EFI w/dual plane manifold??

[67 455 Bird ragtop]

I've read a few posts that the new EFI systems, Sniper/EFITech don't really like a dual plane manifold. I currently have an Edelbrock Performer RPM which is a dual plane manifold. What are my option?? Or is this not really an issue with the RPM ??

[68Formula]

Low dual plane may have an issue with respect for mixture being carried by the airflow and not puddling on the bottom. Probably not as critical with an RPM. And a 1/2" - 1" spacer might alleviate concerns even more.

[67 455 Bird ragtop]

Would cutting a notch between the two sides make any difference ??

[68Formula]

Would cutting a notch between the two sides make any difference ??

Can't really see a benefit in that. I've seen it done on the rear divider for carb applications when it's a little on the small side to improve top end. But because the pressure differential across the individual bores is what determines the fuel demand, it doesn't affect a/f ratio. Not sure even with closed loop, that will compensate correctly with large throttle transitions. But again, I don't think insufficient airflow@ WOT is your concern. If you still want to play with that idea, I'd first try comparing a 1/2" 4-hole spacer to a 1/2" open spacer.

[weircc]

i went through this with the holley terminator the problem is that the divider blocks idle air control. We took die grinder and made room worked fine. I currently have the sniper on my airgap and have no problems at all. I believe it was only the first models like terminator. The newer models like fitech/sniper are good to go

[CliffsBlueCamaro]

I've got a Holley Street Dominator intake manifold with my FiTech. The dual plane intake doesn't seem to cause any issues.

I am considering cutting the dividing wall or buying an RPM Air-Gap just because it seems to gain power in most applications, and I have to wonder if it would help the EFI in some way too. I like 68Formula's idea of using a small spacer first to see how it will react.

But, don't feel like you HAVE to buy a single plane just to get a TB fuel injection unit. It will work fine.

[dobie6982]

I just swapped out a Perfomer RPM for a Torker II. I am having some tuning issues right now. I am letting the Sniper relearn it’s self. There is a lot of backfiring through the exhaust. It appears to be pullin a lot of fuel from the fuel table and taking its time to relearn. I think it’s putting more fuel than I need with the Torker. I’ll meet you posted over the next couple of days.

[dobie6982]

Update: I leaned out the AFR to about 14 and that took care of the backfiring. I lost some bottom end but not much. I think the car is is a little faster now. I made a wide open throttle run from 2nd thru 3rd and it was gone. My AFRs are much more stable. The idle is a lot smoother. So far I’m happy with the swap.