Flow matched injectors

[akaaa7]

Hey guys are there any members out there that have had Nissan oem sidefeed injectors ultra sonically cleaned and flow tested? If so how did they match up, were they well close to each other or big differences? Just wanting to hear experiences before I fork out a few hundred to get 8 s15 440cc injectors cleaned and flow tested which may not show good results when I can get a set of flow matched from a supplier (more expensive)

[MagicMikeZ32]

more info about the build? Surely there are better options

[GTSBoy]

You might need 12-20 injectors to get 6-8 flow matched units.  It's not as if they "adjust" them to flow match them.  Flow matching is just binning injectors with similar flow together.

[Dose Pipe Sutututu]

13 hours ago, akaaa7 said:

 

Hey guys are there any members out there that have had Nissan oem sidefeed injectors ultra sonically cleaned and flow tested? If so how did they match up, were they well close to each other or big differences? Just wanting to hear experiences before I fork out a few hundred to get 8 s15 440cc injectors cleaned and flow tested which may not show good results when I can get a set of flow matched from a supplier (more expensive)

 

With the cost of brand new injectors these days, it's silly to buy a set of 6x used 450cc S15 injectors (they're 480cc at 3.5bar, at 3bar they're 450cc) and get them cleaned, serviced with new seals, pintle caps etc.

Just get a cheap $90 top feed rail, and get yourself 6x new top feed 1/2 height injectors (approx 45mm o-ring to o-ring).

[akaaa7]

They are for a Vh41de running a rotrex c-38. So staying with side feeds as I'm not making custom rails. 8 of these will easily see my power goals on about 8psi. Since I got all 8 for 100 bucks, already have spare pintle caps and can get them Cleaned and flow tested for around 200 it could be a option. I understand you can't change their flow and are matched from a selection. I'm just curious to see peoples experiences on jecs manufacturing tolerances weather they have found jecs injectors to differ much when tested a unmatched set. Or have I got the wrong idea here and am I asking how long is a piece of string is?

[GTSBoy]

There would not be a very large number of people who would have attempted what you propose (just with the injectors, not the engine plan itself).  Certainly not in recent years.  These days, as Dose said above, good injectors are cheap, and also much much much better than shitty old side feeds.

[Rusty Nuts]

There are certainly a greater variety of top feed injector sizes but over the years there has been a growing hatred of side feed injectors. Rather than just call them "shitty old side feeds" give a proven reason why 450cc top feeds PERFORM better than an equivalent side feed. I am extremely cautious of cheap top feeds they can have spray patterns like a dog with diarrhea. 

[Ben C34]

You also want reasons why any other development is better than the previous available option?

 

[Rusty Nuts]

The only reasons I have been able to gather over the last forty years are:

Side feed Injectors

1)Because side feed injectors are mounted in the fuel rail and are surrounded by fuel it provides a better cooling effect, in turn you can run a higher duty cycle and push them a bit harder with less chance of failure than a top feed.

2)Side feed injector rails have to be well designed and manufactured to perform as well as top feed rails. This assumes you dont fit a fancy coloured chinese lookalike top feed rail off ebay.

3) Side feed injector size tops out at 1000cc ( top feed 2000cc or more)

4) Side feed injectors are EXPENSIVE. A set of Deutchwerks 850 top feeds are $300 cheaper than side feeds.

5)Top feed injectors

Much greater variety of vehicles use top feeds, and much greater range of sizes available

IMHO this is a trueism ,  it is just a different way of accomplishing the same thing injecting fuel!

 

 

Light travels faster than sound, that's why some people appear bright until they speak!

Edited May 5, 2018 by Rusty Nuts

[GTSBoy]

Side feed injectors STOPPED being developed a long time ago.  Injector nozzles are better now than they used to be when the industry gave up on side feeds.  Ergo, side feeds ARE shitty old tech, compared to the new hotness tech.

How hard can this be to follow?

[Rusty Nuts]

GTSBoy email Deutchwerks and tell them their side feeds are underdeveloped shitty old tech, they will disagree.

How hard can that be to follow?

 

 

Light travels faster than sound, that's why some people appear bright until they speak!

[GTSBoy]

Um....that seems obvious.  It's not as if Deatschwerks are "developing" these injectors.  The electro-mechanics are direct from the OEM and direct from the original development in the late 80s.  The only thing that DW do is either abuse the shit out of them to make them flow heaps, or have a small fiddle with the nozzle openings.

Meanwhile, Siemens, Bosch, et al, have been making improvements to every aspect of the way these things work for another 20 years.  There have been, what, 3 new generations of Bosch injectors over that time?  Maybe 4?  We all know that EV14s are better than EV6s are better than the petrol pissers that were in 80s Nissans.

[Dose Pipe Sutututu]

4 hours ago, Rusty Nuts said:

GTSBoy email Deutchwerks and tell them their side feeds are underdeveloped shitty old tech, they will disagree.

How hard can that be to follow?

 

 

Light travels faster than sound, that's why some people appear bright until they speak!

DW side feeds are decapped and drilled JECS injectors.

Back in the days they used to buy used 370cc JECS injectors to remanufacture into their version of 740/850/1000 etc.

Five-O are exactly the same, if you ever get a set look at them using a magnifying glass and you'll see marks similar of a bench grinder or belt sander.

Also, side feeds don't have stainless internals so when you start introducing fuel such as E85 then generally seize up after much use if you don't use any ethanol addictive or run normal gasoline through them.

I've tuned several cars with those DW and Five-O water canons, generally they're ok when new but after 1 or 2 years the flow rates between the injectors start to vary dramatically.

Only side feeds I would use are stock ones or Nismo 740cc. Avoid DW or Five-O if you don't feel like rebuilding your motor.

[Rusty Nuts]

On 5/4/2018 at 2:53 PM, akaaa7 said:

They are for a Vh41de running a rotrex c-38. So staying with side feeds as I'm not making custom rails.

Stay with side feeds mate you can progress up to 1000cc is the simple answer. The 2000ish WRX STi used 550cc versions which are cheap and plentiful. and Kudos for a nice supercharger choice.

[Dose Pipe Sutututu]

55 minutes ago, Rusty Nuts said:

Stay with side feeds mate you can progress up to 1000cc is the simple answer. The 2000ish WRX STi used 550cc versions which are cheap and plentiful. and Kudos for a nice supercharger choice.

You'll need collars with Subaru if I remember correctly, just get S15 450cc ones. Easier as people sell them for about 150$ for a set of 4x.

[akaaa7]

Thanks for the replies guys. I love a good debate and I learnt a thing or two from the above posts.
I'm going sidefeeds regardless if their design is outdated, many people have run them in the past and made solid power. I have no pans to run e85 so that doesn't come into the decision. But mainly they fit without spending a fortune and time making rails to run top feeds.

So the question I really want answering is if I get the s15 injectors (that I already have) cleaned and flow tested can I expect them to be all very similar flows? Or does anyone know where I can buy a set that are already flow matched together?

While flow matched injectors isn't something everyone gets done, I firmly believe they solve alot of tuning issues when every cylinder is getting it's fair share

[Rusty Nuts]

I got a set of R33 rb25 injectors cleaned & flowed a couple of years ago, i'm trying too find the results they are in the workshop somewhere, will post soon.

[Rusty Nuts]

Slope flow matching..... my set was flow matched within 0.5%

Offset matching.@3 bar/13.5volts  my set was offset matched within 0.5%

and back in they went to the other Skyline we are keeping absolutely stock.

[Rusty Nuts]

Of course this doesn't mean every set would be this close, I could be the luckiest bloke alive 

[KiwiRS4T]

4 hours ago, akaaa7 said:

Thanks for the replies guys. I love a good debate and I learnt a thing or two from the above posts.
I'm going sidefeeds regardless if their design is outdated, many people have run them in the past and made solid power. I have no pans to run e85 so that doesn't come into the decision. But mainly they fit without spending a fortune and time making rails to run top feeds.

So the question I really want answering is if I get the s15 injectors (that I already have) cleaned and flow tested can I expect them to be all very similar flows? Or does anyone know where I can buy a set that are already flow matched together?

While flow matched injectors isn't something everyone gets done, I firmly believe they solve alot of tuning issues when every cylinder is getting it's fair share

If you really want to use S15 injectors the trick is to buy a dozen or more if you are getting them cheap and use the best eight. The last time i bought injectors was about 8 years ago and I got 550 sidefeeds from DW  and basically that';s all they do - buy lots of second hand Jecs and after cleaning them match them into groups of six - but if I were building an engine today I would get new injectors.