I have a S4 T2, im curious as to what upgrades im going to need to go BNR Stage II, ive heard soooo many different things. I know im going to need a Koyo radiator, a Super AFC, FMIC(working on that), rtek 1.7 but im curious as to what size injectors i would need, i want to run around 13-14psi. I already have a RB Turboback exhaust, FCD, HKS intake, Walbro Fuel pump.

 

the rtek is just a chip that remaps your stock ecu a bit more agressivly, has a biult in FCD, and lets you use 720cc injectors... I don't know why you would want to get that and a S-AFC.

 

I heard you can use both with Rrek because you'd need to control the fuel because rtek is built for use on the stock turbo, not a BNR Stage II.

 

why would you even get the rtek though?

 

"why would you even get the rtek though?"


Not really sure why anyone gets the rtek at all. AFC allows you to turn down 2 720's and gives you a little insight to whats going on. Not a real fan of "trusting" a chip but tons buy them.

 

i'd probably suggest a FMIC, 720cc injectors and an SAFC....

from what i can remember off the top of my head....

 

You could say some of the same things about an S-AFC, it is a "bandaid" for controlling fuel, not really the best thing to use. How is an rtek any worse? The S-AFC alters your AFM signal and lies to the ECU, doesn't seem very "trusting" to me...

 

Hybrid turbo, rtek 1.7, and a SAFC is a great idea. Throw 680's in the primaries and 890's int the secondairies.

The Rtek makes it much easier to run a hybrid with a SAFC. WHY? The AFC has to trick the ECU to run the hybrid. The ECU gets tricked and adds more fuel. The AFC can only trick the ECU so much. And the more it has to trick the ECU the more difficult tuning and drivability becomes. The Rtek reprograms the ECU for alot more fuel than stock. Once this is done the SAFC has to trick the ECU less. This make tuning a hybrid turbo much easier. And this increases the size of the turbo that can be tuned by a SAFC.

 

where the hell can i get a pair of 890cc injectors for my secondaries that are just a drop in replacement, i have S4 block with everything else being S5....

i was told Marren sells them but i dont have a site or anything....

 

Search Marren 890cc fuel injectors in a google. They're site is there and search HondaHaters posts, he made a quick write up on how to adapt Marrens 890cc injectors.

 

wicked, thanx!...

 

So I Googled Marren injection and I came up with.. Predictably enough.. Thier website:

http://www.injector.com/

Now if you guys have a Series 5 harness, you will need to repace the oval plugs with square plugs. Here, let me do even more of your work for you:

05850PI 85 lb/hr (890 cc/min) Pro Import Low Impedance Japanese Low rect. $95.00

These are low impedance BTW, and are a DIRECT FIT for the s4 OR s5 car. Again, if you have an S5, you will just need to clip off the oval injector plugs and install square ones that can be found virtually anywere!

How is this possible? Because the Mazda fuel injecton for the FC was a proprietary system called the Bosch L-Jettronic (I may have fuxr3d that up..). That means that the basic injector design is top feed side plug, just like the Toyotas, Nissans, Hondas, and anything else coming from Japan with FI on it in that era.

 

wow, i dont know what else to say....

basically get the injectors, get the clips, install and tune....

wow....

thanx!...

 

Couldn't agree more. The less you're tricking the ECU, the better.

 

Ok, so it is fine to get rtek 1.7, and a SAFC, so i can't use 720's in the primary and secondary? Because i have a set of 680cc's that i JUST sold because i was goign to go rtek 1.7 real soon and use 720's in the secondary.

 

Check out the rtek website, I'm pretty sure they explain everything in detail including base maps for different injector combos.

 

i know what RTEK requires dude, im wondering what size injectors or ideal for going BNR stage II while using Rtek and a SAFC

 

except you have to get resistors if you put it in an S5 to make them high impedence.... right?

the the rtek stuff makes sense plus it probably retards the timing a bit too...

I don't know, if you buy both of those at that point a stand alone might just be easier...


btw, does anyone know if greddy 720s come with clips? and if not would I be able to get them at like a car parts store?

thanks

 

hmmm, no one even mentioned the timing retard at higher boost levels that the Rtek provides.... it's built in fuel cut defenser or the built in fuel pump cut to correct for flooded engine conditions.

an Rtek is the next best thing to a standalone and costs a bit cheaper. don't get me wrong, it is still a bandaid but it has a few things the stock ECU can't provide.

 

The problem with increasing the size of the primary injectors on a stock or Rtek ECU is that the computer doesn't know that the primaries are bigger. Why is this an issue with the primaries and not the secondairies? The SAFC (correct me if I am wrong) doesn't affect low throttle driving and idle. The secondaires do not come un during low throttle driving and idle. SO! The computer is dumping alot more fuel in under idle and conservative driving. What is so bad about that? Horrible gas mileage, fouled spark plugs, ect.... bad stuff. So primary injectors that are alot bigger than 550 will cause problems.

So why get bigger Primaries at all? Why not just some 1000cc secondaires? There are 2 main reasons. First being that the secondaries do not come on till 3800 rpms (stock ECU) or till 3500rpms (Rtek ECU). This means that below those rpm points you only have two 550cc injectors available... Can you say LEAN? Bye bye engine. The second reason is the large 1000cc secondairy injestors will come online and bog the engine down with a large about of fuel when they come online. This problem can't be solved with a SAFC, a standalone is needed.

So a compromise must be made. I suggest 680cc primaries and 890cc secondaries for a T2 with the Rtek ECU and a hybrid.

OR, if you are really wanting to do it right. Get the rtek, 720 secondaires and an AIC (additional injector controller). Tap another injector in just before the TB and you can tune much better than an AFC.... of course ther is more work, another injector and modified fuel line.

Blah, I'll stop babbling now.

 

I don't see it as a "band aid" myself just because it is nearly fool proof, unless you are a fool installing the other parts. Also I have first hand experience with it and would recomend the Rtek to anyone.

 

You use 10ohm/10w resistors to make low impedence injectors work on an s5.

Greddy 720s do not come with clips (I think rx7.com may have a package deal with injectors, clips, and resistors).

Any bosch style square injector connector or rc engineering connector will fit.

 

yup.. Oversight on my part. You will need the resistors to impedance match the resistors.

 

Long day? Me too.

 

it is only a bandaid depending on what kind of mods are run, an rtek would be fine running lower boost but running even a stage 2 hybrid at full efficiency i would suggest using a standalone so everything can be tuned not just tricking by tricking the ECU's MAF input to push out more fuel.