Here's the situation: I should have a budget of $8k+ to spend on a built S5 13BT. I need some input as to how I should go about getting it built so as to get the best results possible. I plan on using the car mostly as a track car but it will see limited street use (car shows, a couple weekends here and there if I can get special insurance). Therefore, I want it to be at least semi-streetable. I also don't have a huge budget to get rebuilds all the time so it can't blow up after one season of track abuse, if possible. Thirdly, I want it to have a good, useable powerband for the track, and of course, the car's gotta haul ***. I haven't decided which class I'll be running yet, but I'll let you know soon. My idea was to get the following:

Rebuild with new seals n' all that: $1,070 + labor
balanced rotating assembly, flywheel, and pressure plate $500 (from Racing Beat)
streetable intake and exhaust porting: $750 (from Racing Beat)
Racing Beat Type I modified stationary gears: $315
Racing Beat lightweight race rotors: $1,210 or $2,250 for super-lightweight rotors
GReddy TD06SH turbo upgrade: $2,640 (this is a big maybe)
GReddy FMIC, BOV, boost controller and turbo timer: already have
GReddy 550cc/min injectors and Walbro 255lb/hr fuel pump: already have
Haltech E6X: $1,182
3" turbo-back exhaust but I may go larger if necessary (already equipped)
8lb flywheel and ACT 6 puck clutch (already have)
Scattershield for the transmission so I don't die if things go ka-boom. $?
Rebuilt LSD $?
(Prices were just gotten quickly off of websites just to get an idea. I may have forgotten some things, too)

Will there be any drawbacks to this setup (i.e. not fitting my budget, reliability issues, etc.)? Are there any setups you can recommend? I'd like to get 400bhp or more, if I have to throw out a number. I just need loads of advice from people who've done this before so I don't waste all my money on something that's gonna be slow or worse, grenade after a week. Other things that concern me are tuning, since I won't be able to afford a new engine if I blow the first one up (which makes me wonder if I should use stock internals and just worry about a turbo upgrade to get the needed power if I run the risk of going through engines), and how high the redline would be with the above-mentioned setup (10,000rpm's possible? Not so much necessary, but that would be rediculously cool if it could do it) Thanks for any help you can give, I really appreciate it.

 

Get the motor dowel pinned...


-Ted

 

go big or go home.

gt40r with a full bridge.

 

Dowel Pinned? explanation?

 

additional dowels added in addition to the stock dowels. Idea is to allow less flex, solidify the motor more.

 

It's one of the weak points of the 13BT engine.
Mazda tried to fix this with the 13B-REW...this is why you look at the dowel pin bosses, they are noticably thicker on the 13B-REW.

Although now really necessary for your power levels, it does add a significant level of reliability to the engine.

Also, you're wasting your money on the lightened rotors.
You don't need it.
You've got boost.
If you're going serious boost levels (over 15psi), stick with the Zenki 13BT 8.5:1 rotors, cause they are stronger.


-Ted

 

Wouldn't 550cc injectors be way to small for the boost / power your attempting to make??

 

yea, 550's are stock, you would need probably at least 720s primary and 1000 or 1600 secondaries

 

Get it doweled or a stud kit, get S6 stat gears and 7 or 9 window stat gear bearings. you have to get the newer stat gears so the oil gallery to feed the multi window bearings can flow enough oil. Get you E shaft cross drilled ( same purpose ) Use a S6 oil pressure reg and shim the front bypass to increase oil pressure. possilby get a race spec oil pump. Get your e shaft race ( larger ) clearanced to allow for more oil to pool. If you have a S5 use new studs or you can use 2nd hand S4 studs. S5 stud become prone to snapping after being done up more than twice. Use S6 corner seal springs.

Tune rich and then tune back. saftey first.

 

and after this all make sure u brake the motor in rite. if u have to rebuild this setup and you mess up a plate or housing then another set will have to be repinned to match your setup.. <~~~ is where im at now with mine

 

rx8 e-shaft, 3mm RA Super Seals, new rotor housings

 

why go to the 3mm when 2mm is just as good?

 

Evidence?

 

I'd say start fresh and get some new housings instead of lightened rotors. Those would be more for N/A's I would imagine. Or go all out and get new housings and new stock rotors.

 

Check out this site, and give them a call. You will not be disapointed. Glen is the man!! www.azrotaryrockets.com

 

theres been enouph info on that already around here just search it..

 

Damn....It sucks paying retail.

 

Sorry, I just couldn't leave this one alone...

I dunno if you've done this before, but I'm in the process of doing this for a customer right now.
Luckily, I just scavenged the whole front assembly from a 13B-REW I had laying around.
You can't just slap the (front) stat gear off a 13B-REW onto your 13BT...
You'll need to replace almost all of the components under the front oil cover.
This includes the two Torrington bearings, the *PROPER* sized spacer (for proper clearance of e-shaft end-play as dictated by FSM), and possibly the thrust plates.
The mating surfaces are different between the stat gear bearings (FC versus FD), and you need to replace certain parts so everything fits together.
The Torrington bearings do NOT swap between the years.


I don't think going overkill on a high powered 13B is that necessary.
Getting an upgrade OPR should be enough.
A stock bearing'd 13BT with a Racing Beat 80-85psi (street) OPR upgrade is more than enough to handle the OP's power levels.
Higher oil pressures are really only necessary for higher redlines.


I dunno what this really means, but the stock e-shaft is already "crossdrilled".


IME, this causes the engine to smoke excessively.
Others have not experienced this problem.
Do this at your own risk.
IMO, running ~100psi of oil pressure is too much for a street set-up.


Dunno what this means, but I've never heard of a "race spec oil pump".
Dry sump?


Be careful of mods like this...
There are downsides for creating more clearances.
This is not an ultra-high revved motor, so I don't think this is necessary.


What studs are you talking about?
This is the first time I've heard of this problem.
Can you elaborate?


-Ted

 

I would reccomend a stud kit as well if you're going all out, skip the rotors, instead I would get the RX-8 stationary gears and e-shaft and all of the other stuff youd have to change out.

I wonder what everyones opinion on the things that bolt onto where the oil pan goes on that supposedly strengthens the engine is?

 

Yep, sorry for not elaborating on that. Ted is 100% right and its not a bolt on mod. When "building the best 13b" I assumed he would be getting a professional builder to do it and he wouldnt have to worry about the details. I didnt stop to think that joe average building his first motor might actually do it.


I dont know what OP's means but the bearing dont just have to handle a certain power, its all about the load they are put under. Stock single window bearing with raised oil pressure will be good for about 18psi which we all know is not really relevant to power.


Yes it is already cross drilled but i mean putting in and extra bearing feed by cross drilling again.



Like ted said. Personal opinion. Ask your engine builder what you require for you set up.


sorry bad language. I dont have the part number in front of me but from mazda NZ we can get a competition oil pump


Once again its all about Load on the engine. at any RPM



I dont know about US spec engines but the 89-91 model ( cant recal term Zenki , kouki??) have engine studs with a swirl pattern running down them.
This is not a personal experience but one that my latest engine builder shared with me. It may not happen to you, but it has happened so you have been warned.

Please forgive my spelling mistakes.

 

A stud kit or extra dowels will do a better job. The oil pan baffle does help to strengthen an engine from twisting but not like the a stud kit or dowels will.

 

Sorry, OP = Original Poster.

Wow, sounds interesting.
Got pics or write-up for this?


Wow, never heard of this.
Lots of people ask about such beasts, but I've never heard of one.
The FC 13BT, FD 13B-REW, and Cosmo 20B all use 17.5mm gerotor oil pumps.
They are all functionally the same, and people ask for "upgraded" units all the time.
Got more info?


Yeah, Kouki = 89-91 or S5.
I always thought the grooves (in the center only?) was just to prevent fatigue from frequency vibration?


-Ted

 

I will find some pics and post them up. I hate to make my self sound like an *** but this isnt something i have ever done to a motor of my own. ( ive never been going for a really high HP block ) It quite common with most top eng NZ engine builders for Competition motors.



I will get the part number and post it up ( its after 5pm on friday here so i'll have to wait till tomorrow morning or monday )




Thanks Ted, i can never remember which ones which.

That may have been what they were designed for ( im just going from what you said as it sound logical) but it would seam that after being torqued down more and twice they have a tendancy to twist and snap.

I will do my best to get the info for the above.

Hope you all have a good weekend.

Nathan

 

ut oh ... ted is intrigued... is it normal to be scared?

 

How in the hell do you tell the difference between S4 and S5 tension bolts?