We all know how pointless arguing on the internet is...

One final point I'd like to restate: your "proof" is a stock block NA. My experiance deals with my Ported S5 block.

 

what kind of wheel horsepower were you making that you not only switched to 550s, but also added fuel at 6000rpm+ ??

 

Yeah, sadly the only thing I could find at the time! I've however been at the dyno with a few ported cars and tuned their S-AFC's and i've never come accross any N/A car pushing more than 170 that needed the larger injectors, but I couldn't provide any proof for that, so I just left it out. Oh well, he'll be happy with what he gets out of it, so we'll see!

 

My last run at the dyno netted me 172 RWHP at 7500 RPM on a Dynojet.

I switched to 550s because my earlier runs showed that the power was dropping off above 6000 RPM and my A/F was hitting 17+ at 7000 RPM. I had the S-AFC set to +20 and it made no difference.

I guess the thing to remember is that every car is different.

 

im gonna upgrade my secondaries to 550 high imp and get a walbro 255 before going to the dyno (after reading this post). Even if its too much fuel, you can always tune down, but you cant really tune it up. And Im using my old injectors and fuel pump. Ill be sure to post when i get around to the dyno.

 

yes, cars are different, and then sometimes things aren't right. i haven't worked with tuning, air/fuel ratios, streetported n/as, etc, so i don't have much tech advice to spew. what i can say is that it sounds awkward that you're only putting down 172, yet switched to 550s and upped their output. i mean, i hope everything is running well for you and the bigger injectors aren't a type of 'fix-it' solution. just saying it sounds strange to me (which doesn't mean a whole lot).

 

it is when you havent owned the car more then 5 months...i should update the page ive spent more money on it since i did that haha.

 

The walbro AND the injectors will probably be overkill.

If this is your first time at the dyno, I'd do the 550 injectors. Why? New injectors are always better than old original ones. They also drop right in about 30 minutes.

 

<Off topic>

Russ,
R U coming to the NJ Rotorfest?

</Off topic>

 

i have a pair of 550s owed to me, but they aint new! in fact, they may be older than my car (i have a 91). also, i haven't asked what series, so i don't know the ohm rating (this stuff never concerned me before, so i never bothered to learn).

 

hopefully, shes torn apart right now but hopefully she'll be painted by this weekend. so i should be able to. sorry for the offtopic stuff. I apologize. back on topic. i thought anything up to 200hp was ok on the stock injectors? or am thinking of t2's and there larger secondaries.

 

Cool. I'll probably bring the GTUs...

As for the stock NA fuel stuff handling 200 HP: Read the thread. SonicRat and I had a pretty good discussion about it. Not sure if we settled anything but I think we both agree that every car is unique. Blanket statements like "the stock NA fuel system is safe to 200 HP" are not always true.

 

Yeah, we're sort of stuck. How about this.

"The stock N/A fuel system *MAY* be safe to 200, but be sure to keep an eye on yours because it could not be!" Best compromise? Where's this rotorfest you guys are speaking of? </threadjack>

 

Sounds good to me.

<threadjack>
You haven't heard of Rotorfest??? Man, you need to get out from under your hood more! Or at least visit the NE Forum sometimes.

http://www.rotorfestnj.com

This year will be the biggest gathering on the east coast!
</threadjack>

 

<threadjack>
I'm from the MW, just got to the NE a couple weeks ago. Aint' shiat going on up here in NY.
</threadjack>

DEZERTE: You should look into some pineapple sleeves without the rods in them, and installing them permanently to give it a bit better flow into the aux ports.

 

<threadjack>
I didn't think you were originally from NY. Are you in upstate NY?

Seriously you should try to make it to the event. This is our "sevenstock" on the east coast.
</threadjack>

 

AIM me or something, SonikRaT, or better yet, lets find a thread in a section where we aren't postwhoring!

 

AOL works. wozzoomRx7
I'm heading out for the day though. Catch you tomorrow.

 

You're not online! By the looks of it, and what you posted in the NE forum I may be able to meet up with you on 81.

 

about the sleeves... how would the sleeves be held in place? There is no rod to hold the sleeve, so it will spin around and such cause air to get stuck etc?

 

You can rough them up and loctite them in place, someone did this a while ago. Search here I come!

 

can't wait for the dyno sheet! S4 or S5?

 

actualy i think it has like 100k+ miles and is down a little on compression just from being that old. im sure he does a great job maintaining it, but a fresh reman still with stock ports could pottentialy put out a few more ponies.

 

Fuel adjustments from a computer like an AFC are completely different from car to car, that much is totally agreed. Each engine is different with it's own variables to take into account to run "best." This is why ROM tuning is okay for a very conservative running car, and something with some flexibility is best (Haltech, TEC3) to adjust everything to your own motor.

However, no 6 port motor should be making enough power to warrant larger secondaries or a higher flowing fuel pump. Stock 460c's should flow enough to support about 225 @ the flywheel (85% duty cycle) which is about 180 @ the wheels. I believe the most HP any of the NA guys here has to the wheels is icemark with just over 170 and I'm fairly sure his fuel system is 100% OEM (jump in here if I'm wrong Icemark).

Wozzoom: Did you ever check to see what voltage your NA pump was giving you when your AFR's got lean? If it was original it is possible the pump was tired or the fuel filter was clogged (assuming the injectors are tip top). The point is, for fuel adjustment each car is different but the NA fuel pump, when healthy, should support any NA mods on the 6 port motor.

 

Trust me, I scratched my head on this for several months. I started my dyno "fiasco" with the stock pump and original injectors. The fuel filters were all replaced before heading to the dyno. After my first run that topped out at 167 RWHP and high 16 A/F's, I checked EVERYTHING! Fuel pressure, grounds, sensors, injectors, fuel pump voltage. Everything was in tip top shape. Injectors were all cleaned and were within .1% of each other in flow. The pump was seeing 13.5-14V depending on what accesories were on.

Second time around I ran on the dyno with a TII fuel pump. I had a similar result but improved slightly better A/F ratio.

Third time was the charm. I put in brand new 550's in the secondaries. The car came to life on the top end and the S-AFC easily brought the extra fuel under control.

Can the stock S4 ECU actually drive the injectors to 85% duty cycle? I thought the max duty cycle was lower than that.