GT40p Head Comparison

Hi Folks!

Seems like there has been so much interest in OEM combos these days

I got to looking for something typical (Cobra) to put up next to one of the
best set of curves (Typhoon) I've seen from an oem iron headed
combo

Notice the peak hp values are really close
but
Peak hp values just do not tell ... the WHOLE story :Word:

Notice each end of the curve looks quite different

Notice the shorty headers are softer on the low end

Notice the Cobra starts to fall at only 5400

Now ... It is a rule of thumb ......

A mid length runner upper will give up a bit of low end
yet
You see a pretty impressive low end on the Typhoon combo
and
Its all the more impressive IMHO
Since we are dealing with oem iron heads

Here is the deal on how that was done

The LT's were used to offset the shorter runners

Last thing I wanna point out about the Typhoon combo

NO Tune was used
so
His low end could be even MORE optimized

I would like to add just one more thing
since
We got so many noobs lately

Can you see how the Typhoon uses more of the ends of his curve

This is what is meant by extending his power curve

This is a perfect visual kinda thing to show how a steep set of
gears works so well with a combo such as this

and

If we had the Typhoon combo next to a little stocker Stang here ....

You would see very plainly why a steep set of gears does not work the
same with a stocker and h/c/i combo

anyway ... I'm done ramblin now

Grady

Since we don't know how the Cobra dyno pull was calibrated there would be
no way to tell for certain

It very well could have been done with a STD cal as a lot of them you see
these days are done that way

I have always preferred SAE over STD as it was used most of the time when
I started to do all my research several years ago.

I know STD produces higher results over SAE
but
I have not been able to find any kind of ruling or method to convert
STD to SAE

So ... how much higher ... I don't know but it would seem to be somewhere
around the range of 2 to 5% from what I can tell.

While the Cobra tq curve shows higher values in the 3500 to 5300 range
don't discount what is happening at the ends of the curves.

Grady