Possible 4-Port N/A Start? - Page 3

NoDOHC · 05-05-2011, 07:34 PM

Quote:

Originally Posted by My5ABaby

So why did Mazda even make a 6 port?

If you look at my mileage numbers above you will see that they were better on gas. They also would probably make better low-end torque if that awful mess of an upper intake manifold were to be replaced with a decent aftermarket one and some ITBs.

Some day I intend to build a max-effort 6-port with a custom upper intake manifold. I saved 2 sets of irons to practice with for the porting (filling the top of the aux ports will probably prove to be the most difficult part).

RETed · 05-05-2011, 11:26 PM

Quote:

Originally Posted by My5ABaby

From what it appears at least on the above dyno, the 4port basically only makes less torque than the 6 port at idle. If it's around 1k that they equalize it's pretty much the second the gas pedal gets looked at...

Be careful of the comparison...
The 4-port was using a "heavily modified intake setup" - that's already a big advantage.
Most of us know the stock intake manifolds are pretty restrictive.

-Ted

My5ABaby · 05-06-2011, 07:58 AM

Quote:

Originally Posted by RETed

Be careful of the comparison...
The 4-port was using a "heavily modified intake setup" - that's already a big advantage.
Most of us know the stock intake manifolds are pretty restrictive.

-Ted

Ah, missed that part.

NoDOHC · 05-06-2011, 11:50 PM

I apologize that I don't have numbers for a stock 4-port, I have one right now (slated for a friend), but it is too much work to put it in the car (and I don't want to give up the power). I do know a guy who put down 185 WHp @ 7200 rpm and 145 Wlb-ft @ 5100 rpm on a carb'd 4-port (with completely stock ports on a Mustang dyno). However he was not running a stock intake manifold either.

The comparison is not very fair, but the 6-port did have 9.4:1 rotors while the 4-port was running 8.2:1. They had similar tunes (same ECU). I would love to see some dyno curves from built 6-ports.

I have one from a friend with fully ported 6-port, custom intake w/ ITBs, MicroTech EMS and stock ignition. I can't scan the curve right now, but it made 142 WLb-Ft @ 6600 rpm and 195 WHp @ 8400 rpm (Dyna-pack dyno).

05-06-2011, 11:50 PM	#34
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	I apologize that I don't have numbers for a stock 4-port, I have one right now (slated for a friend), but it is too much work to put it in the car (and I don't want to give up the power). I do know a guy who put down 185 WHp @ 7200 rpm and 145 Wlb-ft @ 5100 rpm on a carb'd 4-port (with completely stock ports on a Mustang dyno). However he was not running a stock intake manifold either. The comparison is not very fair, but the 6-port did have 9.4:1 rotors while the 4-port was running 8.2:1. They had similar tunes (same ECU). I would love to see some dyno curves from built 6-ports. I have one from a friend with fully ported 6-port, custom intake w/ ITBs, MicroTech EMS and stock ignition. I can't scan the curve right now, but it made 142 WLb-Ft @ 6600 rpm and 195 WHp @ 8400 rpm (Dyna-pack dyno). __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)