It was exceedingly difficult to get flow rate specs for XJR injectors off the internet. I have just had mine cleaned and tested, here are the results.

Hopefully this helps any of you who wanted this information. My car is a 2002 XJR 4.0

The Before numbers:
Have completed flow test of your injectors as received. The below results are at 3 Bar pressure, 60 second flow rate, static rate (full open pintle), 100 % duty cycle....

1) 356 cc
2) 361
3) 352
4) 360
5) 351
6) 352
7) 356
8) 356

Average flow rate 355.5 cc
Low flow (#5) 351
High flow (#2) 361
Flow spread 10
Deviation 3.46%

The maximum deviation should be 3% or less.


The AFTER numbers
I have completed ultrasonic cleaning of your injectors, and flow testing after cleaning.

I flow tested your injectors at 3 Bar pressure, and also at 3.5 Bar pressure. I believe 3.5 Bar test is more in line with what I would expect them to flow at boost.

The results are as per below.......

3 Bar 3.5 Bar

1) 356 cc 388 cc
2) 364 396
3) 356 388
4) 361 392
5) 357 388
5) 361 392
6) 361 392
7) 361 392
8) 360 392

Average flow 359.5 cc 391 cc
Low flow 356 388
High flow 364 396
Spread 8 8
Deviation 2.69 % 2.64%

The deviation decreased quite a bit, indicating they were somewhat clogged up with fuel olafins. They should be good to refit, and the flow rates good to use for your engine tuner.

You should note....I test injectors using N-Heptane. as does every injector shop. Much more stable, and less flammable than gasoline. Flow rates with USA test gas will be approximately 1.04 % higher.

I would suggest you save this info on your computer, and also print a hard (paper) copy for your files.

Will box them up and return ship to you on Thursday.

Let me know if you have any questions, and thank you.

SD Faircloth
Jaguar Fuel Injector Service
904-289-2020

 

Thanks for the exact results. The flow rates were smaller than most of us expected.

 

Handy to know...getting a few sets done so I hope to add my results to this thread.

Thanks for posting the info WD.

 

Yes, this will set the fuel delivery boundary / limit, and the limit for my ambitions for now. I may consider swapping 4.2 injectors and rails later, since more fuel would be needed to pass the 480 HP mark it seems.

I have ordered an adjustable fuel pressure regulator, as I will now want to run higher than stock pressure.

What do you all recommend I can increase the pressure to? What is stock pressure?

 

Was injector 5 tested twice as much as the others?

 

I don't really know, I just cut and pasted his email to me.

 

There's a lot of extra room, you will NOT hit the boundaries with the mods you are planning.

But you can easily up the pressure with a good fpr, stock is just 43 psi, and you can up it 10 psi for instance, which gives about 10% increase in flow. If you start increasing the boost pressure, the pumps would also have to work harder, so either replace them or go for the KenneBell boost a pump. But as said you need much more power mods to make use of it.

 

I was hoping you would chime in.

The two fuel pumps were replaced with Bosch (stock replacements?) last December, before I bought the car.

My thought was that I can try adding the fpr, and going up only 10 psi and see how that works for me.

Good to know I will not be running out of fuel with my planned mods.

 

You can boost the stock pumps a good bit with the KB BAP, so with some MAF adjustments you could go even further then 20% more flow, but from those levels it will be pioneering with such a setup (as you also then probably surpassed me in HP output).

 

ummm...yeah...I don't think I will get even close to your HP numbers with an eaton. Not without a big blue bottle in the trunk.

If I get to the 470 bhp mark I will probably just stop there. AVOS, do you think I need the boost a pump at the 470 BHP level? A 12.5 1/4 is good enough for me. I'll bump up the fuel pressure 10 psi for now and see what that does. I am going to be reducing back pressure as well with a much freer flowing exhaust than just the "cat back" systems, and may squeak out a deal for better flowing heads as well. I'm only adding an upper pulley, but that extra boost pressure may be offset by heads and exhaust.

Right now I'm just playing around with smaller HP gains with traditional bolt ons, and my nontraditional muppet intake prototype. If I wanted to get serious about big power, the next logical step would be the twin screw. -see JgaXKR, I do listen

 

Can't say, as the Eaton consumes exponentially more power from the engine at higher boost levels, so the engine might even need to chunk out 570 hp (so 100hp for the Eaton and 470 for what you want).

I guess others who have been running very high boost levels on the Eaton that where in the 370-380 rwhp regions, so 450 to 460 hp, need to comment here on fuel delivery. Although usually these guys have a meth/water kit, which could mask a fuel shortage, but lets see what they have to say.

 

The ken bell website shows power consumption of twin screw vs roots as:


Twin Screw Roots
@ 8.8 psi 23 33
@11.8 psi 29 42
so @ 14.8 37? 53?

I'm not seeing how you could justify a claim of 100 hp drag with only an upper pulley. Maybe with an upper and lower pulley, but I'm not understanding 100 hp with just the upper.

It may not be such an issue, since if I do not see the +100 hp I am seeking after my mods, there will be no need for more fuel.

I don't want to have to rely on a meth kit to prevent leaning out, that is a bad idea.

My plan at the moment is to make my mods a few at a time and keep a close eye on the A/F ratios. It may be wishful thinking, but I am hoping I can richen up my mixture a little by upping the pressure regulator from 43 to 55 psi. At some point I am going to have to get a safer/better tune.

 

1: Not sure what Roots blower you show there, but I am talking about jaguars M112 unit
2: You are talking about a 100 hp increase, which is where I refer to, not just an upper pulley that could only yield 10 or 20 hp.
3: I have based my calculations on graphs from Eaton themselves, here is an old post where I estimated some values:
https://www.jaguarforums.com/forum/xj-x308-xj8-xjr-27/upgraded-supercharger-upper-pulleys-porting-35131/#post189725

 

Ahh,

I see...

I did not realize that graph was for the Eaton 112. You make a very good point there, especially since I am hoping to max out on the stock injectors, better to not waste it on feeding the blower if I can max out on fuel delivery by getting more air movement other ways. As I understand it, the main reason people go with the faster pulleys is to get the boost and power band sooner, which may not show well on a dyno as a higher peak number, but is faster overall on the street. But since I am planing on having more power overall (including at lower rpms vs stock), and am already at the limits of traction on street tires anyways, the absolute best 1/4 mile times will likely be had by maxing out fuel delivery by being most efficient with it.

That is very interesting. Since I am possibly going to get a set of ported and polished heads (from a 2nd source), and much freer flowing exhaust, and add my significant ram air set up, I may try the stock pulley and see what boost pressure / airflow / power I get that way. To add the upper pulley later is a very fast and easy upgrade if the blower snout is already ground and ready for a smaller pulley. You have convinced me to try first with the stock pulley, since it is a safer way to go, and I can always add it later if it appears I have fuel delivery capacity left over when I am done with my planned mods.

I was surprised that the stock injectors were as small as they are (360 ish cc), so I agree that if I can get more efficient HP from other mods first, that would be the smart thing to do. This is a very different game when the limit is the stock fuel injectors. My strategy would appear to be different from those who have gone before me. So far, I am doing everything (other than paying retail for a meth kit) on the cheap, so I'm going to first try the higher efficiency mods and see if I can do without upgrading to the 4.2 fuel rail and larger 440cc injectors.

Once again, AVOS, I am in your debt

 

That certainly was a surprise to me too, and I guess to a lot of other ppl as well. I've been looking for a way to use E85 (due to the crazy gas prices over here), but this new info makes it impossible without investing a crazy amount of money on injectors...

This may be a stupid question, but when using a calculator (like the one below) to estimate needed injector sizes for certain amount of hp, should we add whatever hp the supercharger takes to the flywheel figures?

http://www.witchhunter.com/injectorcalc1.php4

 

Being not a mechanic, and new to this sort of thing in general, I am confused as to what the limits are with the stock injectors...

According to some calculators, they are already maxed, which we know is not true since several people, some without meth kits, show dynos of 370+ RWHP

So what are the theoretical max HP figures with the stock injectors??

 

Have no idea what the max is with these injectors; the max I can remember was at least 450rwhp (may have been even 470rwhp), which might be the same as 370rwhp for the Eaton. I have not measured the ipw, only a/f ratio's and have not seen any evidence at these levels that the mixture got lean.

 

You mean you saw a dyno with 450+ RWHP on a 4.0 with these 360ish/cc injectors running stock fuel delivery? No meth or other methods of fuel additions?

Are all the calculators wrong then?

Was this with a twin screw?

 

You need to know what the bsfc is (which I don't know), that determines the output of these calculators. 450rwhp was of course with the twin-screw.

 

And this 450= rwhp was on stock 4.0 injectors??

With all the calculators I was using a .6 factor.

Maybe these twin screws are "magic" blowers