any one keep the column shift with shorty headers and a sbc. using the summit 1 1/2 primary shorties
column shift with headers sbc
- Thread starter j_tizzle_84
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wow find it hard to believe that no one has even tried this to even shoot me down. or has done this to tell me if i can just dont wanna waste my time but really wanna retain a stock look. 🙁
Ok I'm shooting you down just because you complained, why would you use shorty headers they arent any better than factory manifolds other than they look better. Hooker and headman make headers that work with the colum shifter and a 1 5/8" primary would be better anyways.
dont have the manifolds. i find it hard to believe that a individual pipe header could not be better than a cast iron manifold that dumps everything together. and the smaller pipe makes more torque figured i would need more with the 305M.Bailey said:
M.Bailey said:
Why would you say shorty headers are no better than the logs found on the 305s that GM called exhaust manifolds. The manifolds they used on G bodies were the most pathetic manifolds you can probably find.
Well you are correct the G body manifolds are horrible. But were you make the gains with headers is from the length on the tube and collector, shorties have no length and are often very unequal in length on the primary tubes, the longer equal length tube headers scavenge better leading to a better uncontaminated fuel charge. and 1 5/8 is a great size for the 305 and still ok if you step up to a 350 I know because thats what I have on my 355 now and I had on my 305. I ran the stock manifolds before we switched. If you are interested my headers are made by Headman.
M.Bailey said:
I run hedman elites on my 355 vortec with a 2.5" ss system which is more than enough for an unrestricted flow. If you did some research on the cfm your putting out you'll find that your headers total area is 6.5 and even being limited by the 3" collectors so your not even close to having any back pressure created by the headers. I don't know what you have for hp or what your running for the rest of your exhaust but you should read up on exhausts since bigger isn't always better....
to get back to those shorty headers I would love to see some dyno numbers between the logs and some shorty headers and I'll put up whatever you can afford that the shorty headers will blow the logs away...
Please excuse me for under estimating the crappyness of the logs comparing them to even a shortie is not really a comparisson. however recomended tube size for a 305 is 1 5/8 with a 3 inch collector call and ask any header manufacturer. When you get down into the small engines like the 283 265, then you need a 1 1/2" primary. I never said bigger is better but too small is bad. If you were to loose the shorties on your engine you would probly pick up about 5-10 more hp.Put a set of correvette center dumps on your engine and see if you feel a difference you probly wont because that manifold is comperable to the header "upgrade" you did. I'm running dual 2 1/2" exhaust through two delta flow flowmasters and I'm only making about 350hp and way less than that when I had the 305 in the car. I didnt have any idle, drivablity or running problems at all nor do I now. If some research was done it would be found will that for a 350ci engine making approx 350hp an 1 3/4" primary full length header with a 3 inch collector is recomended. and proven to be better than not only the factory exhaust but the shorties as well. so currently my headers are a little on the small side but they will serfice. by no means am i saying that the shorties wont work. but there is more torque and hp to be gained from a full length header. and in an already power deprived engine more is better.
Actually the size of the engine has no bearing on the size of the exhaust required. Header companies are only trying to sell their product don't know how much CFM an engine is taking in or exhausting. For street cars most headers are actually too larger for the application. You should look up the formulas used to calculate the CFM flow and the flow rates of tubing
BTW with 350 HP your CFM exhaust flow would be in the area of 770. A single 2.5" pipe can handle 560 CFM without restricting the flow...since you have duels you can flow over 1100 cfm with no restrictions which is well over your estimated maximum flow.
BTW with 350 HP your CFM exhaust flow would be in the area of 770. A single 2.5" pipe can handle 560 CFM without restricting the flow...since you have duels you can flow over 1100 cfm with no restrictions which is well over your estimated maximum flow.
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