FI and Ignition for 2270 T4

[IanEpperson]

I've been driving Raby's T4 2270 Torquer #1 for some time now. I'm having work done on the engine, and it's finally time to ditch the carbs and go FI. My reasons are a) mileage (15-20 currently sucks), b) better running when driving to the mountains and back, c) easier tuning (I'm more comfy with a laptop than with jets) and finally d) maybe even more torque. It's quite nice on the street now, and I really want to keep it that way. It seems that I could also go distributor-less too and digitize one more adjustment. This is in a '73 Thing and it's often wet.

Right now:
- 44 IDF Webers
- MSD Distributor
- MSD 6AL Ignition System
- MSD coil
- Nylon-sleeved aluminum 3/8" fuel line in the tunnel
- Mallory low-pressure rotary fuel pump
- 3 fuel pump relays to drive the pump with starter or when oil light is out.
- Analog gauges: CHT, Oil pressure, Oil temp
- Tachometer
- 4-2-1 exhaust system

Makes between 170 and 190 HP.

My plan so far:

- Microsquirt (sealed and mounted near the battery)
- 40mm throttle bodies (not sure whose to use)
- Injectors (TBD)
- four LS2 coils (The Dub Shop makes nice mounts for them)
- T4 Crank Trigger (36-1, hall sensor)
- Fuel loop with two 3/8" SS lines in the tunnel.
- Mallory FI fuel pump (should bolt to same custom mount)
- Bypass regulator (TBD)
- Single wideband O2 sensor (TBD) welded in to the manifold
- GM 3 Bar MAP Sensor
- CAN-EGT to monitor 4 CHT under-plug sensors
- Gauges (TBD), probably keep the same tach

My plan after reading the Microsquirt Quickstart Guide is to use their option "3a" - single input (crank trigger) and wasted spark.

Initially, I was thinking of using the CB Performance throttle bodies, but I read in this forum that they're not as nice as others. So now I'm not sure which ones I should be looking at.

I want the 4 CHT because I've had isolated issues with cooling that I've missed because I was monitoring the wrong side of the engine. Sucked in debris that stopped cooling one cylinder, clogged jet that heated up another. I don't want 4 CHT gauges on the dash, and if the Microsqurt or gauges can't consolidate into one I can build a little Arduino circuit to do it for me.


I haven't bought any parts yet, and would love any advice.

(edited to add the MAP sensor, exhaust type and to note that it's a wideband 02 sensor)

[IanEpperson]

Looking at these TBs: http://www.vwspeedshop.com/product.php? ... 395&page=1

[falcor]

I've got those in 40 mm size that I will use for my stock 914 2.0 Engine that I will be upgrading to a 2276 or 2316 later on.

Mario at thedubshop.net can set you up with a complete package including everything you need.

[samcat]

Very similar setup, Raby 2270 T4 (from a kit, one of the first he sold).. Done lots of research and just starting the install.. Probably find some things that I will do differently but the parts list currently looks like:

* Megasquirt MS3X
* Speedshop 40mm throttle bodies
* Dubshop camsync
* Dubshop 36-1 and hall sensor
* LS2 coils and Dubshop mounts
* Innovate Motorsport LM2 wideband (already had it from tuning carbs)
* Filter then Red top pump feeding swirl pot
* Swirl pot has 3psi popper on the top feeding back to tank
* Walbro injection pump
* Fuel injection filter
* Cupril fuel hose, 2 runs of 8mm (feed and return)
* stainless overbraid teflon hose for flexible sections, using AN6 fittings where appropriate

[IanEpperson]

Mario at thedubshop.net can set you up with a complete package including everything you need.

He seems to be out-of-stock on the TBs, will be getting a bunch of other parts from him though. He didn't reply to my first email, I'll try again.

I've got those in 40 mm size that I will use for my stock 914 2.0 Engine that I will be upgrading to a 2276 or 2316 later on.

I'm wondering if I should go with 42s instead of 40s. How closely does the Weber 44 IDFs match up with 40s? Originally I had though of going 48s simply because CB Performance only offers (offered?) 40 and 48s, but reading in this forum I now see the error of my ways.

[IanEpperson]

* Filter then Red top pump feeding swirl pot
* Swirl pot has 3psi popper on the top feeding back to tank
* Walbro injection pump
* Fuel injection filter

When I search for "red top pump" I find a lot of:


Not sure how that'll help your FI system, but you'll look FABULOUS!

But seriously, I guess you're doing this:

I hadn't considered that kind of setup. What's the advantage? Lower pressure fuel lines across the chassis? Allows the use of the existing fuel line?

[IanEpperson]

Ah, answered my own question:

What is a Swirl Pot? A Swirl Pot acts as an External Secondary Fuel Tank Used to Eliminate Starvation Under Low Fuel Conditions, Especially During Violent Cornering, Rapid Acceleration & Hard Braking!

http://atlinc.com/atl-swirl-pot-st540.html

Seems excessive for a street car with mild offroad. I don't think I've ever experienced fuel starvation when I wasn't actually out of gas, but then, I've never run with a custom FI system. Maybe it's more important when running bare-minimum gas during a race to save on weight?

[IanEpperson]

These VW Speedshop TBs look purty.

http://www.vwspeedshop.com/product.php?productid=16821

I think those are the same model that TheDubShop sells, for about the same price (less VAT, GBP -> USD).

[Paul H]

We have those in stock 42mm and 45mm -the 38s and 40's will be a couple of months.You can get them from Mario
On the swirlpot subject I have not found the need for one and just use a large fuel filter

[IanEpperson]

Thanks for the advice here. The BEST advice was to contact Mario at the Dub Shop who has been great at feeding my nerdy engine addiction.

I'm now doing the wiring for an FI system from Mario. Here's my wiring diagram so far:

https://docs.google.com/drawings/d/1XTX ... sp=sharing

Note that the diagram includes the links to the different devices if you wish to follow in my footsteps.



I need to redraw the wiring around the relays, it's gotten a bit ugly as I've modified the layout a bit and corrected from Mario's feedback.

[IanEpperson]

16426289_10155026011679365_5534603242218317015_n.jpg

16299462_10155026011689365_6873610284691017689_n.jpg

[MarioVelotta]

Your schematic is great!

I just want to note that Ian will be using an output from his CAN-EGT to feed his CLT input on the ECU instead of using a standard warmup / clt sensor. It will work at a higher resolution and show actual realtime head temp.

[IanEpperson]

I broke in the engine on Friday and learned the absolute magic of "Auto tune"!

I had gotten it idling decently and buttoned everything up. With my son manning the laptop in the passenger seat, I drove it to the local gas station to get the tank at least half full, then headed up to the Oakland hills. However, not even a mile down the street I realized that I had to do SOMETHING - the base tune was causing sputtering and missing and just running like crap. I pointed out the "Auto tune" and had my son turn it on and click apply... "putt putt sputter sputter putt putt sputter put ... hummmmmmmm"! Magic! And power! It's been about three years since I drove it and have gotten used to our Prius (always works, stupid easy to drive, boring as hell) and suddenly had that kick of a throttle that'll literally knock your hat off!

To get the engine broken in and to walk the tuning map I revved hard up hills, engine braked hard down the hills (no backfires! woot!) stressed it a bit back up the hill in 3rd (no pinging!) and did a few hard starts. 45 minutes in, my fan belt flipped at 5300 RPM and ripped itself apart spewing rubber debris all over the fresh engine. Thankfully I brought a spare, but have to work around the custom exhaust to install it, so had to let it cool for a time, then back on the road for a few more hill charges.

My #3 cylinder is consistently 50 degrees cooler than everything else. (Did I mention that I love that CAN-EGT?) I noticed that it was drawing quite a bit less air than the rest and I wasn't able to adjust it out. Last night I pulled that TB and fabricated up a flow tester using my shop vac the flow meter and a block of wood. Very clearly that throat of that TB flows at 2kg/h lower - #4 (which matches #2 perfectly and is close it #1) was giving me 5kg/h on the bench, but #3 gave me 3! I taped off the air bypass ports and removed the air cleaner deck and venturis to just get it to test only the butterfly - and the exact same result. I backed out the idle set screw and let the butterflies stop the shaft, and #3 was all the way down to 1kg/h whereas #4 was at about 2. So it's the butterfly for #3 closing a hair earlier. I'm going to try and adjust it, but those delicate butterfly mounting screws are not easy to turn. I'll get back to it tonight or tomorrow.

[Piledriver]

Having run both Webers and FI in a daily driver//long distance commute, you aren't going to miss the Webers/distributor... at all.
Once you get it dialed in, you find yourself with a reliable, near zero maintenance setup that drives like a very fun OEM ride.

You should consider a Synclink linkage if you have any side to side balance issues. esp. over time.
I have "gently" twisted Weber throttle shafts to fix front/back balance issues as you are having.

The "auto tune" works truly superbly if the lambda delay is set correctly, the default values are for a SBC with short cast iron manifolds.
Long tube headers are going to need higher values for lambda delay for best/very consistent results.

My day to day/log to log fuel correction was very much in the noise once I figured that out.

Note that the swirl pot setup is really needed on roller cell pumps, they do not suck well, although they are great pumps.

The swirl pot pushes any entrained fuel vapor back to the tank, a gerotor or vane type pump sucks better, but a Holley Red is a cheap "one-season" design, with tiny carbon brushes and a Teflon shaft seal that will leak, and the pump is prone to rust. I have been running the same Carter clacker feeder pump for ages, and it was well used when I got it.
(I bought a Holley red once to use as a feeder, and tore it apart after briefly using it and having it start leaking... short life piece of junk by design)

For a feeder pump with much more flow and a built in 5 micron filter/water separator, I suggest a Facet Dura-lift, has a 3 meter dry lift rating. It really, really sucks. (for a pump, that's a feature)