NA to turbo conversion - questions and answers...

[mikeatrpi]

Another dumb question. Is my oxygen sensor too close to the turbo output? Is there a rule of thumb where to put it? Thanks all

[mikeatrpi]

The drain, again - this is the final product with hose clamps, etc. I put some jb-weld putty around the pan fitting to plug a small weep it had.

 

 

And, here's the oil feed parts. 1/8" BSPT Tee with an NPT fitting on the side... this threads into the block where the stock sending unit was. The sending unit goes to the female BSPT fitting on the tee. Then I have an adapter and -4 AN push-on hose and fitting running to a banjo. All that stuff cost a hair over $50 from British American Transfer... BAT, Inc.

 

 

I put all of the fittings together dry. I know the AN doesn't require any sealant, for sure, and I didn't think BSPT or NPT did either. And - I tried turning over the car a few times to prime the oil line... but I was unsuccessful. Either I didn't crank long enough, or there's just not enough oil pressure until the engine is running.

 

I welded up the tip of the stock banjo bolt, and drilled it to 1/16" to serve as a restrictor. Got this idea from the archives.

 

In the car:

[X64v]

Do I need to set #1 to TDC? Do I then need to orient the rotor in the distributor (by loosening the screw and turning the assembly I welded) so it points to #1? Or does none of that matter and the computer handles the adjustments??

 

Inside the distributor you don't need to adjust anything, if you welded it down where it sits normally then you're fine. It's the plate outside that you want to adjust to about center.

[mikeatrpi]

Inside the distributor you don't need to adjust anything, if you welded it down where it sits normally then you're fine. It's the plate outside that you want to adjust to about center.

 

Thanks Sean. Unfortunately I turned the motor over a few times without the distributor attached. I think that means I do need to set #1 to TDC and bolt up the distributor then.

[kvansic162]

Snow performance meth injection.....check it out.

[mikeatrpi]

Update time...

 

Here's some more stuff attached. The intake manifold fit OK... I also had to trim a little with the dremel on the edges, like I did with the exhaust manifold.

 

Here's what I did for the PCV. Its a variation on Sean's method (X64v). I used some heater hose and plumbing fittings to route the PCV plumbing up to an unused fitting on the bottom of the throttle body. It takes a 3/8" hose easily, which also routes around in a loop without kinking.

 

Here's my megasquirt wiring in progress. I mounted it a small piece of lexan from the depot. I didn't even bother to peel off the paper - I sorta like the white look.

 

I used the stock wire grommet (sadly I had to cut my harness to get it off), and I passed the MAP hose through it and shrink wrapped it all down. The plastic hose didn't collapse, so I think this will work to keep everything neat going through the firewall. The vacuum tee is for my boost gauge.

 

Wiring. I made all of my wires 10 ft in length, and trimmed to fit once in the car. I probably could have gotten away with 7-8 feet and still had plenty. I bought 18ga and 14ga wire spools from del-city.

 

Stock CHTS, and my battery attachments.

 

Coil (I had to move it; it hit my 1g DSM BOV). I just bent the bracket and moved it up. You can also see my MS ground. Don't worry that's not my only one.

 

OK here's the turbo oil feed pulled out of the way, and you can see how I routed and attached the MAP vacuum hose.

 

Ta-da

 

So far, I have the Datsun CHTS calibrated, TPS calibrated, and a tach signal in MS from my locked distributor. Hopefully with my next update I'll have the timing dialed in.

[Clifton]

Man, I wouldn't run vinyl tubing. You want this thing reliable. There's a reason NO car manufacturer uses it other than for windshield washer fluid. When it gets warm it will soften up. If you insist on it atleast run some rubber hose around the engine. You can get rubber cheap (alot cheaper than Autozone or Checker) at Ace hardware.

[mikeatrpi]

For my MAP hose? I used the tubing that came with my boost gauge, but I'm worried about it too. I'll shop for something more reliable. Thanks.

[Clifton]

For my MAP hose? I used the tubing that came with my boost gauge, but I'm worried about it too.

 

Ya, If you go to Mcmaster and look up the temp range for it compared to any rubber hose, you'll see why I wouldn't use it.

[Swervey McZCar]

Where does this PCV terminate?

 

"Here's what I did for the PCV. Its a variation on Sean's method (X64v). I used some heater hose and plumbing fittings to route the PCV plumbing up to an unused fitting on the bottom of the throttle body. It takes a 3/8" hose easily, which also routes around in a loop without kinking"

 

This needs to be after the Throttle plate, right? The only fitting I can think of large enough to plumb to a PCV (on the TB) is the coolant hose that warms the TB. That won't do anything for PCV.

 

If I am way off base or completly misread I am sorry.

 

-Stan

[phil280zxt]

Mike, your upgrade looks great!! Looks like you;ll be firing it up real soon. I was wondering where you picked up your battery cable terminals. I've been looking for something like that for a while now.

[mikeatrpi]

Stan - there's a short section of hose that joins the lower vent to the PCV. Then there's a 1/4 NPT female to female coupler, and a 1/4 NPT to 3/8 hose barb. I run the 3/8 hose to a stray vacuum fitting on the throttle body.

 

You can see the fitting in this picture - its the elbow coming out of the TB, facing away from the camera... not the two fangs in front:

 

 

Phil - Thanks! Actually those terminals are just cheapies from advance. I used welding cable and lugs to make new "main" wires. The megasquirt has simple spade connectors that slip into the ends of the terminal.

 

 

Official update - I got the car to idle this weekend. I loaded up a variation on "metro's" map from the sticky and while it was good enough for a trip around the block its very clear that I still have a lot more tuning to do! I'll be posting some MS logs and MSQ files eventually.

 

Sean, the answer about timing - I simply needed to rotate the back adjuster on the distributor. I just forgot about it. So, I have a nice idle at 10 degrees BTDC with the timing light and a trigger angle of 67. I put both adjusters in the middle as you said - and I have no idea why I ended up at 67 versus your 77.

[cygnusx1]

Well, congrats Mike! Welcome to the worlds of turbo and Megasquirt. Idle should be around 21-27 btdc. Mine likes 28.

[X64v]

I put both adjusters in the middle as you said - and I have no idea why I ended up at 67 versus your 77.

 

That's because there's no 'right' answer for trigger angle, it just needs to be whatever number makes the timing in MS match up with the timing at the crank. Mine isn't exactly in the middle of both and neither is yours, and the vacuum plate in my dizzy isn't welded exactly in the same spot as yours, so the numbers are going to be different. Even something as simple as unbolting the dizzy tower base from the front cover (leaving the dizzy bolted to the base) and bolting it back up can cause a trigger angle change of one or two degrees.

[mikeatrpi]

Thanks Dave. I have a lot of learning ahead of me, that's for sure. Remember mine is an NA block / head with the turbo strapped to the side... not sure if I aim for the stock NA numbers or the turbo numbers. Haynes puts 8 +/- 2 BTDC for NA, and in the 20's (as you said) for the turbo.

 

Sean - Yes I understand all of the sources for variance, but I was surprised it added up to 10 degrees. Question for you - if you pull off your cap can you wiggle the rotor a few degrees back and forth? Mine moves a little... I'm worried I dorked up the welding job.

[X64v]

Sean - Yes I understand all of the sources for variance, but I was surprised it added up to 10 degrees. Question for you - if you pull off your cap can you wiggle the rotor a few degrees back and forth? Mine moves a little... I'm worried I dorked up the welding job.

 

Yup, mine moves a bit, too, and I know mine is welded down solid. This is due to the slop in the mechanical connection to the crank, I think mostly at the slot between the oil pump shaft and the dizzy shaft.

 

If you did botch your welding, it would be able to move as far as the mechanical advance mechanism lets it, which is a lot.

[mikeatrpi]

Thanks again, Sean. Whatever problem I have you've been there done that.

 

And, I have a video of the car idling. At the end of the video it starts to sputter a little... opening the throttle brings it back briefly. Pardon the amateur filming (I'm no big-phil) and messy garage!

 

 

Thank you all for the support, help, and parts.

[X64v]

Thanks again, Sean. Whatever problem I have you've been there done that.

 

 

Heh, it's 'cause our set-ups are so similar, and I've had mine running on MS for right about two years now. Car looks great in the video. 30kpa at 750rpm is a very strong idle, what's the ambient pressure where you are?

 

Attached is that map I PM'd you about. It's actually a .vex file, when you save it to your computer, just change the file extension back to .vex. I changed it to .txt so I could attach it without putting it in a .zip file.

Fuel tune 6-6-08.txt

[JSM]

Mike where is the latest update?

[mikeatrpi]

Hi Jeff, thanks for the bump back up!

 

No real updates... here in NY, its still winter. The car is in hibernation.

 

I am planning to purchase a wideband oxygen sensor, probably an Innovate unit from diyautotune.com. Where else besides the A-pillar can I mount a boost gauge and AFR display?