Hi I have a noob ?
From what i understand the safcII has a maximum fuel adj of -/+50%
Can someone explain the total duty cycle% for each injector.?
Say I have 555cc inj's/Fpr/safcII with a hp goal of 450-500(sae corrected) accordingtou Deatschwerks inj calc at 50% (safcII max)I would need 750cc's
If that is correct explain how "meximax" "hal"& others reached 400+ hp with 550 & smaller injectors? safely on AFC'S
meximax had to be 75%duty cycle at the least right?
I know i'am missing something here and I bet yuh think its simple but not 4 me right now I'AM DUTY CYCLE . feel free to bash ill just out till the post is clear.lol
Thank you

 

thats why you need a z32 maf... z32 maf cuts the maf signal by about 50% to compensate and not run it too rich and also raises the hp/boost limitations.... if you look you can find I30tmiked's writeup about it.. 555cc's + A32 maf=no no - trust me.. 555cc's + Z32 maf can run decently without even fuel computer control... although you would probably need an adjustable fpr to get the right mix... but for full reference look for the z32maf+555cc writeup

 

I don't know what meximax's setup is, but Hal was using additional injectors to supply extra fuel. Another way to get additional flow capacity out of undersized injectors is to increrase the fuel pressure. I would not go overboard with this though as that is just begging for problems. Properly sized injectors with moderate fuel pressure is the safe way to do it.

Final thought - if you think you're going to be able to reach 450-500hp with an SAFC as your engine management you may be in for a rude awakening. I know meximax made 436 with it but you have to understand a few things. First is that the guy REALLY knows what he's doing - based on your post, you've still got a long way to go to get to his level of knowledge. Second is that he is running a VQ35 with VQ30 ECU. This means he is already running the VQ35 at more retarded ignition timing than it ran from the factory which is helping his safety margin - not sure if you'll be running that setup or not. Also he is likely pulling a bit of additional timing indirectly through his SAFC adjustments.

 

Trait Thank you 4 the quick reply.I understand much better now & will read i30tmikes threads. Nealco I was vague with my setup which is in the process:3.5/stephen max Cam/TB/IAC/adapters/
555ccinj/255lph/adjfpr/Maftpro/3bar map/iat/boost solenoid/J&Swith knock/ wbo2monitor/colderplugs/arp rod bolts/cams/built tranny(ppg3rd/quaife)/
spec stg1 upgrading to stg3 or clutchnet6puck red psi plate
t4/t61 .68ar/Fmic/38mm waste gate/50mm?bov/3"cutout/3"exhaust&cat.
The maftpro adjust in 1/2%+/-60%compared to SafcII +/-50%. yes i know its no emanage but it does everything I want it to do.Nealco I understand a few things already.I perfer to be awoken politely.lol.Meximax is advanced but wasnt born that way this is why Iam asking to learn instead of being ignorant ant just buying stuff. I've learned alot performance wise from the org and avoided alot of trail & error thanks to you guys sharing your info.

edit: this is Nealoc187 i tried to quote you and ended up hitting the "edit" button. very sorry

 

OK cool it sounds like you might be on the right track then.

One piece of advice I'd give is avoid that spec clutch like the plague in my opinion. I have personally seen the results of 3 spec clutch explosions (not maximas, two LS1s and a DSM) and I've read about a number of additional ones on various forums. I think spec's quality control is atrocious. I'd go with your clutchnet idea or an ACT.

 

Luckily for you Mr. Accordingtoyou, I have plenty of time on my hands right now. I will write you a short thesis in an attempt to answer your lousy written post.


You are headed in the right path by being inquisitive, but make sure that you understand what you desire to know before you ask it.

Neal properly addressed your fuel delivery questions, and even informed you of the potential side effects of tampering with MAF signals (timing advance/decrease) via piggyback’s (SAFC, MAF Translator Pro, etc). Ignorance of this issue will undoubtedly lead to catastrophic failure. You didn’t ask for side effects, but he is kind enough to inform you.

Injector Sizing

So, how do you get 500 bhp with small sized injectors? There are multiple solutions, and your choice depends on your pocket size and risk aversion. The safest (and most expensive) being standalone systems and cheapest being FMUs. Neal’s suggestion of properly sized injectors and moderate fuel pressure fall in between these two, and to no surprise, the route I chose.

My fuel setup consists of the following:
-Walbro 255 in-tank fuel pump (hard wired)
-RC 550 (at 43psi)
-Aeromotive Adjutable Fuel Pressure Regulator (no really needed)
-Vortech Fuel Management Unit (FMU) with a 4:1 disk

COMPUTING INJECTOR MAX DUTY CYCLE

In the Deatschwerks on-line calculator, punch in my 500 bhp, 6 injectors, 0.6 BSFC (for my SC set-up), and you get 700 cc/min at 75% duty cycle.

Well, I don’t exactly have 700cc/min injectors, I have 550s. How do I get that extra 150cc/min? I do modest bump to fuel pressure with a FMU. My max fuel pressure at max boost is 70psi. If you used the Fuel Flow Calculator on that site, you will discover that my 550s (@ 43psi) turn into 700cc/min at 70psi, right at 75% duty cycle mark I wanted. By the way, the 75% Duty Cycle is not a coincidence. This is what Neal alluded to when he said you should pick properly sized injectors.

FINE TUNING

So you have the fuel you need for the power you think you'll make, but what does the rest of the curve look like? Well, mine looks fine at max boost, but my A/F is rich everywhere else. To fine tune, I use SAFC. I removed a bit of fuel at low RPM, a significant amount (-20%) at midrange, and little to no correction at redline. All this is with a Z32 MAF.

ITS ALL IN THE TIMING

The odds that your stock ECU will work flawlessly after swapping the engine, changing injectors, changing MAFS, and getting forced induction are not on your side. The end results is probably poor idle, poor WOT tune, bad timing, and probably a connecting rod sticking on the side of your block if you drive your car hard on that tune. Research what pre-ignition, detonation, pinging, and knocking are, what causes them, and then try to mitigate it. I am by no means saying I am an expert or that my setup is fool-proof, but these are the steps that I have taken on my set-up to preclude detonation:

- Understand all aspects of your setup (SERIOUSLY)
- Pick a target timing curve by researching timing curves of existing SC and TT VQ35s (try 350z/G35 forums)
- Understand your ECU timing curve by researching, datalogging, etc. As Neal stated, I have a VQ30 timing on VQ35 which makes its conservative, but not conservative enough (except maybe as a race fuel tune)
- Attack the heat: I use a large front mount intercooler, water-wetter on my coolant (which consists of a very small percentage of anti-freeze). A better radiator could be used if desired, I am currently using the stock unit
- Sparkplugs: Use colder sparkplugs, gap them properly, and gap them with the right tool, not that $.99 P.O.S. on the autozone counter.
- Fuel Tune: I use a Innovate wideband for a safe force fed tune and for monitoring (I keep it at or under 12:1 A/F Ratio)
- Tune for your fuel: We have 93 octane in Texas. I tune for that.
- Timing Tune: Remember that your MAF tampering will inadvertently add timing. I use J&S Safeguard to detect knocking and pull timing. My J&S does not detect any knocking on 93 octane, but I still pull an extra 1/2 degree for every PSI starting at about 5psi.

Now that you think you’ve done all you can to prevent pre-ignition and pinging, you are still not safe. Well, at least I am not! Why? Well my SAFC’s tune is based on RPM, my J&S’s timing pull is based on boost pressure, and my Z32 MAF reads volumetric air flow. Changes to elevation, atmospheric pressure, temperature (air/fuel/oil, etc), fuel octane rating, and a donkey cart of other parameters can cause problems. Luckily, most of us reside in an environment that can be considered relatively steady state; with respect to all the parameters mentioned above. Needless to say, keep an eye on your system at all times and you will enjoy plenty of miles on your boosted system.

SIDE NOTE: Your poorly constructed post leads many of use simply skip it (as I admittedly did when I first saw it). If you can’t spend a minute making your post easily readable and legible, then why should I spend 20 minutes responding to it? I hope that you place forth more effort in your car’s build than the effort you’ve displayed when writing this thread. Good luck to you.

 

Thankyou all 4 replying to my thread
Meximax you have me all wrong I understand first impressions stick but Iam no slouch I was doing research and decided to post real quick 5am in the morning. You may have taken my comment personel.when I said "I dont just want to buy stuff" it was not directed towards you but myself.I admire your setup and have shown it to many people with pride in your work.I only used you and hal in this thread as positive pioneers thats all.You will have to excuse me for not going into more detail.I thought a "thesis" would send viewers packing.lol My project car is currently in the body shop due to a work van plowing my passenger side in & various rust spots.While the car is under the knife iam compiling a list of desired mods and purchasing the affordable ones as I go along. so far I have the N/A setup minus: pilot bushing/pftb.
I have a safcII which I am sloooowly learnig how to use.When Isaw turbos13hatches thread on the maftpro I began researching it. like dandy max said its no Eu but its astep up from the safcII. when I saw the 3bar/iat/boostsolenoid/attachments.I thought to mself ALL IN ONE.
Ilooked at your set up and blindly figured I didnt NEED EU for my desired goals.so i asked how duty cycle adjustments work and will 555cc be enough for a 60% max adjustment. which I now know is enough as long as I have the supportive fuel system.You guys are very helpful and I will work on my "lousy"thread promise.lol I think the people on here are a bit critical.so quick to nit pick & correct that they loose focus. I'am on here to learn and share any knowledge I have which seems like none accordingtou-all.
It seems as if you are talking down to me.Lets not forget how far weve come. When people ask me about
Construction/Carpentry/Realestate/Investing/Yaduh yaduh..I never ever shun them or make them feel silly/unprepared.I simply answer them and give as much usefull, positve info as possible.I know that if they dont understand half of what I said. They will still be able to use my info to better themselves and others some how some way like I doDo you see the pattern.I work hard for my money so iam definately working hard to makes sure its well spent. Iwas going with a big fmic but was concerned with removing my bumper support still undecided.The t4/t60-1/61.68ar&the mods I listed above are solid.my wbo2will be aem16 in1/Forward y pipe? undecided/Mardigras exhaust/Ksports/Urethane front end suspension/motor mounts/subfram etc..
I dont want 400hp at the wheel every day but it would be nice to see my dyno tuned 4thgen pushing a healthy 400+ like yours a few times.Thats not too much to ask. hell if i could push it to 500+that could cost me a blown motor $750 & 2 weeks down time 0$Labor$0parts$50 EXPERIENCE PRICELE$$ IMO it would be worth it but thats just crazy talk.