Dyno Results

Discussion in 'Fox 5.0 Mustang Tech' started by [email protected], Oct 1, 2004.

  1. I've seen that chart, and used to reference it, but too many guys discredit it.
  2. I must have missed that.......the sources for the numbers are in the footnotes. Due tell who has discredited the numbers. Do you mean off a couple cfm which is to be expected from test to test, or do you mean not accurate at all? Let us know what the good numbers are - OK?
  3. Darkpony pulled 297HP/326TQ out of P heads and a Cobra intake with an Anderson B25 cam and good exhaust system.
  4. This is the only thing you said I can't agree with - you can balance the flow of the Cobra intake at anything less than about 230cfm or so. Even higher if you weld and do a lot more work.
  5. I've showed it around a bit, and alot of people believe the numbers are off. Especially concerning the gt40 series. Tom if you remember i showed this exact chart on .50tech a while back, and if i remember correctly some even though it was skeptical back then.
    Supposidly (because i don't know for sure) The p numbers are just too high, and the y's aren't that good on the intake side, and aren't that bad on the exhaust.

    When this chart is compared to the one in MM and FF, there is a completely different set of numbers, Pretty far off to say the least.

    I know guys that have explorers with e cams. One only got 237.
    So with all the parts people claim are so great that come off of explorers, such as the p heads, the intake, tb, 237 is better than stock but not so great if you took the time to swap all this to a mustang.

    Just for the record i know none of this for pure fact. In reality i won't 100% sure of any of this until my car is done.
  6. The results of Pheaded cars runs from a low in the 230HP range like you said to a high of 297HP that Dark Pony got. I got 260RWHP without a tune. Illustrates that there is more to making power than just one componant. And If you check the numbers on all the websites, you'll find signifcant variance in the numbers - different benches, different operators, etc. Who's to say what is the "right" set of numbers? Below is a set of reported results from dynos that I picked up off the internet over time - I have the curves for most of them. It's a snapshot in time of each combination. Unfortunately, not many guys run the Y or X heads and post dyno sheets for us to see in the tally. As you can see, the P heads do quite well in stock form. I keep a vigilant eye out for Y and X head results with grpahs, their just hard to find. Maybe this thread will encourage some to post up............
  7. I'll agree with you that numbers are pretty rare for the y's. Even for the x's but i've seen the x's pretty often due to the fact that my local shop likes to use them on cars meant for the street and a budget. But also as you know already, he does require every set of heads that he removes/intalls to goto the machine. So it's possible the numbers are a bit higher, because most get the valve job, seat pressure check and bowl clean up. I'm really hoping for 285-290 from my future setup which is reasonalbe. But my car will also be tuned by a guy that knows exactly what he is doing.

    I've seen some good numbers out of the p's via the internet, but most around me have aluminum heads, best results i see on a normal basis are TFS.

    Your numbers are one of the higher i've seen, and i know by reading your posts that it's not B.S. I just don't see that many other guys putting out great numbers with them, most less than guys with fully ported stock heads, which may be more cost effective. You use your's for a certain class if i'm not mistaken, other than that would you use them?

    I know that numbers vary all over the place, and they always will, that's why i usually compare them side by side. And so far the only flow tests that i've seen that fully explain everything and every part of how and what was done is the Fast Fords one.

    Tom, If you would like to see it, so you can help compare let me know, i'll see if i can scan it and email it to you.
  8. I get MM&FF, just tell me thissue and article.
  9. Sept 03, pg 184, the rest of the article immediately preceeds that chart. Article is MM and FF guide to cylinder heads part II.

    I assumed you get the magazine, just and not sure how long you keep them.
  10. Reading it right now.............and I see why there is a difference in the flow numbers, the comparison is apples-to-oranges. That link above is flow tests on a flow bench, the article you referenced did not say they measured flow on a bench - may have measured actual air flow of the running engine. All that work was done on an engine dyno and the engine used a carb, not EFI.

    Can't really compare them directly without knowing how they measured the flow.
  11. Mine is doing fine w/ 310rwhp
  12. I'm aware that they used a carb there.
    Reason i liked the chart was because every head used the same cam and setup there was no variations, other than the stock heads getting some valve springs. I'm sure some of the better heads would of done better with a different cam, but i'd also think will the less flowing heads the cam would be mostly fair to them.
    Which numbers do you find to be more relevant? I guess there's real world numbers and bench numbers. But on the first page of the article it says "naturally testing included time on the flow bench".
    Done 28 inches (which i hope you will explain to me).
  13. Let's see the corrected figures, cool guy :D
  14. 295..... ummmmmmm. Thats what im least expecting out of my combo, before porting anyway. And i have way more into mine then u. I could be wrong though, factory freak lol
  15. They don't say how the flow numbers were done - head alone like the numbers in the table? Probably, but we don't know cause they didn't say - but we can surmise that maybe by looking at Parts I & III. However, the .450" lift peak flow number was 187cfm - the table you said has been proven wrong indicates about 195 cfm - well within normal variances for casting differences and bench set up/operator variances for flow testing - 7cfm. Also note that the valve lift height where the peak flows were taken was changed - taken @ .450" lift for the E7 and P heads and .550" lift for all the others, but a table with .500" lift was given on page 184 in Part II as well as Part I.

    Note: MM&FF @ .500", table taken @ .500"
    E7 peak - 157cfm MM&FF, 155cfm table
    GT40P - 185 cfm MM&FF, 195 table
    Windsor Jr - 203cfm MM&FF, 186cfm table
    GT40Y - 206cfm MM&FF, 213cfm table
    Canfield - which Canfiled in the table is not given, so can't really compare
    Brodix - 239cfm MM&FF, 243cfm table
    Systemax - 237cfm MM&FF, table 219cfm
    Performer - 234cfm MM&FF, table 214cfm
    AFR 165 - 237cfm MM&FF, table 250cfm

    These variances are not huge and are actually within the variances that you find on the referenced websites when comparing flow test done by others posted there. These variances, like I said, are due to manufacturing variances as well as test bench/set up variances. Is that enough variance to say the table in Stangnet is discredited and should not be used?

    28" of water depression indicates the intake vacuum level used during the test. A manometer is used which is a long clear tube attached to a scale that has inches marked on it like a ruler. The clear tube has red colored water in it and when attached to the vacuum in the manifoild pulls the water up 28". You can see that in Part I and Part III.
  16. Thanks tom,
    Unfortunately i can't find part I or III, so i really can't read the articles.
    I was down at the shop talking to the guys today, and basically they told me to stop comparing head flow numbers because there is too many variables in the testing. Besides also as you stated there's many casting issues. They also gave me an explanation of the testing describing exactly what you said, but i'd probably have to see it in person to fully understand. It was also pointed out to me that flow numbers aren't as relevant as i make them. And it's about more than just cfm.
  17. Looks like this has become a useful post, although my post is not :)
  18. Hey guys could o2 sensors be causing my lean issue ?

    I installed a new 190# pump & filter but I'm still not getting enough gas :shrug: