Does anyone have first-hand experience with adding a POWERAID or HELIX TBI spacer to a 7.4? I want to know if they are effective and really do provide an improvment in fuel mileage and power. And, if so, how much can be realistically expected?

TIA

Mike

I asked my buddy who had a 96 C3500 with a 7.4. He said he didnt think it really gave a power increase, but maybe a little increase in mileage on the highway, like possibly 1mpg. He felt for the cost, it couldn't hurt. I think the only way you could tell if it gave a power increase would be on a dyno.

I asked my buddy who had a 96 C3500 with a 7.4. He said he didnt think it really gave a power increase, but maybe a little increase in mileage on the highway, like possibly 1mpg. He felt for the cost, it couldn't hurt. I think the only way you could tell if it gave a power increase would be on a dyno.

Thanks for the info. The mileage improvement would be worth the cost of the spacer in short order. The power issue isn't that important to me; the truck has power to spare. Again, thanks.

The Poweraide spacer worked quite well on the 5.7 TBI motor in my 91 Silverado. The spacer gave me a better throttle response on the lower end and with the mixing of the fuel below the TBI unit, it seemed to help the MPG numbers. It, by no means will give you a large unbelievable increase, but it helped overall. It was the best $65.00 I have spent on that motor. Easy to install, too. The biggest improvement that I have done to my truck, to get a fuel gain, was taking the standard fan and fan clutch off of the motor and installing a dual electric fan in their place. This opened up a solid mile per gallon increase and the motor idles and runs smoother. I have Edelbrock shorty headers, MSD coil and 6AL spark control, along with a 4" X 14" K&N air filter and a 3.42 posi rear end gear. The truck gets a good 20 to 21 MPG in daily driving.

If your 7.4 has a TBI unit, then think about the fact that the injectors spray against the butterflies and then the mixed gas and air "Dribbles" down into the intake manifold. The TBI spacer mixes that lazy dribble back up and makes it into an active mist again and helps for that good mixture to get to ALL of the cylinders (even the ones on the very ends of the intake plenum). This is what makes the spacer a worthwhile investment.

My dad put apowerdine on his truck but it was with a chip and a new engine, so could not tell you how well it worked bu I'll be getting one for the suburban soon.

I put the Poweraide on my C3500 dually with the 7.4L. I can say that I haven't noticed much of anything besides the whistle. I don't hear it at all durning normal driving but it really whistles when you require the power. I tow some pretty heavy loads with this truck so it whistles a lot.

Fuel.......I'm still getting around 6 to 8 MPG when I am towing a 32 foot gooseneck with hay bales on it. On its own I am getting about 10 in town and about 12 on the highway. This is about what I got without the spacer.

I think that it did give it a little faster throttle response, but on a one ton dually, does that really matter?

The Poweraide spacer worked quite well on the 5.7 TBI motor in my 91 Silverado. The spacer gave me a better throttle response on the lower end and with the mixing of the fuel below the TBI unit, it seemed to help the MPG numbers. It, by no means will give you a large unbelievable increase, but it helped overall. It was the best $65.00 I have spent on that motor. Easy to install, too. The biggest improvement that I have done to my truck, to get a fuel gain, was taking the standard fan and fan clutch off of the motor and installing a dual electric fan in their place. This opened up a solid mile per gallon increase and the motor idles and runs smoother. I have Edelbrock shorty headers, MSD coil and 6AL spark control, along with a 4" X 14" K&N air filter and a 3.42 posi rear end gear. The truck gets a good 20 to 21 MPG in daily driving.

If your 7.4 has a TBI unit, then think about the fact that the injectors spray against the butterflies and then the mixed gas and air "Dribbles" down into the intake manifold. The TBI spacer mixes that lazy dribble back up and makes it into an active mist again and helps for that good mixture to get to ALL of the cylinders (even the ones on the very ends of the intake plenum). This is what makes the spacer a worthwhile investment.

This is the type of feedback I was looking for. I haven't been able to find any info from the spacer manufacturers that explain the reasons behind their claims, which you've just provided.

I had another fuel-consumption condition (no fault of the truck) that has been corrected which I described on another thread on this board (tbi question, by tedbick). I'm for sure going to order and install a Poweraide spacer on the BBC. Thanks for your reply.

Mike

I put the Poweraide on my C3500 dually with the 7.4L. I can say that I haven't noticed much of anything besides the whistle. I don't hear it at all durning normal driving but it really whistles when you require the power. I tow some pretty heavy loads with this truck so it whistles a lot.

Fuel.......I'm still getting around 6 to 8 MPG when I am towing a 32 foot gooseneck with hay bales on it. On its own I am getting about 10 in town and about 12 on the highway. This is about what I got without the spacer.

I think that it did give it a little faster throttle response, but on a one ton dually, does that really matter?

Throttle response or even increased power isn't a big priority with this truck. It's majorly strong for my needs -- towing a 3500-pound racetruck to and from Bonneville and to and from El Mirage from NorCal, which works out to about six 1800-mile trips a year.

Where are you located in NoDak? I spent one of my favorite years in Stutzman County at the end of WWII where my new step-dad taught me to drive powered machines, beginning with a brand-new 1946 Farmall B -- when I was nine years old. It was great fun for a little kid but a very hard life for grown men. I have tremendous respect for all my grain-farming NoDak relatives.

Thanks for your response. Much appreciated, even though I'm not likely to be hauling much hay.:)

Mike

From my experience, when the spacer is installed after the fuel and air are mixed (87-95 TBI, Carbs), you can feel the difference. When the spacer is installed before the mix occurs (Vortecs 96-now) you are only making the air travel an extra inch. They say it swirls the air and bla bla, but think about how many time the air changes direction after it passes the spacer. The swirl will be gone before it makes it to the injectors.

Throttle response or even increased power isn't a big priority with this truck. It's majorly strong for my needs -- towing a 3500-pound racetruck to and from Bonneville and to and from El Mirage from NorCal, which works out to about six 1800-mile trips a year.

Where are you located in NoDak? I spent one of my favorite years in Stutzman County at the end of WWII where my new step-dad taught me to drive powered machines, beginning with a brand-new 1946 Farmall B -- when I was nine years old. It was great fun for a little kid but a very hard life for grown men. I have tremendous respect for all my grain-farming NoDak relatives.

Thanks for your response. Much appreciated, even though I'm not likely to be hauling much hay.:)

Mike


I am in Cass county living just south of Fargo. There I do some Agricultural work. (grains and soybeans) Then I travel West about 20 miles to a farm just south of Casselton where I have pigs and bulls and horses. We are getting some bred heifers here soon as well that have been AI'd to some nice rodeo bulls. We'll hopefully get something good out of them.

A Farmall B. I would love to have one of them as an extra raking/mowing tractor. My SuperM works wonderfully for this, but it would be nice to have 2 machines going at the same time now.

Now, don't completely "Farm Boy" on us. Grew up with a International 350 Farmall diesel and a 656 Farmall.