Pettersen

iTrader: (1)

So i'm almost done building my semi pp engine, and i have started planning what to do with the 6 port engine that is in the car now.

My goal is to make as much hp as i can without sacrificing too much drivalbility, it will also have to be done on a budget.

I already have a lightweight flywheel, Apexi PFC and datalogit and 2*2,25" headers mated to a 2,5" single exhaust with 2 mufflers.

Ideas so far:

Shortblock:
Full rebuild kit, all new gaskets, seals, bearings etc.
Use the stock engine parts if they are within spec.
Streetport*

Intake manifold:
Use the stock intake, but portmatch everything, just so it works as good as it can.

Air intake: I want to try to build an intake wich is fed air from one of the smaller intakes in the front bumper and into a closed filter box, that way at speeds it should help add some hp, and at low speed at the very least make shure the engine doesn't suck in hot air from the exhaust manifold or radiator. (But this would be used for both 6 port and semi pp so it's outside the 6 port budget.)


*Streetport: This is probably the most important point, how big do i go.

I have a Pineapple racing large streetport template for the intakes, i'm planning to use it as a guideline, and then port a slightly smaller port withing the boundries it sets.
But how much smaller?


So please come with input, tell me where i am wrong, what could be done better and so on.

Shredduuhh

iTrader: (11)

what year intake manifold will you be running? 2.5" is too small, you need at least 3" exhaust, 3X 1/2" would be even better

Pettersen

iTrader: (1)

why would not a 2,5" exhaust be big enough?


It's an S4 euro intake manifold (butterfly valves instead of sleeves).

j9fd3s

iTrader: (3)

2.5 is probably fine, you should actually check the backpressure though.

Pettersen

iTrader: (1)

With something like this?

Tool Aid 33600 Exhaust Back Pressure Tester | eBay

j9fd3s

iTrader: (3)

that would work, i use an old boost gauge, you could use a MAP sensor... you're looking for anything under 2psi, so you don't need a fancy rig to check it

peejay

I attach a piece of brake line to something that will thread into the O2 sensor bung, and just run a regular vacuum/pressure gauge on it for testing. The brake line only needs to be long enough to ensure that the hose doesn't get near the exhaust pipe, since no actual hot gases will flow through it.

I make the adapter with a '83-85 12A rear housing plug, drilled and tapped to 1/8" NPT, and then a common 1/8 NPT - 3/16" double flare adapter. Well, common here, anyway. I mainly use it at work to check for restricted exhaust systems.

My car runs open loop all of the time, so the computer doesn't care.

Pettersen

iTrader: (1)

Ok, then i will make one myself if it's that simple.

But what i realy was looking for was porting advice, how big would you guys go on a streetport for a 6 port daily driver?

j9fd3s

iTrader: (3)

i don't really have any good advise, for the port, however i do have a few ideas.

1. the 6 ports close too late, and don't flow well, so closing them later is a bad idea.

2. the atkins/pineapple sleeves seem like a really good idea

3. with the Rx8 Mazda moved the OPENING of the intakes, so instead of opening at -32 the Rx8 opens at -3, which seems like the way to go. on a peripheral exhaust port engine it will add overlap, which is kind of bad.

4. for the exhaust, ditch the NA diffusers, smooth the opening a little, and call it good.

its kind of mild, but if you're working with the stock intake manifolds, the restriction isn't the port

Pettersen

iTrader: (1)

Mild is what i'm looking for, after all the semi pp engine is the one that will be used during summer and track season, the 6port is mainly for daily driving during winter, and as a backup if/when the semi pp needs rebuilding.

I was thinking, what if i just port the primary and secondary port, and leave the 5/6 ports stock? wouldn't that help produce power in a usable area of the rpm range?

Also, as i've said before the intake is an S4 euro intake, no sleeves just butterfly valves, and the butterfly system is long dead on my intake and i doubt getting replacement parts will be easy(tho i can always try). And i would think the irons are different, since i'm guessing a 6 port engine with sleeves removed would flow pretty bad.

I'm looking forward to tearing the shortblock down so i can tell for shure if the irons are any different from the ones with sleeves.

peejay

I am very curious to see what the European 6-port parts look like.

I made an all out street ported Series 4 engine with the ports opening as early as possible, the secondary (lower) ports closing as late as possible while leaving a small amount of metal to separate the two ports, the aux port's closing line only cleaned up for flow reasons, and the primary ports' closing laid back quite a bit. It did not feel significantly different from a stock ported engine.

In short, you really can't go too large on a 6-port since the aux ports already close SO late that it becomes the engine's defining characteristic.

What I would do would be to replace the end housings with Turbo II parts and port-match the N/A lower manifold to mate to it. Much epoxy is required. I DID do this on a half bridge engine with excellent results. Finding Turbo II engine parts is getting rather difficult in 2013, though.

j9fd3s

iTrader: (3)

i do like the 4 port engine with modded 6 port intake, that seems to be a really good combo. we ran out of turbo irons years ago, tons of 6 port junk though

Pettersen

iTrader: (1)

I will stick with the 6 port end housings if they are in good condition, but if one or both need replacing i might aswell get some T2 irons.

ioTus

iTrader: (5)

I'd say it depends on how much you want to spend on it

I've heard that there are very little gains to be had by port "matching" the intake. I've even read that having a little bit of a step in certain points creates a necessary turbulence. *shrugs* i dont know from experience.

1) Large streetport
2) MSD ignition
3) S5 intake with VDI - but I'm curious about this Euro intake - pics pls?
4) Exhaust - I'm looking into the 2.5" collected headers into 3" header-back, as Shredduuhh was talking about
5) If you're in an FC i think the RTek unit would also be a great upgrade to the stock ECU at a fraction of the cost of standalone:
Rtek7 ECU Upgrade Detailed Information

The icing - Standalone Engine Manager - either Fuel only with a distributor ignition or full management with multi-coil setup. At least a grand here so I'd wait till your budget is in surplus

Pettersen

iTrader: (1)

Dude, you need to read the first post

I already have Apexi PFC with datalogit installed in the car, i'm not looking for big power gains just a little bit more punch than stock.



My budget will never be in surplus, i own an fc...

Jeff20B

iTrader: (13)

Mazdatrix sells the 83-85 plug found on beehive engines at the bottom of the rear iron.

11-8000-9951.....PLUG OIL 18MM.........REAR HSG, DIFF FILL.... $ 4.49

You should call them first to confirm that's what it is.

peejay

Diff fill plug from an FC/Miata sounds right, also.

Pettersen

iTrader: (1)

I probably have a 18mm bolt laying somewhere around, at the very least an old o2 sensor.

4,49$ + 30$ shipping is what it would cost me, FML...

Jeff20B

iTrader: (13)

Just look for an old local beehive 12A and grab the bolt.

Pettersen

iTrader: (1)

Closest behive 12A i know of, is around 500miles away, so that wouldn't a cheaper solution :P

Rx7's are rare in Norway, in the city where i live there is only one other FC.

j9fd3s

iTrader: (3)

you guys are making me want to build the "ultimate 6 port street engine"

its a very simple recipe, mine needs to be quiet, and pass emissions testing, so its mild.

1. stock rebuilt S5 engine. basically i want the tightest motor possible
2. pineapple/atkins sleeves.
3. stock exhaust manifold to this guy RX7 1986-1992: Exhaust - Race Pipes: Down Pipe - 86-91 RX-7 - into a high flow cat into my HKS cat back.
4. intake gets port matched.
5. probably a good idea to send the injectors out.
6. the tube from the throttle body to the AFM gets replaced with something bigger. depending on ECU the AFM might go away.
7. some kind of ECU/fuel control. i have an AFC, which would work, although a full ECU would be better

8. is just tuning/tweaking.
9. is shorter tires, 205/50/15's are great on an FC. a 4.3/4.4 gearset is out of the budget.
10. or maybe it goes in a 1st gen, 2300lbs vs 2800lbs for an FC...

Pettersen

iTrader: (1)

4,3/4,4 gearset, where would you get something like that and how much would it cost?

Pettersen

iTrader: (1)

Found it on rhdjapan, should be around 1000$ usd with shipping.

j9fd3s

iTrader: (3)

well the 4.3 is a stock part, so its like $600ish, the 4.4/4.7/4.8/5.12 is a 1st gen gearset that has had the pinion cut, and spliced with the FC pinion to get the right length, so its like $1000, which is out of budget!

its cheaper and easier to get short tires

snivley whiplash

iTrader: (4)

well i run a 6 port with dellorto side draft as a daily and love it. not a hp king but really fun to drive