injector question??

[travellinbob]

just wondering what kind of injectors people are using to generate around 350 rear wheel hp.?
  Also, ( forgive me if this is a silly thing to ask:confused: )
 if i have 4 injectors from something dull, say like a mondeo and the hp rating for the car is 150hp, then if I was wanting to feed a 300hp engine would i need twice the amount of injectors? Or are the factory injectors usually underworked in a factory sense?

[maximtaylor]

You\'ll need 1300 cc or 1600 cc capacity secondaries, or a combination of primary and secondaries, such as 850\'s primary and secondary to give a theoretical cc/min of around 3400 ish cc or more.

Can\'t quote on other cars, but injectors on an FD work on around 75% duty on stock boost levels.

There are some injector requirement calculators out there - I think on some of the US rotary websites.

Max

[bill shurvinton]

Looking purely at fuel required to generate 300HP you are looking at a total of about 2200cc, or 1100cc/rotor. Now this assumes sensible AFRs. If you really must run stupidly rich then add 10% or so.

[travellinbob]

so does that mean that 4 600cc injectors would be sufficient?
 also is it easier to make anengine behave itself with say 6 smaller injectors or 2 big ones?
  this is al very new to me. have always relied on someone else to do these kind of problem solveing and would like to get my head around it.

 cheers bill.

[bill shurvinton]

In the ball park for 300HP at the flywheel. If you want 350 at the rear wheels then that\'s a different issue.

In terms of sizing assuming your ECU can handle it the best compromise is a 1/3 2/3 sizing ratio. So say 600 primaries and 1200 secondaries. This gives you the ultimate dynamic range.

But at the end of the day most combinations can be  made to work.