Tbi injector size 13b sp
 

I trying to find out what size injectors I need for my efi hardware ida style throttle body. The engine is a 13b streetport 4port. Fi swap fb project. I don't see much activity in this N/A forum. Has everyone gone turbo or something. ?

Most activity on the forum is in the turbo sections, yes. N/A people generally know what they want and build the car/engine once and don't have a whole lot of things to post afterwards lol.

The easiest setup currently for n/a that should provide plenty of fuel for up to 300 HP is running 2x ID1000 injectors in the primary position only and not running any secondary injectors. This simplifies your throttle body setup so you only need to run a throttle cable to the TBs and you also don't have to muck around with injector transitions. What engine management are you planning to use?

Efi hardware
 

I thought you wanted to run four injectors. Primary and secondary. I just got a EFI Hardware ida style throttle body. I put four turbo 2 injectors 500cc each. With a adaptronic universal 440d ems. Aem smart coils. I picked adaptronic because I thought it was the easiest to tune. I have no prior experience with aftermarket fuel injection. Especially tuning on a laptop. I always had carbs on my rx7's. Any advice would be appreciated on installation in a first gen. Got pretty much all my parts now. Going to install soon.

You don't need four injectors. Modern injectors and computer hardware are precise enough that you can get away with a pair of 800-1200cc injectors and be done with it.

I went for years with a pair of 680cc injectors and fairly low-end injection that could only control pulsewidths down to the tenth of a millisecond. This led to high granularity when idle/low load pulsewidths were in the 1.6-1.7ms range. Given that large ported engine tend to be less efficient at low load, and we're not shooting for the kind of precision needed to make a catalyst happy, this was more than sufficient.

A word of caution to future readers. GSL-SE ran on 2.5 bar base fuel pressure, NOT 3 bar like practically everything else. 680cc is the flow rating at 2.5 bar. When you buy a pair of RC1000 injectors to replace those and give yourself more headroom, and use them at 2.5 bar, you only get about 900cc/min. No wonder my duty cycles didn't change all that much :) 900cc/min was still sufficient fuel for my bridge port to give me a safe fuel-dump at the top end to slow the engine down so I wouldn't overrev.

Yeah, I agree with most stuff said above. 500cc turbo injectors will probably work, but on a budget I think I would try 4 yellow RX-8 injectors, and with a more spacious budget I would go with a single ID1000 injector per rotor, which is what I run on my semi PP 2-rotor.

Injector technology has come a long way since the mid 80's. Previously they ran 4 injectors because large volume (1000cc/min plus) injectors flow did not scale linearly with duty cycle so they would have very poor idle quality at those low flow duty cycle levels. So you would use a smaller injector and then at some determined RPM and load when the primary injectors start to get close to max flow/duty cycle you would turn on some secondary injectors to supplement how much fuel you needed for the high end.

However, the injectors being made today do not have these same limitations so you can just get 1 for each rotor that can meet your top end fuel flow needs but they still perform very well down at really small duty cycles which completely erases the need for secondary injectors. This does not necessarily apply to turbo applications because often they need considerably more fuel flow (over 2000cc/min per rotor!!!) than a naturally aspirated application. Hopefully that kind of helps clarify and give background to the advice we have given above.

As far as tuning and using the Adaptronic, can't really help you there. I'm just about to install a megasquirt ms3-pro evo into my '86 GXL. However, go hang out in the Adaptronic section of the engine management forum. I'm sure there are some good base maps to help get you up and running so you can actually start tuning. Let us know how it goes!

Well I already got 4 550cc turbo 2 injectors for $50 tested and cleaned . So I'll see how that works out. . Making the harness now using nylon rope as a template cut to the length I need (+3inch).

That should provide plenty of fuel to meet your needs. Let us know how it goes and post some pics!

that is plenty of injector. its just that 2 is simpler. you can run staging with 4 injectors, and that will get around the 'not linear at low duty cycle' thing. 2x550 will idle around 2.2-2.5ms, so you're good there.

i'd try staging with load/throttle position, but you may have to play with that

Efi hardware
 

https://cimg5.ibsrv.net/gimg/www.rx7...f6dfabb385.jpgEfi hardware pro street tapered bore 55/53/50 throttle body.Pic of the set up i got from efi hardware. Thinking about running the rx8 injectors any advantage to running the newer rx8 yellow 440cc injectors vs. the older turbo 2 550cc. four 440cc seems like enough . I can get some pretty cheap.

Hare you got this thing running yet? I looked at this exact set up from EFI Hardware. Interested to see how well this works for you

Any updates on this build? What sensors are you gonna add to run the computer?

I just got it running. Still needs to be tuned tho. Have a appointment to have it dyno tune on 1/8/18. But hopping to get it running well enough to drive it to the shop so I don't have to tow it there. I had a bad plug on the cas that caused me som problems . Now the idle just bouncing up down. I sure it a setting I have to figure out. I have innovative wide band sensor, tps,map sensor. That's it. Love the spark on the aem smart coils. It could be pig rich fouled plugs and it will still fire up.

Well I have to say I'm very pleased with the way it runs now. I learned a lot over the past few months trying to figure it out. I wasted $400 to have it tuned on a dyno. All they did was screw it up. Shop had no clue on what to do with adaptronic. But all is well now. Car hauls ass! It has a lot more in it too. Now that i know what to do. The fuel map could use a few more adjustments.

AWESOME!!! glad to hear your happy with it... I just got an E&J 4 barrel TB since i already have the holley style intake. I am still not sure which ECU to go with but i will figure it out soon. Good luck with your project bro

With the adaptronic ve tuning with map sensor is great if u have a wrap around manifold. But kinda useless with throttle body injection. Something i was not aware of before I got the adaptronic. I do highly recommend the ign-1 smart coils. No matter how rich the fuel mixture is. It will start. I dont know if other ecu have variable dwell for the ignition coils. But It's a big plus to have with these coils.

I'm running adaptronic with throttle body injection as well. Gave up on the MAP tune and switched to TPS. Still fighting transient and idle issues but every time I get close, the weather turns bad and I have to park it. Then I forget where I left off. Found lots of weird stuff in their "base" tunes. One of them has this weird setting where it ignores closed-throttle for certain temperatures. No idea why.

Anyway, figured I'd chime in and mention I've got 4 Edelbrock Pico injectors, 427cc each. I too dropped the fuel pressure down from 45psi to 35psi (~2.5 bar). I don't go above 60 on the VE table with a stock port. I'm sure I'll need more fuel after the engine gets ported.

Attachment 734721

https://cimg8.ibsrv.net/gimg/www.rx7...a5d24540ee.jpg
I went with 1used 2 tps and got it running really good. Map prediction wouldnt work with tbi. I use asynch accelerator tps base enrich. I copied fig.35 in the adaptronic 440d manual. Only thing i added was cutoff % i put at 100. Works really good for throttle transition when u punch the throttle. I use 2 460cc rx8 yellow injectors and 2 FiveO motorsports 550cc modified rx8 injectors for secondaries. By far the one thing that made the biggest improvement in the way it ran was the Efi Hardware fiberglass air box. I saw on my logs driving around town that my intake air temps were really hot. I had the sensor mounted in the middle of the two air horns. With just foam socks over the air horn as filters. With the efi hardware air box with a 5inch hose to a cold air box with k&n that i made next to the radiator. Intake air temps before were 180degrees. Now only at around 100degrees.

180 degrees? What was the ambient temp when you were getting those readings?

Also, could you share your values for the Asynch Accel Pump table after you turned off map prediction?

I looked back at my log and it was 130 degrees and ambint temp was 60. Figured it was caused by heat soak. It would only get that high after driving the hell out of it. On the back roads ofcourse. The accelerator pump i unchecked map prediction. For the transient throttle i have TPS based Enrich at 10. Enrich duration at 700or800ms.(been on 800 lately) Both of the Cutoff% i have at 100%. and Gain% at 5%. I attached a pick of my Asynch Accel. Pump settings. It worked really good for my setup. https://cimg7.ibsrv.net/gimg/www.rx7...038e50f3d2.jpg

Asynch Accel. Pump

Awesome, I'm going to try this out. I've had no luck dialing in the MAP based settings but had no place to start with this table since there is basically no documentation and all of the example base tunes use MAP.

Cant remeber where i got the table from. Think it was the adaptronic form. I added 1 to each rpm then at 8000rpm i put 1 it was 0. Didnt really make much of a differance. I just add it cuz i put bigger injectors on the secondarys. Ive been playing with map1×2tps lately. Map used for the idle part because theres vacuum. Tps for the rest. Only way it works is u have to have the tps map already tuned on 1 unused 2 tps. Then u can do 1map × 2tps. Just in fuel map1 put 1.00 on the whole map. It seems to idle alot better. But i still havent got it figured out. In adaptronic manual 1map × 2tps is the best for tbi. Thats what they say at least. I still go back and run 1 unused 2tps if i want to haul ass.

I should add that i have most settings turned off or at 0. Adaptronic universal select has way more than u need with tbi. I put on digital inputs 1 and 2 to clutch switch helps with closed loop at idle or something like that. Have it wired one to the stock rx7 fb nutral switch, and the other to stock clutch switch.

My REPU transmission doesn't have a neutral switch but I did add a clutch switch. I added a Bosch idle control valve and some vacuum lines to add air on cold starts. It helps during initial warm up but if I let the ECU use it after that it never seems to work right. I keep playing with the idle PID settings but haven't found values that consistently work.

I have all that PID & idle control stuff off or at 0. Idles smooth just a little high but thats what all TBI do.