WizeAss

iTrader: (5)

I am sure Chris has his opinions on cam selections Mike. I bet his Nascar crazy lobes and stuff would kill my hydrolic patriot spring setup w/ 7.4's and high rpm lifters right??

This cam crap is the biggest pain in the ***..... it is where a build can go completely wrong. This is why I think that 403/L92 setup only did 466rwhp on RPMs dyno. When other L92 big cube setups where doing 500's.

skipperbisket

iTrader: (4)

why can't you buy the cam from Patrick?

V6 Bird

iTrader: (15)

No, because it shows a lack of trust you have invested into the relationship of the gent's building your motor. They know or should know what is going on in cam/valve events and know what to do to make power where you want it. If not, then what you are doing is fine. Now, what your second opinion may offer will not always be the same as what your builder has in mind.

My opinion is this. The track record for what they build motors for says a lot. Thats something Ray excels in. All the divisional guys that he builds motors for in NHRA.....are always in the winner circles.

He just took over a large chunk of Dirt Track when his current managing partners took over. SIMS dirt motors are hard to make power with because the rules are tight...This is where R&D and creativity pays off for Ray and Chris. They are successful because of it.

Quik

iTrader: (7)

i still wnat ot know how it went from 551rwhp at 12.8 A/F to 466rwhp at 11.3 A/F

WizeAss

iTrader: (5)

ls2 texas forum section.... for your answer...

fast98

iTrader: (16)

i'd like to know that to

WizeAss

iTrader: (5)

Call the sponsor on the right.... Xtreme Horsepower and ask them... I am sure they know!!! they dyno'd the car and then sent him over to another shop to back it up....Right now there is a nice discussion on whose dyno is off 85+ horsepower!!!!

fast98

iTrader: (16)

ya i know all of that, i would just like to follow along and see what the problem was, but that thread got locked........

WizeAss

iTrader: (5)

Patrick G,

after reading that thread in the dyno section, I saw how you where able to help that fella pick up torque on his 402 by degreeing a poorly chosen cam. Is it fair to say that changing the advance when installing the cam can make up power for even a normal 408 proven cam when you consider the implications that the different style heads may pose? Basically advancing the cam or retarding it can help match the cam to the L92s?? heck I have nooooo clue!

Quik

iTrader: (7)

not a member on ls2 texas or whatever it is. i just wnat to knwo how one place and dyno read 551 and 12.8 and another one read way off

i mean i seen dynos read off some but the A/F shoudl still be close

V6 Bird

iTrader: (15)

Here's an email from someone wanting to know...

"I just got a phone call from Mr Terry McDonald from Dyno Dynamics in Austrailia. He is researching this. He did clearly state when we talked that a DD unit should make less then a Dyno jet unit.

Now with that said heres my theory on fudging numbers with a DD unit. In the correction screen you enter a said amount of % HP you wish to increase numbers by. For example a car with less hp in the beginning will not see a big increase by this addition. Now take a car with more hP like in teh 550 range nad it will see a larger increase in fake hp.

Heres my math as an example with a 25% correction number hypothetically speaking.

Now take some real world numbers of 551/466 and we get..... 1.182

Plug this number into an Algebraic equation of this to find out what the real world numbers would be on a Dynojet if the numbers werent inflated.

551/1.182 gives us the dyno jet number we come up with.

244/1.182=206 which we all know the mustangs in general should make more then that with the mods given for the comparison dyno going by what they are rated at on dynojets across the country in real world truthful testing.

Heres the deal...If you do an increasing amount of fictitional increase instead of a linear rate like i'm using, the correction addition number was probably much smaller on a car that makes less power then one that makes more power. So the correction factor for adding horsepower numbers to be higher isnt linear. Give me some feed back guys. Im not talking about any shops for the records. Im talking pure dyno numbers and their credibility in producing higher then normal dyno results."

Patrick G

iTrader: (14)

In general terms it goes like this: a cam that's too big will respond well by advancing it. A cam to small will pick up power by retarding it. A cam with proper valve event will want little advance.

Advancing the cam will close the intake valve sooner and raise dynamic compression. This is a balancing act as high dynamic compression will help low and mid-range torque, but a later intake valve closing point will make power at a higher rpm range (which typically makes for more power). The problem with 98Z28Cobrakiller's 402 was that his 244/248 111LSA cam was correctly sized for his motor, but he installed it with 2 degrees of retard. Again, this might have been a good move on a too-small 234/238 111LSA cam in a 402, but not on a 244/248 111LSA cam. By advancing the cam to 108ICL, he was able to increase low and mid-range torque without losing his top-end power. He gained area under the curve. He had an advantage of a properly selected LSA.

But let's say he had a 113LSA instead. That would have made his exhaust valve open 2 degrees earlier in the power stroke (compared to 111LSA), bleeding off cylinder pressure and torque. Then let's say you advanced the cam to get to the 108ICL that he found to be ideal with the 111LSA cam...guess what? Now your exhaust valve opening point is 4 degrees earlier than before...again, killing even more torque. So you see, even though the DCR is the same, you can make less torque with a wider LSA if the motor doesn't like an earlier EVO point.

WizeAss

iTrader: (5)

your logic makes sense. I posted on ls2 that it was possible for a lower producing engine to not have as much variation in potential manipulated numbers vs a higher producing engine... more room for correction factors and more at stake with the dyno..... they all laughed.... Goes to show that damn site is useless for tech... but is pretty entertaining!

BTW... major props to the mods and owners of this site... most technical automotive forum on the net with many great guys like Patrick and Hutto etc. that are willing to share the knowledge!

WizeAss

iTrader: (5)

over my head.... where do I send the money??!!!

Quik

iTrader: (7)

so does anyone know the real offical numbers of that 403?

WizeAss

iTrader: (5)

should make 470 ballpark....

issues are exhaust is restrictive... intake sucks.... and the cam needs Patrick's magical advancing techniques. Also apparently the car was setup way rich to get it to idle (common mistake of poor tuners, IMO only) and it was dumping fuel..... so I am sure there is more left on the table if he tunes it. But who cares?? he has cast stock heads with no work to improve the exhaust issues with even more restictive exhaust and small headers behind it.... he is road racing so he doesnt need 550rwhp anyway.

I personally just dont plan on making the same mistakes.... I want the right cam, right exhaust, great tune, and honest shop/dyno. I want to run mid 6's on the motor and low 6's on the gas.

I see no valid point as to why these L92's cant perform if the heads are worked, cam is selected and thought out, while having the right supporting components..... 550rwhp should be do-able.

turbo'd stang

V6 Bird has a good point about that.

The official numbers depend on who you talk to. I know RPM's dyno is accurate, so I'm going with the 450.

WizeAss

iTrader: (5)

there..... fixed it for ya. 466

V6 Bird

iTrader: (15)

Thats an email that was forward to me by someone more upset then Zues at Hera.

Edit*

I just reread that I left out some math numbers from the email. Oh well. Im too lazy to go back and recopy and paste it. We all get the picture the guy is trying to portray with a fixed percentage vs a non-linear correction factor.

Something tells me the uncorrected graph with a little but of untruthfulness was posted. There should be some sort of correction factor listed on the bottom of the DD dyno sheet. At least thats what I have read. I also found out factual information that a dyno dynamics unit should read on par with a Mustang dyno by an undisclosed member and that it should always read less.

I guess if they want to come out and speak the truth about why their numbers dont jive, they can. If they want to save their face that is. I think we all deserve an explanation or at least some hush money. Ill take $50G thanks..lol (im somewhat teasing here)

WizeAss

iTrader: (5)

here is the dyno... notice how the power peaks at 6k rpm....not really taking advantage of a high rpm head!!! needs cubes and rpm to perform! Patrick... what do you think?