2003 Toxic Tacoma

[masterkorp]

Oh totally agree on the mig welder. A mig is great to all kind of stuff and weird positions.
I have a cheapo MIG welder and love it, just made me learn how Acetone is a welder's best friend.

[ToxicGumbo]

1) Throttle entry vs Turbo exit vs Intercooler entry/exit = your correct sizing(s). Tapering up out of the turbo is OK. Otherwise it should stay pretty constant throughout. Measure OD and ID of all four and post up

Turbo: Needs an actual exit flange. Looks like the seller took that off, so all I have is a flat bolt-on location. However, the inner diameter of the exit port at that location is 4cm. The intake is roughly tapered down to 55mm interior, 65mm exterior.

Intercooler: On both sides, 55mm interior, 60 exterior.

Throttle: 60mm exterior. Didn't pull the hose off given that it's a pain in the sphincter.


I also scoped the tach and ignition feedback signals to see if these were essentially the same. They're not. A quick and dirty Fluke test gave an average of 4.8VDC on Tach and 6.7VDC on IGF. I was expecting AC, so that seemed odd. Here's a visualization with the oscilloscope (IGF on top, Tach on bottom):



I have some more stats and video, but nothing terribly useful as I'm still trying to get used to using a scope.


-Jeff

[Fred]

2.5" it is, then! :-) The flat bolt-on location is a good place to bolt a perfectly port-matched tapered piece out to your 2.5" silicone coupler with T-bolt clamps. TIG welding class, or a local fab shop, for that :-)

I look forward to your detailed analysis of the OEM topology re tacho.

Fred.

[ToxicGumbo]

I look forward to your detailed analysis of the OEM topology re tacho.

The OEM ECU uses a multi-layer board, so reverse engineering by sight has been minimal. After playing under the hood and reading through Toyota documentation on their ignition system, I've come up with the following so far:

• This is a coil-on-plug system and Toyota coils use built in igniters
• IGF going into the CPU is a combination of all four CoP IGF output signals
• The ECU knows the firing order and therefore knows which event in the signal to look for to identify expected ignition
• Tach output is produced within the ECU in a manner similar to a single igniter in a non-CoP setup where tach output is provided
• The tach output wire of the ECU is used with aftermarket tachometers just like the igniter wire of earlier Toyota trucks.

Though my scoping around showed that IGF was 2VDC higher than tach, it seems like a lot of people with similar situations used a pull-up-resistor circuit connected to 12V. I haven't found any situations which began with results similar to mine.


Edit: The OEM ECU circuitry leading backwards from the tach pin snakes through and spreads out into some resistors, a diode, a couple of transistors, submerges and dissolves into another layer, into a custom chip, and then onto small plane which may or may not be grounding. The chip might be related to OBD-II, but at this point it's not likely to be much help.

-Jeff

[ToxicGumbo]

Just inspected the radiator in anticipation of recessing it back into the engine bay. It's currently bolted directly to the trunk's reenforced sheet metal and all plumbing going to it is either a flexible hose or becomes one before mating. About 4 spacers and longer bolts are really all that's needed to move it. Easy enough.

Here's where it gets complicated: the fan is bolted to the face of the crank pulley and slightly wraps around it to make good use of space--every bit of which it needs because the radiator's practically on top of it. This is a huge contrast to, say, the mid-90s Mustang I've worked on which could smuggle kilos of cocaine between the radiator and engine since it was designed with an electric fan in mind and didn't require it to be close to the engine.

I'll take some measurements and photos to post here later.

Edit: Though the Tacoma in this article is older and proportioned slightly differently from mine, it looks like this guy's fan choice could possibly free up a couple inches. Even one inch would make a world of difference.


-Jeff

[ToxicGumbo]

Well this is exciting news: a series of evening welding courses at the technical college next door. And I was able to help make it happen!

Time to start up a "gofundme" account.



-Jeff

[Fred]

Dear Jeff,

I'm sitting here with a cold and well-earned Monteith's Crushed Pear Cider in my hand enjoying reading your posts. And of course, I have some comments:

Good work on the tacho research, keep it up! You'll figure it out enough to get a result in the end! :-)

Because all I'm doing is sitting here slugging a cold one, I took some pics and measurements of my fan setup just for you. Total height seems to be about 65mm from face of radiator to peak of motor in the middle. Half that around the edges. They have curved blades - ensure yours do, too. LOL @ me asking if your truck had fan control. Funny fail. It will have an electric fan soon, though, controlled by FreeEMS :-D This is a mod you can do long before you go boosted, which is nice. You can also do it before moving the radiator back in. When you do move it back in, ensure you seal above and below and on the sides so air is forced through it.

Though: Is it actually necessary, or could the IC fit in between as it is without moving it backward? Confirm this first.

Re welding, although I meant for you to just buy one and teach yourself, if I'm able, I'll contribute to your course fees. Especially if they're drip fed. Especially if you post pics of your birdshit welds as you learn :-D

Fred. (who is excited about going to pick up his mrs with his new suspension parts, any minute now)

[ToxicGumbo]

I'm sitting here with a cold and well-earned Monteith's Crushed Pear Cider in my hand enjoying reading your posts.

Definitely earned. You've been especially busy this week and still had time to help me out. Thanks.

Thanks for providing your fan specs. I had thought up until checking that it was an electric fan setup, so apologies for any deception on my part. It looks like people have scene substantial gains in performance by removing the clutch-based crank pulley (parasitic) fan in favor of a fully electrical unit.

It will have an electric fan soon, though, controlled by FreeEMS

Ironic that I just wired up the "Fan" low-side driver on the Jaguar A3 for an entirely different purpose!

Though: Is it actually necessary, or could the IC fit in between as it is without moving it backward? Confirm this first.

Will do. Didn't get a chance to do any measurements today as promised, but they'll be here soon.

Re welding, although I meant for you to just buy one and teach yourself, if I'm able, I'll contribute to your course fees. Especially if they're drip fed. Especially if you post pics of your birdshit welds as you learn

Very generous and very appreciated, Fred. I talked with my fiancé today about this as a full set of classes would compete heavily with money for the wedding, house, etc. So I've got a video in mind and will market myself in hopes of random pity donations. Keep drinking fresh cider for now and let's see how that turns out. Good of you for offering.

For some eye-candy, here are the two proposed header flanges, the smaller having just been bought and shipped for close to $20. Looking at it again, I'm not too happy with the rough surface. It'll likely work out fine with a quality gasket, but a mild, undesirable, texture can be felt via fingernail.




-Jeff

[Fred]

First: Didn't put more cider in the fridge, so none cold right now. Bugger.

Opinions shall spew forth this evening:

Run another wire from the other spare output ;-)

That machined surface looks fine to me. I wouldn't worry about it. Use a crushable multi-layer steel gasket for it. You could ebay/shop for that nowish :-)

I personally would NOT use the OEM downpipe/exhaust housing on the turbo. Pick up a flange for that too and fab your own up with v-band output, no O2, and better wg re-entry :-)

Fred.

[ToxicGumbo]

The flat bolt-on location is a good place to bolt a perfectly port-matched tapered piece out to your 2.5" silicone coupler
...
I personally would NOT use the OEM downpipe/exhaust...fab your own up with v-band output, no O2, and better wg re-entry

Would you say that these two examples are roughly what you're suggesting? Both are amazingly unique in the Evo world for some reason.




-Jeff