I finally attached my G-Tech meter to the windshield and got some preliminary numbers.

The good news is that this car can perform a 1/4 mile drag strip test on a public roadway without breaking any speed limits. My "time trials" were done on a stretch of interstate highway after midnight, and there was no one around to notice or care that I periodically came to a dead stop in the right lane.

The other news is that there's plenty of room for improvement. 0-60 arrives in approximately 15 seconds, although it's tough to get consistent results when I have to finesse my foot around a bog in the accelerator pump. (The O2 sensor readout proves handy, to help me get past that.) The 1/4 mile arrives in the low 20s, at about 69 mph.

All this, on a low mileage but tired motor with 85 psi cranking pressure, and a 3-on-the-tree that is (remarkably) still quite solid. Seems a bit clunky compared to today's 5-speeds, of course... but there's hardly enough horsepower to matter. (In a 20-second car, what difference is a 1-second shift? ) Still, it's a far cry from the performance I've been used to, in many of my previous cars...

Thought you might be interested. Details: 170/1Bbl, non-synchro 3-spd, 3.23rear, P185/80R13 tires, shift points at ~30mph and 50mph (translates to about 4100 rpm, dropping to 2200 rpm.) At 3000 lbs with me in it, that's in the range of 75 HP at the wheels. Assuming 25% drivetrain loss, that's about 95 HP at the crank. Considering the factory rated this puppy at 101 HP, and considering the low compression figures, that's remarkably good!

- Erik

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Lots of early Valiants and Barracudas have crossed my path.
Also a handful of other toys for variety now and then.

I wish I had a G-Tech it would have been fun to see what each little upgrade would have done. Like base then w/ the super six, then electronic ignition, then electric fan and K&N, then the turbo muffler then the 318 BBD now finally head work and headers w/ 2 1/2" exhaust.

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Mine is a 904 w/ a 2.76 rear, when I shift at 4500 I'm going around 42mph the 2-3 shift at 4500rpm is 77mph

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Yep, that's about what it sounds like to me, too. Especially given the lack of hood insulation and minimal firewall dampening (compared to modern cars.) Depends on the rear gear ratio, too, obviously.

But I'm sure 4100 rpm is not out of reach for a Slant, especially the shorter-stroked 170. The only reason I chose that speed is because the engine was clearly starting to run out of steam, and felt a bit more aggressive at 2200 rpm in the next gear. (Well, as agressive as a stock 170 gets. ) To me, that experience highlights the major limitation of the tiny carb (1 9/16) and pea-shooter exhaust pipe.

Yea, I know, I could have been scientific about it, but I chose the shift point purely based on seat-of-the-pants feel.

- Erik

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Lots of early Valiants and Barracudas have crossed my path.
Also a handful of other toys for variety now and then.

2.76gears and i shift outta first at 55mph

An o2 sensor on a 170? I'm obviously misinterpreting this; how does the o2 sensor readout help you on a car without one?

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.

One of the new 'cheats' is to install a bung and one wire O2 sensor in your header pipe right after the exhaust manifold and wire it to a meter or a multimeter to give you an idea during a drive or drag session of what kind of carb tuning you need to do, with the 'input' you make the determination as to changing the jetting, shot size/duration, etc.... instead of a computer.


-D.Idiot

Cool!

I use a thermocouple and pyrometer out of a truck on my VW westy to monitor exhaust temperature and Ive always used that to adjust my mixture, but that's with a stock carb.

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I've been calling it as i see it for my entire life and that's not about to change. Take it or leave it.