Need schooling on fuel injection

Had a lot of fun racing this year....... its kinda gotten back in my bones after a few years of either not having a car, or having a car and not racing much.

Anyhow, considering several changes to my car in the offseason. Little more speed, fixing potential trouble spots( rewiring car) etc, etc.

If you were going to get fairly serious about bracket racing( to me that would entail racing points series at local track) would you consider fuel injection?
Will definately be running gas.

Would car be more consistent wifh FI...... regards repeatibily and fluctuation on a given day
Would car be faster or slower with it
Who makes the best/ easiest to set up system for typical sub 600 horse car. Say 500-600 “ true horsepower”

Thanks in Advance

If I were considering spending a lot of money on an engine that I already had I'd look seriously at fuel injection.
If I were looking for consistency round-to-round and day-to-day that would be another reason for FI. The closed loop using a wideband O2 sensor tunes itself. It tunes itself to whatever parameters are stored in its memory. If a low comes through or the temperature changes drastically the FI will account for that. Maybe bracket racers don't rejet during an event, but it's nice not to have to worry about A/f ratios. (Thumper is starting to get red in the face about now.)

A well set up carburetor can equal or exceed the power from the same engine with FI. That is, it will exceed when the air conditions equal the conditions for which the carb was set up.

On the other hand, if the carb is set up incorrectly or the boosters are such that one needs to run a smaller carb for driveability, then the throttle body EFI allows for much more "carb".

If I were picking a fuel injection system I'd definitely spend more money and get more features, also expandability. For example I like the idea of the computer setting the timing, especially as the distributor machines are being sold on Ebay as antiques. Datalogging is nice to have. Playback can highlight some problems. I can see even putting in a G-sensor.

At this point I'm undecided between throttle body and port injection. I believe that throttle body costs less and allows you to use your current intake manifold. On the other hand, port injection should reduce the fuel distribution issue, maybe eliminate it.

At the latest SEMA show K&N showed a plate system that uses an O2 sensor to add fuel when the A/F ratios go South. It seems like a crutch to me, but it is also an option to consider.

R.

Holley Sniper with the Hyperspark distributor would be very cost effective. You could sell a race carb and a MSD setup and pay for most of the Sniper kit. The Sniper is good for up to roughly 700 hp. You'll need a good high pressure pump and a return line.

The Sniper (buy the Super Sniper) has data logging capability so you can review your runs. The Hyperspark setup lets you control ignition timing with the computer so you get built in start retard, high speed retard, and the ability to build a custom timing curve.

https://www.hotrod.com/articles/holley-hyperspark-install-tune/

My only real concern in a footbrake application would be whether the TBI would/could provide a clean, hiccup free “hit” from a low-ish launch rpm every time.

Port EFI also allows you to use (dry) manifold shapes and plenum volumes that would cause fuel droplet fall-out with a carburetor.
A TB system will have the same mixture distribution problems as the same manifold with a carburetor (almost any dual plane will have this). Is your current or planned manifold known to flow all 8 very close? A port system will improve this if it allows individual cylinder adjustments.

The Sniper has several different AE tables so you have more tuning capability with EFI than you do with a carb. On a carb you have pump shape, pump size and shooter size. The AE tables in the Sniper allow you to adjust fuel based on TPS %, TPS rate of change, MAP rate of change, etc. You can also modify these tables based on temp.

The average bracket racer might need to do some research before understanding their way around the tables, but the capability is there to provide a very smooth AF ratio on launch.

Having not played with any aftermarket TBI myself, I can’t say how effective those adjustments are...... “at the hit”.

With a carb, it’s a mechanical connection to the accelerator pumps.
Open the throttle, and while the lever is moving, fuel is coming out.

With EFI, the computer has to assess what the sensors are reading, and make the call to add fuel.

Perhaps the aftermarket has improved this characteristic over how the oem stuff performs in that regard.
Any oem EFI equipped vehicle I’ve ever driven has a momentary hesitation going from idle, or barely above idle, to wot.......with the type of rapid foot action you do when you’re trying to cut a light.

Perhaps the EFI footbrake racers will chime in with their experiences.

If you’re running a combo where you’re loading up pretty high against the converter, it’s probably less likely an issue.
But my car used to ET better when leaving slightly above idle.

Good observation. And i am a foot breaker. Leave at a repeatable 2k
On pro tree 3k, buts thats one weekend a year at Norwalk.
I dont want to change that because everything else i do is based off that

I run the Holley multi point injection and there
is zero lag..the injectors are right at the heads
so any distance is gone..never had any issue of
that nature.. I can blow the tires off at the hit

I have been real happy with mine. As complicated as it is it also keeps things simple and easy. It runs the fans, water pump, ignition, and fuel pumps. I just have a key for ignition and a starter button the rest is handled by the ECU.

Pictured with a celebratory cold one after drag week.

Excellent choice on the Yuengling!

Yes it is. Until earlier this year it wasn't available in KY, or at least my part of the state.

It is good stuff and not yet available in my home state, so I make sure to import some whenever I have the chance!

EFI also allows small spans of RPM, vacuum, etc. (like when the exhaust wave returns more than once) to be adjusted separately, as you would with emulsion tuning blocks in a Holley, except without getting wet. In many systems you can save multiple programs and try them back-to-back as straight A>B swaps without changing atmo and track conditions.

The closed loop will allow the system to adjust, but for consistency, I would turn it off once the system is dialed in.

Also the availability of built in data loggers, high resolution spark/fuel tables, no more spilled fuel...lol

If you want to get more advanced, you would also have the ability to have temp/pressure dependent timing corrections, i.e. pull timing in good air to run the same number no matter what the conditions are...this would take some track time to dial in, but could be deadly.

Yes, except for one evening I think we were able to one of these with dinner.

Let me dispel a few misnomers about efi...Even port injection benefits from good balanced air flow. It means less tuning to get things right and plugs look better. Improper porting or bad or uneven air flow can be made to work with efi, but efi does not fix it.

TBI's work really well too. Get the squirter shot right and target AFR, and mine repeated back to back within .03s of a well tuned carb.

What does inprove, drivability, cleaner plugs, cold starts, data logging......It also lesson some of the finicky tuning for perfect AFR..EFI will maintain this level of tune all the time.

What "misnomer" are you referring to?

I suggest remedial English, and remedial manners.

A port system doesn't improve it, it doesn't fix it, it doesn't make it go fast.......All it does is allow you to match the fuel to the air flow for that cylinder so you don't foul out the plugs on the worst ports. You don't want bad port flow... . You want even port flow, wet or dry. It makes just as big a difference in efi as it does with a carb to port match and fix any air flow issues.

So if your only goal is to poodle around at car shows, port injection is fine with a intake that has bad port flow.

Apparently telling the truth is bad, and now the name calling starts...Nice. Bet your neighbors love you being so well mannered and versed in English...

By "the truth", of course you mean your opinion?
Must have missed it - what name did I call you?

Don, just see what the guys who are consistently winning the big bracket races are doing. You know the heavy hitters at 131, take a survey. The thing I notice with some of the people I know, methanol.

Most if not all are carbs.
Probably more involved with FI to bracket race than i might want to deal with.
Interesting hearing everyones thoughts. Very good information.

I'm not 100% sure that EFI is more consistant then a carb.

Anything is going to change HP with weather changes (EFI or Carb). As long as you have a way to predict that and change the dial in accordingly, that's what's matters most.

So if an EFI motor automatically corrects fuel curves for a big air swing, is that really better? Or does that just mean you're going to have to move the dial in further then usual?

If you were going to index race, I could see where being able to have timing curves adjust for weather conditions as advantagious. That way you didnt' have to move throttle/timing/shift points/weight around to hit the number. But that seems like a lot of work, and probably YEARS of data collection before you could do that well.

I can tell you my scat pack challenger is absolutely horrendous to bracket race with. Couldn't run a consistant number to save it's life over the 70-80 passes I've put on it this summer.

But in all fairness, that is a lot more complex system then what we're talking about here...so not really apples to apples.