I'm about to get a Haltech E11 and was wondering what people are runnin for inectors for a hp range of around 300-350hp? I was thinking about 720primaries, but uncertain about the secondaries.

Until I upgrade my turbo however, I would also like to know what size injectors people w/ E6K's are running w/ their stock turbos around 11psi? Does anybody know the efficency range of the stock turbo?

 

For the stock turbo, 720cc secondaries will work fine. For 300-350 hp you should be able to use all 720s. Efficiency of the stock turbo is said to be about 12psi with the stock intercooler. With a good fmic I've heard that 14 or so is good without stressing the turbo too much. I plan to push my boost to 11 with the stock i/c and when I get my fmic set it at 14.5.

 

About what is the duty cycle on the 720 secondaries w/ a stock turbo setup at 11psi?

 

what is the duty cycle of the stock 550's at 12 pounds with a walbro 255 fuel pump? I know it has to be pretty close to maxing out, but how close.

 

i put 14psi through my stock ic but my turbo been high flowed its got some garrett wheel on the cold side

 

4X720 should give you what you need on stock or close fuel pressures.

Duty cycle questions... I think RX-7.com has a calculator for that, under fuel systems.

 

i'm running a walbro 255lph rite now too. I don't have a FPR yet. So you're saying that you recommend 4x720 for running stock turbo and intercooler around 11psi of boost?

 

I am in the process of getting ready to install a T04 and Haltech, but previous to this I was running the stock turbo pushing 13psi with a walbro fuel pump, 4x720's and the older HKS intercooler and I dynoed 243 to the wheels with the car running really rich at the time. Oh yeah and a SAFC to tune the fuel a bit.. with my setup basically after the secondaries kicked in all i was doing was taking away fuel. dyno chart link in sig

 

stock injectors are fine for that... you won't be making over 250hp

 

that's a pretty flat torque curve you got there. what times did it run at that level of tune? or if you haven't gotten times, what kinda cars has it beaten?

 

Yeah the torque curve is nice. Unfortunately I never took it to the track that current state of tune. Never really raced anyone with the car, except some hondas that were no match at all. I just don't get any races with the car, I think it scares people, cause all of the other RX7 guys in town get tons of people trying them.

 

if youre using a standalone, i would spring for some 1600cc's. they are cheaper and with 2 of those and stock primaries, you're set for like 500hp injector-wise

 

I agree with Funk.

If You're getting a Haltech, then just go with 720pri/1600sec. That way you won't have to upgrade again, and you have the controller to manage the large injctors.

Plus your duty cycles will be nice and low (ie under 80%)

 

The injector setup depends on what you intend to do with your car. 720/1600 are fine for drag racing where you are only concerned about 2 things: Idle and WOT. For road racing, your engine will run much better with 4x750s. Also note that the new E11 has much better resolution than the E6K, which would also help in a road race setup, but wouldn't make as much difference on a drag car.

Here is an injector worksheet:
http://www.rceng.com/technical.htm

 

Evil Aviator....that was my exact concern running such large secondaries and stock primaries. For road racing, where you need a smooth and more usable power curve, I don't think that kind of setup would work. I think that the 4x750's would be a better idea for what I'm doing. What's the maximum horsepower 4 720's could support about?

 

Whats the max psi for stock wastegate?

 

Well, that depends a lot on your setup. Assuming .64 BSFC and 40psig fuel rail pressure they should be good for a little over 300bhp. You could get more hp out of the 720's if you increased the BSFC or fuel pressure, but I don't think that you will get much past 250bhp with the stock IC and turbo running at 11psig.

 

yea....so it sounds like the 4x720's will be good for a stock turbo/intercooler setup