4 vs 8 injectors

I agree with this theory. But would love to see some actual tests on flow and of course power when it's all done.

I considered doing something similar with mine, due to the R32 injectors being buried deep in the head, but it'd be a mare as i'd have to stagger them due to the unequal port lengths (or mapping it with different injector times to compensate.)

The main reason I didn't like the idea was safety. I just don't like the idea of having high pressure fuelling items in the crash zone, I'm sure that's the main reason manufacturers bury them in the head, not jsut for emissions and smooth low rpm running, it's because they are usuall protected by and inlet manifold so it doesn't rupture the fuel rail in a smash.

Remember that smashed up R32 I broke a few years back? the engine was through the bulkhead...fuel rail didn't split.

 

Good call - should be a thread in its own right. What's the rest of the spec of that engine, Glen?

 

The engine in the pics is just a dummy - an old KR block bolted to the stand, with my spare standard ABF head used to hols some of my cam stock!

It lets me mock up the ignition side of things (Ford coil pack, wasted spark but using the dizzy hall sensor for sequential operation) , and make the loom (completed).

Currently the engine in the car is:
Blydenstein 0.5mm bigger valve, one-off 'B pack' ported head, lightweight lifters, titanium retainers, matched exhaust manifolds/downpipe, 100 cell cat + 'sports' exhaust, Schrick 268 in / std ex cams.

I'll try both 268 cams...but since I also have some Schrick 276s, I really want to try a Schrick 276/268 combo...in theory (there it goes again! based on the 'odd' things my engine does) that set up should work pretty well.

Either way, I'll need the stand alone ECU up and running to get the damn thing running properly.

Get the Jenveys on, mapped then play with cams...
Get the cams set...then play with injectors...

Whilst saving my pocket money for a high compression bottom end.

 

maybe we can include injector choice in this thread also......

quality as well as quantity

whats the spec of 1.8T injectors? flow rates/hp limit/impedance/design (no.pintels) etc etc

 

I disagree - we both have race-spec 16v engines in a high state of tune.

Some of the logic is cost benefit, it has to be. A second fuel rail, 4 more injectors, bespoke install, new ECU, mapping - it all adds up. That's more than likely been factored into the conversation.

Clearly there was no point in turning up to the kitcar or BTCC party without them, so the incremental gains are there for the taking if someone is prepared to spend the money (and get fabricating).

Look forward to seeing what comes out of infinity's, and now Ess Three's 8-injector 16v set ups.

 

At the moment, installed are 2 x sets of 1.8T '180' EV6 'short' type injectors:
Bosch 0 280 156 061
VAG 06A 906 031 BA
Which look like they flow about 315cc @ 3 bar.

But I also have a set of Ibiza 1.8 (I think) EV6 'short' type injectors:
Bosch 0 280 155 731
VAG 030 906 031 E
Which look like they flow about 100cc @ 3 bar, so I'll likely end up with these at the idle > 4000 RPM-ish injectors.

Due to space limitations, it had to be EV6 type for the outers...or they would be going so far down the bellmouths it's hardly worth doing!

 

I guess 8 injectors are like many things - another factor in incremental gains, as you say.
I expect that with a mild set of cams and standard bottom end, the gains will be limited...
But going to big cams and higher compression, there should be more to find.

I thought I'd be as well fabricate the whole lot before I fit the ITBs - even if they don't add anything - as it's easy to re-jig the software and turn them on once the cams go wilder and / if the bottom end gets upgraded.

I have tried to do it on the cheap where possible, using home fabrication and parts available at the local scrappies.

Coil pack bracket next, finish the fuel lines...and then start the car loom.
The engine loom is complete.

 

I'd agree

Nice you're going to wait for the high comp bottom end before concluding.

 

Yeah, it's a long way away yet (it's taken me nearly two years to get the ITBs to the stage they are at now, after I picked up the bare bodies!)...but I'll soon have the head/cams/inlet set-up I want...

And the man-that-can has already been consulted regarding a bottom end....will it never end?

 

I like this set up
My bogo standard road Ducati comes with 2 injectors per cylinder,1 "shower" above the trumpet and the other in the usual place.
Just food for thought but i'll post some pics of them up tomorrow.

 

Nope - its a disease - serial modifier

 

Great! What diameter are they and what's the price? !

 

I thought I'd cured it...my 5 years running a Porsche cured my VW spending...
The 911 has gone now..and I'm back in the garage, diseased up.

 

Its all relative - what I mean is that they are not in a high state of tune compared to a kitcar or touring car engine where these injector setups are most commonly seen, and top spec hillclimb 2L duratecs are now doing 315-320hp

All I am suggesting is that what works with these factory engines might not work with ours. I have info from a man I trust (and who has a rather good results CV I'm sure you would agree) that suggests there are better things to do, but hey, its nice to see as much info as possible.

Latest data from the man is 5 ftlb increases on very pokey engines from some new injectors he is trying - more info on this soon as the storey develops

 

I knew that!
Before I got the Jenveys, I was playing about with motorbike ITBs and it had occured to me that 2 sets of Ducati 999 (I think it was 999 I considered) ITBs/Injectors would be just about spot-on.

 

Havn't measured them yet but i'm sure they are the same size as 45's
Interestingly the bottom of the fuel tank is also the top of the sealed airbox just like 1 of the berg cup cars in another thread (except that uses the bonnet lol)
Not for sale unless you buy the whole bike (for now )

 

Mines a 998 but uses the exactly the same engine as the early 999
65 bhp per cylinder standard.

 

Its efficient from a performance point of view, not from a fuel point of view due to fuel drop out when running low rpm or at low engine temperatures. Given that you have a set near valves for low rpm you have the drop out ends of things covered. The second ones coming in at higher rpm I guess. It would be a good Idea to let the outers carry all the fuelling at higher rpm, the inners coming in once the rpm drops again. Im currently working on a controller/loom that looks after this changeover for something Im at myself. Nice work, keeping an eye on this one.

 

We know a 16V VW engine, in a 'high' state of tune, won't do Duratec power. Ignoring the 'canted' 305bhp Audi Sport engine for now, since it is somewhat off piste, a 'high' state of tune for a factory-component based engine/head is 260bhp (1998). Lehmann eked it up to 280 later on.

Discount that for the optimised fuel they used (100 RON max, but the 3 stuff), mapped to the limit of det on a proper ECU, and I don't think we're sandbagging at all.

I assume he explained why it might not work.

If it works on a Ducatti, works on the Pug mentioned, on what basis can we dismiss it on a VW engine running 12/13:1 compression?

 

That's the plan Brian,
I think I'll get the engine running on the inner set of 1.8T injectors, then using the sacling features of the ECU, set it for small inners and 1.8T outers, and prove it all works.
I plan to phase the outer injectors in at around 4000 RPM, as my engine seems to start coming 'on cam' at 4000-4500, so all additional fuelling will be from the outers.

I'll have to play about to see whether I leave the inners sitting at a fixed duty cycle from 4000 upwards, with the outers just adding the additional fuel from 4000 to 7500 or phase the inners out, so that by, say, 5000 RPM the outers are delivering all the fuel.
I'll have to play and see.

I'm running the inners sequentially fired, triggerd by the dizzy sensor, with an individual injector outputs (as standard), with the outers in batch fire mode, triggered off the crank signal, and fired by the additional two injector outputs.

Being an ABF, the 12v injector supply is already there, along with the 4 individual inner injector wires...only the additional two had to be run.