I had the LUCAS 560 installed first along with the turbo upgrade.The car would not idle at all.Those things were leaking bad at idle and I couldn't do anything about it.The AFC could not compensate and I ended up switching to ND 550s.

 

I don't have first hand experience, but I would think that the disc style would work better. Check out this comparison pic from the DSM Performance website:

http://www.dsm-performance.com/ourinjectors.htm

Supposedly the finer spray pattern on the disc injector leads to better atomization. I will probably buy a set of disc's next time I upgrade my injectors.

 

Thanks for the info so far

Yep, I've seen that pic. I tend to agree, but two things bug me about that pic though...
They could've used different pressures, maybe even a bad pintle injector. "Advertising fluff."
The spray from the disc style injector doesn't even look that "even." Kinda "blobby," lol! (Like a paint gun with not enough air or too much fluid.)

As for the pintle style, lots of previous success with them, lots of high dollar OEMs use them(although that could be bad too, hehe.) I found a webpage awhile back, that stated even BMW was going to ND injectors. That extra $100 will almost get an SX fuel regulator, if you know what I mean.

I guess I'm really curious about the possibility of the faster reaction due to lighter components, supposedly. This might help when at idle and dealing with minimum injector pulse width? Not sure, just theorizing. Nothing specifically about it in the digest archives though. And fourg63's experience doesn't bode well, hmmmm...

 

I read this some time ago and bookmarked it:

http://www.supras.com/~riemer/sonictech/fuel_injectors/RCtech.html

Its a very interesting read, and while it doesn't answer the whole question, we get the the feeling that the Lucas disc type, while being very fast at responding, are not a very good fit in high volume flow rates.

 

Re: Thanks for the info so far

Yep, I've seen that pic. I tend to agree, but two things bug me about that pic though...
They could've used different pressures, maybe even a bad pintle injector. "Advertising fluff."
The spray from the disc style injector doesn't even look that "even." Kinda "blobby," lol! (Like a paint gun with not enough air or too much fluid.)


The injectors are coming from the same fuel "rail" and are the same distance from the pipe leading to the rail (center between the two injectors going up vertically)

 

i've read i think from venom's website that you certain cars come with disc and other with pintle from the factory and you should stick with the same kind if you upgrade or you may have bad results. And those people that are experimenting with high impedance injectors in our cars are probably not getting the best results out of their car because high impedance injectors react slower and are made to be saturated as opposed to peak and hold. Read:
http://www.venom-performance.com/HP Injectors.htm

this page, and tech page 1-3.

 

Re: Thanks for the info so far

Yep, I've seen that pic. I tend to agree, but two things bug me about that pic though...
They could've used different pressures, maybe even a bad pintle injector. "Advertising fluff."
The spray from the disc style injector doesn't even look that "even." Kinda "blobby," lol! (Like a paint gun with not enough air or too much fluid.)

I just checked this site out, and based on the test setup, they are being fed by the same manifold and would consequently be at the same delivery pressure.

I find a few things amusing about the site: #1. it states this is a 550 cc injector being compared to a 450 cc injector. As we all know, the 450 cc pintle stocker, isn't a 450 cc injector unless its at an elevated fuel pressure to being with, so actually its more like a 400-425 cc vs. a 550 cc injector comparison. #2. The dispersion cone on the ball/disc injector is relatively cylinderical vs. conical. A wide dispersement of fuel isn't necessarily the best option, usually you want a nice conical atomization pattern that is aimed at the opening intake valve(s). A wide pattern can cause droplets to be formed along the boundary layer (e.g. the intake runner walls and intake bowls).

So, I wouldn't say the ball/disc is better than the pintle based on their evidence alone. I would like to hear from the experts on the subject, such as RC. I find it interesting that the RC-550 injectors I have are pintle...

 

I read this some time ago and bookmarked it:
http://www.supras.com/~riemer/sonictech/fuel_injectors/RCtech.html
Its a very interesting read, and while it doesn't answer the whole question, we get the the feeling that the Lucas disc type, while being very fast at responding, are not a very good fit in high volume flow rates.

The two paragraphs under "Atomization" are the most tell tale. At least, IMHO, after a quick read through...maybe Mitsu knew what they were doing after all.

Good info dsm4eva, everybody should book mark that page!
Ha, new replies as I'm typing, hehe!

I really tend to agree with FastGSXauto, on the right impedance injectors. Not sure, nor have I played with it, but it just makes sense.

Yeah guys, good call on the same rail feeding the two injectors at the same pressure, I missed that point.

Wow thanks for all the rapid input! I'll stay with the pintle style and spend the extra $100 elsewhere.

 

I wonder what pressure they are running to the injectors, I know it I had the 550 disk type I would be running more pressure the the injector alowing it to atomize the fuel better unless the 550 is at the right pressure and the stock one is being over pressured so it would look better than if it were at the pressure it was supposed to be. I have not started to look into injectors yet but I need to soon, I need 650cc at least, do they even sell pintle injectors of that size? I know Turbo Trix sells some 1000cc injectors just wondering what they would be ball, disk, pintle. whats with the bad rap on the pintle as long as it has the cc reguired and it atomizes well?
good questions

~John

 

Sometimes you dont want the injectors to give a good even mist. A lot of times the engine is designed for other injectors on purpose. Look at the venerable LS1 found in the Vettes. Their injecors are pintle, also have a horrible looking spray pattern, but for a reason. The fuel sprays onto the backside of the valve and vaporizes due to the valves high temperature. If you had a "good spray pattern" you really wouldn't get as good of atomization.

That is why it is suggested that you stick with "stock style" injectors. Sometimes that engineer really knows what he was doing...sometimes not.

 

It would seem that they might be better, but I would like to hear from people that actually use them.

I use them. I can't compare them with the pintle style injectors of the same size (650cc), but don't have any complains or problems with them either. The car idles at steady 750 RPM (just like with the stockers) with hacked MAF, S-AFC and small 16G.

 

I went from stock 450 cc to 650cc ball style. the one thing that i noticed of the bat was that when I started my car it fired right away. It doesn't even turn over once. My stock ones took a couple of cranks and I know that the stocks ones where OK becuase I had them flowed and balanced a couple of months before. I heard that the ball style ones that DSM-Perforemance sells are custom made for the head configuration on DSMs they are not designed to be used on any other make. The spray pattern is large enough to spray evenly into both valve openings but not so large that they hit the walls and saturate.

 

I run 1000cc ball style injectors and can idle at 1000rpm reliably. If I had pintles there would be no way to get the pulsewidth down enough to get a good idle. I can run as low as .9ms pulsewidth reliably and they can sustain high duty cycles. If your looking into bigger injectors I would seriously condsider spending an extra $100 for better idle and high duty cycle capabilites, its well worth it.

 

Hondakiller I thought that you still had the stock injectors. Or is this a recent install?? YOu could run your stock ones to 100% duty will a haltech correct??

 

I installed a big fuel system upgrade about a month ago. It included -8 fuel line from the pump to the rail a high flow fuel filter and 1000cc msd injectors. This upgrade moved my duty clycle from 100% at about 18psi to about 52% at over 20psi. The very low throttle (20-25in mg)and low rpm ranges (0-1500rpm) are pretty rich but for normal driving the injectors are fine. Typically I hit mid 40% duty cycle for 16psi (which is what I typically run on the street). I turned it up to 23psi the other day (it would trail off to about 18psi by 6.5k) and the car hauled an ungodly amount of ass. About 20 minutes later the car blew first gear completely up :-( Damn that thing had some power goin on! I typically run 0-60 in 4.1-4.2 seconds at about 17psi but this felt A LOT FASTER! I'm guessing 3.8-3.9. When I'm running my 4.1's I run with cars in the 108-109mph range(beat c5's form a roll pretty bad). I honestly thing the car has signifigantly over 110mph capability on the 14b. But I'm taking the oportunity to finally install a turbo worth a shit on the car. I'll keep everyone posted once I have the car fixed and some tuning on the new turbo done.
OK enough of my ramblings ......