Single plane vs dual plane intake using performance throttle body EFI

[folkenheath]

Do you have these charts plotted against mph?? That would show the converter coming in and may provide further analysis..

Yes they sent me the data files and I downloaded the software, so I can show the data however we want...here is the same single plain vs dual plane vs MPH instead of RPM...I think the operator hit the record button and punched it at the same time (after slowling ramping it up to RPM in 3rd gear). So you can see the power climb up fast but you can't really tell the difference between that and the converter that I can see.

We dropped the max RPM to just above peak since the tires were shaking so bad at those higher speeds. Which is why the blue graph drops off sooner than the red. He also must of stopped recording right before he let off, as opposed to right after. This also why we did most of the pulls with the smaller tires and only swapped back just for comparison purposes to the previous data.

You can start the pull lower than that really or it will downshift and ruin the data. (This VB is not full manual, I modified it so I can hold it in a lower gear, but I cannot hold it in a higher gear).

 

[Bent77]

Thanks for the data

@6872xtc

 

[6872xtc]

Thanks for the data

@6872xtc

I have been watching.

Thanks @folkenheath

 

[beags86]

I have been watching.

Thanks @folkenheath

But are you doing anything about it?

 

[folkenheath]

No problem, glad the info is useful, even if its not groundbreaking. There aren't a lot of us that use this type of data but we're out there.

 

[6872xtc]

No problem, glad the info is useful, even if its not groundbreaking. There aren't a lot of us that use this type of data but we're out there.

What you probably don't know is that I changed heads and put shorty headers on a 350. I didn't change cam, but did go from a TBI adapter with separate spacer, to having it all in one. I have been trying to cure a stumbling problem in the lower rpms since then. So this is food for thought.

 

[folkenheath]

What you probably don't know is that I changed heads and put shorty headers on a 350. I didn't change cam, but did go from a TBI adapter with separate spacer, to having it all in one. I have been trying to cure a stumbling problem in the lower rpms since then. So this is food for thought.

No I didn't know that. You mean you have one adaptor or you have an intake with no adaptors now?

 

[6872xtc]

I have an adapter that my son made out of 1.5" aluminum to take the place of the 3/8" adapter plate which had an additional 1" spacer.
This is on top a an Edelbrock performer. It used to run good until one of the milled '72 heads cracked. Now with Edelbrock heads, it stumbles badly from about 1400 to 2100 (?). Just where I need it to run good down the road.
Your research has me thinking.

 

[folkenheath]

I have an adapter that my son made out of 1.5" aluminum to take the place of the 3/8" adapter plate which had an additional 1" spacer.
This is on top a an Edelbrock performer. It used to run good until one of the milled '72 heads cracked. Now with Edelbrock heads, it stumbles badly from about 1400 to 2100 (?). Just where I need it to run good down the road.
Your research has me thinking.

View attachment 282161

How do your plugs look? That's what I would look it, if the plugs are obvious which plane they are on it should help. If the plugs look even its likely a different tuning issue...

 

[Bent77]

@obijuank5

 

[6872xtc]

How do your plugs look? That's what I would look it, if the plugs are obvious which plane they are on it should help. If the plugs look even its likely a different tuning issue...

There was a very small difference in the plugs, so I believed that it was only a very small part of my problem.