I finally put some good miles on the FD, and did some dyno tuning. I have to admit I was wrong. I was estimating that the stock intake manifold would only yeild 275rwhp with a good street port, and good header, and 9.7 rotors. But after some fine tuning, put out 313rwhp and 221 Rwhtq. I am very surprised. This is on a dyna-pack keep in mind, so dyno-jet numbers would be in the 340rwhp.


http://www.youtube.com/watch?v=3XVrZUJZ-Ws

 

NICE! Sounds great. That certainly is the preffered way to be wrong.

 

sweet

 

Man that sound nice as.

 

damn sounds AWESOME! Good job!

 

Good god that sounds like sex.

Nice #'s too!

 

Sounds beautiful!

 

I might of over read this information in your other thread ... but who did your porting?

 

whoa.

 

Nice!!!

 

We do all of our own porting.

 

That sounds sick man. I love it!!!

 

I M N V S!

 

The 4 port intake manifolds flow a hell of a lot better than the 6pt. Not that there what ever a 6pt 3rotor.

But what I'm getting at is I've seen a 13b-re with a big port job with 9.0 rotors and the stock intake and TB make 196WHP on a mustang dyno with no turbo's and a nice header/ and exhaust.

Hasn't this even been done with a 13BT?

Anyways add in an extra rotor and use 9.7 rotors and over 300 is exactly what I would expect.

 

i thought all 3-rotors were 6-ports?

I'm just being an ***.

 

Well, actually... *all* 20B are 6-port.

There were never any *nine* port 20Bs...

Sure it wasn't his also?

The aircraft guys do it all the time.

Plus I heard about a roundy-round class in Oz where they run bridge ported N/A 13BT-based engines. Stock intake manifold, injectors, and rotating assembly, and they make about 300hp. Basically just take a 13BT core, strip off the turbo and throw it in the trash, bridge port it, and run the sucker.

 

Well just remember that the 20b intake uses the same size Throttle body setup as the FD 2-rotor does. This is the problem, its small. Yes, I have made 206 rwhp with a RE 2-rotor, but a three rotor breathing through a tiny TB and still making over 100 more horsepower is not what I would expect. If you get what I am trying to say.

 

Now you have me curious. How large of a streetport did you do?

 

Com'on Logan.....pictures of the ports!!

Great job by the way!

 

If I told you, I'd have to kill you. Haha, seriously they are not large. I'd say more medium. I'm not a fan of "big" ports.

 

I gotcha. To me, that translates to the difference between '74 spec 13B and '76-'85 spec 12A ports. It's minor. So basically a mild port on primaries and secondaries, right? Aren't you supposed to open them a little earlier? Especially since it's NA? The 20B has very late opening ports from the pictures I've seen. I've yet to tear mine down, but it sorely needs it. Smokes and has sloppy 3 piece seals.

 

Perhaps it suggests that the throttle body is not a limiting factor.

Or, perhaps it suggests that there is more of a plenum effect, similar to how a large V8 "likes" the same size carb as a much smaller V6. There is more displacement but it's spread among more intake pulses so it ends up being a more constant flow. Likewise, large plenums like smaller TBs and vice-versa.

 

I wish, you should see how much vacuum its pulling past 6.5k rpms. The pumping loses are huge.

 

Nevermind then!

 

The 20B and 13b-re have the same size ports with same size runners right?

Just because you have measurable vacuum at peak power, I still think this shows that the TB isn't the limiting factor.