Ronbo's engine done

[Ronbo]

Well Lance at KC sent my engine package out. I was suprised by the numbers he gave me, check 'em out:





The Mass-flo system is well worth it seeing this... (50hp / 30ft-lb gain over carb)

[Great Asp]

Very nice. Do you have a link on the Mass Flo?

[Ronbo]

http://www.mass-floefi.com/

The FE version is one of the most expensive setups ($4k), but still a great all-round system IMHO.

I'd love to see the 2000 ~ 4500 RPM numbers compaired to a carb. (this is supposed to be the greatest improvement range over a carb)

[RICK LAKE]

Ronbo with some of the great carbs on the market now and a good carb tech, your FI system will be about 5-8 hp less that a carb. This is under dyno room conditions. With the FI system are are getting the best drivibility over all. The other thing is you can get a carb in up to 1,400 cfm's of flow. Most FI systems run a 1,200 cfm throttle body. This is great for street driving but gives away big time to high rpm racing. The TWM setup will beat a carb up to maybe 5,600 rpm after this the carb starts to catch up and pass. Rick L

[patrickt]

Originally Posted by RICK LAKE

Ronbo with some of the great carbs on the market now and a good carb tech, your FI system will be about 5-8 hp less that a carb.

I, for one, would instantly notice the difference between 633HP and 641HP in a Cobra....

[Barry_R]

Back before the marketing BS took over, four barrel carbs carbs were SAE WOT airflow rated at 1.5" of vacuum drop below the throttle while flowing a standard fluid with characteristics that were supposed to be comparable to gasoline. You NEED a standardized vacuum level to establish any comparable flow rating. The 1.5" was used in 1957 because it was 1/2 of the 3" standard previously used for two barrel carbs - - the test equipment already in place would not pull 3" with a four barrel. The value derived is simply a measurement, and is frequently and improperly used to determine the best carb size for an engine.

EFI throttle bodies are rated - it seems - by taking a wild assed guess and multiplying it by at least 150%. Same holds true for many "race modified carbs". There is simply no way that a carb shiner upper can get 1000 wet cfm @ 1.5" out of an 850 base plate on a 750 carb body - - so the wild numbers are guaranteed to be "dry" ratings.

I would guage airflow potential by just comparing throttle plate diameters (and booster/venturi dimensions on carbs). Just remember that carbs are wet flow, and will thus deliver a lower real value than EFI throttle bodies - fuel takes up room. Perhaps 20% of the flow rating....

As to power for EFI versus carb - - we've tried that - - published in Hot Rod in August 2004. Took an EFI converted Dove intake on a 505 inch FE and ran it with a comparable bore HP carb. The difference was in the carb's favor by single digits for power and TQ throughout the curve. The EFI was much better driving in the car though - particularly at idle and part throttle/transition.

[Ronbo]

Well I did leave out the other obvious advantages and expenses I'm eliminating like:

As stated overall drivability will be better.

The system will be continually re-tuning itself instead of me (or a good carb tech at ??? $$$/hr) having to do it.

Turning as much gas as possible into forward motion as opposed to washing down the pavement. More miles per gallon of gas / I get to drive more.

My very expensive engine will last longer, again more driving.

Sure you can possibly pick up a few HP's going with a carb but at these levels I doubt it will have much effect on the volume of fecal matter in my underpants. Not to mention your biggest problem in high RPM racing is the Winnebego - like arodynamics of the Cobra body...

I think it's gonna be a great ride...

[RICK LAKE]

patrickt Pat if you go in the evening on the BMH and cruise you will find that 7hp without any changes to your car. Nice cool heavy air. It's free also.

[RICK LAKE]

Barry R. Barry I have the same setup with the dove converted manifold for FI. They are finding out that the injector location can be worth up to 28HP. The angle down the port is also important. The info not released is which injectors are being used and what the spray nozzles are. The angle on my injectors is 78degrees. If you have the room and can get into the 40 degree range they are finding more power. I also think you have a little supercharging of the port with the fuel being forced out of the injector at 45 psi at a better angle than the one we are running. Rick L.