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914World.com _ 914World Garage _ Horsepower Expectations
Posted by: MikeInMunich Dec 4 2014, 03:52 PM
Hi guys,
I just got sad news. My rebuilt (to) 2-liter engine with headers, free flow muffler, mega squirt fuel injection and MSD / Petronix ignition was just on the dyno today. 80 HP at the wheels. 
I reckon this means something like 100 coming from the engine (?)...
Can you knowledgeable experts out there offer some thoughts on this please? The headers were from OBX, bought, by the way, before I knew they were a knock-off of Kerry Hunter's product. The valves were adjusted and plugs are new.
I do not have leak down or compression numbers at the moment but assuming they are what they should be, what do you think his thing should be putting out?
If we are under what you think it should be, do you have any suggestions? Is there a way to easily improve air intake?
Thanks for your time!
M.i.M.
Posted by: mr2by4 Dec 4 2014, 03:54 PM
What cam are you running?
Posted by: Mark Henry Dec 4 2014, 03:58 PM
The headers are the only thing you listed that would help make more power...and OBX sucks.
I'd expect about 110hp.
Posted by: monkeyboy Dec 4 2014, 03:59 PM
What were you expecting at the wheels?
Was the car tuned fully, or just run on a dyno?
There may be more power to be had, but probably not a lot.
Posted by: MikeInMunich Dec 4 2014, 04:15 PM
What cam are you running?
Stock.
Posted by: MikeInMunich Dec 4 2014, 04:16 PM
The headers are the only thing you listed that would help make more power...and OBX sucks.
I'd expect about 110hp.
Thanks Mark.
Posted by: MikeInMunich Dec 4 2014, 04:17 PM
What were you expecting at the wheels?
Was the car tuned fully, or just run on a dyno?
There may be more power to be had, but probably not a lot.
We were hoping for about 115. It was tuned, as far as I know. Just got the result and haven't gotten answers to questions yet.
Posted by: MikeInMunich Dec 4 2014, 04:21 PM
Additional question of importance...
It measured just 80 at the wheels. Is an expectation of 100-115 as a test result measured at the wheels or is something like e.g. 25% added to the figure measured at the wheels to estimate what the engine is putting out?
IOW, if one would expect 110 am I down 10 or 30?
Posted by: neilca Dec 4 2014, 04:29 PM
No one goes to the dyno and are surprised by how much more HP they have over their expectation. A very humbling experience.
Posted by: Racer Chris Dec 4 2014, 04:40 PM
Drivetrain loss should be around 15%.
That means about 94hp at the flywheel in your case.
I would not expect any more than 100hp based on your description.
OTOH, you could have gotten 125 from the proper combination of parts in a 2056 build with stock FI.
Posted by: Kansas 914 Dec 4 2014, 04:42 PM
Drivetrain loss should be around 15%.
That means about 94hp at the flywheel in your case.
I would not expect any more than 100hp based on your description.
OTOH, you could have gotten 125 from the proper combination of parts in a 2056 build with stock FI.
Posted by: Jeff Bowlsby Dec 4 2014, 06:03 PM
Here's factory specs
http://bowlsby.net/914/Classic/zTN_EnginePerformance.jpg
Posted by: Mike Bellis Dec 4 2014, 06:49 PM
Maybe it's metric horsepower? 
Posted by: SirAndy Dec 4 2014, 08:22 PM
That means about 94hp at the flywheel in your case.
I would not expect any more than 100hp based on your description.
OTOH, you could have gotten 125 from the proper combination of parts in a 2056 build with stock FI.
For a stock rebuild with a stock cam, 80ish at the wheels sounds about right ...
Posted by: DBCooper Dec 4 2014, 08:47 PM
Drivetrain loss should be around 15%.
That means about 94hp at the flywheel in your case.
I would not expect any more than 100hp based on your description.
A couple of years ago I spoke with a Ford transmission engineer who also mentioned that 15 percent number (and a little better, actually) as a rule of thumb, but the interesting thing was him saying that was about half the energy that older drivetrains lost. He was pretty proud of that improvement, part of a company priority to improve fuel economy. I don't know about the 901 specifically but suspect it would be one of those older less-efficient transmissions, and if it is then his crank number might be a bit better than that. Car won't be any faster, of course, but maybe he'll feel better about it.
Posted by: pisces914 Dec 4 2014, 08:47 PM
please remember that dyno results are relative to that dyno - you could use another dyno and get a very different result - make sure to use the same dyno as you tune - hope this helps
brad in seattle
Posted by: Maltese Falcon Dec 4 2014, 11:05 PM
Hi guys,
If we are under what you think it should be, do you have any suggestions? Is there a way to easily improve air intake?
Thanks for your time!
M.i.M.
Mike,
Some dynos yield higher #s than other dynos, for instance; the Dynojet 248c usually shows higher #s compared to the Mustang (brand) Dyno.
Then there are uncorrected #s (higher) and corrected #s (lower).
The location / altitude of the Dyno is important, like Denver vs. Long Beach. Your 2.0L with light mods seems just a tad low. Our 2.0 efi club racer makes less than 100hp, with limited mods, no headers. We do use a (allowed in class) high flow cone air filter .It does not make big hp but keeps the revs up between shifts and helps all around throttle response.
Watch + hear it run at Willow short track, on the home page at
Www.msdsinc.com
Marty
Posted by: Alphaogre Dec 4 2014, 11:53 PM
Maybe it's metric horsepower?
Posted by: Bleyseng Dec 5 2014, 08:17 AM
That's about right for a 2.0L with a stock cam.....
Here is my dyno chart from before I went with a Raby cam.
Attached thumbnail(s)
Posted by: eyesright Dec 5 2014, 08:36 AM
That's about right for a 2.0L with a stock cam.....
Here is my dyno chart from before I went with a Raby cam.
(Please excuse the blatant hijack. Enquiring minds want to know...)
After?
And which cam, P&C's?
My "stock" 2.0 L FI with 9550 and flat top pistons FEELS nicely stronger. I'm very happy just having a well running car but having before and after numbers would have been intriguing.
Posted by: Bleyseng Dec 5 2014, 04:12 PM
After the Raby cam and lifters I dynoed at 105hp rearwheel. I lost the dyno chart so 120ish. 96mm P&C's, 9550cam, 9to1CR,Bursch exhaust w/SS exchangers, lots of tuning for the MPS. Still get upto 30mpg on the highway and the tranny has short 3rd and 4th gears so it's fun.
Posted by: MikeInMunich Dec 5 2014, 05:39 PM
After the Raby cam and lifters I dynoed at 105hp rearwheel. I lost the dyno chart so 120ish. 96mm P&C's, 9550cam, 9to1CR,Bursch exhaust w/SS exchangers, lots of tuning for the MPS. Still get upto 30mpg on the highway and the tranny has short 3rd and 4th gears so it's fun.
On my next rebuild, that's what I'll be going with!
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