76 280z microsquirt project

[darom]

Hi guys,

I will be working on installing microsquirt v3 in my California edition '76 280z stock car which came with EGR/catalytic converter and an exhaust manifold. The car runs fine with the exception of typical lean conditions which gets resolved with a potentiometer pot.

 

The plan is to do it in 2 stages:

Stage 1 (getting "my feet wet" with learning to tune the car with TS):

Milkfab's 36-1 wheel (crank pulley mounted)

Microsquirt v3 + IAC stepper adapter

LM7 truck ignition coils

Pro Tunerz fuel rail (14mm) intake/throttle body/GM ICV

14point7 spartan 3 v2 wb

keeping stock exhaust + LSU 4.9

high impedance injectors

 

Stage 2

Headers + Turbo upgrade

 

In my infinite wisdom I figured I would kill both birds, aka project stages, with one stone - and purchased the Bosch 440cc 'green giants' injectors EV1 (part 0280155968), length 65 mm, Long style. Flow: 43,5 PSI (3 bar) 430cc / min = 41 lb / h. My assumption was to use them on a stock engine, get a turbo installed later, and re-use them. I got a great deal on them and they are authentic Bosch.

 

After reading the mega manual, now I am concerned about the idle pulse width issues and fighting over enrichment conditions running a stock L6 engine. I spent a lot of time going through this forum looking for anyone running similar injectors on an n/a engine and found that in almost all cases guys are running turbo engines with large injectors (supra injectors are popular).

 

The stock engine needs 15 lbs/hr or 158cc injectors. Obviously the 440cc ones I got are a major overkill.

 

Am I over stressing over the issue? Will i be able to tune these injectors for the time being?

 

Or I should keep on looking for 190-200cc injectors on Stan Weiss's site at http://users.erols.com/srweiss/tableifc.htm ? I found a few leads by cross referencing the part numbers and what rockauto has in stock. A lot of GB reman and BWD ones.

 

Do you have any recommendations? I'd like to keep 14mm/14mm top/base long, high impedance injectors, preferably Bosch.

Thanks!

Den

 

 

 

 

Edited July 15 by darom

[madkaw]

Since you will have made the effort of a fuel rail and use high impedance injectors why not go to a pick n pull salvage yard and buy some cheap used Bosch that are a bit smaller . Can’t tell you if 440cc will work or not . I run them in my 3.2 NA but I have 230 rwhp . I think before these I was running 36lb VW injectors . I moved the 36 lbs ones to my 720 truck that probably has 115 hp at the rear wheels - no issues 

[darom]

Thanks, madkaw. I might be able to squeeze by with these injectors. I will test them. If they run too rich, I will start looking for a set of cheap smaller injectors.

 

I need to start documenting the progress otherwise I just procrastinate.

 

Last week-end I made the coil bracket out of 2 chevy truck ones (came off LM7 truck), they overlapped nicely to get an idea where to cut/weld together. Fit mock-up, I might need to move it to the right side to align spark plugs better:

 

 

 

The coils will be grounded to the bracket to the welded bolt behind, the bracket is bolted on the right side to the cylinder head (black wire, ground to engine block). The coil bank connector will be attached to the same location as where Chevy put it originally (left side, there is a clip between coil 5 and 4).

 

The 1st cylinder's spark plug is too close to the coil, will have to lift the bracket up by 1-1.5 inches to make the spark plug wire fit. I ordered a set of spark plug wires to play around with:

 

And a simple visio wiring diagram for the coil plugs:

Edited July 22 by darom

[darom]

Made little progress by fab'ing a relay board for the MS to be installed in the stock ECU location.

A plate:

and the ready to be installed the relay board:

The stock plastic ECU cover will cover up the board.

 

The diagram of the relay board:

 

Finished the coil wiring (cables are exposed for now in case there are any issues). Readjusted the coil bracket to give more room for the plug No.1:

 

[darom]

I made some progress, installed the oxygen sensor. I had to drop the exhaust, fortunately last time I did it, I had used antiseeze on the threads, the manifold exhaust nuts were easy to take off:

 

The Protunerz' intake, my Bosch injectors and rail are in place. The throttle cable from 240SX took a while to adjust. The pedal didn't have enough angle to do a 100 percent open throttle blade opening. I ended up shimming the gas pedal's 'pedestal' to give additional room for pedal to go. The floor pedal adjuster is almost bottomed out:

The fuel pressure regular is going to be mounted by the battery. I bought all the right AN parts to attach it to the fuel rail, however I have major concerns about open exhaust below/dripping fuel from another source. If it drips, it will drip on the passenger side I am waiting for the AN 8 ORB to 5/16 barb (rail) and AN 6 ORB to 5/16 (regulator) to be delivered to move it to the new place.

 

I am having hard time finding a silicone hose reducer (3 in to 2.75 in, or 75mm to 70mm) to use my stock air filter with my new throttle body. I can find the right size, but not the length. I need a 12 in long 45 degree reducer hose, the longest I found were 8-10 inches:

 

If you guys know a place that can custom make or already sells a pre-made silicon reducer hose that size, please let me know. Thanks.

 

Edited September 2 by darom

[darom]

Forgot to mention that I had installed the MilkFab's trigger wheel that gets mounted on the 280z a/c harmonic balancer. This is their picture (I didn't take one):

 

Last time I changed the timing chain (6 years) ago, I advanced it by 4 degrees, the notch is to the right of the cam gear mark:

 

The MilkFab's instructions are calling for centering the sensor on the 6th tooth: "Adjust the trigger wheel while the mounting screws are loose to align the center of the sensor to the center of the 6th tooth if using the 36-1 wheel."

 

I couldn't get the 6th tooth aligned (not enough adjustment), I could center it on the 7th tooth. I thought I had done something wrong. Searched the forums and found Chickenman's post (whose opinion I respect on this forum), who is recommending to use 7th or 8th tooth: "The missing Tooth should be 7 - 8 Teeth ahead of the sensor. Each Tooth = 10 degrees. So missing Tooth has to pass Crank sensor 70 to 80 degrees BEFORE TDC. This is very important. Re-position Crank wheel to get the missing Tooth ahead of Crank sensor by 7 to 8 teeth Minimum. "

So my understanding is that my setting is at 60 degrees before TDS plus an additional 4 (physical cam advancement), 64 degrees.

36-1 wheel is a 10 degree per tooth. We need to count gaps. I placed mine on the 7th tooth, 6 gaps, i.e. 60 degrees (plus 'built-in 4 degree advance), 64 total.

 

I hope I got it right.