currently iam about to buy a SMIC (probably greddy or PFS) and I want to run 15psi. Anyways I dont know what size injectors I need or what combination to run so any help would be great. my current mods are as follows.

94 Auto
rx7 store raceport motor, everything blocked off and turbos non sequential, DP, MP, CB, intake, PFC, greddy profec B, walbro 255,

I have a extra set of 850 secondary's that need to be sent out to RC but I dont know if 4 850's will supply enough fuel. also the car idles like a harley as it is because of the port so I dont know if it would help the idle if there were 850's in the primary spots.

please help

 

I read that 850's all the way around will be good up to around 400bhp @ 80% duty, but some people have problems using primaries that large. Many just replace their secondaries with 1300cc or 1600cc injectors.

I'm actually in the process of doing this myself, that is, 850cc x 4.

 

I was considering running 1300's but dont they have a history of failing and blowing motors?

I mean does anyone think ied have idle problems running 4 850's with the auto tranny and huge port? The thing idles preety crazy as it is so I dont want to do this and have the thing stall when I come to a stop light.

 

My initial response to that would be that there are quite a few people who will overbore their 850cc injectors to 1300cc. Something I don't particularly care to do.

Then again, there are a few reasons why injectors fail. I can't say I blame it on 1300cc's though.

 

In the past, people didn't use 850's in the primaries as it made the idle really bad. However, with the newer ECU's (like the PFC) available; proper tuning takes care of that problem.

 

any tuning tips for the pfc

 

For best results, hire an experienced pro

 

i bought 1600's. using the stock 550's in the primarys, running the same mods you are. its more then enough fuel, and i wont have to upgrade when i go single (hopefully r-85)

 

I'm running the RX7Store extreme fuel system with 1000cc primaries, its been a challenge to get a good idle, but im getting closer, hopefully when i have a "real" tuner work on the car it'll be great. I just fooled with it to get the car running to move around, and it isnt half bad for a couple tries by an amateur. Personally I wouldn't do the 850 primary swap, unless I seriously misunderstood how it was supposed to work it seemed extremely ghetto as the secondary injectors are substantially different from the primaries and didnt seem to fit very well. I'd just go with the 1600 secondaries and rail, 1300s are almost invariably just bored out 850s or 1000s, 1680 (most people call them 1600s, they're 160 pound per hour, pph x 10.5 = cc/min ie 1680 cc/min) is a stock off the shelf size for bosch injectors.

 

I've got 550's and 1300's. I'm running 15psi and making 385rwhp. I didn't want to have to go through getting a new rail and regulator so I got the 1300's. I've had no problems at all.

 

I dont know.... I want to go 1300's but I dont want to risk blowing the engine I payed about 3K for. I was thinking about having my current 850's sent out to Rc to be cleaned and bored to 1300's but they have about 90K miles on them. What would you guys say is a safe mileage to have this done at?

 

I bought brand new 850's that were bored out to 1300's.

I've got over $40K in my car and I don't worry at all about my secondary injectors. I think the 1300's blow engines is a bunch of BS... It's a lot of hear say I think.

 

i have the rx7store 1680cc secondary kit with the rail, fpr, lines and everything i needed.

The transition between injectors isnt bad at all long as you can get it tuned. It still idles like before, and i have plenty of fuel for over 400whp.

 

Save your money for a new tranny, I smoked mine with just bolt ons and a PMS, the power your talking will destroy it sooner or later, most likely sooner. I am suprised yours is holding up as well as it is now.

 

upgrade the trans (ASAP)... before doing anymore power mods. you gan build the auto trans to hold over 400 HP so I am being told. ts not going to be cheep but worth it if you don't want to do the 5 speed swap. call around to trans shops that do race transmissions to see what they can do for you and the mods you want to add.
Jeff

 

I actually have been making 310whp on that tranny for a year and a half and the ATF isnt burnt. Ive known a couple auto guys that install tranny coolers and royal purple ATF the make 365whp reliably. I dont know... iam starting to think that the auto tranny can hold more then most people think.

I plan on converting to stick next year but until then the auto will do.

 

We should hook up some time and you can check out my RX7 store fuel system, you don't really need the big primaries, but you can check it out if you want. Btw this is Big Wheezy/Big Mike/whatever. I didn't even notice I was replying to a fellow Ohioan's post when I wrote that, lol.

Edit: If I have my way this winter I may have a nearly complete stickshift driveline for sale minus the pedal cluster and a few other small peices.

 

I didn't make it but a few months at that much power. The bad thing is when it let go it just let go. I was doing 15 mph taking my dog back from the vet and the thing just decided to quit working.

Would love to see how much power the thing can hold, I rather enjoyed my AT FD.

 

For fuel, get yourself a walbro 255 pump, FPR, KDR 2ndary fuel rail with 1600s you cant go wrong and you'll have plenty of fuel.. I currently have 850x2 and 1600x2 but I went single and i'm going to add 2 more 1600s..

 

oh yeah your also on the lot spot I forgot. iam actually gonna be getting billy's tranny here soon so I might need some parts from yeah still. So when are you gonna take that 7 to the lot? when need more rotary's up there.

 

Whenever I decide to quit taking it apart, lol. I noticed you're looking for a set of turbos, I still have my 60k mile set floating around here somewhere if you're interested, modded non sequential, alot of cracks but none that are real bad, we rounded them all off so they shouldnt get bigger.