ib042129

Start from POST NUMBER 3 for the more interesting stuff.
Edited due to merged threads.

Hi,

I am having trouble with one of the vacuum lines, when I am bolting up a turbo to the engine. It's the vacuum line that runs from the bottom of the intake manifold into the engine block.
The problem is that that port is right on top of the turbo outlet and I can't attach hoses to it as they do not clear.

What does that line do? And can I get rid of it, or reroute it somehow?
THanks.

NismoPick

Yep... it's the PCV valve (open up your FSM / Haynes manual ). Same problem when using the N42 intake on a turbo setup.

Go to your local hardware store & pick up a cast iron elbow (house water / gas line piping section). There are pics on the intrawebs about this fix.

ib042129

I might as well put this all in one thread so that my questions and issues are organized.

I could not find a source 280zxt, and I could not get that turbo swap on sale from e-bay.
This is my plan instead.
I bought the turbo, exhaust manifold, downpipe, oil lines, turbo injectors and stock j-pipe from borini.
In addition to that, I got an e-bay intercooler and a piping kit. As well as a BOV for safety.
(The reason I got the j-pipe is because I plan to cut it up and to make piping to the turbo directly much easier.)

Now here is the part where people might have an issue with. The fuel management:
My plan is to go with larger injectors (ones from the turbo), adjustable fuel pressure regulator, and an FMU.
I will turn the fuel pressure at idle down to accomodate for larger injections on the stock ECU, and the FMU will pull the pressure back up at boost.
I got the 8:1 ration FMU, but that may actually be too much and I will be running rich. But rich is safer than lean and I can recallibrate the FMU later.

I can't do much with the timing, so I just have to retard it a bit at the distributor.

Of course a Air/Fuel and Boost gauge would be added as a safety precaution.



As of now, I have taken off the fuel-rail, intake manifold, exhaust manifold from the car.
I have bolted up the turbo manifold and the turbo to the engine.
(I am confused about the talk of different shaped exhaust manifold pipes: square vs. round vs diamond. I was expecting mine to be different from the turbo version and I would have to play with matching a gasket to it. This was not the case. The ports matched just fine. )

The air flow meter has to go before the turbo. (Is that correct, can I place it after.) This becomes a clearance issue when I also have to route the intercooler pipes. (No problems if it's just the J-pipe.) I managed to relocate it to the general area of where the ignition coil used to be, and I will have to get a bit creative with the air filter.

I will have to cut the metal on the front of the car where the intake used to feed though to clear the two intercooler pipes. More on that later. (Unless people have a serious issue with it.)

The other issue as of now is the vacuum line that goes from the bottom of the intake manifold to the engine block. I don't know what it does and if I need it. But the vacuum port is right above the turbo outlet and it interferes. I looked at some photos of other ZX's and it seems like that vacuum port is for some reason further back than usual. Or at least further back than the turbo versions. Trying to see if I reroute it or cap it off or, what.

I will do my best to take photos, as I go. And I am sure I will have more issues in the future.

(I guess can someone merge my other threads with this one: the A/F gauge and the vacuum line? Thanks.)

Positive and negative feedback is most welcome as usual.

Edit: Added pictures of the AFM connection. This just uses a 45 degree elbow and silicone fittings.
I saved the stock plastic connection because I want to keep those ports at the very least to route the BOV exhaust to.
http://www.flickr.com/photos/11194201@N03/5822787803/http://www.flickr.com/photos/11194201@N03/5822787803/ by http://www.flickr.com/people/11194201@N03/, on Flickr
http://www.flickr.com/photos/11194201@N03/5823351120/http://www.flickr.com/photos/11194201@N03/5823351120/ by http://www.flickr.com/people/11194201@N03/, on Flickr

Edit: This if the picture of the very front of the car (the radiator mount. ) I plan to use the stock intake hole for one of the IC pipes. THe red circle is one plan to drill a large hole to route the IC return pipe. The AC line is a little bit in the way and would have to be bent. The alternative it to cut open the bottom of the stock intake feedthrough hopefully to fit two pipes.

http://www.flickr.com/photos/11194201@N03/5822787603/http://www.flickr.com/photos/11194201@N03/5822787603/ by http://www.flickr.com/people/11194201@N03/, on Flickr

JSM

My buddy did the same thing without the RRFPR. He did this on a stock 77 EFI system. He ran the 280zxt injectors, calibrated the AFM to run richer and was on his way.

He had a stock ZXt motor, with and upgraded T3/T4 ebay turbo set at 8 PSI. His car was pretty quick. He would walk my punched out NA car by a little bit.

ib042129

http://forums.hybridz.org/index.php/...-vacuum-setup/

That link is the answer to my vacuum line question. Thanks to NismoPick.
Basically it's the N42 manifold that has the PCV valve in an annoying location.
People replace it with an elbow to create clearance.

Edit: Made the elbow modification for the PCV. Note the brass fitting.
http://www.flickr.com/photos/11194201@N03/5822762803/http://www.flickr.com/photos/11194201@N03/5822762803/ by http://www.flickr.com/people/11194201@N03/, on Flickr

ib042129

Doesn't it run really rich off boost then?
At this point I hope my engine does not blow on stock boost.

JSM

His did not. I was shocked as well. I know he spent a bit of time messing with the AFM.

ib042129

Actually, the running rich thing is me quoting people off the internet.
And this is the thing. The AFM measures how much air goes in. And it sits in front of the turbo. So it should measure proportionally more air under boost. In principle the ECU would just compensate and there is not need for an FMU.

JSM

Partially true. If you go past 8 PSI of boost you will need the FMU (RRFPR). The ECU should only open to 80 % of the duty cycle of the injectors to not over work them. That is why when you choose injectors, especially for Standalone, you base it on 80% of the flow.

Running the injectors at 100% duty cycle is not good for them. Well with the stock ECU, you can't anyways.

ib042129

Okay. Do you know if the FMU ratio of 8:1 is okay? I based it on the difference in N/A vs Turbo injector sizes, the turbo stock fuel pressure. Then I went to Vortech's website and they suggested the same ratio based on just the size of the injectors. I think I am safe in terms of not being too lean, but am I going to be too rich?

JSM

That I can not answer. I've not gone this route myself, just seen lots of posts about them. Debated it. I've got an Electromotive Tech III ECU. Not hooked up yet just collecting parts myself. Stuff is crazy expensive, but very percise.

The down side of the FMU much less control. Your start working of pressure and not injector size.

I would research what the pressure increase would be though for the 8:1. Do you have a high output Fuel pump?

NismoPick

I'm excited to see the final results of this turbo swap.

As for the RRFPR, 8:1 ratio seems outrageously high... you do know that means for every psi of boost (starting at 1) it raises the fuel pressure by 8psi (over what you have already set as the baseline). So if it's set at let's say 30psi base, at 8psi boost, your fuel pressure will be 94psi. Just want to make sure we are understanding this...

tonsoffun300zx

duh nismo don't cha know all noobs know everything! gosh these damn mods think they know more than us registered users.

ib042129

The high pressure is always the argument against the FMU (RRFPR). The reason I am not afraid of it yet is because my base pressure would be low (turbo injectors are 40% bigger than N/A so I expect base pressure to be 40% less. Probably close to 20psi) The stock boost on that turbo is supposed to be 6psi. So 6*8+20=68psi at boost. Which it big, but not ridiculous.

But I agree, I will have to watch the fuel pressure with the initial tuning. I might get the 4:1 pressure disk for the FMU later on. I am just afraid of the engine running lean.

12:1 is supposed to be the most common ratio when turbocharging a car.

JSM

I thought they were adjustable from 1:1 - 8:1? Did you look into BEGI? They're not cheap. I know someone had a used RRFPR on hybrid for sale for like $100.

Edit:
Here it is:
http://forums.hybridz.org/index.php/...i-fpr-for-sale

NismoPick

Where are you getting this info? 12:1 is insanely high for anything remotely stock.

2nd on the BEGI (Bell Engineering).

ib042129

I was looking into the Vortech type FMU's they are not adjustable on the spot.
You have to take them apart and put in new membranes.

BEGi was expensive, so I went ahead and got the Vortech type. Maybe if I get a used one, it will be okay price.

Vortech's site and writeups from mostly Honda people. The stock injectors on those engines are very small. And most people who turbo charge their civic never go beyond like 4psi. I guess that is what makes 12:1 ratio common.

JSM

I don't know if I believe this to be true. Are you basing this purely on math because of the bigger injector? At idle the injector is not going to stay open very long. I think you need to also take into account duty cycle of the injector at idle. You may want to try this first to verify.

Unless you plan on trying to force start at 20PSI base pressure some how, but then I'm not sure how you are going to get the car to run, even at idle. My stock 78 does not like much below 30 PSI at idle before starting to run poorly, 20 PSI forget it.

ib042129

Of course I will need to calibrate it. But the injector response should be linear. Id it is open for the same amount of time, half the pressure should mean half the fuel delivered.
Of course this becomes non linear for very low/high pressure values.

ib042129

Added some photos in previous posts. Fixed the PCV clearance issue. Hope to put the intake manifold back tomorrow.

ib042129

Installed the Intake manifold, the fuel rail with the Turbo injectors today.
(Note the PCV fix and the close clearance in the photos (red)
I removed the old fuel pressure regulator and replaced it with just a fuel hose. The other side of the engine has so much free space, I want to relocate the FPR and the FMU (RRFPR) to that side. I can mount them somewhere next to the fuel filter.
(See green in the photos)
http://www.flickr.com/photos/11194201@N03/5826553571/http://www.flickr.com/photos/11194201@N03/5826553571/ by http://www.flickr.com/people/11194201@N03/, on Flickr
http://www.flickr.com/photos/11194201@N03/5826553527/http://www.flickr.com/photos/11194201@N03/5826553527/ by http://www.flickr.com/people/11194201@N03/, on Flickr

The next thing on the list for me is to do as much intercooler piping as possible. I know I don't have all the pipes and fittings I need so I will start now, get an idea of what else to buy, then work on the oil lines and the exhaust while the stuff is in the mail.

FricFrac

Rising rate is an old school patch job. It's not really the proper way to do it. Modern electronics can easily and much more precisely manage the fuel with PWM on the injectors. I can understand guys trying to figure out how to upgrade with what's available when the Z31 ECU was the only upgrade available but why would anyone spend the money on an Z31 conversion when you can have a modern ECU like Mega Squirt, etc for the same money.

ib042129

Ah. I was waiting for somebody to make that point. And my answer to that is, I am trying to end up with a turbo 280zx for a price that is comprable to that of an engine swap. I could not find a donor car in the area. Shipping an engine as a swap is expensive. And junkyards never keep it as a swap either.
But getting a turbo and some pipes shipped to you is really not bad.
It is the fuel management that gets expensive.

Anyways, I got that BEGi FMU that was being sold on HybridZ. It is a smarter choice than the Vortech stuff, and not at a ridiculous price.

ib042129

I mocked up the intercooler piping today.

I decided to drill the return hole in that corner next to the headlight. Used a 2 3/4 drill and then filed the nasty edges down. (Marked by a red circle in one of my first few photos) It worked quite well.

Most of the pipes in the kit that I bought work, I will need another 90 degree aluminum pipe. And a bunch on silicone elbows and couplers. (See the black and red for the imaginary routing in the second photo)
Stupid piping kit came with the BOV bung welded in the most awkward place. I will have to cut that pipe, flip it 180degrees to have the BOV face out. And then flip the 90 degree aluminum elbow.

http://www.flickr.com/photos/11194201@N03/5834607569/http://www.flickr.com/photos/11194201@N03/5834607569/ by http://www.flickr.com/people/11194201@N03/, on Flickr
http://www.flickr.com/photos/11194201@N03/5834608123/http://www.flickr.com/photos/11194201@N03/5834608123/ by http://www.flickr.com/people/11194201@N03/, on Flickr

FricFrac

MSIII kit is $373. You're not going to be doing any upgrades any cheaper than that....