|
I'll see if Gary will give me the numbers. If I remember correctly though, he wouldn't let the operator pull the engine up as high as we did on the engine dyno, so the results will be skewed. Also, the carb was set up in the car so that the linkage wouldn't let it open up all the way. Gary found it later and noted that it felt like a completely different car at WOT.
I've seen dyno numbers vary from builder to builder. I know for a fact that one engine has been dyno'd on the dyno that I use and then was taken across town to a Superflow and showed 5% higher. You'll also see builders dyno at 120 deg water temp, where I try to dyno closer to 160-170, a temp that is closer to what the car will see, but isn't hot enough to cause issues under a full load. I also really don't agree with comparing engine dyno numbers to chassis dyno numbers, especially in a Cobra. One member here (Excalibur) stuck his car on a chassis dyno, made a pull, then removed his side pipes and made 100 more RWHP. There can not be a direct correlation when golf-ball sized pipes are used, when restrictive air cleaners are used because of hood clearance, etc. All of those things play a big part in numbers, and if the engine wasn't dyno'd in the exact same setting, then it's bogus. |
Quote:
The main difference in the car he mentioned to me was pulling off the dry sump. But yeah, the chassis dyno is a world of difference in setting up the car with the engine. Too bad ours was not completely installed when Gary's car went through since it would have been good to baseline it against 40 other or so engines in the same car by different builders etc. Keep working on the charts, it's a great resource to offer. |
Quote:
The printouts I saw all had "STD Corrected" on them, so I just assumed that's how it's done... I know air density/elevation plays a big part in HP... Down here in Louisiana at sea level it's one thing,other areas are another.......I used to drag race my street car a fair bit down here and one year went to Tulsa for the Shelby meet and ran it there.....I was 4/10ths off my "normal" time and asked others if saw the same thing, one big time racer said that was normal because of the elevation change.... I couldn't believe that would make that much difference, but it does.... David |
Quote:
|
Quote:
As long as everyone remembers that dyno numbers *should* be used as a general tuning tool, things shouldn't get out of hand. However, my intent was to just show what typical engine combos make, where they make the horsepower, etc. Its nice to be able to look and see what difference a set of heads can make, what difference a camshaft should make, etc. And what David says holds true in every respect. It's very difficult to dyno an engine here or build a carb here and it be in perfect tune as you send it to a different region in the US. |
That's why you should show the graphs, it tells more than peak etc. Take time with it and show the bigger story on a few engines. So many hours in one build, a few more minutes to convey each one.
|
Altho graphs will show how much hp/tq was made at what rpm, sometimes you may get a graph that has a funny look to it that is the result of a time difference that actually effects the look of the line but not much the numbers.
I recently was doing an 57 chev with a gross assortment of components that as a result of the small diameter, long tube headers, and cobbled exhaust system (rump,rump,loud) and a manifold for extreme high rpm that had a slump? in the curve after the initial hit from down low (after header tune rpm) and before it got to the manifold tuned range------wasn;t something you could feel in drivability tests but the dyno did show it up----just a slight lessening of the curves but when done on a graph/chart without TIME as a basic looked weird! |
Quote:
http://www.maseratilife.com/forums/a...-coupe_116.jpg |
thanks for the info you guys are awsome i was afraid to go bigger than .560 lift on my hyd. cam but not now.
|
Talk to Blykins about what you want, he will guide you to the direction of the golden light...:)
|
| All times are GMT -7. The time now is 04:10 PM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: