Wait a minute...I get the turbo slant Toyota project done on Sunday, and it turns out that a new forum has been just been started to help me get it tuned? Can't be. I'm never that lucky.

You'll see pics of this monster in a couple days as soon I get the photos hosted, but for now I got a few questions.

Background Info: turbo is a draw thru based off a 70s Buick Regal setup. Carb is an Edlebrock Performer 600cfm. Everything else is basically stock....well, except it's in a Toyota box truck. HEI ignition with a stock coil. 1.75" exhaust thru a cat and muffler. Manual trans. Turbo itself is unknown, but I think it's a T04.

1. Timing - the carb has a "timed vacuume port" and also a regular vac port. I assume I should be using the timed port. I have no idea at what rpm it opens up, but I can find out.

2. Assuming the above, where what would you set the initial timing to? I'm guessing 0? 5 deg BTDC? What's the max timing I can safely run at about 3000rpm?

3. Coil: Looks like the stocker, but it came recommended at Summit for HEI. Think I need to upgrade it? Seems to work just fine.

4. This turbo arrangement has a provision to run engine coolant under the base of the carb. While I'm sure it's bad for max power, I'm guessing it's good for drivability - any thoughts?

Drove it for the first time today. Runs pretty good. Hard to start, wants to stall when it revs down to idle. Power is really strong from 2000-3500, but I'm too chicken to put my foot all the way into it for fear I'll break something.

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1965 Valiant wagon Turbo slant (work in progress)
2000 Chevy 155" cargo van - The Abductor
1970 Newport convertible
1996 Buick Roadmaster Wagon
1966 CruiseAire motor home
1990 Toyota 1 ton box truck TURBO slant (scraped)

Thought I'd reply to my own post. Typing out my thoughts helps me organize them.

Went ape today. I cannot get the idle down to under 1000, though it was at 700 yesterday. What happened? I messed with the timing, but put it back to 5deg BTDC. I also put the distro advance to the timed spark port. Hard to say because the timing tape I put on the balancer lasted about 10 minutes before it flew off, but I'd guess at high revs with no load it's at 30deg BTDC total. I have no idea what's safe for this motor, but I don't hear any knock.

Starts hard, seems to struggle off idle. I'm commiting to using this turbo setup to go to Pittsburgh tommorow and Detroit on Friday, but if it's finicky I may have to go back to the regular old Holley 1945. It'll mean I cut a big hole in the hood for nothing, but who cares. I'd sure like to make it work well with the turbo because I am now, officially, ADDICTED to the sound and power of this thing when it comes on boost.

Kip

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1965 Valiant wagon Turbo slant (work in progress)

2000 Chevy 155" cargo van - The Abductor

1970 Newport convertible

1996 Buick Roadmaster Wagon

1966 CruiseAire motor home

1990 Toyota 1 ton box truck TURBO slant (scraped)

sounds cool, what carb are you using with the turbo setup?

kev

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Carb is an Edlebrock Performer, which I believe is the smallest 4 barrel they make at 600cfm. It's bone stock, but I can say for certain that I'm going to have to learn how to do the jets and rods because it's running rich. It's also VERY easy to flood, which may be due to the ignition not lighting off completely.

HOT TIP: go to Summit and view the Performers. Right on the page is a bunch of videos about how to tune the carb. Pretty cool.

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1965 Valiant wagon Turbo slant (work in progress)

2000 Chevy 155" cargo van - The Abductor

1970 Newport convertible

1996 Buick Roadmaster Wagon

1966 CruiseAire motor home

1990 Toyota 1 ton box truck TURBO slant (scraped)

I've been playing with holleys for awhile i've never touched an eldebrock so I dont really know if ill be able to offer much help with knowledge of that carb. When you say rich do you mean at idle or part throttle or full throttle or all around rich. Because i was thinkin it may only be rich when your not under boost which might put you in a lean situation under boost if you lean it out are you using an afr gauge? may wanna try the old put new spark plugs in floor it then shut the engine off as soon as your done flooring it the get an accurate full throttle plug reading.
Just a thought that may help

Kev

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Check the float level and wither the needle jets and inlets are working correctly/ My brand new out of the box 500avs had misadjusted floats and leaking inlet jets.

600 cfm is probably to small for a draw-thru setup.

The stock Buick setups used a 850 cfm q-jet with the secondaries staked to about 3/4's open. One of the performance enhancements is to remove the stake. Hook up the water lines to the plenum, it will improve drive ability. The Buick q-jet also have the primary rods connected to the manifold after the turbo. Thus the rods enriches the mixture under boost, exactly the opposite of your Edelbrock. Holley sells a very expensive 750 cfm, vacuum secondary carburetor that does the same think, it is made for draw-thru superchargers. I would suggest trying to find the Buick q-jet.

Good info on draw-thru setup is the "Back to Black" section on the turbo Buick web forum. A nice bunch of guys that know quite a bit about draw-thru turbo setups.

Kesteb,
I had stumbled on that Back to Black site. It'll take a while to sift through it all but thanks for the tip.

The new plugs trick is a GREAT idea if you, like me, are far too cheap to buy a AFR gauge. Thanks for that one.

On the carb size, it's hard to tell what's too big or too small. Looks like at high rev, high load I'm making 6-8lbs of boost. That's more than enough and I'm not really looking for more from this engine. I'm not smart enough to be able to tell you that 225 inches turning 4000 rpm will flow X amount of cfm and so I need X cfm carb. My thinking is smaller is better.

I still have three options to try before I start messing with the jets/rods. One is to go ahead and add the under-carb coolant setup. All agree that will tame it down a bit. The other is to start messing with the wastegate. It's vac operated and works freely, so it's a place to do some tweaking. The third is the pump shot - I can try the different holes (that's what she said).

I'm about to trot off for a 280 mile trip today and we'll see how she does. With no baseline to start from, sorting this combo is a lot like playing Battleship.

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1965 Valiant wagon Turbo slant (work in progress)

2000 Chevy 155" cargo van - The Abductor

1970 Newport convertible

1996 Buick Roadmaster Wagon

1966 CruiseAire motor home

1990 Toyota 1 ton box truck TURBO slant (scraped)

Just found this from Shaker from a few months back regarding a turbo /6:

FROM DOC:The vacuum advance is a different story, it is difficult to get the VA to work as designed with a turbo. set-up... unless you have a draw thru a carb. system.
You may want to go with a mechanical advance system only and get additional 'light load' / no boost advance with an electronic controller activated by a pressure switch.
DD


FROM SHAKER:Not true. I set my base timing at 20* and under light acceleration (non boost) and cruise, the timing is at base 20* plus the 12* vac advance. Under heavy acceleration, the vacuum advance is "off" and the timing naturally retards to the 20* base. This is with a blow thru.

Now THERE'S an idea I hadn't considered. My vac gauge is plumbed to the manifold, and it shows 20-24 inches at idle, doesn't start making boost till around 3300 rpm. Plumb the vac advance there and we have a normal car at idle and a retarded car at speed. We have a retarded driver at all times.
Kip

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1965 Valiant wagon Turbo slant (work in progress)

2000 Chevy 155" cargo van - The Abductor

1970 Newport convertible

1996 Buick Roadmaster Wagon

1966 CruiseAire motor home

1990 Toyota 1 ton box truck TURBO slant (scraped)

Ya the spark plug thing worked when tuning my n/a motor so im sure the same full throttle reading would work on your motor

Kev

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Hi, kipamore. The coil used with the HEI module should have 0.5 Ohm resistance, I have seen that some coils advertised for HEI, are actually intended for computer-controlled engine management systems.

Olaf.

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Aspenized

Olaf,
Excellent tip. I'll measure it.

The turbo engine ran into some snags on the maiden voyage. Fatal snags. Read the full story in the Engine Forum in the "talk me out of this" folder.

Kip

_________________
1965 Valiant wagon Turbo slant (work in progress)

2000 Chevy 155" cargo van - The Abductor

1970 Newport convertible

1996 Buick Roadmaster Wagon

1966 CruiseAire motor home

1990 Toyota 1 ton box truck TURBO slant (scraped)

Finally got some pics.

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1965 Valiant wagon Turbo slant (work in progress)

2000 Chevy 155" cargo van - The Abductor

1970 Newport convertible

1996 Buick Roadmaster Wagon

1966 CruiseAire motor home

1990 Toyota 1 ton box truck TURBO slant (scraped)

Too cool!

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Scott - waywardgarage.com
Why is the rum always gone?

I just love this project.

Nice to see you in action behind the wheel, too!

Olaf

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Aspenized

How did you (or Did you) boost reference the "power enrichment system" on the Performer/AFB carburetor? There needs to be a plate under the carb with a manifolf reference signal that runs to the"metering rod chambers on both sides of the carburetor for the Performer/AFBs power metering system to work and provide fuel enrichment when needed. Using the GM "draw through" system off of a Turbo Buick, the Performer/AFB would never see boost on the enrichment system and would tend to run lean.

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David Gibson