60 lb injector verification

Thats awful damn pricey. I found these high impedence injectors from racetronix, however, the body doesn't look right, but the connector does.

Check this out.
 
George, they gave me a quote for $60 a piece.

42's are only good for 330rwhp at 5k with the 4r70w. (Todd Jelle maxed them, and I maxed them at this point) I will probably make more power than that at 6K if it wasn't going lean. I don't think 50's will do it if I am reving the motor faster (less time to get in fuel) and even with them there wouldn't be any head room. These should be safely good for 400rwhp with some headroom for cold days etc.

^^We found this out on the dyno with Dalke tuning it. So be warned, they sound excessive but I don't think they are at all.
 
Jullian I talked with Coy Miller on the phone about 3 weeks ago after buying his head and cam package and he told me that he found out through his dyno that he needed 72lb injectors to keep up with the air flow and suggested I use them too.
 
There is no real drawback with going to a bigger than needed injector. I have found that the 60's do idle fine and provide decent mileage comperable to a 42. I do have some reservations about the 72's as I've heard of them shorting out and blowing EEC's. That may just be a rumour, but it's what I've heard. If you are serious these days, 60lb injectors aren't excessive.
 
Sparky,do you think I will be able to find a much better deal than $60/injector? If I could get them for 50 a little later then I will wait, but otherwise I want to get the car to a safe state, and idling.

Jakke, with an ar, good heads/cam and reving to 7k I could see that. 60's were as big as I could find with high impedance, and probably anything past that is more then I will ever need.

I know I will eventrually swap in a 5.0 for something new, and 8x 72#'s would be an insane amount of flow. Neibert probably has bigger on his turbo though.
 
dyno.JPG
 
I know I will eventrually swap in a 5.0 for something new, and 8x 72#'s would be an insane amount of flow. Neibert probably has bigger on his turbo though.

Julian you are correct...I'm going with 83# low impedance injectors and those are considered a little on the small side for my power goals.

Please keep in mind that a 255lph high pressure pump can only support about 400-450 rwhp...after that your gonna need a voltage booster (for fuel pump)or another pump.

BTW, I think the 60s will be fine.

David
 
David Neibert said:
BTW, I think the 60s will be fine.
David
Pimp juice.


DN, just for poops and giggles, what does it take to run low Z injectors? Are you using a stand-alone fmu?
 
Got to make sure you are running the correct fuel pressure for the injectors you get. Each injector is rated for its specific flowrate at a rated fuel pressure. If memory serves most are rated at 3 bars or 43.5 PSI which is not the pressure you get with a stock regulator (2.7 bar or 39.5 PSI is stock)
 
Julian,

To run low impedance injectors the right way, you need what's called a peak and hold driver. It supplys more current to snap the injectors open them reduces it while holding the injector open. Accletronics sells a driver for about $350.

The other way, is to construct a simple resistor box with a 20 dollars worth of resistors mounted to a plate (one for each injector). This is what most people do when converting from high impedance. It's not a true peak and hold driver but it works fine for the power level I'm looking for.

With either one you have to rewire the injector harness to include one resistor for each injector. The turbo shop will be doing mine as part of the install. So if the 83s I'm starting with aren't big enough, I can easily upgrade to 96s or 120s.

Not planning on a stand alone yet...Dave Dalke is going to tune it with an SCT chip and the stock EEC. If that doesn't work out, I'll be converting to an AEM stand alone.

David
 
Duffy, that is not going make much of a difference in flow (4psi). I used to have an adjustible FPR on there but it doesn't work with the new fuel rail for the AR.

And besides, when it is leaning out I am at 60psi of fuel pressure (20psi boost, WOT), I think the high pressure is only good to 67, so that is not much breathing room if I up the rail 4 psi. I have made more than 20 on good days as well.

So can you or George update my dyno numbers now that i have you attention?

Alright, I am ordering the injectors this moring. I doubt they will get here for the weekend but hopefully I can get them on next week in time for club clash.
 
T-bird4vr said:
So can you or George update my dyno numbers now that i have you attention?

Alright, I am ordering the injectors this moring. I doubt they will get here for the weekend but hopefully I can get them on next week in time for club clash.

Julian, according to the current rules for SCCOA HP submission your car is not valid. You and I are one of many who are facing the same situation. It is time for the club to address this issue.

David
 
spARky, I thought it was cool as long as you told them like n20 and such.

Besides, isn't Anthony's 400rwhp twin screwed (#1 on the hp list)?
 
T-bird4vr said:
Duffy, that is not going make much of a difference in flow (4psi).
Julian, it makes a huge difference in capacity, 4 lbs of pressure reduces the injectors to 55.5lb/hr. It is also significant in keeping proper spray pattern, especially under boosted conditions. Though David can tune around it, the proper way to address it is with an AFPR. You would also be in a much better position if you run either a boost a pump from KB or my preference of a Jacobs accuvolt unit which allows you to dial up the voltage and regulate it. Here is an article on it: http://www.4x4review.com/products/electrical/accuvolt.asp
T-bird4vr said:
And besides, when it is leaning out I am at 60psi of fuel pressure (20psi boost, WOT), I think the high pressure is only good to 67, so that is not much breathing room if I up the rail 4 psi. I have made more than 20 on good days as well.
That is incorrect. The high pressure pump will go beyond 67psi, it will just continue to reduce flow rate. Here is a chart posted on APE's site showing the 255FI model flow, pressure and current:
hp255lph.jpg


Paul
 
If you plug it in here, it looks like it is 57.2, that was a little more than I expected, but it is still not a lot. Nor do I fully believe those numbers. Without actual flow data from the injectors it is all somewhat of an estimate.

It is also significant in keeping proper spray pattern, especially under boosted conditions.
Where does this come from?
The injectors will see a fuel pressure difference of 20psi regardless, so if there is one optimal point (which I don't argue) what does it matter if I hit that at 4#'s boost or vac?

I really just made that comment before to state the fact that it will not run out of fuel at 39.5psi because the motor would be at a vac (ie part throttle), whereas I am worried about WOT.

I do appreciate the link, I should read up on more of this stuff.

Paul, nothing on my car is "ideal". Hell I have been driving around with the ar on now for 5 months or so, pegging the maf by 2k, and 100% duty on the injectors by 5k. I am not saying any of this is right at all, but I also refuse to dump 20k into a car to ideally hit 350rwhp. I'll just slow the blower down if I need to make the car safe.

Non-the-less, this is all good discussion and something new for a change.

Hell, I remember before I ordered the AR kit that I told DD if I was going to need to buy bigger injectors right any and run a second fuel pump that I didn't think it was a wise decision for me to make at the current time.

Well, it turns out that I do need that stuff to keep it "ideal"...
And I get such great gas mileage right now as it is. :rolleyes:
I don't remember when exactly I went from 26mpg highway,17city to 20hw, 11 city but it sure does it. And now my idle is stuck ~1500 which I am sure helps. Nothing like holding the brake to drive under 45mph. :rolleyes:

Sorry, I am venting now, most of that stuff I should be able to take care of next week. These damn finals and hw are just pissing me off. I just want my damn degree already.

So to sum up, the 60's are going on, my thermostat housing still leaks, idle sucks, pia to drive the car, it is dirty and torn apart, swaping injectors is going to be an 6hr job with the ar (new kits will be easier) got a system dynamics final tomorrow morning (DD that is the class about transfer functions etc, which I am kickin as in), this dam english report that is due tomorrow and a complete was of my time is pissing me off, but I have a date on friday so it is all good.

Cheers, :D
 
Oh ya, and I left my $90 MatLab program cd at the library monday night, so I get to buy a new one of those too. :rolleyes:
 
Julian,

Welcome to the over 325 rwhp club....it's a whole new level of spending and frustration.

I keep telling people to stop at 13s and enjoy their cars, but nobody listens.

David
 
It's my fault since my car runs 12's and doesn't seem to mind. :p

Julian, try referencing the bypass valve to the inlet plenum instead of the return plenum. That will delay the bypass from closing as early and may allow you to get better mileage.
 
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