I was told the stock ecu would be able to handle a hybrid turbo without any additional piggyback, standalone, reflash, etc etc etc.

Ontop of that I was told throwing 720s in would help. As long as I was not pushing excessive amounts of boost, that the stock ecu (in my case a JDM ecu) is capable of running the car.

How true is this?

 

You could probably get by, but I wouldn't risk it.
I'd feel ALOT safer with larger injectors and a fuel controller at the very least.

What kind of hybrid are we talking about here? If you were thinking about throwing 720's in the secondaries only, you can max those out pretty easily.

 

Yea, what kind of hybrid are we talking about here?

Well, w/o an FCD or computer of some kind you won't be able to hit more than 8 psi anyway, hybrid turbo or not. And the stock injectors can handle that much just fine. In fact I've heard they'll can be pushed to 10 psi (on the stock turbo) @ their limit. Any higher than that and you'll definitely need those 720's. You could wing it at lower boost levels (hopefully w/ a wide band...), but anything much higher than 10-12lbs is probably asking for trouble w/o at least An Rtek or safc

 

I personally wouldn't upgrade the turbo at all without having some way to tune (at least) the fuel-curve.

I would highly suggest a wideband O2-sensor and at least an SAFC... You really don't want to blow your engine if you don't have to. If you're strapped for cash, you can find SAFC's for close to $100. Shoot, I just picked up an Innovate LM-1 wideband with everything for $170 shipped.

 

Where?

 

Any increase in injector size without corresponding electronic changes (remapped ECU, fuel controller, etc) will result in richer mixtures, less power and wasted gas. The ECU has no way to compensate for the greater fuel flow. Sure it'll run, but it's a crude approach.

 

From another forum-member.

 

U could probably run the stocker better than the hybrid set-up

 

Depends on how well you want the car to run.

Will it run... Yes. Will it run well... maybe. Will you blow your engine... maybe. Your leaving a lot to chance.

Get some kind of fuel controller. It is always cheaper to do things right the first time rather than fixing your mistakes after you realise they don't work.

 

A fuel controller is not going to make anything safer. Despite the disadvantages, not having a fuel controller is probably the safest way to run with upgraded injectors, as the mixtures will always be richer than they should be. Using a fuel controller to lean out the rich mixtures will improve efficiency, power and mileage, but by definition is moving closer to the point of detonation. That's why it should be properly tuned by someone who knows what they're doing.

 

Sorry, forgot to add that it needs to be properly tuned or the controller is useless.

 

550/720 with SAFC, walbro 255, and innovate wideband. It is a proven combination. It's not the fanciest way to do things, but it will work.

And you can figure out how to use an SAFC pretty easily.

 

Lucky bastard! haha

 

Your best bet would be this:

Rtek 1.7, 720cc secondaries, cleaned/flowed primaries, Walbro pump.

OR

Rtek 1.8, 4X 720cc secondaries, Walbro pump.

Either set-up nets you these advantages, second option just has more headroom for fuel:

Lowered staging point for injectors, makes up for quicker spooling with exhaust.

Increased duty cycle limit ~5%, gives more leeway before secondaries come online.

Tuned for the injectors, still has great stock-like driveability. (I still get 25.5 mpg on trips with mine).

NO Boost-Related Fuel Cut, and it pulls extra timing at higher boost for greater safety.

Deflood engine by simply flooring the gas pedal.

Best of all it is cheap! Now I don't know if it can be done on your JDM ECU, but it wouldn't be very hard to find a USDM ECU and have the Rtek chip put in. If you want something close to a stand-alone, their Rtek 2.0 has adjustable fuel and ignition maps, PALM Pilot programmable/datalogging, and AFM DELETE.

Vince

 

Rtek 2.1 now

No AFM delete yet.

 

That's completely wrong. The secondary injector staging point has no effect on anything except avoiding maxing out the primary injectors. How could it? There should be no change in AFR when the secondaries come on.

 

Maxing out the primary injectors is what would happen if the turbo spools much quicker as a result of a free-flowing exhaust (i.e. 3" downpipe, no-catalyst, etc.).

According to the guys at Digital Tuning (makers of the Rtek), it is possible to hit the duty cycle cap before the staging point... This would mean that it would begin to lean out since no more fuel could be delivered in this situation. As a result, they lowered the staging point AND increased the duty cycle cap ~5%.

Below is a quote directly from Digital Tuning's website:

So, how exactly am I completely wrong?? I left out this explanation to make my post easier to read.

Also, on the AFM delete, they had indicated it would happen last time I checked their thread on teamfc3s.org about 9 months ago. I just assumed they would've gotten it done by now

And another thing about the SAFC and other "Fuel" controllers, they are also "Timing controllers" because of the way our ECU works:


Vince

 

No afm delete and the poster I beleive has an S5 now.

 

My, bad, I misread your post and though you said "Lowered staging point for injectors makes for quicker spooling with exhaust". I missed the word "up" in there. My apologies, you're completely right. I noticed even with a stock turbo and a 2.5" DP I could hit 70% IDC on just the primaries.

 

I'll let it slide this time, lol.

Vince

 

i have been on stock ecu with BnR stage 2, fcd 550's and 680's at 10 psi for 2 years and handfulls of events and the frankenstein engine still rips no problems

 

if you are going the Rtek route, do the 1.8 or 2.1 and run 720/720 if you are upgrading the turbo.