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914World.com _ 914World Garage _ Needed: stock 1.7 dyno graph

Posted by: airsix Jul 22 2003, 12:57 PM

Ha! Does anyone have dyno graphs for the mighty 1.7? lol3.gif
I am looking for some benchmarks to compare against my PEFI tuning. I know my peak power is good, but I want to make sure I'm getting max torque across the full range. Thanks in advance. Please withhold all 1.7 jokes. I have class-restriction reasons for keeping it (for now).
-Ben M.

Posted by: airsix Jul 25 2003, 03:58 PM

Come on, throw me a bone!

More questions:
Were all the '73 1.7's rated at 72hp or were non-CA cars different?

To assist with my PEFI tuning I'm using a narrow-band O2 (to get roughted in)and http://www.charm.net/~mchaney/homedyno/homedyno.htm. I pulled a standard-atmosphere/temp corrected 60hp at the wheels last night. 15% powertrain loss puts me at 70.5hp at the crank. Not to far off the factory 72hp assuming that's the correct figure for a non-CA '73 1.7. Dave Hunt got 80hp on his 2.0 dyno pulls, right? So 10hp drivetrain loss sounds good.

I know, I know. "Who gives a flying turd about 1.7's?" Me, 'cuz I owns one. Besides, this is practice for tuning the turbo version and later the 2.7 six.

-Ben M.

Posted by: Brad Roberts Jul 25 2003, 04:12 PM

Your SOL with me. I have nothing on them.

B

Posted by: tryan Jul 25 2003, 04:25 PM

the owners manual should have an hp/torque/rpm curve. got rat milk?

Posted by: garyh Jul 25 2003, 04:48 PM

QUOTE(airsix @ Jul 25 2003, 01:58 PM)
Were all the '73 1.7's rated at 72hp or were non-CA cars different?

49-state cars were advertised as 80 HP.

Posted by: Mueller Jul 25 2003, 05:20 PM

I'd think the factory 2.0 dyno graphs would be close enough, just take into account that the VE of the 1.7 is a few % below that of the 2.0

Posted by: airsix Jul 25 2003, 08:48 PM

For any of you tinkering with stuff like this I highly recommend this home-dyno software. It's pretty cool. Here's my graph from last night. Notice how wild the torque curve is. I'll be working on that. wink.gif Anyway, my point is this really sheds some light on things. I can clearly see what RPM points need mixture adjustment. I'll see what I can do this weekend and post a followup. Hopefully I can make that torque curve nice and flat.
-Ben M.


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Posted by: Andyrew Jul 25 2003, 09:28 PM

Thats a torqy 1.7! ohmy.gif.
I would be happy with that on my 2.0! (the tq number, not the hp wink.gif )

Posted by: airsix Jul 26 2003, 12:07 AM

QUOTE(Andyrew @ Jul 25 2003, 07:28 PM)
Thats a torqy 1.7! ohmy.gif.
I would be happy with that on my 2.0! (the tq number, not the hp wink.gif )

Well, if 49-state '73 1.7's were 80hp that means I've got another 10hp to go root out. The car is very drivable at this point, but as you can see from the saw-tooth torque curve, the mixture is still all over the place. People aren't kidding when they say you need a dyno and gas analyzer to really do this sort of thing. I don't have any gas analysis, and it's only practical to do one 'home-dyno' run per night since you have to dump the recording to a pc. It's slow, but I'm making progress.

-Ben M.

Posted by: redshift Jul 26 2003, 12:20 AM

A worn 1.7 is anemic, a decent one is a stump puller.

We have tractors, you knew that, right?




M

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