. If the seats can seal off the gas at 10psi while engine is running. The bowls are not pressurized, so what difference does it make the pressure. Admittedly many years of my racing was with fuel injection where pressure definitely matters but on a carb, other than flooding it which in this case it is not even at idle. What difference is it. The fuel in the bowls is not under pressure where it would effect the amount delivered.... help me understand what I'm missing.

quote:

Originally posted by XPS fan:

quote:

Originally posted by seabass:
How do you get the individual cylinder timing to log? I don’t see that option in the grid.... or was it not a grid

Yes on Grid, individual data is possible with the V500 because of its extra inputs.

Do you know if using Racepak Sportsman model, could you select only one or two cylinders to log ignition timing on if using ICT in Grid ?

I'm surprised that pressure that high doesn't have an effect on the float drop amount.

Curtis

quote:

Originally posted by XPS fan:

quote:

Originally posted by seabass:
How do you get the individual cylinder timing to log? I don’t see that option in the grid.... or was it not a grid

Yes on Grid, individual data is possible with the V500 because of its extra inputs.


.

ahh, v500, that makes sense. Thanks

quote:

Originally posted by markemark:

quote:

Originally posted by XPS fan:

quote:

Originally posted by seabass:
How do you get the individual cylinder timing to log? I don’t see that option in the grid.... or was it not a grid

Yes on Grid, individual data is possible with the V500 because of its extra inputs.

Do you know if using Racepak Sportsman model, could you select only one or two cylinders to log ignition timing on if using ICT in Grid ?

I have a v300 , you would rthink it would have enough channels to do it but I guess not. I dont even see individual cylinder logging in the grid software under the racepak tab...

quote:

Originally posted by ski_dwn_it:
Vnet sensors rubber mounted to firewall on slight side to side angle - vertical otherwise

Regulator is rubber mounted, or hanging from lines as recommended to reduce vibration.

Ed you do realize this is on alcohol.

yes

where is the actual vnet fuel pressure sensor installed/mounted?

Here's mine on my dragster, in the regulator...



The Firebird doesn't use a Vnet sensor, rather a takeoff is plumbed from the rear of the fuel log into a Racepak Pro Transducer box...

https://store.racepak.com/prod...box-original-series/

same for oil pressure...

This message has been edited. Last edited by: 1320racer,

They are the on the firewall, rubber mounted off -4 line.

quote:

Originally posted by seabass:

quote:

Originally posted by markemark:

quote:

Originally posted by XPS fan:

quote:

Originally posted by seabass:
How do you get the individual cylinder timing to log? I don’t see that option in the grid.... or was it not a grid

Yes on Grid, individual data is possible with the V500 because of its extra inputs.

Do you know if using Racepak Sportsman model, could you select only one or two cylinders to log ignition timing on if using ICT in Grid ?

I have a v300 , you would rthink it would have enough channels to do it but I guess not. I dont even see individual cylinder logging in the grid software under the racepak tab...

Grid uses the 7555 to set the #1 sync pulse. Apparently Racepak can take the shared Engine Timing channel from Grid and determine the #1 sync pulse and then determine the actual engine timing for each cylinder from that ??

My question is, can it only use 1 or 2 channels to display the 1 or 2 cylinders that I want to look at?? Or does it need to use all 8 channels for this feature to work?? Perhaps XPS knows or Greg Kelly could answer this.

quote:

Originally posted by markemark:
Do you know if using Racepak Sportsman model, could you select only one or two cylinders to log ignition timing on if using ICT in Grid ?

To my knowledge you can't even do overall actual timing with a Sportsman. Racepak is always updating and improving their stuff, maybe Greg will help us out here.



.

quote:

Originally posted by ski_dwn_it:

Regulator is rubber mounted, or hanging from lines as recommended to reduce vibration.

Admittedly many years of my racing was with fuel injection where pressure definitely matters but on a carb, other than flooding it which in this case it is not even at idle. What difference is it.

Mounting them off the engine is the best way to do it. Lots of sensors get killed from engine vibrations.

Why O why did you go backwards and put a carb on it if you had EFI to start with?

I have never owned a drag race car with a carb, but they have always been on my generators.......

Mike, the sensor above screwed into the regulator is in use for the past 4 seasons.

quote:

Originally posted by XPS fan:

quote:

Originally posted by markemark:
Do you know if using Racepak Sportsman model, could you select only one or two cylinders to log ignition timing on if using ICT in Grid ?

To my knowledge you can't even do overall actual timing with a Sportsman. Racepak is always updating and improving their stuff, maybe Greg will help us out here.



.

You can do overall timing from grid, and i do. Just need the channels availability. Can do transbrake on/off...to get around connecting 12v event directly to transbrake, which is illegal. Grid sending signal is not. I have 12v event going to electric shift solenoid, now. Might also have it or move it for wot switch to know exactly the time in run I dump someone.

Efi was whenthe car was a small block and i ran it on the street. Went best of 9.7at 135ish. It had custom single plane i turned into efi so it would fit hood. Bought new vette for street and this became the racecar. Didn't have time to fabricate another for bbc, so i went to carb.

This message has been edited. Last edited by: ski_dwn_it,

My understanding of an alky carb. Mr. Whitener can come along and correct me if I’m wrong.

Since an alky carb uses so much fuel it almost works like fuel injection. The needle and seat pretty much stay open flooding the float bowl with fuel hence the higher pressure requirements as specified by APD. That is my understanding anyway.

I still feel that alky works best with injection.

quote:

Originally posted by Cashflow:
My understanding of an alky carb. Mr. Whitener can come along and correct me if I’m wrong.

Since an alky carb uses so much fuel it almost works like fuel injection. The needle and seat pretty much stay open flooding the float bowl with fuel hence the higher pressure requirements as specified by APD. That is my understanding anyway.

I still feel that alky works best with injection.

I get the consumption part. But it's open (vented) to atmosphere so as soon as the fuel leaves the needle it's lost its pressure...no?

quote:

Originally posted by ski_dwn_it:
You can do overall timing from grid, and i do. Just need the channels availability..

What I was referring to was actual timing, the only thing the Grid is giving you is the program ie what you told it to do. With all the different systems we have manipulating the ignition timing I need to know exactly what is happening. It takes another crank pickup from Racepak and a tach signal from the Grid and you get what we call actual timing. As far as I know the Sportsman cannot do it.



.

quote:

Originally posted by XPS fan:

quote:

Originally posted by ski_dwn_it:
You can do overall timing from grid, and i do. Just need the channels availability..

What I was referring to was actual timing, the only thing the Grid is giving you is the program ie what you told it to do. With all the different systems we have manipulating the ignition timing I need to know exactly what is happening. It takes another crank pickup from Racepak and a tach signal from the Grid and you get what we call actual timing. As far as I know the Sportsman cannot do it.



.

Gottcha. I interrupted it as thinking events from base timing.