Which injectors for turbo 4 cylinder? (look inside)

n2oklze · Post by **n2oklze** » June 13th, 2005, 2:23 am

This is not your typical "I haven't searched, so feed me everything like a baby" question about injectors so hear me out. I currently have a klze MX-3 on a 75 shot of nitrous, and have had Mx-3's for the past 4 years so I know a great deal about k series motors, v6 bodies, and Mx-3s in general. I know the basics and a tad more about turbos, so please don't tell me to go buy Corky Bell's "Maximum Boost" book. With my current Mx-3, I'm going to be Megasquirting, dropping in Nissan injectors, and boosting with a t3/t4, basically going all out. With my new Mx-3 things are different. I just got a 4 cylinder for free, and have access to cheap turbo parts from a friend. I'm not so informed as to what will fit though. Ok here it goes.. If anyone is familiar with the K series engines, they know that the Millenia S injectors flow at 280 cc, compared to the stock kl injectors which are at 220. With K series, you can drop the Millenia's in with the stock ecu and not have to worry about controlling, as they are not very much higher flowing than the stock injectors. Sure, they idle a tad rich, but no biggie. I'm loooking for a similar injector to work with my 4 cylinder. I actually get the car tomorrow, so I'm not sure if it's the SOHC or DOHC though. Given any scenario, which injectors flow a tad more than stock and will fit in the SOHC and/or DOHC engines?

By the way, I'm going to be using a WRX turbo, Cartech FMU, Walbro 255 fuel pump, and a small saab side-mount intercooler. Not going for big boost, just trying to reach 200 hp with it. Please nobody suggest stand-alone ecu, it's not happening on that car. Thanks guys.

facko · Post by **facko** » June 13th, 2005, 4:46 pm

well i have the dohc and im running between 7-10lbs of boost and i got injectors from a 1.8L miata. im using my stock fuel pump and a vortech 12:1 fmu and i have no problems with leaning out on fuel.

rebel2k4 · Post by **rebel2k4** » June 13th, 2005, 4:52 pm

Now, if I'm not mistaken, the SAFC works on your car, correct?

If thats the case, I suggest ditching the FMU all together and running 310cc (88-89 PGT/MX6) or 330cc (90-92 PGT/MX6).

As far as a small increase, whats the stock injector size? 1st gen MX6/PGT n/a injectors may fit the bill if you're looking to stick with the stock ecu with no changes. I cant remember the flow rate off the top of my head but I would assume theyre a bit larger than your stockers, but not too huge. Compare them and see.

Also, if you're looking for even bigger, FC rx7 n/a's have 460cc injectors that are also a direct drop in, as well as supra turbo's (440cc) and 1G DSM's (450cc)

nos92mx3 · Post by **nos92mx3** » June 13th, 2005, 6:02 pm

people have swapped the 1.8 litre miata injectors and have had success.
Though does anyone know how close they were to maxing them out, last thing youd want is an injector to go out at 6k rpms. If your interested i have a set of 450's 330's and 310's. Though with these you will need something to control the fuel.
Let me know.

BuGS · Post by **BuGS** » June 13th, 2005, 11:21 pm

Um I have a set of Stock BP ones, like 220ccs. But It is a SOHC you won't reach 200 without blowing something. The DOHC I think can make it. The WRX Turbo is a little big for the 1.6L. 1.8L BP's have noticable lag with them on.

forcedairram · Post by **forcedairram** » June 13th, 2005, 11:38 pm

We have a set of 323 injectors, i think they are 330cc but im not sure on that, im running rc engineering 440s at 10lbs on a small 16G turbo and i have to buy a fuel pressure regulator to get anything else out of my engine, im already adding like 45% on the S AFCII.

facko · Post by **facko** » June 14th, 2005, 12:59 am

not to get to far off topic or nething...but i thought the SAFC didnt work right on the 94+ ecu's...like you could tune the idle, but as for the rest of the rpm range it didnt work because of it reading the throttle as either close or wide open...not 100% on that but i remember reading somethin along those lines before i turbo'd my car

n2oklze · Post by **n2oklze** » June 14th, 2005, 1:48 pm

Well, I may be interested in those injectors if I can find out our stock flow rates. Putting in 220cc injectors with a stock ecu would be a very bad idea if the stock flow rates were like 140cc or something puny like that. I had a SOHC way back when I was 17, but I do remember a few things about them. Aren' t SOHC and DOHC both B6 engines? I was under the impression they had a similar short block. If that was the case, then the SOHC short block would definitely be able to handle 200 hp, since many DOHC's have done it. Maybe I'm way off, I'm going to hang around the 4 cylinder section a little more to touch-up my four cylinder knowledge. Thanks for all of the good input guys, keep it coming.

BuGS · Post by **BuGS** » June 14th, 2005, 8:13 pm

Um racingmazda.com had an SOHC going. I thought I remembered them blowing it up around 180 or 175 whp.

95 rs · Post by **95 rs** » June 14th, 2005, 8:34 pm

ok so if im gonna run the stock turbo and all the goodies from a 323 gtx what else would i need to upgrade if i was using the injectors or should i just stay with my stock 1s if im only gonna be running 7-10 psi??

nos92mx3 · Post by **nos92mx3** » June 15th, 2005, 4:22 pm

well the stock 330's on the 323's run out at around 15 psi (i believe that is towards the upper end of the duty cycle(85-90%))

You also have to think at what duty cycle your stock injectors will be running at, like i said before you wouldnt want a injector to go out at 5k rpms.
PM me if you want to talk prices on injectors. (i have sets of 310's, 330's, and dsm 450's <-- these will require a resistor box which i dont have. Though you can get a local electronic stores)

95 rs · Post by **95 rs** » June 15th, 2005, 6:16 pm

so if i run the 330's i wont have to change my ecu or anything??

n2oklze · Post by **n2oklze** » June 15th, 2005, 7:13 pm

BuGS wrote:Um racingmazda.com had an SOHC going. I thought I remembered them blowing it up around 180 or 175 whp.

People have different definitions of "blowing up" an engine. If they put a rod through the block or snap it in half, that would tell me that maybe the SOHC may have trouble handling all of that power. If they melted a piston or spun a bearing, that might tell me that they were running lean or had oiling problems. I'm open to new information, but when someone says something can't be done and don't give proof to back it up, I really pay no attention to it.

cjthor · Post by **cjthor** » July 2nd, 2005, 2:38 am

facko wrote:not to get to far off topic or nething...but i thought the SAFC didnt work right on the 94+ ecu's...like you could tune the idle, but as for the rest of the rpm range it didnt work because of it reading the throttle as either close or wide open...not 100% on that but i remember reading somethin along those lines before i turbo'd my car

I have a 94 and my TPS vaires between 0 and 4.5 volts. I am running a SAFC too.

forcedairram · Post by **forcedairram** » July 2nd, 2005, 8:33 am

All the super afc needs to read is closed or wide open throttle, and thats not all it reads thats just what your TPS sends. The only downside to the super AFC is that you have to tune it to one setting, like for example.... on my car anything under 3500 rpms has to be very light or to the floor, anything over 3500 rpms is half throttle or to the floor. this being becuase the Stock TPS only sends a open or closed signal. But its really easy to work around it.

MX-3.com

Which injectors for turbo 4 cylinder? (look inside)

Which injectors for turbo 4 cylinder? (look inside)

330s

Safc