Kim

Yes I searched but didnt find much that I could use.
Im getting my bonuscheck in a few weeks and wants to buy a partscar, pull out the motor and take it apart.

What I want to know is: What kindda porting is possible on a 6port motor, both intake and exhaust, just exhaust or just intake???
Ive been told that I would need a piggyback fuelsystem to be able to control fuel when going for a ported motor. Would an Apex-i Fcon or whatever their name is do the job.
I really want to do this myself so that I can learn abit more about how my motor works
Thanks
Kim Nielsen

P.S: I have the eurospec butterflies if that makes a difference

bill Shurvinton

HI Kim,

Oddly enough I picked up an S4 NA motor for that purpose today. By eurospec butterflies do you mean on the throttle body, or on the aux ports?

All my research on 6-ports had indicated sleeves, so I was confused to find butterflies.

As for the porting. It can be done. To get the best you really need to throw away the whole upper and go with something better. PM me if you would like the details on what you could do if you were feeling adventurous.

As for power 220-230 at the flywheel is there to be got.

Bill

Kim

You got PM

marcus219

throw away the whole upper? meaning manifold? Or go 4 port..........

bill Shurvinton

Upper manifold. If you are lazy bung a racing beat weber adaptor on. You can also get IDA adaptors for 6-ports now, which are better.

I have nefarious plans involving motorbike throttle bodies and mig for my engine.

AngelSlide

more details please

mazdaspeed7

Eurospec cars had butterfly valves to operate the 6 ports as opposed to the US spec cars with had rotating sleeves.

Everything you ever wanted to know about porting can be found here.

bill Shurvinton

Actual implementation details are still up in the air, but the gist is

1. Score a bike TB setup from ebay. $70 will usually get you a suitable one, with injectors map sensor, TPS, FPR etc etc.

2. Decide if you want to run 3 or 4 throttles. Bike EFi stuff is usually nice and modular.

3. Graft onto 13B as you/your abilities see fit. You could make up a simple adaptor and have a downdraft arrangement on the existing lower manifold, or have them coming out closer to the horizontal, like the lake cities manifold, or that nice TWM dual weber setup. IN my case I need to angle up at about 30° (RHD car).

4. Add desired EFI computer. I like megasquirt as its cheap (like me).

5. Adjust inlet to get tuned length required. If you get it right you might have to cut a hole in the hood and have the airfilter sticking out. Looks neat and free cold air. (sorry, british thing: all real cars have trumpets sticking out bodywork)

If you are good at fabrication you could probably do everything for $250.

Can't be more detailed until I actually have it up and running on a car.

pengarufoo

the only problem I can see is bike throttle bodies are typically pretty small diameter, the ITB configurations ideally used on 2 rotors are typically ~50mm in diameter. How large are the bike ones you are referring to?

bill Shurvinton

Work out the area of 2 50mm TBs. Then work out the area that 3or 4 smaller TBs would need to equal that.

Factor in the fact that with a bike TB your throttles are right by the ports and the taper is after them and you realise they are more than big enough.

Bike butterflies are usually between 36 and 45mm.

Bill

pengarufoo

well, the simplest to adapt configuration would be two throttle bodies, one per rotor.

but just to calculate it, lets go for 3 throttle bodies, 40mm diamter.

3.14 * 20^2
1256.00
1256 * 3
3768


now with two 50mm throttle bodies:
3.14 * 25^2
1962.50
1962.5 * 2
3925.0


two 50mm is more area than 3 40mm... but hey, it's close, and if you're in the cheap I think the idea definitely has merit.... just not sure how well it wil work

mazdaspeed7

Stock is 3 x 45 mm

pengarufoo

do you happen to know the stock diameter of the S4 UIM runners?

bill Shurvinton

Better than a wrap around and a big improvement on stock. As the stock setup has 20% more throttle area than a 50DCOE TB, but as the DCOE is not restrictive in any sense you soon realise that there is more to this than pure throttle area.

Just measured the lower manifold runners on a euro 6-port S4. The primaries are 31mm and the secondaries are 40mm. Smaller than a T2 runners.

At the port you have 2 28mm ports on the secondaries, although about 1/3 of the aux port is taken up with the horrid butterfly.

At the end of the day it depends what you are optimising for. I'm using 36mm TBs as that's what I have. If I find that I still have vac at full throttle, I just get a bigger pair of secondary TBs for $70. Not much wasted. On the other hand for 3HP at the top end I might prefer more mid range that the smaller ones give.

Kim

Reading the replys to my beautiful thread has made me kindda disencouraged*grammar*.
Im a simple guy and would like to keep the stock intake setup, modified in the usual way ofcourse
Thanks for the KICKASS link Mazdaspeed7

bill Shurvinton

In that case you are un likely to get over 200HP.

Kim

How much power can be expected from a large streetport maybe even a bridge and the usual porting the manifolds

bill Shurvinton

The problem is that the stock airflap on S4 cars is a major restriction and the ECU is not mapped for best power. So whatever you do to the inlet and porting you will not realise the full performance potential of the engine. This is why for years people have trotted out that you can't port a 6-port. That's not true, its just the OEM setup can't make the most of it.

If you are going to the bother of porting the engine, you might as well do it properly and get the whole system set up for more power.

mazdaspeed7

Very well put.

Kim

Well now that ive been reading on that other forum, im more likely to take om the project myself, I have the time to do it now I just need to find a sparecar.
Guess that ill go to the land of no speedlimits soon, they got quite a few sevens for sale at decent prices(1000euro and up)

Kim

So Im guessing that a few of these 50$ airhorns could make a big difference in airflow??
Seen at Atkinsrotary.com

mazdaspeed7

Yes.

j200pruf

iTrader: (4)

What kinda difference would it make if you used longer air horns?

bill Shurvinton

Having a proper horn on the inlet is vital to getting the air moving in the right direction and getting a proper reflected pulse from the inlet tuning, but is only 1 part of the system. You have to balance a number of parameters, but the basic rules of thumb are:

- tune the system to your required peak torque
- Runners should be just big enough and no more
- smooth, but not polished helps air flow
- Air doesn't like to turn corners
- Bumps and lumps in the inlet really hurt airflow.

Now the caveat. The more you tune for high end power, the more you are likely to lose lower down. If you were bought up on V8s then this may be a problem. However I guess, like me, you were bought up on 1.3l Opels and the like and torque is an alien concept. To give you an idea, in the recent Rb article on tuned 6-ports that can be found on the TWM site, if you compared the Dellorto carb with a slightly larger injection TB then the carb had about a 15HP advantage at 5500 RPM, but from 7000 up the injection was ahead by about the same. So in fact for a lot of driving the lower HP setup would end up with a faster car. These were both on identical inlets, the only difference being the bore and length the respective fuelling systems.

There is probably a way to get close to the best of both these approaches, but it would take quite a lot of dyno time and money

marcus219

Do you guys feel that the racing beat intake manifold and a holley carb would flow good and compliment a side or bridged motor enough to make good power?