I am curious to see what you guys think of this.

I have a couple of clients that want to upgrade their car but want to stay with the twins for the moment.

I don't want to install 1300cc because of the reliability issue people have had with them. I know that 1300 would be the best size for that power level (15 PSI on the twins for example).

I also know that the 1600cc are overkill for the twins but i really don't want to go with the 1300. Do i have other options?

Installing 1600 is so cheap and you are ready once you want to go single. This is why i like that setup.

Does 850 all around would be a better choice? That would be fuel for what kind of power level and what kind of boost?

let me know what you think on the subject.

thanks a lot

puma

 

I believe that 1600's with the stock primaries cause a hick up of fuel. But that's all i've heard.

pm mdpalmer about this. His set up was exactly what you are talking about. That is stock twins, 1600's, boost at 14 psi. ect.

 

I get a slight stumbling do to a rich condition caused by the 1600's when they open up @ around 3000 rpms at partial acceleration. Never any problems @ WOT. Again it is very slight. Not bothersome. I have heard some others have bit more problems. We tuned my car on the dyno. Then drove it on the street and "cleaned up" the cruise maps which helped significantly. 550's in front by the way. G

 

its very easy and inexpensive to drop in bored out 850s to 1200 or 1300 into the secondary rail. I don't understand how 1600s are cheap to install considering you need lines, a new fuel rail, and a fuel pressure regulator. Last I checked 1600s don't drop into the stock fuel injector location.

I've been running 1300s for years w/o issues but some people have had issues with them.

I know ccarlisi (spelling) had done 1600s on his twins running sequentially back in the day. I think he had a thread on NP about it.

850s all around pose their own challenges since you need to remove the primary rail under the rats nest, have it bored/milled to fit the 850s and reinstall w/o breaking anything. After that you have to tune the bitches which can be troublesome.

Goodfellafd3s had a great thread on fuel systems that you might want to search for. It might be linked in the FAQ with a bunch of other threads on the fuel system.

 

Actually the thing is that i am afraid of those 1300, i really don't want to have someone blow an engine because an injector broke. Unless some of you guys tell me that issues with the 1300 braking is over, i amust admit i am tempted of going with the 1600.

A fuel system from rx-7 store is 580 while two 1300 is 330 but with the fuel system you get the aftermarket regulator which means you can remove the stock pulsation damper because the regulator has one kinda built in.

Everytime i work on a car for the first time, i always replace the FPD because they are well know for engine fires. That is an other 150$ right there that you don't need with the fuel system.

I know the 550/1300 or 850/1300 is by far the best combo, it is just the reliability issue that scares me.

Who are those that had engine blow because of those injectors?

 

that doesn't really bother me because as i said, i need to remove the primary rail to change the FPD anyway. Plus, i always change the OMP line while i am in there.

What kind of HP or boost can a setup of 850 all around can take? I guess it must be enough for the stock twins at say 15 PSI?

 

I ran 1600cc secondaires and 550cc primaries when I still had my factory twins. It was a great upgrade because a few months later my twins took a **** and I ended up going single.

As for the "hick ups" that people are talking about; I have never experienced it. I had a map put in by Jason from the rx7store and it just runs slick.

R.K.

 

i kinda like your strategy puma - replacing stuff that will probably fail eventually (if they haven't already been replaced). following that kind of strategy i can understand why your cost differential is not as large as it would be for installation of the fuel components alone.

there is another place that recently started making a real nice secondary rail for 1600 injectors that made install and routing of lines much simpler and reliable. I don't remember the thread, but I would suggest doing some research on that rail and system before committing to a vendor.

Gotham Racing also sells a nice secondary rail and fuel system.

 

the more i think about it, i will be going with 4 850cc i suppose that would be enough fuel for a light streetport with stock twins for around 15 PSI of boost.

what do you guys think?

 

^ I think you'll need this:
http://www.gothamracing.com/catalog/...roducts_id=862

 

I say 1300s....I ran the 1300s for years....then when I went single upgraded to 850/1300 and never once had an issue

 

for those that run 1300, do you still run the stock fuel pressure regulator, the fuel pulsation damper and the OEM banjo bolt between the primary and secondary rail?

wouldn't those be some sort of bottle necks for the system? Mostly for those running on single turbo with this setup

thanks, i like that discussion.

 

I have 1600cc secondary running about 14 psi on stock seq. twins and stock primary, and my IDC is only hitting 60% or so. no issue here, plenty of fuel, just have a little bouncy idle here and there..no big deal.

 

well the idle problem certainly has nothing to do with your secondary, i can tell you that

 

steve kan recommended me to get 1300cc for my car and i wouldnt really doubt his words

 

I've been thinking about changing the injectors on my FD too, I'm running efini turbos at stock psi, changed the vaccum hoses and coolant hoses, and i've been thinking about changing the intake and catback. If i change the intake i'm gonna put in a power fc but i was curious if it's possible to reach 350 hp without changing the injectors?

 

What ECU are you running?

 

This allows you to keep a stock ECU? chipped ECU like Pettit?

 

nope, it has nothing to do with it, he just pointed out that if i want to install 850 as primaries, i need to get the fuel rail machined because the injectors are not the same size.

engine management and injector sizing is a complete other story.