SPOautos

Hey guys, I've got a rx3 with a carb setup and I'm thinking of bolting up a T2 turbo and manifold I can get for free and fabing a IC using a NPR core. Anyone run a blow thru carb setup on the street? Does it feel pretty good on a street car? Anything I should know?

How did you add fuel? Anyone use a purely machanical fuel compensation method that doesnt require a fuel computer but still works good? Something like a rising rate regulator to add in the fuel?

Thanks,
Stephen

Swolbynos

you can get a regulator that reads vac/boost and ups fuel pressure 1/1 for boost

SPOautos

Yea but that wont increase the fuel, that just keeps it constant. There are some rising rate regulators that are like 1/2 and higher. That way for every psi of boost you get 2psi of fuel pressure....some add even more than that and some increase the ratio as the boost gets higher and higher.

Anyone have any experience with this???

Stephen

SPOautos

Here is a good example of what Im refering too

http://www.1320straightliners.com/Ri..._p/rcc0016.htm


Only prob is that one is designed for efi and the base pressure starts at 30psi.....for a carb I need one where the base can be more like 7psi

Swolbynos

they are usually adjustable.

and i would search in the first gen section. that is where most of the blow through people go

bladz311

iTrader: (1)

I never used it, but my friend has a blow through setup for sale. It was on his turbo 2 engine when he bought the car. It also had a rising rate FMU. I'm not sure what the ratio was. He just wants to go back to stock fuel injection. I could give you his email if you want.

mwatson184

With a rising rate fpr (greater than 1:1) you will flood the bowls. You want the difference in air entering the carburetor, and fuel pressure to be constant (6psi for holleys).

My blow through experience is only in holleys, so I will speak on those. Boost enricment is achieved by enlarging the PVCR's (power valve channel restrictions). The power valve is an on off enrichment switch activated by a difference in pressure (vacuum). The amount of enrichment is regulated by the PVCR's. When you get deep into the throttle, the power valve opens and allows more fuel into the main wells through the PVCR's. Since boosted cars need a richer fuel mixture, you drill the PVCR's (usually to 5/64ths of an inch) to allow for this greater difference between cruise and power AFR's.

I have owned 3 blow through rotaries. My 91 TII got 20mpg on the highway, and was smooth at all throttle positions. After taking rides, people were shocked to find out it was a carbureted car. It's all in the tuning.

-Marques