Contour Enthusiasts Group Archives Forums General Dyno and Drag Best Dyno Runs from N/A 2.5s

Originally posted by Dan Nixon:

---

On the other hand, nobody has built up a N/A 2.5...it would cost ALOT more than a lesser built, similarly performing 3L.

---

Yup.
There inlies the reasons for no love for the 2.5L after a certain level.

Originally posted by Derk2000:

---

Originally posted by Dan Nixon:

---

On the other hand, nobody has built up a N/A 2.5...it would cost ALOT more than a lesser built, similarly performing 3L.

---

Yup.
There inlies the reasons for no love for the 2.5L after a certain level.

---

That and the fact that by running a Full oval port 3L you get the extra oil drains the 2.5L "painfully" lacks.

Well among many other benefits. (like the oval heads beat even ported 2.5L large valve heads )


~~~


No I don't have a turbo on my engine. No forced induction of any kind.

Just a meager low compression oval port 3L and running those horrible split port manifolds even.

Originally posted by DemonSVT:

---

That and the fact that by running a Full oval port 3L you get the extra oil drains the 2.5L "painfully" lacks.

Well among many other benefits. (like the oval heads beat even ported 2.5L large valve heads )

---

Originally posted by Dan Nixon:

---

To the latter I would pose a question to you. Your 2.5L "split port" was running times consistant with about 200 FWHP. Your "oval port" 3L is running times I would expect for about 240 FWHP. Assuming these dyno "guesses" are accurate...this is the same HP/L for the 2 configurations (in the background of a really good flowing I/E and ECU program).

Doesn't this suggest the heads (stock SVT vs ported oval port) are (proportionally) similar in flow? Of course..if you dyno that beast at 300 FWHP..I retract the above!

---

Those guesstimations sound close.

However remember I dropped over a half point of compression going from 2.5L (~10.31) to 3L (~9.78) as well.


Though if you had checked out the intake & head data pages on my site you would have seen that the intake port to valve ratio of my modded 2.5L to 3L is the same to the percentage point. (114% port to valve ratio)

For Ref - A stock oval port intake ratio is a pitiful 78% while a stock SVT is 110% Big difference!


My exhaust ratio is 10% higher on the 3L then the SVT 2.5L though. (106 vs 97)
Any stock Duratec has very small exhaust ports though. SVT has the best ratio by far at 97% but just look at the stock oval port's 83%


So if I can achieve the same output with less compression I would be ecstatic. (I bet it's close at least)
Especially considering the manifold volume did not increase the same time the engine size did. I had the EHing done long ago so that was some of the top end gains on my 2.5L