FAST intake question.
11-06-2021, 04:11 AM
#1
FAST intake question. For "reasons" I am curious to know if changing the angle of entry for the airflow in a fast intake has a significant impact on air/fuel distribution. I do not believe this is a topic that anyone has really delved into on this forum. If I am wrong, point me to the correct thread and I will read until my eyes bleed.
11-06-2021, 01:28 PM
#2
What angle are we talking about here? The angle of the throttle body?
It's the runners inside the intake that smooth out the incoming flow and that happens well after the throttle body flange. If we're just talking about TB spacers that change the angle of the TB I don't think they would have a measurable effect on air distribution. And so long as the runners inside the manifold haven't been altered, the air distribution isn't going to change and therefore the fuel atomizing shouldn't change either.
It's the runners inside the intake that smooth out the incoming flow and that happens well after the throttle body flange. If we're just talking about TB spacers that change the angle of the TB I don't think they would have a measurable effect on air distribution. And so long as the runners inside the manifold haven't been altered, the air distribution isn't going to change and therefore the fuel atomizing shouldn't change either.
11-07-2021, 01:15 AM
#3
What angle are we talking about here? The angle of the throttle body?
It's the runners inside the intake that smooth out the incoming flow and that happens well after the throttle body flange. If we're just talking about TB spacers that change the angle of the TB I don't think they would have a measurable effect on air distribution. And so long as the runners inside the manifold haven't been altered, the air distribution isn't going to change and therefore the fuel atomizing shouldn't change either.
It's the runners inside the intake that smooth out the incoming flow and that happens well after the throttle body flange. If we're just talking about TB spacers that change the angle of the TB I don't think they would have a measurable effect on air distribution. And so long as the runners inside the manifold haven't been altered, the air distribution isn't going to change and therefore the fuel atomizing shouldn't change either.
11-07-2021, 09:03 PM
#4
On this particular application, the throttle body is several feet upstream ahead of a 2.3l whipple blower. The intake has an adapter to allow for air from the air from the FMIC to enter. The current configuration has some interference between the intake for the FAST and the exhaust for the blower. It is still enough to destroy 4l60 parts, but is not nearly what I would expect from the same boost with a turbo. I can eliminate this with a bit of custom cutting and welding, but I have no clue what this will do to individual cylinder distribution.
someone sold me a fabbed adapter that allowed for a 90mm tb. That was a big improvement.
As far as your specific question, I don’t think the angle into the plenum area is critical assuming you are post blower. Specially with a blower that size and a good size plenum like most ls cars have. (Instant boost pretty much)
I would try to keep the opening as large as possible and as straight as possible. Keep in mind how many turns even a stock “side mounted” set up has.
11-13-2021, 02:47 AM
#5
sounds like you are running an older “side mounted” whipple. I had one on my 04 truck and boy it was fun!
someone sold me a fabbed adapter that allowed for a 90mm tb. That was a big improvement.
As far as your specific question, I don’t think the angle into the plenum area is critical assuming you are post blower. Specially with a blower that size and a good size plenum like most ls cars have. (Instant boost pretty much)
I would try to keep the opening as large as possible and as straight as possible. Keep in mind how many turns even a stock “side mounted” set up has.
someone sold me a fabbed adapter that allowed for a 90mm tb. That was a big improvement.
As far as your specific question, I don’t think the angle into the plenum area is critical assuming you are post blower. Specially with a blower that size and a good size plenum like most ls cars have. (Instant boost pretty much)
I would try to keep the opening as large as possible and as straight as possible. Keep in mind how many turns even a stock “side mounted” set up has.
11-13-2021, 07:43 AM
#6
You are correct about the side mounted Whipple. I am one of only a few who has ran one through a proper FMIC. It makes an enormous difference. The original kits were the definition of cobbled together bullshit, but they had the capability of almost anything. I still am not sure if anyone has ever done any proper testing that would answer my question, however. At low boost it would not matter, but when pushed into a narrower tuning window, individual cylinder distribution becomes much more important.
I am not an expert by any means but my understanding is that everything after the TB would count towards plenum volume. Which intake are you running? And how drastic would the bend at the intake be?
Maybe take hints / cues from elbows used for carb style intakes?
the fact that you are feeding from the front and pushing air in , along with good plenum volume (truck intake) may minimize the impact.
would love to see some pics.
my ol truck sure loved that side mounted whipple. Made a lot of heat, but meth helped cool it down. 8 pounds on a 6 liter was a blast to drive.
