mmendenhall

I've been debating on just going all out and saving up the money to do a reliable 13B PP build but at the same time keep it as quiet as i can maybe daily it? I don't work to far from my job and i hardly ever pass cops the past 2 years i've worked there. But maybe i'm probably asking too much because i'm not too familiar with the reliability of the engine when ported to that extreme. Can anyone chime in and enlighten me? I don't really like bridge ports, i had a street port and it was fun but now it gave me the hunger for more power.

But if anything i have a honda beater for my back up if there ever was a problem

John Huijben

iTrader: (1)

Reliability is not an issue, the peripheral port alone does not make the engine fail, the apex seal does just fine passing over an open port, it already does that at the exhaust port. Most people who build these motors intend to make great top-end power though, and therefore build the motor to make a LOT of rpm, which shortens engine life. This is not necessary though, you can build the motor so that it makes power at 7000 and doesn't turn much more than 8500rpm, and it will last a long long time.

Keeping the engine quiet is a challenge though, the engine will HATE any exhaust restriction, not only does top end power suffer from a restrictive exhaust, driveability and mileage will also suffer, even when your driving slow. So you will need open mufflers, as large and many as you can fit under the car. I think I would try a 3" center muffler, and 2 large 2" mufflers in the back. Another thing to keep in mind if your worried about sound is intake noise. The PP motor makes a lot of it, so if your planning open filters you might want to consider building an airbox and muffling the intake pipe.

Oh and you need to figure out what do to with engine managment. The engine will greatly benefit from a programmable ecu, but a carburettor can be made to work.

j9fd3s

iTrader: (3)

John is basically right.

for noise, you NEED some kind of airbox, when i fired mine up without it, the neighbor came downstairs holding his head.

the exhaust, the FC is nice because you automatically get 2 mufflers, instead of 1.

i have crammed a ton of mufflers/tips/and even banana on the tail pipe of my car. i found on mine that muffler tip size makes a bigger difference than anything else, i have this crappy resonated 2x2" tip, and when i clamp it on the 3"tail pipe the P port car is quieter than my turbo... power isn't noticeably affected on the street (i can't use it all)

mine is a 12A, and with a stock 12A air cleaner its making ~170rwhp at about 5500rpm, and passes sound at the racetrack on a clear day, (103db limit) without the silencer.

the center muffler is a bit tricky, they didn't do much, and mine broke in 2 laps, next revision i'm going to remove them and use a better rear muffler

mmendenhall

Yeah an aftermarket ecu is def on my list.. Fuel management ill probably have to do some research and read up some guides on what ill need i dont plan to go all out but i defiantly want to build it right and as correctly as possible. Thank you for the info ! Very helpful guys i appreciate it. Do you guys have recommendations for apex seals and other various seals i need?

mmendenhall

This car will be strictly street, maybe see one track day to see what it can do but defiantly trying mold it into a daily. (Yeah i know daily pp im crazy) 😏

j9fd3s

iTrader: (3)

if you can keep the revs under 9500, stock seals are perfectly fine.

for fuel management you don't need anything fancy, i'm just running an IDA weber and a locked distributor and its totally streetable. EFI would be easier, because the car is already setup for it, and once you dial it in (this will take a while), it should run like a stock car with some attitude

mmendenhall

Dang i'm impressed ! I would probably want 11k limit so i can take it to 9500 all day at the least what seals would be best for that ceramic ? Ive heard various mixed reviews on them

j9fd3s

iTrader: (3)

11k gets dubious, as the clutch is supposed to explode at like 8500....

peejay

I take my bridge to ten but the clutch scares me...

Peripheral port seems more exhaust sensitive. That is to say, I had EFI and peripheral and used the same exhaust on a bridge and the bridge tolerated it more whereas the peripheral would foul plugs very rapidly. Like, drive out to the street to start tuning and the plugs would foul within a couple blocks.

I have about 34k miles on my current bridge engine, it's a-verra-nahhs, very streetable, idle at 700rpm if I want it to, drive it around town and on long highway trips no problem.

RTRx7

iTrader: (2)

Seems like a lot of money and work for not a lot of upside.

mmendenhall

True but, i make ridiculous money for a 21 year old and im infatuated with my vert so i just wanna dump my money i can be proud of and say i built it. I dont really want a new car also. Im intrigued with the PP gains and i know all of the downfalls that come from it. Dang would you need a crazy stage 3 or whatever clutch to handle it ?

mmendenhall

Im a custom fabricator on top of being an hydraulic tech. So i can draw up and weld custom headers and exhaust to fit my build if that helps any.

peejay

Let's speak in real world terms instead of marketing speak.

The clutch issue brought up is not one of clamping force, but simply being able to deal with spinning that fast without the pressure plate turning into a fragmentation grenade. That's where you see 7.5, 5.5, even 4.5" multiplate clutches in use.

Dak

Will the stock FC tranny even shift at 10 or 11k? I've read they don't like shifting up past that 8.5 to 9k range. How livable are multi plate clutches on the street? Are they like a light switch or can they be slipped some?

John Huijben

iTrader: (1)

That's odd. I had tiny restrictors on mine to get the car tech inspected (2x 3/4" restrictors on a 4-rotor PP) and it didn't foul the plugs. In fact, I have yet to foul a single plug with this engine , Just running BUR7EQ / BUR9EQ plugs. I guess race plugs will be more sensitive to fouling.


Meh, it all depends. You can make it as expensive as you want, but it can be (and has been) done without spending a lot of money. For example, you don't need expensive MFR or Racing beat rotor housings for this, a lot of people have already modified used oem housings just fine. And you don't need an expensive haltech, a megasquirt or something like that will also be fine. And you don't need a big $$ itb setup, used throttlebodies can be found cheap and made to work fine aswell.


No, the FC tranny will NOT like that much rpm, especially a TII one. Besides the tranny refusing to shift the ratios are horrible aswell. The amount of clutchplates does not define how driveable a clutch is. That is mostly dictated by the friction material, clamping force and damping. Single plate clutches need a grippy material and tons of clamping force to hold a lot of engine torque, which is why those clutches are awfull to drive. Multiplate clutches can get away with using a lot less clamping force, and more normal materials, so they are generally much nicer to drive. I have an OS-giken 3-plate, and it's awesome, drives better than the stock clutch.

j9fd3s

iTrader: (3)

i didn't spend very much doing mine, and its almost all upside.

i would think some used 150k mile FC trans would die quickly, and the gearing is horrible. i think the low buck solution is the miata gearset in the FC case.

multi plate clutches vary, i've driven a fresh OS gieken that was like stock, and a worn Re-Amemiya that was like a light switch. so i think a fresh one would be totally fine.

however if you're willing to stick to 8500-9000rpm you can just use a stock clutch...

maybe you're doing it wrong? i fouled a few tuning mine, but the P port is actually harder to flood than a stock engine, and if you do, its also more forgiving.

mine was pretty inexpensive, and its very basic too. in fact for a rotary you can't get more simple.

the T2 trans also takes 80hp to spin at 9k...

peejay

Yeah, the transmissions really do not like shifting at those speeds. I have datalogs where it takes 400 milliseconds to shift on a 10k shift. Normally I can click off shifts much more quickly than that. That is why, in competition, I only use the RPM if I am going to slow down soon, meaning no time for an upshift. If I do have time for an upshift then I shift around 8-8500.

I hate to think how much more power the T5 will take to shift, but the ratios I will have are better than Miata (still not awesome, but at least better than anything Mazda did) and dogbox conversion for T5 is very cheap.

mmendenhall

All this knowledge i love it 😍, wow would a t5 be more beneficial for the PP 13b then the stock? I mean of course but i will have to dig into some threads for info. Theres t5's for days in junkyards around my house

mmendenhall

Ratios would be the only reason i would stray away

mmendenhall

Sorry meant info* not ratios .

peejay

They might break less often... T5s are weaker than Turbo II trans but stronger than smoothcase. But the synchros are much much worse, so I would only go to a T5 if you were going to convert it to dogbox, since a $800 T5 and $3000 gearkit is cheaper than a gearkit for a Mazda trans.

Or you could just respect that you have to wait a little on the trans.

j9fd3s

iTrader: (3)

the Rx8 trans is an interesting idea, the ratios are the same as the competition trans, but with a granny 1st, and it can handle 230hp and 9k pretty well

Kenku

I've been seriously looking at an NB Miata 6 speed with an RX-8 bellhousing, just to avoid the RX-8s dumb 4th gear spacing.

j9fd3s

iTrader: (3)

does that work? the miata shafts and gears are all different, the miata is all NA sized, and the Rx8 is turbo sized

Kenku

For sure? Dunno. I'm obviously not sure what the clutch/flywheel would end up as either, though a QM or Tilton makes that easier. I am almost certain that the center cases are the same though; look at them. For that matter every single ratio other than 4th is identical. I wouldn't put either behind a turbo but for NA use it looks pretty decent.

I'm not far enough along on my Miata project to buy a trans yet but it's what I'm planning unless I run across money to throw at Ron in Barrington.