1600cc injectors that will fit stock secondary fuel rails?
is there such a thing?

 

Ive read on a site somewhere, they could be modified to fit the stock rail. It didnt look too hard.

 

You must have a really big turbo...are you sure you need 16's? :-\

 

Its easier to just have your stock fuel rail modified to work with the 1600's The hole has to be 0.562".

 

No, I'm not sure.

This car is not a street car, it will only be used for auto-x and road course tracks.
I’m going to be running the new Microtech LT-8 on a series 5 engine with a hybrid turbo (BNR stage 1). I plan to us the stock intercooler (for now), Walbro fuel pump and the injectors will be run in parallel. My goal is about 300rwhp. I will use the stock primaries that I just had cleaned by RC but I’m not sure what secondaries I should use. The fuel calculator that I used said that I could get 300hp with 720cc secondaries at 80% duty (is this to high?).
OR should I get the 1600cc secondary injectors? That would be all the fuel I would ever need but will I have a stumble when they come on line?
So what would be a good auto-x set up?

what do you think?

-Bill

 

was that 300hp with just the 720's? or 300hp with the 720's and 550's running at the same time

Daniel

 

Sorry, it was 550 primaries and 720 secondaries @ 290hp but I just noticed that was flywheel hp. I guess my main question is can I use the 1680cc secondaries without bogging or stumbling when they come on line. Remember I have a Microtech LT-8 in the mail.

-Bill

 

A 550/720 combo is good for ~340hp @ 80%, more if you run higher fuel pressure. Four 720's would be good for ~380hp, so will easily cover your 300rwhp goal. 1600cc/min secondaries are massive overkill for your requirements (~570hp!), while the smaller injectors will meet your needs and not require modifications to fit.

 

Thank you, thats what I needed to know.

so is this fuel calculator wrong?

http://www.rx7.com/cgi-local/2catalog.cgi?cat=12

 

720's that are low impendance or high impendance?

 

I'm going to be running 720s and 1680s. I'm only shooting for ~350 at the wheels, though. More fuel = more room.

Marren Injectors (www.injector.com) has some that will fit the stock fuel rail, but they are not listed on the site. Email them. (They are slightly more expensive.)

 

It does seem very conservative. They also claim the ECU can't exceed 60% duty cycle, which I think is completely bogus. If it were true,the TII injectors and ECU are only suitable for 190hp, yet S4's exceed that with just an exhaust and S5's have more than that stock!
I use a figure of 8cc/min per flywheel kW (a guide figure that I've seen many times over the years) and 80% max duty cycle. And that doesn't allow for running higher fuel pressures, so I think my numbers are already on the safe side. It doesn't really matter. The stock ECU must see high impedance, so if they're low-impedance injectors you just add resistors.

 

Thanks again.
I'm not using the stock ECU. I have a Microtech LT-8 on the way. I was told that I could use any combination of imp. that I want, just as long as the primaries are the same and the secondaries are the same.

low-high or high-low