Which do you think is better for 400hp?
street motor, 3.23 gears, lt-1 intake
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Which do you think is better for 400hp?
street motor, 3.23 gears, lt-1 intake
Personally I would go for the SR Torquers, they have the smaller intake port volume, so keeps the gas velocity high at lower revs. This gives you the broad torque band that a street motor needs to make it liveable on the street.
I wouldnt mind losing a little power down low if it picked up substantially in the top. Do you think 200cc runners are just way too big?? 170s come stock on vortecs, it just seems a little pussified to buy new heads for performance and go with a stock size. I want a reasonably wild street car. Thanks for the help.
Oh the SR's will pick up in the top over a stock head quite well, it's not only runner volume, it is also shape as well. The most important part of the runner is the 1 inch before the valve seat and the 1/2 inch after the valve seat. The shape of the pockets behind the valve create a very strong swirl motion of the intake charge into the chamber. Use these heads with the right cam and your car will take off !
If I could use these heads I would, but I cant because I am restricted to factory heads by class rules. So I am using the old 462 double hump heads that can be modified. When they designed the SR's they looked at the best parts of the fueli heads and improved on them, which was quite a bit. A stock untouched pair of SR's will outflow a set of ported fuelies, especially in the midrange.
How much better do you think they are than a pair of stock vortecs?
Ah ! now it gets interesting. The chevy vortecs are a good head and flow well. At .500 inch lift they will flow 210 CFM with the port in stock form. Now comes the flip side, with the design of combustion chamber these heads flow well in the .400 to .500 lift range, go higher than .500 lift and the chamber shape starts to restrict flow, This is where the SR's are better, because of there better chamber shape they have a better power band with cam lifts over.500 than the vortecs. Butttt.... you will be getting into pretty high valvetrain wear with normal solid lifter cams at those lifts,unless you are using a street roller cam setup.Quote:
Originally posted by Batass
How much better do you think they are than a pair of stock vortecs?
so if i wasnst going over .500 the vortecs would be almost as good?
Yep from what I see on them the L31 vortecs flow well, chevy put a lot of effort into those heads. Just remember chevy did such a good job on the ports that any further porting wont give all that much better flow for effort and money spent.
Theres only one performance intake for tpi that will fit the vortecs right?
To point you in the right direction for that question we will have to talk about the rest of the motor, is it a 355 0r a 383 ? apart rom the mention of gearing and the lt1 intake dont know about the engine gearbox combination, you know all the basics static compression ratio's, carbureted or injected ? points or electronic dizzy ? auto or maual gearbox and type of car it's going into. This will bring into question hood clearance heights for the manifold being either a high or medium riser.:HMMM: Now after saying all that I notice you mentioned TPI there ???
I better say now I am old school and work with slosh bowls ( carburetors ) and am pretty basic about electronic fuel injection, Denny would be the man to see about TPI
The motor isnt built yet, im looking for parts. I was going to start with the heads and base everything else around them. I think im going to be set with the vortecs though, ive seen some dyno charts and they are pretty impressive for their cost. $3-400 vs $800 for aftermarket. I was planning on using the lt1 intake but its power range is something like 3000-7000rpm. thats a little high for what im doing i think. I wish i was dealing with a carb but emissions laws wont allow me to do so. Thanks a lot for the help. Im planning on running about 9.5:1 cr so I can put a centrifugal supercharger on later.
WHY 400HP?
why not
Ok heres another question for you. This intake that I am looking at has an average(tested on a couple different motors) peak tq at 4700rpm and hp at 5618-6282. They make a manifold to fit vortecs, would it be a good match?