just gonna go ahead and ask, running a LARGE streetport on stock ecu/rtek safe?
 

Literally have searched/read upwards of 50 threads on the subject, and have yet to find a definitive answer.

Some people will say that a streetport on a stock ecu/rtek will run the motor lean, and blow it. Some people say that it will run rich and need adjustment.

My set up is:

Rebuilt s5 jspec
Ra classic apex seals
Solid corners
Race springs
Huge streetport intake/exhaust
Rebuilt 550 primary
Brand new 750 secondary
Walbro 255
Aftermarket fpr set at 43.5psi
Stock turbo at 8-10lbs
Stock tmic
3" downpipe-2.5" exhaust
RTEK 1.7 ECU

last night I seen a guy post dyno sheets of a stock motor/injectors with a big street port, and walbro 255. It made 260hp/tq @ 10-11.7 afr. Why do some people say that it will run lean?

That guy is probably maxing out his injectors, which you don't want to do. 550cc secondaries are too small for a street port. Period. You will run them way to hard and they will just break. Also, you NEED to be able to tune your car with a large streetport. You have to get an rtek 2.1 at least. 1.7 or 1.8 won't work because there is no ability to tune fuel. You could get an safc or something, but I wouldn't recommend it since that's just tricking the ecu and not really tuning it. Look at everything in your build. Just spend the $500 and save yourself several grand and a heartache. Don't fuck your build up over an obvious thing like tuning.

Just realized you're the guy that pm'd me asking me about this and I told you the same thing pretty much. Looks like your dead set on going the cheap route.

The Rtek will give you the possibility to turn the boost a bit with the tweaked fuel map for the 720cc secondaries. But as for the porting I'm not sure how much it will affect your AFR if so at all.

On a side note, fc3spro.com is considering the addition of a fuel management system (Apexi SAFC) way before going into porting to get the ability to tweak and fine tune AFR's. So you might want to give that lecture a try.

More like out of $, and time. As I said before though, I only plan to break it in on the rtek. Adaptronic is in my near future, although not immediate future.

Okay. Break in will be fine. Just don't hit boost until you get your adaptronic.

I kinda agree, and would never run stock injectors, on even a stock engine. But that doesn't explain why his car is running perfectly, making tons of power on stock equipment, and running at perfect AFR's.

I also have another buddy that ran 10 PSI on a streetported motor on all stock equipment for 2 years. And that car actually ran RICH.

I assume you've ran a large streetport on stock equipment before? How was that?

the worse part about you and all your buddies is your guessing. you throw parts together like a receipt for soup and leave your self no room for adjustment at the end.

if you are lean how will you know and what will you do? the knowledge will cost you $300-500 and the adjustments are a money pit... meaning you make the wrong one and your engine is toast... how will you know whats the wrong one? the will cost you.. a motor.,,
you're already outta money? sell the car dude.

why do you people even reply to post like this, let it get bumped out off to oblivion... this subject has been beaten to death.

Thanks for the kind insight. Although, I personally wouldn't call DAILY driving it for two years "guessing"

Also never asked you personally what you thought, or cared for.

I seek definitive evidence that it's a bad idea, because in my weeks of searching/reading, I have yet to find anything. All you did was pop up in here and complain, which actually seems counterintuitive having also said "why do you people even reply to post like this"

there are two approaches.

the JDM tuners will run a stock ecu + port and keep the boost around stock (~8psi). this works, you make more power because it moves more air, but its still in the parameters of the stock ecu, so it stays together.

the tuner is to see how the thing is at 8psi, and if its ok, try 10psi, and if that is ok, try 12psi. in theory you have enough fuel to do 12psi, but the turbo isn't going to be very happy, and the IC is looking a little small. this approach requires you to actually be a little careful and notice how the car is actually running, so this is why everyone is telling you to never run boost ever

In reality, I'm shooting for around 200whp give or take. All I'm worried about it running lean due to the port.

I didn't DECIDE to port the motor. I bought a motor, tore it down, and found some really awful ports, and had to port bigger to clean them up.

I only wanted this to be a cheap, and effective rebuild. But it has turned into a money pit(as do 99% of FC's) so I ran out of build money QUICK. Now I'm at the point where:

A: I can run the motor as is, with my really modest power goals, and hope to not have issues. Have fun. The "cheap" way.

B: Spend yet ANOTHER $1500 on a computer/tune that can support 5-600+ hp. In which case, I'm NOT going to pay for a tune on the STOCK sh*t, and will have to shell out YET ANOTHER $1000+ for a turbo, IC, DP, Manifold etc. I don't see the point in buying a stand alone, when my goal is 200whp.

well you get the hp that your engine combo will make... all you can do is turn the boost up until it leans out, back it off a couple psi and that is it.

i'd imagine you could pull the turbo off an do 180rwhp... so 200 is very realistic

actually i left the first time after i saw no one else posted... hoping they'd be smart...

AS LONG AS you know where cheap is going to get you, a wide band is not that much, and an rtek 1.8 would save you from going lean, they're not pricey..

I have an AEM UEGO :)

and if you didn't see in the first post, I'm using an Rtek.

the lean spot is before the 2nds come online. i saw.. i hadn't seen anything about a wideband and thats what my fuss is about.

Not that I'm some genius, but I'm nowhere near stupid enough run without one haha

So you're saying I might max the 550's before the 750's kick on? That sorta worries me

im no expert at all, but my personal experience on my car, i had a t2 streetport, hybrid turbo, fmic, running factory boost setting 7.5 with stock ecu, fcd, and a walbro in the tank. ran perfectly with no problems what so ever. ran like that for 2 years, been on the track, hundreds of street pulls, never had an issue. I say keep the boost low/stock and you should be alright until u get a standalone.

with 3" intake/exhaust, the stock turbo will put down 250whp at 5-7 psi, but only at redline where its running out of steam. turning up the boost only gets you more torque, not peak power. so even low boost, you need injector for 250whp



op, if your wideband shows decent AFRs, you should be ok. I would retard the CAS a few degrees to be safe. of course going full standalone will potentially be much safer setup, but its all a tradeoff. cheap, fast, reliable.. pick 2

i just wanted to chime in a here as i have just come across a street port engine put into my tii that i wasnt expecting. long story short i now have a stock tii with what i would assume is a standard street port. from what i have gathered. the rtek 2.1 would be enough interms of management since your hp goals and mine are about the same. im not looking for anything crazy and i wanna keep my t2 dd as simple as possible. the rtek upgrade from 1.x to 2.x is waay cheaper than a complete stand alone. its only $349 as apposed to like a $1500 stand alone ecu and harness. and the rtek 2.1 still lets you tune gas and timing and all that good stuff. you can even tune it to have the secondaries kick in at a lower rpm. i think the range is 2400 - 3800 so you can def take care of that lean spot. that with some bigger secondary injectors, i was thinking of 720cc my self and a upgraded fuel pump (some one told the fd pump would suffice for modest hp and stock psi) wideband 02 and palm os handheld and you can monitor your motor your self and we should be set.. correct me if im wrong anyone.

Yeah, the 2.1 is cool, and you are right about all that.

I will probably end up with it. But really, I'm just wondering WHY it's needed. some people run fine with a streetport, and others not so good. I don't see why there should be a variance

The variance comes in with the condition of the injectors and fuel system. No 2 injectors are alike. Unless new and flowed to make.sure they are balanced and flow correctly.

better safe than sorry in my book. and for a few hundred bucks as apposed to thousands its a good trade off.

i hear you the variance as i wanted to just do the 1.8 my self.

i think what it comes down to is the quality of the motor. how it was built, other mods, fpr and fuel pump and injectors. there are a lot of factors.

the way i see it. we probably could get away with just the 1.8 and stock everything. but the question remains... for how long. how hard its driven and all that. even with that setup you state that your buddies have. i wouldn't foresee it being a long lasting reliable build. something is going to give out sooner or later. in some cases its just later.

i too once had a stock ecu with a street port 720s walbro mostly open exhuast ruinning 7 psi....
ran the stock intake to keep it choked down..........with mine i could put the aftermarket intake i had and run lean before the 2nds come on. Not all intake and exhaust flow the same, and the higher flowing ones result in lean.

another benefit of the 2.1 is you can adjust timing, ive heard timing on the stock ecu and 1.7-1.8 is somewhat advanced at high rpm for a street ported engine. also with the large port the engine is swallowing a lot more air at the same boost levels, at a lower rpm since the turbo will spool much faster. u can adjust the 2.1 to have the secondarys come on even sooner like 3300 rpm I believe also.

theres lot of varience, every port is different, some large some small,
every injector is different, some flow perfect, some overflow, some flow less, or are dirty, same with fuel pumps and pressure,

temperature, maybe one guys romping on his in a cooler climate, one guy is beating the shit out of it in 110 degree desert heat.
even elevation, high elevation less dence air less fuel used, less power.

you don't want to be in the varience zone, if u see some people running into problems, it means there on the edge of the dangerzone cliff, why leave it to chance?