Digging this one up. Why would this not be feasible? It would be a bit difficult to get it down to just the post but could be done. The flow rates could be even more finely tuned than a Z32. I mean if the difference between injector and MAF is 5% that is substaintial.

So, the 370's flow 54.16% more than the 240's. To make the A32 maf flow that much more it would need to be 86.9cm in diameter. This is not accounting for the flow hindrance of the post. Some measurements would need to be taken of the post to figure its restriction. But we know it posses a restriction. Why not make the ID of the PVC about 85cm and then remove the parts of the post as deemed necessary through dyno/street testing and logging with wideband? The opposite support point of the post wouldn't be used anyway if the sensor was stuck into some PVC. So trimming it down to very near the thermoresistor would increase flow substantially(Like 1cm away from resistor). The same could be accomplished with the 550's.

Hmm... After typing all this I realize there is something to be said of air coming from small piping to a cavernous MAF and back into small piping for the TB. Idealy one of the monsterous MAF's would work best on the intake side for this reason.

 

W O W !

 

i just got my z32. i need a harness to hook it up though.

 

My 2cents...
Swapping Z32 maf with proportionally larger injectors will kinda work. It would work great if everything was linear, but MAF voltage signals are NOT LINEAR. Further more, each MAF has a different voltage curve. Your ECU is calibrated to your specific OEM MAF voltage curve. This means you will run rich at some loads and lean at other loads.

I'm not saying it won't work, I'm just saying your AFR's will be at least a little out of wack. Be carefull and check your AFR's

IMO, the "hacked MAF" is a better idea unless you have an SAFC.

 

A lot to absorb. This air/fuel thing is killing me, but I just want to clarify. Im getting the impression that the 300zx's injectors and MAF coupled with a 255lph walbro fuel pump will run safely on the engine. And im assuming that an AFPR and FMU will not be needed, but at SAFC will help in fine tuning. Also, this kinda of setup would work for low boost applications like 9-10psi?

Someone correct me if im wrong. I just really need to figure out it I need to buy an AFPR and FMU or not because I will be getting 3 free runs on a dyno, and dont want to have to run out and buy them and then pay for the dyno. my wastegate spring is 5.8psi, but I will probably bump it up to 8 or 9.

Thanks

 

youre gonna need a fmu unless you go with a ems or ecu. you need your fuel pressure to raise with your added boost. the walbro is just a constant feeding source, unless you get that kenne belle boost-a-pump. as for the adjustable fuel pressure regulator, some people have gotten away with using the stock pressure with no problems.

 

No, the larger injectors take the place of the fmu. If you're injectors are large enough, then they can provide enough fuel when boosting without resorting to raising the fuel pressure with an fmu. This is really the preferred method of fuel management, assuming you have the means to properly control fuel injector duty cycle based on maf or map information. The fmu is pretty much a band-aid, although it works suitably well in most cases.

 

All you need is Z32 injectors and a MAF, either be a Z32 or A32. Then use a SAFC or E-manage to tune.

I think people use the FMU if they use stock injectors.

 

no, you use the fmu to bump fuel pressure at the top end. The fpr is basically a 1:1 (or similar) rising rate fmu. With 370cc injectors, it needs a little fuel at the top end. mostly needed at 8 psi or above (which is what most s/c's are upgraded to run)

Now with your turbo, you may not need it until you are upping the boost.

 

What is this boost a pump? Does it just alter the voltage to the pump to make it flow more? Is it finely adjustable?

 

http://www.kennebell.net/accessories...boostapump.htm

 

Thanks guys. Thats what was confusing me, I figured the whole purpose of getting the larger injectors, MAF and fuel pump was to handle the fuel demand for the boost. The injectors I got flow 400cc at 43psi, so i think they will do fine. I plan on using an SAFC, I just need to buy one and get it in. I guess i can tune with that on the dyno. Is the only potential problem of not using a AFPR that the engine may flood during cold starts because of open loop' fuel dump?

So the 370's (even though they flow 400cc at 43psi) will go lean at high RPM if I raise the boost to 8psi? If so, i might get one is the 3:1 or 4:1 disk the best bet? Im still unsure if i want to tune and run 5.8psi for a while until i adapt to the needs of a turbo car, or crank it up to 8-9psi and tune it. decisions, decisions

 

hmm.I wonder if stephen's idea would work on a 3rd gen..
I have the z32 injectors already installed on a fuel rail waiting to be installed...I was going to go the JWT route, but since I already have the z32 maf, I might go with stephen's idea..

My setup would be stock ecu, z32 maf, z32 injectors, and a SAFC..I have an adjustable FPR, would it be needed to turn down fuel pressure since I have a Walbro pump???

Would this setup be good if Im only pushing 8 psi of boost???

If so, Im going to take out my cartech fmu....

 

And maybe sell it to me

 

I will once someone says that the setup I mentioned would work....

 

So is the Kenne Bell a decent alternative?

 

3rd gens are a little different. you have plenty of other options other than jwt. i would go with the www.zemulator.com

uses your stock ecu AND gives you personalized tunability.

 

Your incorrect.

on a dyno using a WB02, I found that the correction factor with the Z32 maf, safc2, stock ECU, and 400cc injectors, the correction factor was more than +20%

 

I want to try to use what i have for now...With what stephen is saying is that a sotck ecu coupled with z32 maf and z32 injectors would run fine as long as i take it to a dyno to tune it with a SAFC....

 

I don't know of anyone on the org that has tried it. We know an fmu and SAFC combination can be made to work pretty well, though.

 

Good point. Do you think I'll be totally okay with just an SFMU on the 3.3 V1? Eventually of course I'll get 370's and Z32. But will it be safe and reliable? Mike was saying my FP is gonna be skyhigh. I hope he's been tokin' that turbo pipe too much.

 

With the right sized fuel injectors, and fuel computer, an FMU is not needed whatsoever. Fuel tuning resolution with an FMU is crappy.


If you have the right injecotrs and tuning tools and are STILL leaning out on the top end, it is likely due to weak voltage at the fuel pump. Fixing this problem with a FMU is not a good idea, that will put even more strain on your pump... lean out... detonate... you know what happens next.

Weak pump voltage is a common problem in higher powered SR's, DSM's, and RX7's. No need for a high $$ Kenne Bell boost-a-pump though... Just hardwire your fuel pump and I am sure you will see a big improvement.

 

Just do the math. (1/2 x base fuel pressure) + (boost psi x FMU disk size)

I am running 80+ psi through my stock injectors to support 260whp. I hate seeing that high of fuel pressure and will be changing my set up soon

 

I need to search on hard wiring the fuel pump. Anyone got a link handy?

Mike, I was joking. I can't tell if you took it seriously and I hope you didn't. Do SFMU's still use disks or is the rising rate totally adjustable via a set screw? See I don't know how to estimate what rising rate I'm going to need. I remember you saying TC fuel requirements were higher than SC fuel requirements. So I'm hoping I won't be seeing FP's that high. Although your not running 8lbs yet. I just want it to work so I can get familiar with boost. I don't wanna have to get 370's and Z32 right off the bat. That will delay the boosting by at least two months.