If NHRA Pro Stock went EFI....

[airflowdevelop]

Darin,
Certainly the plenum manifold works better on the sprints...Most of the guys around are area (dirt track heaven), are scared to dickens of the "light switch motor". The plenum allows the engine to have an abundance of volume, intern when you grab the throttle the power is there. Most of the outlaw guys like the motors "soft" off of the corners so I have been told.

the EFI tech box or less expensive BS3 boxes can control the injectors at higher rail pressure. If possible, you want the injectors in the plenum, 10-12 degrees over perpendicular to the runner. Most of the time you try and get the fuel from the opposing side of the plenum to the injector your are feeding. I would stay away from some of your "mainstream" units when trying to fire an injector with big pressure.

www.efitechnology.com
www.bigstuff3.com

Next time you get on a project like this, feel free to give me a ring.
Dennis

[Darin Morgan]

Next time you get on a project like this, feel free to give me a ring.
Dennis

You bet I will!

[67RS502]

A friend who builds sprint car motors, has done R&D on the MSD high pressure mech. injection

http://www.msdignition.com/2005/2005_15.htm

[Syclone0044]

It's exactly there..WOT that I have to wonder about why the EFI setup in the article couldn't be made to equal or surpass carbs.

Just how much tuning was done on the EFI system? How much time was put into it? Were different injectors tried? Was it just duration time that was altered with the software? What fuel pressure variations were tried with which injectors and at what injector durations?...see what I'm driving at? It seems logical to me that the proper research and testing should yield at least an equalization if not improvement over carbs, no matter what the application is. I don't want this to sound wrong but without knowing the level of tuning attempts that were made to tune the EFI in that article, I can't quite choke down that EFI can't be made to work.

I lean toward not enough R&D being done....

I agree 100%. I read the article at Pro-System (http://www.pro-system.com/scoop92102.html) on carburetion vs fuel injection, and I was left with the impression that the article was really a carburetor sales-pitch masquerading as a scentific review. Taking a further look at the site, I found some reader Q&A http://www.pro-system.com/scoop10_04.html where someone asked which to use for their combination (asked in such a vague manner that I suspect it was a "staged" question) and the "Answer" responds by pointing out 3 considerations, in all of which the carburetor shines (naturally). One experienced with logical fallacies could have a field day with what I would describe as the "commentary" and not "scientific review" provided on this website...

I'm interested in the Fuel Injection vs. Carburetor debate myself, but I'm awaiting a more scientific, and unbiased comparison. I know John Lingenfelter outlined a comparison in his book "John Lingenfelter on Modifying Small Block Chevy Engines" where he engine-dyno tested the same engine with a port fuel injection setup, and then an adapted carburetor on top of the same intake manifold. He found the peak horsepower and torque differences to be negligible, if I recall correctly. (I could find my copy of the book and post the specifics if anyone is interested.)

Josh Straub

[larrycavan]

It's exactly there..WOT that I have to wonder about why the EFI setup in the article couldn't be made to equal or surpass carbs.

Just how much tuning was done on the EFI system? How much time was put into it? Were different injectors tried? Was it just duration time that was altered with the software? What fuel pressure variations were tried with which injectors and at what injector durations?...see what I'm driving at? It seems logical to me that the proper research and testing should yield at least an equalization if not improvement over carbs, no matter what the application is. I don't want this to sound wrong but without knowing the level of tuning attempts that were made to tune the EFI in that article, I can't quite choke down that EFI can't be made to work.

I lean toward not enough R&D being done....

I agree 100%. I read the article at Pro-System (http://www.pro-system.com/scoop92102.html) on carburetion vs fuel injection, and I was left with the impression that the article was really a carburetor sales-pitch masquerading as a scentific review. Taking a further look at the site, I found some reader Q&A http://www.pro-system.com/scoop10_04.html where someone asked which to use for their combination (asked in such a vague manner that I suspect it was a "staged" question) and the "Answer" responds by pointing out 3 considerations, in all of which the carburetor shines (naturally). One experienced with logical fallacies could have a field day with what I would describe as the "commentary" and not "scientific review" provided on this website...

I'm interested in the Fuel Injection vs. Carburetor debate myself, but I'm awaiting a more scientific, and unbiased comparison. I know John Lingenfelter outlined a comparison in his book "John Lingenfelter on Modifying Small Block Chevy Engines" where he engine-dyno tested the same engine with a port fuel injection setup, and then an adapted carburetor on top of the same intake manifold. He found the peak horsepower and torque differences to be negligible, if I recall correctly. (I could find my copy of the book and post the specifics if anyone is interested.)

Josh Straub

Yes, I drew the same conclusion on that article and the point was driven home the more I looked at the web site.

I don't pretend to hold a candle to guys like Darin who work in the Pro ranks for a living. Go visit their website and you'll find informative, non biased articles in the tech section. They're not trying to sell you on a product, they're freely offering their "earned" experience with high performance engines. To me, it's a bit puzzling that EFI is not yet common place in Pro Stock. I do feel the day will arrive though...

Larry C

[shawn]

I was fortunate to be involved with a efi program. I'll preface this by saying it was a few years ago,so thing have definatley changed. After spending a bunch of bucks, we could never get the efi to make as much power, or run down the track as well as carbs. There were a few "big name" efi guys that helped out that couldn't get it better. My non tech conclusion is that you can't make something "artificial" work as well as carb that is working off of the pulses a motor creates. It's like using a pacemaker, it won't work quite as well as the real thing. I agree and can't help but think that with more developement efi will one day be better than a carb in a drag race application, but i just don't see that time coming all that soon. Without have a rule in place that will allow bigger bugets to spend their valuable time and resources on it who will go out and make it a better piece? Just my $.02.
shawn

[larrycavan]

I was fortunate to be involved with a efi program. I'll preface this by saying it was a few years ago,so thing have definatley changed. After spending a bunch of bucks, we could never get the efi to make as much power, or run down the track as well as carbs. There were a few "big name" efi guys that helped out that couldn't get it better. My non tech conclusion is that you can't make something "artificial" work as well as carb that is working off of the pulses a motor creates. It's like using a pacemaker, it won't work quite as well as the real thing. I agree and can't help but think that with more developement efi will one day be better than a carb in a drag race application, but i just don't see that time coming all that soon. Without have a rule in place that will allow bigger bugets to spend their valuable time and resources on it who will go out and make it a better piece? Just my $.02.
shawn

Well said....

[MadBill]

In contrast to my signature, here's some pure opinion, uncontaminated by data:
Someone touched on the point a couple of pages back about cost. Does anyone think perfecting EFI, whether the final result was better, worse or even with carbs would cost anywhere near what has and is being spent on carbureted systems? Typical pix of Pro Stock shops I have seen show discarded mega dollar hand-built carbs stacked like cordwood in the background. Ditto manifolds: What percentage of the average yearly budget for them is going into fuel rather than air management?
Also, what if there was traction control concealed or legally present within the EFI system? Is there a reason why camshaft development is a sacred part of getting down the track first, but electronics development has to be cheating?
My guess is that with unlimited electronics/EFI the same teams would spend the same total $$ and achieve the same overall results, but that the spread from first to last qualifier would get even narrower.

[larrycavan]

In contrast to my signature, here's some pure opinion, uncontaminated by data:
Someone touched on the point a couple of pages back about cost. Does anyone think perfecting EFI, whether the final result was better, worse or even with carbs would cost anywhere near what has and is being spent on carbureted systems? Typical pix of Pro Stock shops I have seen show discarded mega dollar hand-built carbs stacked like cordwood in the background. Ditto manifolds: What percentage of the average yearly budget for them is going into fuel rather than air management?
Also, what if there was traction control concealed or legally present within the EFI system? Is there a reason why camshaft development is a sacred part of getting down the track first, but electronics development has to be cheating?
My guess is that with unlimited electronics/EFI the same teams would spend the same total $$ and achieve the same overall results, but that the spread from first to last qualifier would get even narrower.

The "hidden" aspects of other benefits from electronics might well be something that is holding it back. Consider the recent posts on the BMW V10 engine and it's electronic management system. How much of F1 engine management technology is still left in the shop and didn't find it's way into that new package is anyone's guess. Tech inspections might have to accelerate into a new realm to prevent cheating..

I really have no idea as to what is checked now or the difficulty involved in adding an extended dimension through full open electronic management systems.

As for cost...I don't know..can't really get my arms around a viable reason why EFI development would be extraordinarily expensive in this day and age...and ...like you pointed out...look at the $$$$ stacked up in used carbs and manifolds....

I think there needs to be a distinction drawn between EFI for fuel delivery benefits and EFI with ultra advanced engine management systems. I do suspect one would lead to the other though...

Just my guess...

Larry C

[Torquemonster]

This is a brilliant thread!

moving away from Pro Stock to other applications for a mo...

From what I've understood from Darin and Dennis in particular - the best compromise on current publicly available tech for a dual purpose race motor that needs a very wide power band would be low impedence direct port injectors sequentially fired for low to medium speed and partial throttle use then - a racing carb or two on top of a plenum that siwtched the fuel on as rpms pass a certain point at WOT... lol - a hybrid



I've always wondered what would happen if you developed a decent EFI motor to run at 500+ psi fuel pressure.... I feel that once the safety aspects were worked out, the injector patterns and angles etc - that could give perhaps the best of both worlds - extremely good atomization even at very high speeds and flow rates and the obvious advantages for low speed operation. The problem would be finding injectors that could operate efficiently between such a huge range of flow conditions from almost off to feeding very high power at high speed.

I've definitely started thinking about a piggy back system being a viable way to achieve this - using the usual direct port injectors to a point then having top mounted top end feeds phase in to simulate a carb as well as current EFI can anyway.

A carb may still rule the HP wars in Pro Stock but I guarantee it won't beat EFI for fuel efficiency in dual purpose engines. We have a 950rwhp 500 cubic inch V10 getting close to 30mpg - I'd like to see the carb that can achive that!

[jacksoni]

Easy to have an EFI drive 2 sets of injectors with small, low pressure, shoot at port/valve for low speed to mid throttle application and then 2nd set with bigger, more pressure and set higher up in the manifold.

As has been said before in this thread, engine is just air pump. Design the best carb manifold you can and then the best EFI manifold you can (and they won't look the same), if tuned right, they should make the same power. Problem is making the manifolds match the rest of the fuel system, air flows, air/fuel flows (wet vs dry) etc and that is hard to do so you can fairly compare carbs to injection. Bit too much apples to oranges. JMHO

[motage]

Switching to EFI will most definitely drive up the cost! I can tell you from my experience at Roush from 2 Road -racing programs that I worked on. Here are some of the reasons.

-You will use many sets of flowed and grouped injectors of varing spray patterns probably as many sets as carbs. There will be development on injectors, the latest and greatest will cost plenty.

-All of the diferent sensors have tolerances. These tolerances will require a calibration check and/or recalibration any time anything is changed. I promise that there can easily be 15 hp difference betweeen 2 sets of injectors if both sets don't get a calibration. This calibration is done on the dyno and takes time. What is the lifetime of a P/S engine? You will need a separate dyno just for calbration.

- You had better have your best calibrator at the track with you cause if the weather is different you will have to tweek the cal again. What is his salary? How much will the best cost? Can get a guy who understands or knows the code?

-Intake manifolds will be more complex. There will be a lot of development around things like injector placement, distance, angle and multiples. Better hire another fabricator just for manifolds... salary.

Scoops wont go away either. You will still want to pressurize the induction even if it is slight. Look at the scoops on F-1, IRL and LeMans LMP-1.

[J-Rod]

The argument has always been that EFI was easier to set up than a carb, and it would be easier to find folks who can tune. Unlike a carb which has a precious few folks who are really a genius witha carb. But, I guess when you go looking for those thousandths you can get just as anal with an EFI setup. The issue as I see it is the whole box of worms. You can hide anyhting in an efi (traction control, etc...)

I was speaking with Erik Koenig over at S.A.M. about carb vs EFI. He said in their dyno testing that EFI won where you had a lot of throttle change (road racing, etc...) but in dyno testing a race motor (drag racing) that a properly tuned carb always made more power than an EFI in their testing.

I'll admit I'm partial to a properly tuned EFI especially for a street car. For the forced induction application most especially especially the turbo stuff I don't even think its benefits are in question. But, I don't think a set of Donkey's on a sheetmetal intake are going anywhere anytime soon.

As for raising fuel pressure. You get into the area of a diesel like injector at that point. But, keep in mind a couple of innovate thinkers put the fuel world on its ear back in the day with their innovate digger which ran crazy pressure unlike the low pressure systems their competitors ran. They were a couple of college kids who understood fluid dynamics, and engineering and used it to their advantage.

[craig]

Totally anecdotal:

NHRA prostock bike finally allowed Harleys to run EFI at the begging of a Top Ranking team.

Oddly they won championship the last two years. Also took the crown for first six second bike on gasoline.

For 2006 it looks like the import inline fours will be allowed to run EFI as well.

If it can’t make more power or at least be more repeatable someone should tell these guys they should be going slower, not faster.

[BobW]

As far as the Harleys go, if they didnt get the weight breaks they do, they'd still be sucking hind tit to the Jap bikes. It doesnt have anything to do with EFI. Make em weigh what the Jap bikes weigh and see where they finish.