Thread: does this make sense?

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stumbled across this manifold last night? why 8 injectors? especially with such a small inlet?

Because racecar.

really? it doesnt look like you could get any air in there at all.. and would 4 smaller injectors be better than 8? or do the other 4 kick in under boost.i remember someone builing a car with 8 injectors a while back. the first 4 sprayed pump gas out of boost, and the other 4 sprayed race gas in under boost to control detonation. sorry for asking so many questions, i just like to learn about this stuff

The engine is restricted by a tiny 30mm inlet restrictor because racecar. Anything larger than that is an improvement.

Almost always, yes. The only reason it is not better is because of cost and complexity.

It is probably not that simplistic, but yes they are probably staged injectors (not all of them are active all of the time).

so 8 injectors in restrictor racing would make more power? or just sustain higher rpms? im just trying to understand the logic

The reason for the 8 injectors doesn't have to do with the restrictor necessarily. Mainly they are used on very high power cars so that idle and low fuel situations don't suffer. Huge injectors have a hard time metering the proper amount of fuel when only a little bit of fuel is needed. So instead of using one huge injector you can use two and have the fuel control you need. Since this car likely only makes up to about 320HP that reason is probably not why they use dual injectors.

There is another reason to use two injectors. You get twice the spray pattern, and a bit better fuel atomization so the fuel and air mix better and you can get a more complete burn, and thus more power. This can be especially important when the restrictor creates slower than ideal air speeds.

It is also possible that the second injectors are set to inject only when anti-lag is being used. Rally cars will inject fuel when off the throttle (during an up-shift for example) to create explosions in the exhaust manifold to keep the turbo spinning to make sure there is power there when the throttle is applied next.

sending big backfires through a turbo wont kill it or damage it?

Yes it will damage it pretty quickly. Rally teams replace them on a regular basis due to the damage.

Really, this forum is not designed to answer all of these types of questions. If you have general car performance questions like this, I suggest you do your own research. We are not a one-stop-shop. If you don't learn to research for yourself and expect to learn everything here you will more than likely be severely disappointed.

thats seems like such a waste. thanks man