mamo= LS induction

If you can port stock 243s to have 330 cfm, you should port just them for a living and you would be a millionaire!!!

 

Just remember RX7 no-one will ever believe you unless it was done in the US first
Its just the way it rolls from what I can see

 

Apparently you have vision problems. Nobody here has said anything about him being from Australia or it not happening in the US first.

 

am i wrong in the assumption that the debate is on flow numbers n/a yet he is running boost. wouldn't the change in how the air flows through the port when pulled versus pushed cause a difference. wouldn't the "back up" of air change significantly? if a set of heads is designed to keep fuel suspended while n/a, it seems that different criteria would be required under boost as it pushes the fuel through too? (seriously don't know and not sarcastic-just curious) if the heads were as delivered and ran a number on the track, then botched with a valve job and ran the same number, wouldn't it reason that there was a problem somewhere else? perhaps the heads were not used to their full capacity to begin with? i applaud anyone with the skill and patience to port / test heads and be able to understand all the dynamics. as a future purchaser of ported heads, this piqued my interest.

 

it can be done,not as hard as you think.but the hard part is to do it and have QUALITY airflow,not just quanity.you can have a head that flows 330 cfm and it's a piece of crap,and another that flows 290 cfm and puts down big numbers.
no doubt,Mamo is one of the best in the business.but understand that even so,there are other people with his skills that have very different theories on airflow dynamics in a cylinder head.go on Speedtalk and you'll see what i mean.a lot of really smart people on there but they argue like little kids somtimes.
bottom line there is a lot more going on in the LS world than LS1 tech.and IMO,the Aussies are way ahead of most of us in the States when it comes to these motors.

 

Their steering wheel is on the wrong side....

 

our steering wheel is on the right side, yours is on the wrong side...

 

But you drive on the wrong side

 

Bingo, plenty of guys can get 330+ cfm out of 243's, I'm a good 10cfm at .700" down on the best.
Plenty also agree on a head backing up being a bad thing & they've also got the runs on the board to prove it.
There are always multiple ways to skin a cat, I think my way is one of the best, but I'm not going to say similar results canot be achieved any other way.

Dales car was the first to run into the 8's on an IRS rear, since he's stepped up to a live axle etc the car has not shown it's full potential, we'll get it there.

 

But.....you drive on the wrong side

 

Your a stand up guy tony and i love the AFR product. My next build will include another set of AFR heads.. Also,you can get big flow numbers from a head,but it's don't mean it will perform like a top head. I removed a set of high flow number heads for lower flow top company's heads and gained 20hp under the curve,10hp peak and 15tq all over.

 

A couple runs from the vehicle in question...

http://www.youtube.com/watch?v=hPsYY...w5vtJw&lf=plcp

 

That's definately a relevant question.

Turbo applications do differ from NA, you're moving the same 'volume' of air, but that air is denser.
Which means it is heavier, at 1 bar boost the air is twice as heavy as atmospheric, which means it is even harder to turn at velocity.
Take a 2000lb car around a road race circuit, then take a 4000lb car around the same circuit - the lighter car, all else being equal, will have a much higher corner speed than the heavy one, try to take the heavy one around the same corners at the same speed & it'll end up on it's roof in a sand trap.
So, the air is heavier & does not want to turn as easily, you need to give it more room to turn & a more gentle curve to follow in that turn to prevent it coming unstuck & going turbulent.
Unfortunately there is no way to flow test a head with 'dense' air, best we can do is look at how the airflow behaves at higher velocity to get a rough idea of how it'll behave with denser air - momentum is a factor of weight & velocity, so if you can get a port to behave at higher velocity with the same weight air then it *should* behave at lower velocity with heavier air.
You can do that by cranking up the flow bench depression and/or testing at higher lift to increase the amount of air through the port & get an idea of where it's headed.

So, tested at a regular 28" these 225's backed up after .500", with the valve job fixed they backed up over .600" lift - throw denser air into the equation & they will have been backing up hard as low at .400" lift.

Actually, you can work it out, at 290cfm they started backing up, with, say, 1 bar boost the air will be twice as heavy, so the port 'should' start backing up at 145cfm (same mass of air). Which actually occured at about .200" lift. Meaning through the entire meaningfull lift curve on a boosted engine the flow through the port will have been unstable & turbulent.

That's why it wouldn't make top end power.

When I've got the heads sorted & stable at higher lift I'll be happy, actuall flow in cfm at 28" depression is not something that is going to concern me all that much, I'll give up cfm for stability & not think twice about it.

The proof will come once the car hits the strip again.

 

Stock cast iron heads seem to make more power under boost conditions then a set of heavily ported heads. Yet they suffer from headflow. I could be wrong on this but it is what has been published. I wouldn't consider the afr 225 to be an all out race head.

 

I'm yet to see an iron LS head...........

Besides which that's plain old wrong, a stock iron head from X engine V's the same head casting ported to suit a boosted engine will crap all over the stocker from a great height.
Same as NA, better heads for the application = more power/better power curve.

I did an online experiment years ago to prove that porting makes even more difference in a boosted application than it does NA, I did it to counter all the monkeys saying boosted engines will see no benefit from ported heads, you should just crank up the boost.
I took a stock 2J head from a well sorted combo & ported it, then retested it & compared it to the stock head with everything else the same.
I can't remember the specifics, but it hit full boost somewhere around 500rpm sooner & picked up close on 100rwkw for a massive gain in average power.

 

dont let facts and actual results get in the way of a good old dick sucking KnightEngines..

i can smell the **** dribbling from some peoples bottom lips all the way over here...

 

Now you just sound like a piece of ****.

 

Yeh im over it..

you called my bluff, infering i was full of ****, i showed you hard facts and a ******* fast car and still the dribble keeps on coming..

unfortunatly i dont have the budget to go and throw some new heads on it or these heads would be in the bin..

i cant wait to get it all back together and go and run some 7sec passes.. once i have done that ill go and get some of these so called awesome iron ls1 heads and give them a try..

 

I never said anything about iron ls1 heads.

I called BS on your super awesome handjobbed 241's making 1100hp....you made it sound like your turbos had nothing to do with that.

"oh me hand ported 241's made 1100hp............oh ya, I was also running 22psi but w/e"

GTFO

That power could have been made with any other decent head.

Just move on man. Some douche bag mangled a set of good heads and you were stupid enough to buy them. Accept the dick that the guy put in your *** when you paid him and move on.

 

you really are a ******* idiot that cant read arnt you?

the heads were brought new not second hand ********...

you tell me how a set of 241's will make 1100hp with out boost... lol