Airbox restriction
12-16-2010, 01:36 PM
#16
Race Car
Oh I agree, getting it relocated is better than to not do it, and will increase flow, but if I had to pick from relocating the stock afm or getting a maf and running it in the air box, I would go with the maf in the airbox. For those that want the stock airbox look, etc.
Then there is also the investment required to change the air metering strategy.
12-16-2010, 02:36 PM
#18
Race Director
12-17-2010, 02:19 AM
#19
Three Wheelin'
Spinning the wheels is immature and frowned upon by real track enthusiasts. It's also frowned upon by those who don't have enough power to break them loose. It sure can be fun when you do though 
With my (almost) stock airbox and snorkel, spool-up suffers, but not power. The cold, denser winter air is awesome too. I went for one more run up the peaks last weekend, and the car felt amazingly fast. If I stay above 3500 RPM there is no lag. When I got to the top (about 9k ft elevation) and turned around, I shifted hard into 2nd and the wheels spun (with LSD) all the way through 2nd. I got it pointed straight just in time to shift- great fun and adrenalin rush with a mountain face to the left and cliff to the right
. It was probably 40-50 degrees up there and the tires were plenty hot from the drive up. Nice job on the AFM mod Eric, I like it.
Not sure I agree with that. All of the restrictions add up. The smallest diameter or area restriction isn’t necessarily the worst one. It's kind of like the turbo exhaust necking down into the downpipe and opening up into a 3" or larger exhaust. The downpipe is a smaller diameter, but the larger exhaust after the smaller downpipe helps a lot. By getting rid of the long snorkel and airbox airpath, the stock AFM is still a restriction, but not as bad. I got rid of the AFM restriction so now the snorkel/airbox is the limiting factor. I'd guess that the restriction of Eric's vs. mine are similar. Obviously the normal MAF/ cone filter gives the best flow and spool.
I'll be putting on a 3 or 4" exhaust before enlarging the snorkel because I feel that's my next biggest restriction for spool-up. I think the snorkel is the next biggest restriction then the airbox entrance, then the J-boot bend.
As 76 911s said, I'm trying to keep mine as stock looking as I can.
12-17-2010, 03:36 AM
#20
Freedom Enthusiast
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It's also frowned upon by my wife when I have to buy new tires.
It's nice that you can get out and play when you are not slaving over the spec car.
There are some strange restrictions in our cars. The stock pipe from the intercooler to the throttle body is smaller than the intercooler outlet and the throttle body inlet? Why the small pipe?
Spinning the wheels is immature and frowned upon by real track enthusiasts. It's also frowned upon by those who don't have enough power to break them loose. It sure can be fun when you do though
With my (almost) stock airbox and snorkel, spool-up suffers, but not power. The cold, denser winter air is awesome too. I went for one more run up the peaks last weekend, and the car felt amazingly fast. If I stay above 3500 RPM there is no lag. When I got to the top (about 9k ft elevation) and turned around, I shifted hard into 2nd and the wheels spun (with LSD) all the way through 2nd. I got it pointed straight just in time to shift- great fun and adrenalin rush with a mountain face to the left and cliff to the right. It was probably 40-50 degrees up there and the tires were plenty hot from the drive up.
Nice job on the AFM mod Eric, I like it.
Not sure I agree with that. All of the restrictions add up. The smallest diameter or area restriction isn’t necessarily the worst one. It's kind of like the turbo exhaust necking down into the downpipe and opening up into a 3" or larger exhaust. The downpipe is a smaller diameter, but the larger exhaust after the smaller downpipe helps a lot. By getting rid of the long snorkel and airbox airpath, the stock AFM is still a restriction, but not as bad. I got rid of the AFM restriction so now the snorkel/airbox is the limiting factor. I'd guess that the restriction of Eric's vs. mine are similar. Obviously the normal MAF/ cone filter gives the best flow and spool.
I'll be putting on a 3 or 4" exhaust before enlarging the snorkel because I feel that's my next biggest restriction for spool-up. I think the snorkel is the next biggest restriction then the airbox entrance, then the J-boot bend.
As 76 911s said, I'm trying to keep mine as stock looking as I can.
It's nice that you can get out and play when you are not slaving over the spec car.
There are some strange restrictions in our cars. The stock pipe from the intercooler to the throttle body is smaller than the intercooler outlet and the throttle body inlet? Why the small pipe?
Spinning the wheels is immature and frowned upon by real track enthusiasts. It's also frowned upon by those who don't have enough power to break them loose. It sure can be fun when you do though With my (almost) stock airbox and snorkel, spool-up suffers, but not power. The cold, denser winter air is awesome too. I went for one more run up the peaks last weekend, and the car felt amazingly fast. If I stay above 3500 RPM there is no lag. When I got to the top (about 9k ft elevation) and turned around, I shifted hard into 2nd and the wheels spun (with LSD) all the way through 2nd. I got it pointed straight just in time to shift- great fun and adrenalin rush with a mountain face to the left and cliff to the right
. It was probably 40-50 degrees up there and the tires were plenty hot from the drive up. Nice job on the AFM mod Eric, I like it.
Not sure I agree with that. All of the restrictions add up. The smallest diameter or area restriction isn’t necessarily the worst one. It's kind of like the turbo exhaust necking down into the downpipe and opening up into a 3" or larger exhaust. The downpipe is a smaller diameter, but the larger exhaust after the smaller downpipe helps a lot. By getting rid of the long snorkel and airbox airpath, the stock AFM is still a restriction, but not as bad. I got rid of the AFM restriction so now the snorkel/airbox is the limiting factor. I'd guess that the restriction of Eric's vs. mine are similar. Obviously the normal MAF/ cone filter gives the best flow and spool.
I'll be putting on a 3 or 4" exhaust before enlarging the snorkel because I feel that's my next biggest restriction for spool-up. I think the snorkel is the next biggest restriction then the airbox entrance, then the J-boot bend.
As 76 911s said, I'm trying to keep mine as stock looking as I can.
12-17-2010, 09:58 AM
#21
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Originally Posted by kevincnc;8138909
Not sure I agree with that. All of the restrictions add up. The smallest diameter or area restriction isn’t necessarily the worst one. It's kind of like the turbo exhaust necking down into the downpipe and opening up into a 3" or larger exhaust. The downpipe is a smaller diameter, but the larger exhaust after the smaller downpipe helps a lot. By getting rid of the long snorkel and airbox airpath, the stock AFM is still a restriction, but not as bad. I got rid of the AFM restriction so now the snorkel/airbox is the limiting factor. I'd [I
Not sure I agree with that. All of the restrictions add up. The smallest diameter or area restriction isn’t necessarily the worst one. It's kind of like the turbo exhaust necking down into the downpipe and opening up into a 3" or larger exhaust. The downpipe is a smaller diameter, but the larger exhaust after the smaller downpipe helps a lot. By getting rid of the long snorkel and airbox airpath, the stock AFM is still a restriction, but not as bad. I got rid of the AFM restriction so now the snorkel/airbox is the limiting factor. I'd [I
guess[/I] that the restriction of Eric's vs. mine are similar. Obviously the normal MAF/ cone filter gives the best flow and spool.
I'll be putting on a 3 or 4" exhaust before enlarging the snorkel because I feel that's my next biggest restriction for spool-up. I think the snorkel is the next biggest restriction then the airbox entrance, then the J-boot bend.
As 76 911s said, I'm trying to keep mine as stock looking as I can.
I'll be putting on a 3 or 4" exhaust before enlarging the snorkel because I feel that's my next biggest restriction for spool-up. I think the snorkel is the next biggest restriction then the airbox entrance, then the J-boot bend.
As 76 911s said, I'm trying to keep mine as stock looking as I can.
See, we all see first hand how much difference cold charge air intake makes, yet we still drag our feet on buying/hooking up water inj., which serves the same purpose; myself included. lol However this first snow made me decide to put the car on jacks and get to some back burner projects like installing my meth injection kit. Then even when it is 95 degrees out, the charge air is still 40. So why isn't everyone with a turbo not running one???
Also in regards to colder air, I have seen dyno tests of intake systems and they proved less colder air resulted in more hp than more hotter air. Cold air is key! Hence Porsche using the snorkle, aka cold air intake.
Yes, the restrictions do add up but for me, I like to get the most results for the least cost/work. So the MAF was a 2 for 1 because it gets the afm out of there and the air box all in one swoop.
Also, I agree with going bigger on your exhaust, but I would think you would need to get more air in first, before worrying about getting more out. Because you still have that barn door as a choking point. And MAF's are so cheap now if you look around, then get some chips and you will see a major difference in spool up, throttle response and overall performance.
12-17-2010, 01:50 PM
#22
Three Wheelin'
Eric, the Spec car is in Phoenix now, I assumed that YOU were working on it now.
My AFM is just looks like it's stock, I bored 3" straight through and put in a MAF, so now it's just the airbox and snorkel restricting. After the exhaust, maybe I'll break down and do it more like Eric's with the cone filter in the wheel well, and bigger I/C pipes.
My AFM is just looks like it's stock, I bored 3" straight through and put in a MAF, so now it's just the airbox and snorkel restricting. After the exhaust, maybe I'll break down and do it more like Eric's with the cone filter in the wheel well, and bigger I/C pipes.
03-11-2011, 06:27 AM
#23
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How does Broadfoot relocate their stock flapper AFM ?
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