-78 1800 at a chassis dyno

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Nut124
Posts: 748
Joined: Wed Oct 25, 2017 6:39 pm
Your car is a: 1978 124 Spider 1800

-78 1800 at a chassis dyno

Post by Nut124 »

Last winter I rebuilt my -78 1800 engine using the Guy Croft book as the guide.

Took a while to get it running good. A few weeks ago I took it to a chassis dyno just for curiosity and entertainment.

The operator asked me what I expected at the rear wheels. I said the car seemed to run like 130-140 crank HP based on 1/4mi times, so maybe 120 at the rear wheels.

He said most most builders are disappointed by the results at his dyno. He said he tested an early Miata with some bolt on parts recently that did 89HP at the rear wheels.

Anyway, 1st pull produced 139HP at the wheels. 2nd pull did 141HP at the wheels. Hotter oil makes more power. Peak power at 7200rpm. I was happy but a bit skeptical. He was a bit surprised but swore by his dyno numbers. Common thinking is RWHP is 15% less than advertised engine HP.

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jon8christine
Patron 2018
Patron 2018
Posts: 130
Joined: Sat Mar 12, 2011 10:05 pm
Your car is a: 1976 Fiat 124 Spider
Location: Wyoming

Re: -78 1800 at a chassis dyno

Post by jon8christine »

Cool to see the charts and nice build. Thanks for posting
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