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SignUp Now!Refer to post #3.hello people: tell me what do youz think of the ported ones on a stock engine and turbo.
IBBY
Tim when you flowed your 70 with alky did it have a air distribution plate on it?IMHO, the more alky you spray, the better the alky distribution will be in the manifold.
The air out of the 70mm TB will be moving slower than a 62mm.
The air / alky has to turn down 90 degrees into the plenum from the TB.
The air then has to turn another 90 degrees into the ports.
Alky is much heavier than dry air.
It cannot turn as fast as the air does.
The alky HAS to stack up in the back of the manifold.
The reason the dyno doesn't see a HP difference is because the "happy" tuning range on alky is many times larger than gasoline, so the air/alky ratio doesn't make much difference. But it is there, the difference in air/alky ratio from front to rear cylinders.
If you can make enough HP by throwing more boost and alky to the motor, then don't concern yourself with this. If you want to make more HP with less boost and alky, then there is HP left on the table.
Since I am an old analytical bastard that has lived on a flowbench for over 40 years, I have done some experiments with stock and ported TBs, as well as the 70 that I have on my car.
I took the output from my flowbench and ran it thru a combo of TBs, up pipes and required reducers. I measured the differences in flow in the runners individually with each combo, with and without the correct port plates for the combos.
Then I added flowing alky too. Yeah, it was messy all over the driveway, but even without measuring the flow, I could see that there was more alky coming out of the rear ports.
To each, his own thing.....
I don't race anymore, but I run a 70 on my street car anyway.
Mebbie I just over think things.....
TIMINATOR
When we pull the plugs with the rjc plateAlky is much heavier than dry air.
It cannot turn as fast as the air does.
The alky HAS to stack up in the back of the manifold.