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Discussion Starter · #1 ·
Can anyone out there tell me why the RC/Lucas 30lb injectors are better than the Bosch/Ford 30lb injectors? I know they are a bit different, and both have their pros and cons (Lucas are disc-type, Bosch are pintle-type).

I've run Ford injectors for years with no issues in high-HP applications.

However, if there is something funky in the sophisticated PCM strategy of the Z06 that could somehow determine even minor differences in injector flow function, I do not want to screw something up.

RC/Lucas = $600+ while I can get a brand new set of Bosch injectors for ~$220.

Also, a number of people seem to be getting away with no PCM reprogramming. Anyone out there install a larger set of injectors and run into problems?

Thanks!
 

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Sorry I can't be definitive, but I think the stock injectors are pintle type.

Haltech says the RC's he uses are blueprinted. I don't know if ALL of RC Engineering's are blueprinted, or if this is a additional cost.

The RCE site is pretty informative and inpressive, but a lot of C5's are running the Ford SVO injectors with a lot of luck and a lot of mods to boot with no problems.

I think one of the main purposes with the larger injectors is not only the ability to flow more fuel, but to lower the duty cycle. with mods and the need for more fuel the smaller injectors are working near ther maximum.

sorry to ramble

:cheers:
 

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Discussion Starter · #3 ·
fyrcaptain said:
I think one of the main purposes with the larger injectors is not only the ability to flow more fuel, but to lower the duty cycle. with mods and the need for more fuel the smaller injectors are working near ther maximum.

sorry to ramble

:cheers:
You're 100% correct...and this is especially true for the '02 cars that have smaller injectors than the '01s.

I've got a pretty good mod list already made out and I'm just trying to figure if I can do it cheaper by buying the parts individually myself, or going with a "package" like the T-1 Sidewinder kit.

If the stock injectors are pintle type then the SVO units should work fine. I have found these injectors to be extremely durable over the long haul in high-performance applications.
 

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WA 2 FAST, I also have a mental list of potential mods, and I am watching the posts on this forum carefully to analyze data before I make a purchase. I appreciate your question as I have wondered the same. I also have considered the T-1 package, but seems to me that with that package you may also need exhaust mods (headers,x-pipe) to complete the system. By the time you do all those mods, I have to consider the option of supercharging. Many more horses, cost around 6-8 grand. Or would that be going to far??? These questions confound me, and I ponder them often.
 

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SVO's are essentially the same (pintle) injectors that are already in the Z06, just not as loud. If you add an intake, the A/F ratio should become lean. Then when you add the larger injectors, the A/F ratio will become rich. You will need to tune in the A/F with a MAFT and a scanner (Ease or AutoTap). No need to completely reflash the PCM. Allot of extra hp will be found when everything is tuned in just right!
 

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I have had the SVO injectors installed for about a month or so, no problems. I did a idle relaern that's it. Now I have a MAFT and it just gets better. I did this due to the Blackwing issue, which I ahve yet to see proof on paper, only theory. The blueprinted inj. vendors are selling may very well be better, but for the money I went with the SVO. I would love to only use the best of the best but I am not a racer and can't see blowing half the cost of a good set of headers for these. Anyway, I am so far having very good results from this package and I am still dialing in. I hope to have dyno sheets soon.:D :z:

BTW the Ease scanner I have plays a key roll in all of this. I would not tune on a dyno.
 

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Discussion Starter · #7 ·
02ZO6 said:
The blueprinted inj. vendors are selling may very well be better, but for the money I went with the SVO. I would love to only use the best of the best but I am not a racer and can't see blowing half the cost of a good set of headers for these.
This was the reason behind my question. :D

First of all, I wouldn't be quick to claim that the RC injectors are "better" in any real way. I have a set of pintle style injectors on my '90 Mustang. They are 50lbers. They work great and safely supply the engine to insane power levels for a street car. In fact, there are some disadvantages to a disc type injector.

I'm not saying one is better than the other, though. But if the SVO 30s will work perfectly, then its kind of a no-brainer.

MOUTAINWOLF...I'll send you a PM today and maybe we can discuss this offline. I'm going to go with a small/conservative nitrous shot. FWIW, I'm a big fan of centrifugal blowers. I've run one on my '90 Mustang for over 8 years (Vortech), and I've installed them and tuned them on a number of late model Fords. I've also been the nitrous route and have my own convictions on going this route on the Z06.

My goals are pretty simple and I believe very attainable. 385+rwhp on motor, and ~490+rwhp on nitrous...using 93 octane fuel.
 

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Discussion Starter · #8 ·
pc1663 said:
SVO's are essentially the same (pintle) injectors that are already in the Z06, just not as loud. If you add an intake, the A/F ratio should become lean. Then when you add the larger injectors, the A/F ratio will become rich. You will need to tune in the A/F with a MAFT and a scanner (Ease or AutoTap). No need to completely reflash the PCM. Allot of extra hp will be found when everything is tuned in just right!
Do you have any experience with Halltech's AFC2 unit? I know the MAFT is cheaper, but is it better/more effective?

Please realize that I'm new (but learning fast!) to GM EFI tuning, but consider myself way down the learning curve regarding late model EFI stuff in general (I just have played with Brand X cars before this purchase). ;)

My car will not stay stock past the 500 mile break-in period, but I'm also not planning to build a bottom end or do heads/cam right away.

Thanks for the help!
 

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WA 2 FST said:
Can anyone out there tell me why the RC/Lucas 30lb injectors are better than the Bosch/Ford 30lb injectors? I know they are a bit different, and both have their pros and cons (Lucas are disc-type, Bosch are pintle-type).
There are four reasons why the Lucas/RC Engineering injector is superior to the Bosch: 1) The Bosch is an old design more prone to fouling than are the Lucas, 2) The Lucas is a rotating disc type of injector and that type of design usually results in a small improvment in the injector's ability to respond to changes in duty-cycle and that, in turn, improves throttle response 3) Lucas injectors have all stainless steel internals so there is absolutely no possibiliy of corrosion due to any moisture in gasoline and 4) Lucas injectors typically are very closely matched in flow right out of the box. Mix-and-match to get a set of eight that flow the same is almost never required.


(snip)
However, if there is something funky in the sophisticated PCM strategy of the Z06 that could somehow determine even minor differences in injector flow function, I do not want to screw something up.
If your LS6 is stock or near stock why do you want to change to a higher capacity injector? It probably doesn't need the amount of extra fuel a 30 lb/hr injector can supply. When you put oversized injectors on an engine you have problems with light load and idle.

On the other hand, if you have a highly modifed engine, with air flow capacity that's been significantly increased, then you might need a higher capacity injector. Before I'd buy, I'd find out exactly how big an injector size increase you need. Injector experts, such as RC Engineering, can offer consulation on that.

FYI, My 1995 ZR1 has a 500 hp (95 hp above O.E.) LT5 and it ran best with RC injectors only one flow step above stock.
 

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Discussion Starter · #11 ·
Re: Re: A definitive answer on the different brands of 30lb inj?

Hib Halverson said:


If your LS6 is stock or near stock why do you want to change to a higher capacity injector? It probably doesn't need the amount of extra fuel a 30 lb/hr injector can supply. When you put oversized injectors on an engine you have problems with light load and idle.

On the other hand, if you have a highly modifed engine, with air flow capacity that's been significantly increased, then you might need a higher capacity injector. Before I'd buy, I'd find out exactly how big an injector size increase you need. Injector experts, such as RC Engineering, can offer consulation on that.

FYI, My 1995 ZR1 has a 500 hp (95 hp above O.E.) LT5 and it ran best with RC injectors only one flow step above stock.
Hib,

I appreciate the informative reply. From my understanding the '02 model cars actually have smaller injectors than the '01s and run an awfully high duty cycle right out of the box. Seems that many guys are just bolting on intakes and seeing the duty cycle increase to over 85%.

I have asked people on this board over and over if running a slightly larger injector requires reflashing the PCM or a recalibration of the MAF (in order to bring back stock-like driveability) and the answer has been a resounding "no", that the stock PCM does just fine with a 30lb injector.

Trust me, I do not want to fight driveability demons here.

My goals are to get an additional 30-35rwhp on motor and then I plan to spray it with a small shot of nitrous (which doesn't really require larger injectors to safely do...but they can still be of benefit).
 

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Wow, don't see Hib around much, but you've got to listen when he speaks. Good info on the RCE injectors and disc vs pintle. I learned something and thats a good thing.
thanks Hib!

:cheers:
 

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WAY 2 FST, I have no experience with the Halltech AFC2 unit. But it seems to be essentially the same thing as a MAFT, the only advantage I have heard of is having the ability to tune from within the cockpit of the car. If this is in fact the case, the advantages of the AFC2 over the MAFT doesn't, to me, justify the cost difference. Contact Jim Hall via e-mail and he will gladly tell you every thing you need to know about his product so you can make an educated decision.

I will say this, when you add an after market intake, if it is working properly, your A/F ratio will be leaner than stock. Your injectors, particularly '02 Z's (26#), will most likely exceed 80% duty cycle because of this condition, thus increasing the chance of injector "fouling". In order to lower the duty cycle (and increase injector performance/reliability) you must increase to larger injectors (30#). The larger injectors will make your A/F ratio richer than stock. You can use a scanner throughout this process to verify. A MAFT will allow you to adjust the air flow measurements BEFORE they reach the PCM, thus "fooling" the PCM into supplying the proper fuel input without actually reprogramming the PCM. But remember, this cannot accurately be done without the scanner, and it takes several adjustments to get it exactly right.
 

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:-? If I may comment and what i'm reading here. i'm not sure about the z06 PCM but it is an OBD II computer. this is simular to what the camaro guys have. if your sticking 30# injectors, of different manufacture than factory, and this is a different fuel delivery rate than the factor injector you have to reprogram the PCM for a 30# injector. you also have to consider the injector offset and injector constant for that particular manufacture. since your/our PCM is programed for a 26# injector (i believe that is what a z06 has) and you use a 30#'er , the PCM is pre-programed to pulse the injector as a lower volume 26#, when in reality your using a 30#'er. More fuel (richer running) will be the result. The PCM and the O2's will not orrect for this. Injector offset, is the lead time for the injector to fully open. Different injector have different lead time and injector constants. Injectors made by different manufactures, measure their flow rate at different pressures, lucas at 45 psi and gm multec at 43.5 for example. My point is, just becareful here. the z06 motor was very carefully planned by GM and unless your going with better flowing heads and a bigger cam, i'd leave the injectors alone and look at other areas to improve your performance if that is what you want. good luck.
 

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Discussion Starter · #16 ·
carl97ss said:
:-? If I may comment and what i'm reading here. i'm not sure about the z06 PCM but it is an OBD II computer. this is simular to what the camaro guys have. if your sticking 30# injectors, of different manufacture than factory, and this is a different fuel delivery rate than the factor injector you have to reprogram the PCM for a 30# injector. you also have to consider the injector offset and injector constant for that particular manufacture. since your/our PCM is programed for a 26# injector (i believe that is what a z06 has) and you use a 30#'er , the PCM is pre-programed to pulse the injector as a lower volume 26#, when in reality your using a 30#'er. More fuel (richer running) will be the result. The PCM and the O2's will not orrect for this. Injector offset, is the lead time for the injector to fully open. Different injector have different lead time and injector constants. Injectors made by different manufactures, measure their flow rate at different pressures, lucas at 45 psi and gm multec at 43.5 for example. My point is, just becareful here. the z06 motor was very carefully planned by GM and unless your going with better flowing heads and a bigger cam, i'd leave the injectors alone and look at other areas to improve your performance if that is what you want. good luck.
Carl,

I understand and agree with everything you say here. Trust me, I've been modifying late model EFI cars for over 10 years now.

The only reason I thought it would be ok to swap to a slightly larger injectors on these cars is because of what the people on THIS forum have said.

"Oh, you don't need to reflash the PCM. It adapts just fine." Or, "I don't get any codes and the car doesn't run rich." You get the drift.

From my understanding the '02 models actually come with smaller injectors than the '01s (which doesn't get around your point about having to reprogram the PCM for optimum performance with a larger injector). But, I've heard a number of stories of people getting just a filter/intake tube kit and then seeing the car run a bit lean on the top-end.

I'm going to do my mods first and get concrete A/F ratios (and check the plugs) for my car before I swap in a larger injector. My mind is still a bit boggled at how the stock PCM will learn around a larger injector so quickly so as to not cause idle/part-throttle driveability issues...but, there's a lot of people here who are convincingly saying that it indeed does do this.
 

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Wes, Being very very carefull were you get your advice is the best idea. There are Rams,sheap,and lambs sniffing around the sheep. Take the time to call one of the rams.(LPE,ARE,ect.) Takeing some of the imfo found on the fourms could be costly to YOUR car. Talk directly to one of the engion builder tuners not the wantabee's. JMHO Ric
 

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Discussion Starter · #18 ·
Ric,

That is great advice. Over the years of the ever evolving Internet I've come to the same realization myself.

Being new to the GM side of things, many times I give more credence to this stuff than I should.

My experience and common sense says that what carl mentioned is correct. I just hear reports that this particular mod works with basically no problems. :-?

Trust me, I will continue to research this.

Thanks.
 

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I just wanted to give a point of reason. the LS6 is a potent engine and i know GM spent alot of time on the PCM on the '02 Z06. I'd hate for you/us to ruin an expensive package for an extra 20 rwhp. Any experienced tuner will tell you, that GM has done a good job on their programs lately. I'm not going to say they can not be improved on a car by car basis, but, all cars may not respond well to a change that did well in another car over the long run. My experience with mod ideas from the net has not been good. alot of unintentional mis-information. what appears to work for several cars may not work on the other 5000 in the production run....smile. yes, we may be able to tune 20 rwhp without a PCM correction and everything may appear good, but after 10, 20 or 50,000 miles what damage may it have caused?? Fuel wash?? clogged or burnt out cats?? over the long term, a burnt piston ?? My feeling is that a factory set up is setup to have a long life. if i want more RWHP, i do it the old fashion way in this hi-tech time. we have an air pump and i increase it's efficientcy, sometimes that means more cubes, porting, intakes, headers, exhaust,& cams. and sometimes i need better internal parts and the proper PCM re-calibration by someone with a great reputation. You got a nice piece here, let's just becareful and have fun. :roll: :roll: :cheers:
 

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Discussion Starter · #20 ·
Carl,

I agree with you wholeheartedly. No matter what mods I do (and I don't plan to go into the motor yet), I will feel a lot better if the PCM is reprogrammed...should the mods throw something out of whack.
 
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