rdgfx3
Well-known member
I was "slumming" and found this.Is this safe and/or workable?
This modification was performed on an 87 Vette with approx. 100K on the odometer, a gutted MAF, a K & N air filter, Jacobs 8.5mm plugs wires and Delco sparks that are 2 heat ranges hotter than stock.
I tried this modification and my fuel pressure went from 30# to 40# with only this fifteen second mod. The modification is that I removed the vacuum line from the factory fuel pressure regulator. Also, I capped the fuel pressure regulator connection, so no dirt would get in, and plugged the vacuum line, to maintain vacuum on the engine. I tested the car and noticed a serious change in acceleration. I then took it on the highway, set the cruise for 70 with this mod I was getting an instantaneous reading of fuel mileage of 28-29 miles per gallon. I pulled off of the highway and switched back to having the vacuum line connected. I immediately noticed the power had reduced. I again took the car over the same stretch of highway and the mileage went down to 26-27. I thought the second mileage test would be higher than the first. I checked with my mechanic on this and he said the car is just running more efficiently with the mod than without. One other thing that got better for these test runs with the mod was the temperature of the engine went down. Normally, when the car is warmed up and going down the highway, it'll usually run about 208-211 degrees. With the mod it went to 184-187. My mechanic said that that may be caused due to the cooling effect of more fuel entering the cylinder. I don't know if the temperature differential is going to be a constant, because as you can tell, the tests I did were not scientific in any way. But, I feel there is an improvement, if only in my car.
I was told about this mod. via someone who works on, restores and sells parts for nothing but Corvettes. So I thought I'd give it a try.
Just make sure that the pressure you attain, if you do this mod, is not too high for your system. Of course you can always put a small needle valve in the vacuum line to reduce the press., if necessary.
If it does work,how would I know the pressure I attain would not be too high?
This modification was performed on an 87 Vette with approx. 100K on the odometer, a gutted MAF, a K & N air filter, Jacobs 8.5mm plugs wires and Delco sparks that are 2 heat ranges hotter than stock.
I tried this modification and my fuel pressure went from 30# to 40# with only this fifteen second mod. The modification is that I removed the vacuum line from the factory fuel pressure regulator. Also, I capped the fuel pressure regulator connection, so no dirt would get in, and plugged the vacuum line, to maintain vacuum on the engine. I tested the car and noticed a serious change in acceleration. I then took it on the highway, set the cruise for 70 with this mod I was getting an instantaneous reading of fuel mileage of 28-29 miles per gallon. I pulled off of the highway and switched back to having the vacuum line connected. I immediately noticed the power had reduced. I again took the car over the same stretch of highway and the mileage went down to 26-27. I thought the second mileage test would be higher than the first. I checked with my mechanic on this and he said the car is just running more efficiently with the mod than without. One other thing that got better for these test runs with the mod was the temperature of the engine went down. Normally, when the car is warmed up and going down the highway, it'll usually run about 208-211 degrees. With the mod it went to 184-187. My mechanic said that that may be caused due to the cooling effect of more fuel entering the cylinder. I don't know if the temperature differential is going to be a constant, because as you can tell, the tests I did were not scientific in any way. But, I feel there is an improvement, if only in my car.
I was told about this mod. via someone who works on, restores and sells parts for nothing but Corvettes. So I thought I'd give it a try.
Just make sure that the pressure you attain, if you do this mod, is not too high for your system. Of course you can always put a small needle valve in the vacuum line to reduce the press., if necessary.
If it does work,how would I know the pressure I attain would not be too high?