i only took one pic


seemed decent enough quality. no glue holding things together so its not completely chinese.

anyway as far as manifold, i bought a flange from racingbeat. was going to have my buddy help me build a tubular manifold out of 304. i was thinking a big wastegate like tial or hks in the 60mm range. cant go too big on wg, at least thats what i was told.

as far as fuel, i am using bosch 044 pump and 850 primaries and 1600 secondaries.

 

That looks beautiful. I'll go ahead and get the one off of eBay.

I'll look for a 60mm waste gate, too.

Thanks for the info on your injectors. I'll look at what I've got here to see if I've got enough 850s.

Are your 1600s high impedance?

 

I don't think you can get hi flowing injectors in a high impedance. I think anything from 1100cc (saturated injectors) and up will be low.

 

I think I'll start with 550s and keep out of boost while it breaks in (lol duh). Then I'll swap to 850s for primaries and by then I should have a better understanding of injectors to go low impedance on the secondaries.

Thanks man!

 

we don't have anything good, but my other buddy has plenty...

early casting motor? maybe 300-350? start running off the wastegate, get the tune right and then start raising the boost.

i think its easier to put bigger secondaries in, just cause its a "normal" injector.

it seems like the 550's were plenty up to like 8-10psi which is probably going to be really fast in a 1st gen...

 

Looks like 850 primaries would be a bad idea. https://www.rx7club.com/power-fc-forum-47/obsolete-injectors-927585/
What are your thoughts on this subject?

I don't plan on much above 9 psi due to the early castings. It should be plenty fast in a 1st gen with just 9.

I got the rotors all loaded up with new stuff. The engine builder scribed rotor weights in grams on each one. F 3695, C 3702, R 3705. Hey that's a ten gram spread!

Jeff Bruce recommended the rotors for the 4 rotor 12A be within 10 grams of each other. Looks like my 20B rotors are good enough. Probably good for 8k, wouldn't you say?

 

You can get away with Bosch Indy White 1600cc injectors running in High-Z mode on a megasquirt v3 pcb. I have a pair of the buggers wired in parrallel. They are actually 4.6Ohms which is low but on the higher side.

Remember if you have a 20B with 3x stock 550cc primaries, and then 3x 1600cc secondaries, you have a LOT of fuel, to the point where you can drop rail pressure to probably 35psi, stage to 85% primary duty cycle with probably a 2 cycle no reduction stage, and never feel it.

From my own testing, staging like this the secondaries come online and both primary and secondary pulsewitdh drop to 3.5mS around 30% injector duty. High enough for smooth running, long enough duty cycle that 'slow' injectors are OK. Also the duties are still short enough any overheating would be minor.

 

The other thing to remember is that this puts less load on your fuel pump. As absolute fuel pressure goes up, current draw goes up, and maximum flow goes down. Furthermore fuel leaks are MUCH LESS LIKELY with oversized injectors at low pressures than borderline injectors at 43-50psi.

AND MORE :P As you increase fuel pressure the injector opening and closing times go up, making the amount injected less precise. You also increase the load on the electomagnet pulling the pintle.

 

I wish I knew as much about EFI as I do about older carbed setups.

 

so since im running a similar setup.. jobro, you are saying that running stock 550 primaries and 1600 secondaries @ 35psi is the way to go?


also.. i wound up going with a 46mm wg. was told that was plenty big enough.. i hope that is right

 

I haven't purchased anything yet because I've got to get the engine together first (just waiting on an order from Mazdatrix) and running in NA mode next (already got the badly made header for it sitting here) before going turbo for better street running and quiet exhaust.

So is 46mm really a correct size? My engine is streetported but the side plate castings are early so this means low boost which obviously equates to low power. Maybe I can get away with a wastegate smaller than 60mm. 300 to 350 HP is what I'm aiming for, but 400HP is the absolute maximum I'd do. Not sure if huge secondary injectors are necessary, but the old saying goes "you can never have enough fuel delivery" made by DirectFreak I believe.

 

yeah i dont know. i guess if it has boost creep problems then ill have to go bigger

 

That is

2x stock 550cc 195500-2020 Purple top S5 TII injectors
2x 1600cc Bosch Indy Whites from bmotorports.com

At slightly lower pressures you can 'de-rate' them to ~400cc/1200cc pair, making them similar to a 800cc pri/sec combo but with more resolution on primaries I needed about 4x900cc, but I was not impressed with Siemens 3105 injectors (they do work A-OK on a microtech however) in the past. And I didn't want to spend $800 getting 4x1000cc sard injectors.

Gave my mates dad 2 6-packs of lime beer to turn the Indies down on lathe.

See minor wheelspin in top end 2nd gear with LSD and street slicks

 

Damn I wish this thread was up early last year when I started building my intake. I built it to take the older Ev-1's that came with my 20b. It looks like the Ev-14 are quite a bit shorter. I think I have some in my shop off some junk engine parts. I also like that they are higher resistance on the saturated versions. Would it be worth my time to later on convert the secondary's to these new style injectors? I know the Ev-14 are newer tech but what makes them so good?

 

Bosch 'white-top' pn: 0280150846 is probably EV-1. I don't know or care they work bloody well in the secondary holes.

http://www.youtube.com/watch?v=kK8KKfUgzcw

 

Hey thanks for the info on those injectors Jobro. I think I'll get some but I'm not sure whether they need to be turned or modded to fit in my stock 20B secondary rail.

According to rx7.com, they need a little work to fit in an aftermarket rail for an FD, but they don't say anything about 20B or 13B-RE. http://www.rx7.com/store/rx7/fdfuel.html

This link about the pintle cap change is news to me as well. http://www.rx7.com/store/rx7/1600ccPintle.html

I'm kinda confused here. If I understand correctly, this means if I were to buy some cheap 1600s from eBay, they'd require the pintle cap changed and the upper part lathed down. I don't have any experience with any of this. I'd rather buy some that were already modified so I don't screw up anything. But are these modifications necessary to fit in a 20B rail and LIM?

A better option might be to buy these already modified Bosch whites with EV-1 pigtails included (since I'd need some bosch style connectors anyway). http://cgi.ebay.com/ebaymotors/2-Bos...Q5fCarQ5fParts

Is that a decent price on some already modified Bosch whites? I wonder if that seller would sell a set of three injectors instead of two...

 

I found this 60mm wastegate. Is it appropriate for my needs? http://cgi.ebay.com/ebaymotors/60MM-...Q5fAccessories

I found this intercooler. It's the style PercentSevenC is getting for his FB. Think it will be large enough for me? http://cgi.ebay.com/ebaymotors/ws/eB...m=330496838536

 

As mentioned earlier in this thread, I have a GSL-SE gas tank and 5/16" send and return hardline under the car. I also have an inline Walbro 255. Are these going to supply enough fuel for three 550 injectors and three 1600 injectors? Or will I need to get a second Walbro (hooked in parallel) and up my send hardline to 3/8"?

Note I still have my OEM fuel rails and don't really want to swap them to aftermarket.