Been bracket racing with my son in my Skylark. He’s kicking ass, but I’m not a fan of the eldebrock that’s on it now. 30 over 455, mild cam, headers…any recommendations? Thank You in advance!
Yes it’s hard to beat a custom Q jet from Ken at everyday performance or Mark northcutt from Q power. The only downside is that the holleys are super easy to modify and tune or re jet. Also the Q jet has trouble over 600 HP. Anything under 600 Hp they are hard to beat.
I had Mark build my Quadrajet and I love it. My local mechanic who knows racing complimented the carb saying it was perfect and he wouldn’t have done anything different. The car starts instantly with two pumps, idles great and is very responsive. Cliff
I guess if your racing the best carb will be on you are able to work on ifvwhen needed. I ran an edelbrock 750 into high 11s on my car, had to drill jets to get enough fuel......thought it ran good, put a holley on and went 2 tenths fast on a back to back test day. But the holley was and 850.....so not exactly an apples to apples test. But I find with the right adjustment qjets, holley, eddy they all can run correctly......but when adjustments are needed if you don't have the correct rods, spring, cams, jets, power piston, etc then is that the carbs fault. I find certain makes easier to tune than others........does that are 1 better than other just because 1 can't make the correct adjustments on that carb? Not really its my error bot the carbs. And any carb will only be in perfect tune one 1 particular weather condition....as heat and humidity and pressure change that tune will no longer be a perfect setup......its a comprise that works ok enough.......how long the ok window last, guess that depends on the I erson driving it and how bad ok enough bothers then
Find yourself an untouched core and reach out to Rob Ross here on the board. Get it done right the first time.
While a Q-jet is a great all around carb, if your just bracket racing, then I would recommend a 4150 Holley. The simplicity of tuning, and super easy parts availability will be a benefit, and you have no concern about fuel mileage. A complete jet/rebuild/gasket kit can be had for a reasonable price, whereas those parts for a Q-jet are a small fortune, if you can even find them.. Secondary rods are particularly becoming harder and harder to find in various sizes. I would recommend this 950 QF carb https://www.holley.com/products/fuel_systems/carburetors/street_strip/parts/Q-950 Whose Holley carb works good right out of the box is a bit of a moving target, when I buy a carb, my first call is to my dyno shop to see what is working these days.. they see hundreds of carbs a year.. If you had asked me 3 years ago, my answer would have been an HP Holley.. but ever since Holley purchased Quickfuel, they seem to have lost their way with their HP series carbs.. Don't worry about the CFM, all 950's have the 1.75" throttle bores.. that's the 600/750 size.. and they smooth the main body out for more airflow. So you can grow into it, with no downsides. Good luck JW
You will get better mpg with Q-jet or TQ driving to track. I drove to the track running high 10s with an 850TQ that was modified (outer booster rings and choke removed) to be close to 900 cfm.
Carbs are one of those things that few get right. You could line up 10 cars at a local track,and probably one of them have their act together. For what you are doing,a properly built and tuned Q-jet will be more than enough. You can run dead consistent and plenty fast with a Q-jet. When you get to the point that you are running 10:20’s or faster,then I would look into a custom Holley style carburetor,but still nothing off the shelf. Whatever you run,you also need to tune it to the fuel you will be running in it. Different fuels have different weights and require different tunes. I spend a little extra dyno time doing this for some engines. I will have a cat pee tune and a race gas tune. I also see this problem with some novice carburetor rebuilders. They will take something like a 1970 carburetor,completely restore it,then claim it runs like crap. The problem is often that it was built back to 1970 specs,which is what you do NOT want because we don’t have that type of fuel now.