Topic sort of says it all. I'm kind of curious to hear if anyone has ever run say a 7 or 8 hole injector in a first gen before? Or would more holes mean running the risk of blowing out the tip of the injector? I mean some guys run as big as a 6x.022 right? there can't be too much meat left with an injector that big is there?
Just sort of wanted to start a discussion on this because I've been wondering about it for a while now. I would kind of like to try something like a 8x.010 injector or something if it's even possible. If it's possible I'd like to see how they'd run. They should flow a fair bit of fuel but in reality would they have a better more efficient burn too? In theory they should, right? because of more holes giving more spray helping the fuel atomize better.

Thoughts?

 

I've always wondered this myself....

 

Yes. The powers that be say they are not as good as the 6x18 or 6x16's I think PULLTILBROKE played with 8 x11's or some thing along those lines.

 

I know Brian Block played with a bunch of different injectors, and came to the conclusion that 6 holes were the best for 1st Gens. If I'm not mistaken, with a single turbo and 6X.016's he made more power than he did with 6X.018's, with the same set up. However, when he went to twins he made more power with 6X.018's than with 6X.016's with the same set up. So it seems like with a single, 6X.016's are the best choice, but with twins, 6X.018's are the better option.

 

I am by no means an expert but I heard on 1stgen.org that once a 10 hole injector wouldn't have enough material between holes so they could warp or something to that effect. I can't see any reason you would need to go bigger than 6x21 or something like that.JMHO.

 

I believe there was somebody that ran a set of 6X.022's and hated them. He said he made more power with his 6X.016's because the other ones dumped way more fuel than the VE could handle. 6X.018 is as big as I would go.

 

I ran a set of 8x.11 and they smoked like crazy. Egt's were hot with the 60mm on the h1c. They smoked all the time. I think the spray angle was off. I never dyno'd with them.

 

I would think 8x.11s would flow a heck of a lot of fuel so it would make sense they would be hot. Maybe they could be an alright injector if you had the turbo to back it up? I got a math friend as my room mate I wonder if he can figure out a rough flow rate for those injectors

Anyone know how they'd (an 8 hole injector) be for fuel economy?
I'm liking the discussion going on so far guys! thanks for the inputs. Anyone else have any info on the matter? I'd love to hear it!

 

Yeah, I got a set of 8x11s with a 9mm tip and 155* spray angle(These have a cross sectional area about the same as 435s), all the VE guru's say they don't make as much power as a 5 or 6 hole stick but i'm gonna try to make some power with em, in the near future I'm gonna dyno back to back with my stockers to get a base line and the 8x11s to see what they do(hey, they were cheap)

Like DLittle said they are smoky but we both were runnin a hybrid, mine smoke everywhere,goin down the hiway you can see a grey trail, when you floor it you get a total eclipse of the sun and they don't clean up at all with the 60mm but they did clean up pretty good when I had a borrowed A5K on at 45 psi but then the stock clutch wouldn't hold

(my idea of hot is probly a little different then most) but on the hiway they ran around 900 cruising and would get up to 1100* on a hill but this was with a maxxed pump,.020 shims, pump was on the head and with the hybrid and no intercooler but they do feel real strong, I have yet to run em with the I/C

I'm not to worried about the tips cracking on mine because of the 9mm tips

IMO, I think they can make some decent power if you have the air to clean em up

Just my .03c

 

Anyone know how they'd (an 8 hole injector) be for fuel economy?
I'm liking the discussion going on so far guys! thanks for the inputs. Anyone else have any info on the matter? I'd love to hear it!



For fuel economy they don't do to bad if you keep your foot out of em.
The longest i've street drivin mine is about a week and didn't notice any ill effects on economy but that was with a light foot and a tight AFC, the reason I took em out was because of the smoke

I can't give you actual economy nubers because my odo doesn't work

 

I've often thought the same thing, but also i've heard that more than 6 holes don't gain you anything but smoke. So here's my theory:

With the diesel injector each hole puts out a stream of diesel, as such you need air all the way around the stream in order for it to burn. So this ends up almost like a blow torch. Now if you have 8-10 holes now there are that many streams of fuel and they probably start "touching". So now there is not enough room around the circumference of each stream for air to contact and you end up with incomplete combustion. Now this would be true for all the holes and you'd end up with like a funnel looking stream. So you need to think of this in surface area, is there more surface area in the funnel shaped stream of fuel, or more surface area in 6 individual streams? My guess is the 6 individual streams. Thus with a 6 hole injector you get the same amount of fuel delivery without the excess smoke and heat.

OK did anybody read through all of that? haha Its just a theory I just came up with after thinking back to my engines class and watching high speed video of the combustion process.

Aaron

 

AP it actually makes sense for the most part but I wonder if there is a way to remedy the problem, if indeed that is the problem. Maybe 7 holes? or going slightly smaller for an 8 hole injector.

 

I was just reading a thread on another forum about the same thing, and one thing that was mentioned was the ability of the fuel stream to penetrate into the combustion chamber. Which makes more sense i think. Because the ve pump is relatively lower pressure injection you can't make the holes too small as the stream will be small and weak and won't penetrate (get your minds out of the gutter). One thing to remedy this is a higher pressure injection (reason for CR), or less larger holes.

Aaron