SoloIIdrift

1st. off PRE-SEARCHED!!

I'm having a friend build the motor for me. Depending on the condition of the internals will either rebuild the series 4 motor, or if I can find a used series 5 cheap, I'd build that, here's the plan I've come up with after extensive research.


Mazdatrix streetport templates (anyone know if this is a smaller streetport or larger?)

TII intermediate housing (Bigger primarys I guess?)

TII Exhaust housing (no silencer thingy)

Possible porting of intake manifolds.

I will be running a stock chipped ECU and series 4 electronics.

Not sure about- 3 window race bearings (pros-cons?)

Anyone have any suggestions?

I know obviously good intake and exhaust, I'm talking about stuff to do while the motors out and internals-wise.

On a side note, none of those good N/A threads were ever put into the archives

tweaked

iTrader: (4)

sounds like you are on the right track. Waht I plan on doing is large street port but I am not goin gto make the intake and exhaust ports closer as most do. basicly i only remove material from the sides and lower (on the exhaust) and upper ( on the intake) this keeps the stock timing the same so you don't loose as much drivability. there is the issue of water jackets so if you go big, you will have to fill these. ask around to builders and see what they can do. mine is going to be dome by RX7 Heaven in Memphis TN

SoloIIdrift

looking to make around 230 fly hp...

SoloIIdrift

ttt

Angel Guard Racing Team

Remove the metal covers from the exhaust and pot using the template. Port intake on housings, install 84-85 gsl-se injectors, MSD would be very good, Racing Beat Header. For Christ's sake get the race template not the street, you will waste time using the street. We only use one kind over here... RACE!!!!

wankelhead

if u end with a s4 motor,[wich,by the sounds of it,would be the way to go,since,if ur using s4 ecu,there would not be anything to control the electric omp,on a s5 block],you can use the s5 rotors,they are lighter and have slightly higher compression.you have to make sure you get everything balanced,as far as i know,u just need to use front/rear counterweight of a s5,if ur going with the s5 rotors.but,check around.
~david
ps:no matter wich series block u get,i think it would definately be advisable to use the s5 intake,it is definatley higher flowing then the earlier one.

Merovign

I haven't finalized anything, but I've started gathering parts - here's my thinking in these wee morning hours:

- S4 housings (because that's what I have), mildly ported. I may consider a turbo intermediate housing or something like that, but I'm not sure what I'd gain over a ported S4.

- S5 rotors and counterweight, lightened, if I can afford it, possible filling to bump compression a few more points (10-10.5 would be ideal, as high as 11 if I'm sure I have good fuel control). Not many people do this.

- S5 intake, ported, port-matched, preferably flowbenched and ported for velocity rather than volume

- Ported & polished Throttle Body, possibly larger butterflies (probably not needed) Still researching if polishing is only bad for air/fuel mixture flow, i.e. is roughened surface only better with fuel or is it better for plain air (turbulence vs. adhesion).

- re-shaped exhaust sleeves, RB headers, single or dual cat setup (will be marginally street-legal-ish (will pass smog)

- Upgraded ECU, with aftermarket fuel-only computer (such as S-AFC), injectors

- Pineapple Racing 6-ports

- Upgraded AFM, possibly TII or 929 (though there may be incompatability between the 86 ECU and the later AFMs, even if I modify the signal to get a "real" airflow rating)

- 3" Cold-air intake in front of radiator (already have that)

- Lightweight flywheel (currently a TII tranny in an NA - flywheel way too heavy!)

- A few more things, currently "top secret" because I have no idea whether they'll work or not and don't want to come off a fool. One or two of them might be marketable, but I don't want to give away the ideas just yet.

I have more time than money at this point, so that means I can do some research. It seems to me that most people upgrade their cars on the "buy a few parts" theory, and most of the people who go beyond that get trapped in the "one thing well" theory, i.e. they go all porting and nothing else, or all exhaust and nothing else, or they rip out all the smog gear but use the stock (and now confused) computer. It don't work well that way.

Oh, darn. Sleep time.

Good luck, hope I gave you a few ideas,

Chad

SoloIIdrift

Hmm very interesting....

As far as porting the intake manifold in the S4, would it be worth it?

I also wonder what is need to run the S5 rotors in the TII housings or S4 housing?

Since I'm getting an aftermarket flywheel it comes w/ the rear counterweight, I wonder if that will balence it all out?

Merovign

#1 I'd go with an S5 intake manifold if possible, they don't cost that much, but they do require a little grinding on the block to fit. I also hear it's easier to electronically control the 6-port activation, but I'm still looking into that (I hope to have the two intakes side by side here soon).

#2 Might want to ask the people who sold you the flywheel, but I believe it's the front counterweight that you get with the set (the rear one compensates for the lighter flywheel) BUT they all work together so they must be matched.

I will likely order a flywheel/counterweight set for an S5, use S5 rotors and front counterweight...

I'm trying to find a source for either CFM ratings for the various ports (intake, exhaust, manifold, etc) to see just what is neccessary. If the intake ports flow more air than the engine pulls at 8000rpm, then I don't need to hog them out, just a little matching, blending and radiusing. This is an NA, after all, even though the velocities in the runners mean the air in the chamber enters at more than 1 atmosphere (I'd ideally find out what that pressure is stock and calculate what effect manifold porting has on that).

All this math will probably only net me 5hp, but I have the time now and other people could benefit if it works out. If I were insane I'd get me a flowbench... I wonder if there's an Okie-Engineer way to make a CFM meter to use on AFMs and Intakes and Housings....

SoloIIdrift

hmmm I didn't know there were TWO countweights, a front and rear you say....

SoloIIdrift

SoloIIdrift

anyone else?

SoloIIdrift

should I use the TII intermediate housings or just use the stock S4 ones? Is there a big difference? With the motor be unbalenced?

mazdaspeed7

Ill take a pic of the TII center housing vs the n/a center housing. I have both. Go check out the beefy n/a thread, page 6 and 7, im building an engine with the TII center housing, and it talks about it in there. My rough estimate is that the TII has ~20% more area unported, with about double the casting thickness. Thats a lot of potential.

Not only are the TII ports bigger, there is more casting than the n/a ones, so you can port more too. The TII center housing will have no effect on balance or anything. How could it, it doesnt move or even touch the ecc shaft.

SoloIIdrift

Yeah I was checking that other post out, but thought I'd still throw this one up ttt just in case.

My engine builder is kinda queesy about using the TII intermediate b/c he thinks it will be to big with the stock EFI system and 550cc secondarys, he doesn't think the car will run right. I'm trying to convince him that it'll be fine.

Basically the STOCK TII center housing is 20% bigger than the stock S4 n/a. right?

mazdaspeed7

20% was my rough guess, Ill get you a pic in a little while. The car WILL run fine with a TII fuel pump and the TII secondaries, but if you have a way to control the fuel, you might as well go 4 x 550.