Stock 7m Intake(over the top) vs aftermarket or modded FFI (front facing intake) which is better and why? i see on www.7mpower.com that the ported stock manifold was on the #1 of the top ten... whats up with that??
7m Intake vs FFI
- Thread starter Joel W.
- Start date
stock is good. ron builds them and sethron iirc the name modifies the stockers and they flow better. he flow tested it and it flowed more then the stocker! FFIM is better!
I'm going to give you the contractor's answer.
It depends.
Stock gives you more even flow across all cylinders.
FF gives you shorter IC pipe routing, a cleaner engine bay, and of course can be manufactured for higher flow than stock.
If you were going to make a new intake manifold from scratch, there are lots of techniques that will contribute to a higher, more even flow that could be used. One of the European guys built a crazy intake manifold with a surge tank the size of a big briefcase!
I think it's safe to say that the intake isn't the problem in the flow until you hit some pretty big numbers. Unless of course you've already replaced your turbo, IC, IC piping, exhaust manifold, wastegate, downpipe, had your head ported, installed bigger valves, and moved up to at least a three inch exhaust.
It depends.
Stock gives you more even flow across all cylinders.
FF gives you shorter IC pipe routing, a cleaner engine bay, and of course can be manufactured for higher flow than stock.
If you were going to make a new intake manifold from scratch, there are lots of techniques that will contribute to a higher, more even flow that could be used. One of the European guys built a crazy intake manifold with a surge tank the size of a big briefcase!
I think it's safe to say that the intake isn't the problem in the flow until you hit some pretty big numbers. Unless of course you've already replaced your turbo, IC, IC piping, exhaust manifold, wastegate, downpipe, had your head ported, installed bigger valves, and moved up to at least a three inch exhaust.
ok i can see how it would effect even flows under vacume, but once boost hits, wont it be pretty evenly distributed? (pressurized)
Not neccesarily - depends on the design. Take a real example - an air conditioning system for a building. The pipe to each vent is the same size, however, you get less air flow the further the pipe runs from the main HVAC unit.
Now make those pipes smaller, but they carry 30psi instead... a bad design is very capable of flowing different amounts to each cylinder.
It is less of an issue with forced induction, but it can still have a large effect.
Now make those pipes smaller, but they carry 30psi instead... a bad design is very capable of flowing different amounts to each cylinder.
It is less of an issue with forced induction, but it can still have a large effect.
i used to build and install HVAC so i like your example very much grim.. i was always told to make your trunk lines big and taper it down smaller and smaller as you take off runs, but in the new class i took last, their teaching that hi-pressure trunklines with way smaller trunk line diameter pipe will actually work better.. i disagreed with them untill i installed one, and it worked well, granted in HVAC the pressures are much less, and thier idea is to save money on pipe. that being said, i forgot my point.. ahhahahha
Front facing manifolds are nice because they clean up the engine bay and greatly improve throttle response. Mine made a huge difference at 26 psi. With the stock manifold I made 557 rwhp and 533 rwtq and with the FFI I built I made 604 rwhp and 544 rwtq.
Sean
Sean
Xman, improved throttle responce? is that just because the ffim is less pipe than the 9ft of ic pipe required on the 7m type manifold piping, I measured it once for the shock value... Or could it have been the manifold? pretending the ic pipes were the same length...
hope you guys dont mind me asking, like to hear your oppinions..
i definately like the ffim look... way clean and shorter.. kinda beed answered i guess..
thanks much..
hope you guys dont mind me asking, like to hear your oppinions..
i definately like the ffim look... way clean and shorter.. kinda beed answered i guess..
thanks much..
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If you dont plan on racing competetively and need every ounce of power why bother with fabrication. The Cartech unit flows way better and cools much better than stock. And it is about 800 less than HKS and Greddy.
I understand "cleaning up" the engine bay, it just isnt worth the work to me.
I understand "cleaning up" the engine bay, it just isnt worth the work to me.
sethron has shown that a modded stocker will flow more, and more evenly across the cylinders.
i have one, and its not a simple conversion....
i have one, and its not a simple conversion....
The stock manifold has been proven to flow very well. Will Neely made 684rwhp (all boost) on a T66 with it. The 3 main advantages of a FF manifold are: Less heat soak on the piping, improved throttle response(shorter piping), and a cleaner look to the engine bay. But for all out power, I don't beleive a FF manifold will help much over the stock design.
I wonder if the response problem has to do with people using intercoolers that are designed for a FF manifold. I bet that 180 degree intercooler bend coming off of the right endtank causes a lot of pressure drop. Hmmm.
I wonder if the response problem has to do with people using intercoolers that are designed for a FF manifold. I bet that 180 degree intercooler bend coming off of the right endtank causes a lot of pressure drop. Hmmm.
Biggest + for the FFI's is keeping as much of the Cool side of the pipework out of the engine bay away from the Hot Exhaust so you're not reheating the charge air.
Shorter pipes are a bonus but won't change response times that much on their own as the gas speeds through the pipe as so high we're talking milliseconds difference.
Shorter pipes are a bonus but won't change response times that much on their own as the gas speeds through the pipe as so high we're talking milliseconds difference.
MRSUPRA said:
well it depends
all this is, for not if the total volume of the IC piping is the same as stock or even more.
How can it be the same or more?
bigger pipes (using 3 inch pipe throughout the IC system) increase volume area fast.
i am a big fan of ffi as well. many advantages of using it. but, as far as how much it is increase real world performance, its gonna depend on the car and what you want it to do. we can talk all day long about size and volume. i can say -10 fuel line well outflows -6 fuel line. but if you are running a stock fuel pump at stock fuel pressure the -10 isnt gonna do a thing. well, except maybe look cool.
At the CFM most guys are running 3" is too big a drop in gas speed for me coupled with the extra volume may be responsible for the perceived slow response.figgie said:
joel w. said:
I think some of it has to do with shorter piping, and some to do with getting rid of the swing tree linkage the 7m uses stock. You also get the benefit of keeping things cooler. I went to a 3 inch primary(turbo to IC) pipe and a 3.5 inch secondary ( IC to TB) pipe plus a bigger TB and still had alot better throttle response.
CryoSLash said:
are you kidding?
http://www.7mpower.com/will_neely/will_neely_04.jpg
i think it's pretty obvious...
and IMO, that's not "clean"