Round II Fellas
 

Here we go again.....Getting conflicting info else where. I want new injectors. I DONT want HUGE power gains. Just a LITTLE bump. Im not looking to be a dyno king (especially with these crazy D-maxes and Cummins guys) but I do dyno OCCASIONALLY. I do drag race OCCASIONALLY. Just to support events. It IS my DD and the family wagon. I will be towing an 11,000lb+ trailer. But most of all it is my DD and it has PMRs. Id rather not replace my turbo unless I really have to. No way would I ever have the cash flow to fix a windowed motor(get a new one) if that were to ever happen (knock on wood). So Im being very cautious. SO which injector should I get?

I made some phone calls and the 175/146 single shots fit my needs. Now, some other people were saying small Hybrids are they way to go and even stage 1's. What the heck is a stage injector? But it seems that hybrids are for big HP gains. I dont want that. I know its all in the tuning but the way I see it is, if Im gonna spend a lot of money on something Im gonna want to use its full potential. I know the 175/146 injectors have potential but not as much as the Hybrids.Guys, help me out. PLEASE......

I understand your frustration.
I'm laying out the path to upgrade my injectors early next year and I am doing the research. My '97 is a forged engine, but I too want to concentrate on towing and manageable egts.
I am going to talk to Swamps and Beans when the time comes. I know that both of them will point me in the right direction, sorta looking at AC code injectors right now.
Stage just means a performance level, 1 is frst step, two is more, 3 is much more, etc.
Ask around, concentrate on meeting your needs not someone elses.
You'll be fine.

This is a good question and one that really doesn't get addressed very often.

I will be putting together a full article on the basic differences between injectors and how they vary from company to company.

Stay tuned... :)

From the RDS website

Stock = ~98cc

Stage 1 = 160cc and stock nozzle

Stage 2 = 160cc and larger nozzle

Stage 3 = 230cc and nozzles 100% over stock

If all you want is a little get up n go with no plans for more powah down the road just get a single shot stage 1 injector. That's all I got and with my rig I tow a 22.5K trailer with no real issues.

Where I think some of the problem is that some may call 160cc/30% nozzle injectors Stage 2 and others may call 175cc/30% larger nozzle injectors Stage 2.

Then you get into Hybrids, Mini-Me's, 530's, and all that other fun stuff.

Just to let folks know, I will be talking to the following:

Rosewood
Swamps
Casserly/Beans
Dynomite

I want to get final specs on each of their injectors. It's late and I'm tired (running on 3 hours of sleep). If there's anyone I'm missing, let me know.

Take care.

Bill for what it is worth an article on the injectors for those of us trying to learn would be very much appreciated, by me for sure.

I second that Bill. Its hard finding info when people are so biased towards a single product. I have had a bunch of replies and PMs saying I should go with this one and not that one. Its aggrivating. And when I ask WHY, all they say is oh they are so much better. Seriously!!! How many different ways are there to build an injector??? Why is one injector better than the other???? What is this mystery all about???? And why cant some people understand that not everyone want HUGE HP..... I happy with what I got!!! All I want a a bit more than stock....But safely!!! Well I got that out of my system, much better....I think I might just go get a Cummins!!!!


































JK......

you should be able to see some MPG improvements with the right injector/tune combo too... hopefully Bill can speak to this in his upcoming injector article:2thumbs:

AHHHHHHHHHHHHHHHHHH! My bleeding ears! :eek:

:smiley_roll1:

I know.....I just couldnt do it!!I would catch so much crap if I did that!! Especially after all I have done to my truck.....NEVER!!!!

OK....After reading the injector article more than 3 times it looks like the 175/146 single shots will be fine (Stage 1.5) on my PMR truck. Just a tiny bit more than stage 1. So Hybrids are a no go on a daily driver due to the high oil pressure requirements?

Bill, can the 175/146 single shots (if I choose to get them) be tuned to safely give me a bump in power, tow 11,000lbs+ , with minimal risk of hurting my baby? I think thats it....:shrug:

Dan,

Here's the deal... We can tune injectors down (within reason) to any level that we need to maintain good driveability characteristics and keep the engine power output levels within the capabilities of the hardware (block, rods, etc.).

175's on your truck will be absolutely no problem to tune and shouldn't be any more of a concern than stock PSD injectors. In fact, for upper power levels you're better off going with the larger injectors because the timing demands to achieve power output on smaller injectors are much more aggressive and can ultimately lead to premature engine failure.

Unfortunately, injectors have gotten a bad rap because a few tuners have gone with the mentality that many of the parameters would remain the same and hadn't looked at what was really going on with the timing curves versus the amount of fuel being injected and how fast it was being injected. Consider the following examples:

Stock injectors will deliver ~135cc in about 3.5ms. Using the following table.

RPM - Deg/ms
2000 - 12.0000
2100 - 12.6000
2200 - 13.2000
2300 - 13.8000
2400 - 14.4000
2500 - 15.0000
2600 - 15.6000
2700 - 16.2000
2800 - 16.8000
2900 - 17.4000
3000 - 18.0000
3100 - 18.6000
3200 - 19.2000
3300 - 19.8000
3400 - 20.4000
3500 - 21.0000

...you can see that even at 2000 RPM, the crankshaft is rotating about 42º in the time it takes to fire the injector. When switching to a larger nozzle and reducing injection time to about 2.5ms, you're looking at about 30º to complete the injection, even for the same volume of fuel injected.

So what does this mean? It's pretty simple if you stand back and look at it like this (forgive the crudeness of the graph)...

* = crank rotation
[ = start of injection
; = spray time
] = end of injection
: = burn time
! = TDC

Stock injectors @ 3.5ms of spray time
|***************[;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;]:::::!:::::

Modified injectors @ 2.5ms of spray time
|***************[;;;;;;;;;;;;;;;;;;;;;;;;;]:::::::::::::::!:::::

As you can see, larger nozzled injectors will complete the injection and start the full burn process significantly sooner than a stock nozzled injector. Of course, this is just a rough idea of what's going on, but I think it illustrates the point that if you aren't making significant timing considerations, you are missing a large part of the picture and are putting an engine at risk for damage.

The bulk of the engine damage occurs when the flame front causes the rapid rise in cylinder pressure before the piston and crank are at the proper location to utilize the energy. What ultimately happens is the rise in cylinder pressure becomes a downward force against the piston at a time when the piston is trying to still rise in the cylinder.

This early pressure can significantly increase both linear and torsional loads on the connecting rod because not only are both the piston and crankshaft pushing against both ends of the rod, but the crankshaft position has the rod at an angle and the rod is not able to properly handle the forces being exerted on the piston. Also, because the pressure on the piston is actually being applied to the wrong side of the skirt, this can lead to excessive piston wear and fracturing of the piston and rings.

We've talked to a large number people that have "windowed" or "ventilated" their engines and there are some very significant similarities in nearly all the cases of engine failure. One curious similarity is that contrary to what you would expect, the engines would often fail while just cruising down the street and NOT while actually under extreme load, which is where you would expect. There are some very good reasons for this.

First, consider that the time it takes to combust a certain amount of fuel is relatively constant and for the sake of argument, let's say it takes 1ms. Also, we'll keep this extremely simple and assume a base SOI offset of 10º. Using the previous graph, at 2000 RPM the crankshaft will travel 12º in 1ms while at 3500 RPM the crankshaft will travel 21º at 1ms. In most of the files we've seen where engine failure has been observed, there is usually about a 3º difference in the SOI point with 2000 RPM being about 9 degrees of timing and 3500 RPM being about 12 degrees. Looking at these values, the 2000 RPM event will begin at 19º BTC and complete 12º later at 7º BTC. Conversely, the 3500 RPM event will begin at 22º BTC and complete 21º later at 1º BTC.

Again, this is an oversimplified example used to illustrate some of the basic concepts and issues that arise when tuning for injectors. It doesn't take into account variables such as timing offset caused by ICP changes and other similar factors. However, it should help clear up a lot of confusion. When you stand back and look at what is going on from a mathematical standpoint, everything becomes much clearer as to why these engines fail when they do.

We've been saying for years that timing kills these engines, but I guess nobody ever actually sat down and properly explained the reasons behind it. I hope this makes sense to everyone and not just me.

Take care.

Excellent write up Bill!! Well, after reading that about a million times I think I got!! I will be giving you a holler sometime this week!! Thanks again!!