Dommination of FI cars.

[Speedracer]

From reading the rulebook,I have another question.In the STOCK section,under carburetor,it says that replacement carburetors are permitted provided they are the same model,type,throttle bore,and venturi size.
In the fuel injection wording,it says larger fuel injectors permitted,provided no modifications or redrilling of manifolds is performed.My question is this:Why are larger fuel injectors permitted?
I'm sure there is absolutely no performance gain with a larger fuel injector,so why are they permitted?
Its not the same logic as changing to a larger jet in the carburetor,right?

[Chad Rhodes]

Originally Posted by Speedracer

From reading the rulebook,I have another question.In the STOCK section,under carburetor,it says that replacement carburetors are permitted provided they are the same model,type,throttle bore,and venturi size.
In the fuel injection wording,it says larger fuel injectors permitted,provided no modifications or redrilling of manifolds is performed.My question is this:Why are larger fuel injectors permitted?
I'm sure there is absolutely no performance gain with a larger fuel injector,so why are they permitted?
Its not the same logic as changing to a larger jet in the carburetor,right?

actualy it is the same as changing the internal metering in a carb, although EFI can "back up" from the max flow rate, where a jet or oriface cannot.

[Paul Neal]

As power/performance increases, the "pulse width" (the amount of time the injector is injecting fuel) needs to be made larger. The options, then, are "small" injector with a "large" pulse width; or a "large" injector with a "small" pulse width. It relates to the efficiency of the injector, which as I understand it drops off as you continue to increase pulse width. The use of larger injectors allows the user to keep the injectors in their "sweet spot".

[Speedracer]

I'm not going to get into ANY kind of arguments with anybody,but telling a Stock racer (that reads the rulebook) that he needs to use the correct venturi size on his carburetor is not really fair when the car in the other lane has fuel injection.Thats all I'm going to say.

[Jeff Lee]

A carb meters air & fuel and so does an FI system. I've been able to alter A/F ratio's on a carb (on an engine dyno) along with BSFC numbers to my satisfaction in both Stock and Superstock. And that's using a 4300 Autolite; a carb with no secondary jetting or metering rods. And I would be willing to bet most small block cars (as I believe all the FI cars in S/SS are running a small block) cars have more carb than they need (i.e., T-Quad & Q-Jet). So I could care less about injector sizing or even spray pattern. I would think the tip-in of an automatic transmission FI car would be easier to manage as your not dealing with pump shot and secondary air-valve opening rates. But all those "problems" have been solved bythe sharp tuners.
The bottom line is (like Evan Smith said), they all perform the same functions just in different ways. Some can't even figure how to tune a carb so don't knock a system such as FI when you would be even more lost! I predict there will be more heads up runs in '08 and I agree whole-heartedly this is the best way to go along with counting more runs. The fast cars will be forced to show their hands and the HP factors will adjust accordingly. I would love to see a maximum weight overage also; either 100#'s or must race at next higher class; no 300# overweight cars.

[Alan Roehrich]

The booster venturi is NOT the same as an injector. Nor is the venturi itself. Changing a fuel injector is the same as changing a jet. A fuel injector DOES NOT change airflow (not by itself, unless it protrudes into the air stream, and most do not). Changing a booster venturi will change AIR FLOW, as well as changing HOW fuel flows. The reason you are not allowed to change the booster venturi is because in many cases you can change to a booster venturi that will allow you to flow more air. The amount of misinformation and disinformation disseminated by people who have no idea what they're talking about is amazing.

Fuel injected cars (SOME of them anyway) will have an advantage, at least to begin with. The way to fix that would be to force them to trigger a review with the AHFS. If you take your carbureted car and go home and whimper, it'll never change. If you go race them and make them show their hand, it might just change.

[Larry Munk]

Hows about this one Boys and Girls. Everyone with a small block gets a 750 Holley and everyone with a big block gets a 850 Holley and everyone gets an aftermarket intake. As someone who is working with a fuel injection combo I'd like to not have to do all this programming stuff forget the $500 tuner or the $1200 aftermarket computer system, leave the $1500 laptop at home too. BY THE WAY LET EVERYONE HAVE A 350 SMALL BLOCK AND JUST CALL IT CRATEMOTOR. The guy with the 2 second tune-up should be easy to find in the pits too, he's towing his stocker with the Brinks Truck.

[Gary Smith]

Although not very detailed, there is a really good EFI article in the current Car Craft rag (Feb 2008 issue) on page 50. In reality, if you can wire a car, you can set up an EFI system. To support what Evan Smith pointed out earlier, there are advantages AND drawbacks to EFI systems. Same goes for carb engines. The trick, no matter what you run, is knowing how much fuel to apply based on what the engine is doing. THE ONLY ADVANTAGE OF AN EFI SYSTEM is it's ability to add or take away fuel throughout the RPM/power range based on engine load and oxygen readings. I run a simple speed density system without an O2 sensor (runs in open loop). The "tuneup" is just like selecting proper jetting and power valve choice on a Holley style carb. Matter of fact there are carbureted cars out there using sophisicated wide band O2 sensors that are tuned better than many EFI cars. Then there are those EFI cars that run better than many carb cars out there due to the amount of time and "homework" the driver/builder/tuner has put into the setup. So in the end, it's still all about rated horsepower. Induction properties will always be proportional to the limitations of the intake system, whether carbureted or EFI. Simply put, it all comes down to combination choice.

[Billy Pires]

Originally Posted by Alan Roehrich

Fuel injected cars (SOME of them anyway) will have an advantage, at least to begin with. The way to fix that would be to force them to trigger a review with the AHFS.

the LT1s just got hit with 5 HP (336 to 341) and we were at 325 when we were kicked out of the traditional stocker classes and given our own classes because of the bitches. So dont say "the AHFS needs to do it's job", i think it's working out just fine. And DONT tell me the 396's havn't made any more HP than they did when we were given our own FI classes. Since Top Stock became popular in D1, i've seen some really fast runs out of carburated cars, including mopars and fords.. not just 396's. Do any of you monkey's even race against LT1's or LS1's, or even the older TPI cars? Propbably not, especially that dope, GALE FORCE. haha nice bogus name you homo. The best part about this thread is the title, "domination of FI cars" when we havn't even raced together again in the traditional classes yet. Perhaps Gale Force is the second coming of Nostradomus?

[Rich Biebel]

Billy you forgot to mention that genius Speedracer.......he loves to make little comments that insinuate this or that and probably races a Matchbox car........but it don't even run the index.