deciding injector angle in intake manifold

[sps]

hello to all...
i am converting my carburetted engine to MPFI by using the PE kit.. we are using kawasaki ninja ZX6r engine... i am doubtful about the injector mounting angle in the intake manifold.. can any one help me to get out of it...i.e. what procedure should follow to decide the injector angle in the manifold... i will be very thankful....

[sps]

hello to all...
i am converting my carburetted engine to MPFI by using the PE kit.. we are using kawasaki ninja ZX6r engine... i am doubtful about the injector mounting angle in the intake manifold.. can any one help me to get out of it...i.e. what procedure should follow to decide the injector angle in the manifold... i will be very thankful....

[wweissin]

After speaking with the guys at Injector Dynamics and T1 Race Development. They have not seen much power gains with regards to injector location or spray pattern on most race engines. With that said it has been recommended to point the injector so that it sprays on the peak where the 2 ports meet if it has a pencil spray pattern or directly onto the back of the valves if it is a cone type spray pattern.

[poe21]

I would look at stock fuel injected bikes, and just mimic something close to that angle. We run an f4i and actually run the stock throttle bodies gutted as part of our intake manifold. We previously had problems with leaks, but now, we are good to go.

[RenM]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by wweissin:
After speaking with the guys at Injector Dynamics and T1 Race Development. They have not seen much power gains with regards to injector location or spray pattern on most race engines. </div></BLOCKQUOTE>
That is very dependent on the spray geometry of your injector. We have seen differences of up to 7%.

[wweissin]

7% is a good gain on any motor but what kind of engine and at what power levels are you talking about? Was it a 7% gain across the whole graph, mid range or peak power out put?

[Drew Price]

Behold. Injectors not even in the runners.

Renault F1 Engine (http://www.youtube.com/watch?v=m27xXVgg1nc&feature=PlayList&p=8D637A61032CE89C&index=8)

I spoke with a gentleman from one of the race engine development companies who told me that they even experimented with things like having the injectors pointing upwards at the trumpet inlet or like in this video to get more evaporative cooling effect of the inlet charge.

At your stage copying something close to reasonable from a stock configuration should work fine, if you can play with it later all the better.

Best,
Drew

[kapps]

Is there a version of this engine that was fuel injected? If so, try to find the stock injector locations.

Alex and poe21 both have good points. If the engine was never fuel injected, Alex's comments are as good as any. When we made injectors for our f4i, we modeled the stock throttle bodies and machined new bosses that housed the stock injectors in the stock locations.

[VFR750R]

RenM, is that 7% after re-optimizing injector timing? Is that comparing similar sized injectors?

[RenM]

Honda CBR600RR
Custom Bosch Injectors with different spray geometry at 3.8 bar and same injection rate.

The difference is most noticeable at high injection rates.

EOI was always at the optimum setting (changing the EOI for different injectors was not necessary)


Anyone who has the resources should test different Injectors and Injector positions on the dyno, because spraying directly onto the back of the valves might not be the best spray targeting in any case.