Those 1:1s might have been 660 center shooter carbs. They seem to work well on t-rams.
>my guess with a geared secondary is that it will fall flat on its face (bog) when punched at the starting light. hard to beat a vac. secondary.
Depends on the tuneup - I run a 650 DP on a 302, 4000 stall, 4:11 gear, 28" slick. 1.78 60'. No bog. On the 351s I run a home brew "750 DP" that flows about 840. Just hammer and go. The Mustang stalls about 4600, 1.58 60' time so no problems there. With a "street" type converter, say 2200, mild gears and regular timing setup - probably have some issue with a big carb. The issue with vacuum secondary carbs in brackets - Holley specifically - is that you need to control the secondary opening rate to be consistent. IMHO, the Eds weighted air vane is superior to the box stock spring arrangement on a Holley. A light spring can let the secondaries flutter on opening that that can kill your 60-330' or 330-660' differential times. Makes the car harder to dial. A Holley VS against a DP in most cases will show the DP to be more consistent, provided the rest of the car is working.
I also do not use timing curves - when you run high stall converters, you don't need one. 302 is locked at 36, 351Cs like 38 or 40. That does make idle more tuneable too. 10 degree start retard in the ignition and a good starter means the cars are easy to light.
One thing for sure running the t-ram taught me - at least on the Eds - both carbs need to be in sync. If the throttle settings were off a bit, they'd let you know. I set them both up the same. Testing showed they both needed "one step" - about 4% - up in calibration (from dead stock) both primary and secondary. To set the carbs, remove the linkage and plug in a vacuum gauge to the rear carb manifold port. Set mix and idle, then move to front. Set for same vacuum - that should theoretically set the primary throttles to the same opening. Only then connect the linkage so as not to disturb the primary shaft setting. I used 1:1 between the carbs so I backed off the secondary idle screw to keep it out of the mix. At that point, I was basically running a 600DP with additional vacuum secondaries. The important other difference between the Eds and Holleys is the weighted air vane. All 4 barrels on a 1406 open at once, just the upper air vane keeps the secondarys holding until air flow is sufficient. With the 302, that came about 5600 RPM. I could feel the car change attitude at that point, but cam limitations required the shift be at 6000 so I didn't care for that and there was no way to adjust it out.
Also, a single 650DP vs a t-ram 600 "dp" on a mild motor had a cost for the t-ram of about .1 (1.88+ vs 1.78) in the 60', no change in MPH so power production was the same.
Once the dragster is running on a single 4, I will put the t-ram back on the 302 and start testing the two 1850s I have to see how tuneable things can be. The holleys will also probably sensitive to the secondary static throttle setting, which experience says will have to be matched.
We have also run the Ed 1406 back to back against a Holley List 4776 600DP. The 600DP hits a little harder with good gear and stall, maybe worth +.05 60' and 1 MPH.
Side note - The t-ram got retired because it got real out of whack. I thought it was the carb(s) until I finally pulled the intake. The Weiand ram has very little meat below the ports and the GT-40 heads are a bit thin there too. The ram hit the Ultra Seal gaskets such that the sealing ring around the ports was just below the casting on the bottom of the ports. Like, just a hair. Sealed up for a couple of months of racing then started to let go - maybe bog this pass, maybe not the next one. Drove me nuts. So when it goes on back - glue.
But running duals is fun. "That's way too much carb!" Yea, watch me.
