General Category > Quadrajet Carb Talk and Tips
Suggestions For Next Drag Strip Testing Day
Cliff Ruggles:
I'm familiar with that converter and used one for quite a few years before moving to the 10" version which is still in the car today. Below is a run leaving at 1000rpm's and most runs are typically 1.59-1.61 60'.
https://www.youtube.com/watch?v=6zVdoLR-VzM
That isn't the kind of converter that you "load" against the brakes, too efficient. It LOVES leaving off idle or less than about 1100rpm's and will "hit" the tires much harder, wind up the suspension, transfer weight and 60' better.
It's been so long ago I don't remember all the details, but I do know that he was using 3.08 gears and a TH400, and the smaller 10" converter from Continental.
My 13" Continental unit flashed to right at 2800rpms (leaving off idle) behind my old 428 engine topped with 6X heads (about 8.8 to 1 compression and HO Racing HC-01a cam), and 3200rpms behind the RAIV cammed 455 topped with the same heads that replaced it. Loaded hard against the brakes you couldn't get past 1700-1800 for any reason. It was locked nearly solid on top end and the car ran deep into the 12's with it. I saw a solid .2 and 2mph with the 10" converter and no other changes with that old combo.
For your combo you have some room to grow. MPH is down for one of those engines so there is some additional power lurking in there someplace. I just hope it isn't the small cam pinching off some upper mid-range and top end charge.
If you looked at the dyno chart I attached the larger HR cam made 1hp/CID but still finished by 5200rpm's. At 1hp/CID it would push 3900-4000lbs DEEP into the 12's closer to 109-112mph with good traction and a well chosen converter.
The 3.08 gears hurt NOTHING behind the 455 Pontiac engine. I've seen several cars run well into the 11's and one car I know of runs hard into the 10's with 3.08's in a 455 powered T/A.........
Cliff Ruggles:
If you don't think a 455 Pontiac LOVES a lot of cam take a look at the attached dyno chart.
The first cam was chosen by the "tech" at Comp Cams. It didn't make chit for power and pinged at 9.3 to 1 compression.
The second cam is the one I picked for the same engine.
The overlaying dyno charts indicate only the cam swap, no other changes were made. I'd add that with the larger cam the engine idled better, smoother off idle and made more power (torque) at every RPM, plus a BUTT-LOAD more upper mid-range and top end power......
Cliff Ruggles:
Forgot to add that the 455 above was topped with #96 heads ported to 250cfm, not the excellent 73-74 Super Duty heads. They would have made even more power in the same build......
Brian B.:
Good Stuff!!! I've viewed your pass on YouTube several times in the past and even gave you a thumbs up and commented how well your carburetor performed! Did your customer run headers on their SD car that ran 110 to 112? Thanks!
Brian B.:
Oops. I just saw your comment about headers above. No need to reply. Sorry for the redundancy.
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