I have decided to switch over a few of my cars to EFI this year. Is a tunnel ram with duals better or single intake better for big CI Hemi (605" and 582") and wedge(493" and 500") for race cars and street cars?

I would opt for the most air possible, especially on a drag race motor

Largest runner cross section is best....And TR's generally are best, but not always.

Do you have some reason thinking a single is better on an EFI TR, other then maybe cost?

More possible air flow is always better. You can't "overcarb" with EFI like could happen with carbs. The draw backs to multiple throttle bodies are:
* More costly
* Off idle tip-in is more aggressive so use throttle bodies with progressive linkage
* You use only one IAC (or none) so one TB needs to have it's IAC ports blocked off.

tunnel ram will have longer runners for low end torque boost. single plane converted to efi works, but most manifolds are designed for wet flow not dry flow like multi port injection. also runners on tunnel rams are more equal in length compared to a single plane. you can still run a single 4bbl throttle body on a tunnel ram. or you can build a custom top and add a front mount throttle body, or the list is endless

The aggressive throttle problem from a big throttle plate can be fixed with a snail cam in the primary linkage. Read my comments on my site here:
http://victorylibrary.com/mopar/TB-linkage.htm

The linkage is only part of the issue. TPS/blade relation for accel enricments can be a problem with some systems when big/ multiple TBs are used with some combos. Older TPS styles don't have the resolution of some newer stuff. I had a guys 355 inch SBC with an 871 and enderle 3 blade hat, converted to efi. It used a tps from a tuneport gm. The 3 sensors I tried were horrible with voltage "notchyness". Very difficult and finicky.
I always use a cam lever or progressive linkage on stuff I set up.

So the problem is NOT the size of the efi throttles, more the accuracy, sensitivity and calibration of the sensors, with current technology, that is the problem, correct?

This is all great information!

I have learned so much from Mike, Rich, Trendz, and Monte...I am going to the Holley EFI for my GTX. These discussions are well worth their weight in gold!

Mark

With all of the modern efi control systems, the capability is there to get the programmed values perfect. If the main fuel table is set up correctly, you need "almost" no accel enrichments.
The issue is getting an accurate, linear TPS. You also need to remember that that if you are using multiple throttlebodies, you still only have one TPS. This effectively cuts the tps resolution down by the multiple of throttle shafts.
Now that single tps has to account for all of the throttle shafts positions.
It would roughly be like using one accelerator pump cam to control the pump shot of two carbs.

I personally have just never had these "tip in" issues some describe, even on cars with dual throttle bodies or huge singles. I prefer 1:1 linkage and that's what I always use. What you need to look out for is PEDAL RATIO. Don't make the throttle so fast on the pedal. That is what makes some EFI stuff so touchy on throttle, is that if you wiggle your foot, the TPS changes 20%

Everybody likes what they like. Just sharing what I've been seeing with cars set up and "tuned" by others before being brought to me.
Monte, what kind of TBs did you put on the reaper camaro? Slick looking units. Never saw the car in person, but from the TV views, I can't see how the are fastened down. They just look round with no flange.

Those were some old NOS brand throttle bodies that he already had. They are 0-ringed on the bottom and have countersunk bolts in the middle.

His were very early ones and the shafts were not splined. I threatened to beat them off there several times with a claw hammer, before I got the linkage sorted...........LOL!!!