rcpython59

So I haven't started my build quite yet,I'm trying to figure out how much is gonna end up being,I'll start with some background,then what I'm trying to achieve.

This will be my first car (please don't tell me I can't do it as a first) and aside from massive amounts of reading and researching,have no first-hand experience with rotaries. I do not have the car yet,saying that now so I don't have to say it 10 more times later.

Assuming I do all the work myself (I have almost any tool I need available to me at work) how much will it run me to do a peripheral port 13b single turbo running high psi (20-30 range? Not sure what's practical in terms of cost for beefing up the engine) and I'm looking for reliability,I don't mind rebuilding,but I do mind broken parts deciding when the rebuild is.

And just a noob question,on a pp,why does everybody run circular ports? Wouldn't a smaller diameter oval give just as much flow and slightly less overlap?

Thanks in advance for the advice.

j9fd3s

iTrader: (3)

the factory runs an oval or D shaped port, depending on the housing. the round ports are supposed to be a little tamer, although mine has huge rectangular ports and its a happy little engine.

to do P port turbo is big money, because you need everything. you need housings, seals, big turbo, custom manifolds, a big intercooler that doesn't come from china, ecu, lots of injector, expensive spark plugs, coils, fuel pumps, big clutch, transmission, axles, diff, etc etc etc etc etc

if you get the P port turbo setup running right you're looking at 900hp, which is about 600 more than too much.

i think the cheapest you could do P port turbo, starting from scratch would be in the 20k range, and that is if you got everything right on the first try, which is impossible (P port turbo isn't really done in the US). if you did a really nice build, you could easily spend 50k

back in the day KSP had an FC that was 730hp on a bridgeport, engine was mostly stock, except the port, twin HKS GT3037 turbos running low 20's PSI, stock trans, diff... just doing that would be much cheaper and easier than full P port

my buddy has a full bridge T51 car, and @500hp he passes turbo Porsche's like they are stopped, the Rx7 is light, and the rotary has a wider powerband, so it is fast

rcpython59

Yeah,rectangles do make even more sense,over looked that.

Why would I need new housings though,stock isn't strong enough? And wow,that is a lot higher number than I was expecting,I was thinking closer to 4k on engine. And being on minimum wage,even with no living expenses that's not gonna work for me. Unless I get hit on the head by a fairies magical wand and get free parts I'm gonna have to go a more conventional route. And does a manifold have to be from a factory? I thought since I'm running carbeurated it wouldn't be hard to weld my own.also,is your estimate off of new parts? Cause used could drastically reduce price.

Also,what kind of hp could I get from na pp?

peejay

You need new unless you can fabricate yourself, since I don't think anybody who modifies for peripheral port does so on used housings.

4k will probably just barely touch the turbo and exhaust manifold and injectors. I don't think you will find a workable carburetor solution since the typical carburetors seen on a peripheral port tend to have fuel flow issues even at nonturbo power levels, which is where you see people installing huge needle and seats and modifying the bowls for additional volume.

j9fd3s

iTrader: (3)

you might wanna do some reading, a P port turbo setup is basically the highest hp thing you can do, and you're looking at 800hp, which means your old used housings aren't good enough. the stock trans will break, you need a giant turbo, on a custom manifold, lots of fuel injectors and pumps.

its not the engine that is so expensive, its the rest of the car you need to re-engineer.

there are no factory PP manifolds, you need to make something, which isn't too hard

a turbo PP setup is going to be tricky, and it probably won't work with a carb at all

an Na PP engine will do about 300 at the flywheel, you could probably get the engine built with 4k, and need 2-3 more to get the chassis/transmission squared away. at 300hp you can use used parts, but they need to be very good/excellent. a carbed NA is fine, although EFI is cheaper

rcpython59

Alright,thank you,that's tons of good info. That is very doable in that price range,if I drive conservatively until I can afford a better tranny that would work.

And from start you guys are saying I could work my way up from all stock na pp and build up structurally then boosting?
Thank you guys a lot for putting up with and answering my noob questions

John Huijben

iTrader: (1)

You can, but you have to account for the turbo when building the engine. Port timing will be a little bit different, and you have to figure out which apex seals to use. High rpm n/a engines often use carbon seals, but they aren't really suited for turbo use. You can use steel seals that can be used with turbo, but they don't like high rpm's. Ceramic seals can do the rpm's and the boost, but it's expensive.

rcpython59

Alright,I didn't know carbon seals weren't an easy all around seal. With ceramic will it at least last longer than other seals?

88 SE

I have an old saying:

"If you have to ask, it's too expensive"

For 4-5k you can have a properly rebuilt stock 13B-T with and upgraded turbo. Peripheral port is out of the question on mimimum wage.

j9fd3s

iTrader: (3)

you can totally do a P port for 4-5k. the P port is actually very basic, well NA its very basic. turbo P port is uncharted waters

rcpython59

Well being a teenager I have no living expenses,the fact I'm on minimum wage doesn't mean I'm neglecting higher priorities.

So are you guys saying I gotta choose between pp and turbo? For my budget at least?

Also,can someone point me in the direction of a pp crash course so I don't have to ask do many questions? thank you

Samito Built

iTrader: (38)

Noob,

The answer is yes if money wasn't the issue then sure you could do everything you wanted to do. But even for the experience rx-7 builder it's not the easiest to do full p port single turbo blah blah. I would suggest you pick a goal first rwhp. Then what does it take to make it to that goal. Turbo or natural aspirated! You can pretty much track anything rotary related at that point it's about suspension tuning and developing driving skills. If your planning to daily drive and track the car then keep it in mild level. Nothing that takes complete re engineering.

diabolical1

iTrader: (3)

1. The simple answer is yes. Saving works but so far. Scouring Ebay and Craigslist and such will not likely work. There are going to be some purchases that will REQUIRE all the money up front. Unless you have a plan to get your hands on hundreds (and sometimes thousands) of dollars at a given time. At least if you choose one or the other, you have a chance of completing something significant before you're 25.

2. What kind of information are you looking for? If you want a starting point. There is a thread in the New Member section to help you. If you're looking for more advanced answers, you'll need to ask specific questions.

rcpython59

Well my goal is breaking 10 seconds on a quarter mile. I'm not sure how much this is gonna take,but I'm thinking I will be pretty similar to the promaz 323 build. I am using a 323 most likely btw,mainly for lower up front cost and insurance reasons.

I am however thinking my goal is slightly unrealistic. also,this car is going to be a daily driven weekend warrior,daily driving is less than 2 miles to everywhere I need to go and about 25 to the track. As for the drivability I don't think it's an issue being in a rural town,but somebody with more experience should probably tell me if that will be an issue.

Do you guys think I'd be fine running a couple pounds of boost? Not much,but I love turbos to the point it's almost a fetish lol. Obviously when I say that I mean after rotor housings and seals etc.

And on deciding between turbo side port and na pp, basically which can give me the most power in my budget? (4-5k on engine) because as I upgrade driveline etc I will eventually go turbo pp,but may wait to get upgraded housings until then unless I really need them for a bridgey. Can I get above 500hp on a bridge? Because I will sorta let my pride get in the way of the fact I won't get embarrassed by diesel trucks and riced civics.

And diabolical,I am looking for all the info I can get,I'd rather spend hours reading than many more hours working to get enough money to fix my mistake.

Again,thanks to all you guys for your help and info,I'm learning a ton and can hopefully become a usefulmember here eventually.

88 SE

If you're going to drive it as your daily car, peripheral ports are out of the question plain and simple .

Now you're talking about bridgeport? You're all over the place here.

Take a step back and understand that this is way too large of a project for someone in your position.

Start with a more reasonable goal like building a 300hp engine. You'll be amazed how much you will learn and how difficult it will be your first time.

Don't make the same mistake thousands have made by starting a project too big for your budget and knowledge .

rcpython59

Alright,well I. Just didn't wanna run into the issue of having the most expensive 300hp car ever made because I like to buy an overkill top of the line part once,rather than buy the part twice cause I cheaped out the first time.

Also,is 300 that difficult on a rotary? From what I'm reading I could get that on a na pp or a mild turbo monster port,or a mid turbo bridge.

As for being all over the place this is just brainstorming what I should start on as I have invested no money in anything yet. I'm starting to think I will not do a pp until later because I really want the turbo and I'm thinking I can get more power with turbo bridge,is that correct?

And just to clarify,what is going to cost me money on a turbo pp? Building up the engine/driveline?

way back to the topic of intercooler,can I get a cheaper one if I run a cai and pre turbo water injection?

j9fd3s

iTrader: (3)

check out this car, https://www.rx7club.com/auxiliary-in...rbo-wi-974884/

notice the first combo is a stock engine with a big turbo, and they are running close to 500hp, which is going to be insane in a 323.

its also a stock engine, so it takes nothing special to rebuild, and you can tune it at stock boost and work your way up to pretty nutty hp levels.

500hp in a 2000lbs car is gong to run circles around just about everything. modern cars make big HP, but they are also really big and heavy.

as for the P port, you really can't run a couple psi of boost on it, the P port is not really going to like a turbo sitting in the exhaust, so you need a really big turbo, and at that point you might as well run real boost, and that is going start at like 600hp, and go up from there

a P port can be totally streetable, i know of a couple actually. notice, the street... he's got a bunch of videos just driving around.... for a while that was his DD.

rcpython59

Ok,thank you for the info,but that link didn't say anything about if it kept temps down enough.

Also i think pp is not gonna be in it for me till I'm outta college as a bridgey will be giving me more power and I get to use a turbo.


And also, for small boost on pp can I use a large turbo for free flowing exhaust but have the waste gate/bov set real low?

diabolical1

iTrader: (3)

a part of the beauty of belonging to a forum like this is for guys like you (and me) who have to make budget-conscious decisions when feeding our sickness is learning from others' experience. this board spans many tax brackets. expensive does not always mean better or more effective/reliable. sometimes it's just more expensive.

you don't need anything special for 300 HP. you can run stock ports up to well over 500 (REW) with the right management and supporting mods. also, given you plan to run a 323 (i'm assuming the GLC ???) you basically have no constraints because you're pretty much going to likely have to re-engineer the car, lest the engine tear it in half.

unless you want the race ports simply as a conversation point or something, you will be making A LOT of power before you actually NEED them for power.

yes. turbo bridge will trump an N/A PP, but again, neither will be NEEDED until down the road. i suppose the one point for doing it all sooner rather than later would be not having to buy parts again because it will likely need more turbo than you stock or street ports.

i have no clue, but i suspect it will be in the tens of thousands when all is said and done.

just quoted this because i thought it was funny when compared to your opening statement.

j9fd3s

iTrader: (3)

sorry, the point was that he's running 10's (or low 11's) with a STOCK engine, and small turbo, in a 323/GLC, isn't that exactly what you want?


sorta looks like a 500hp car with no brakes or steering...

peejay

For some reason, I love street driving videos like that. No racing, no being a dipwad, just driving around in a sweet car.

It is too bad A-RF doesn't have ALL of their videos on YouTube. I remember their peripheral N/A FD (injected) long videos on the street... and also their peripheral N/A FC (carbureted) videos on the track... and you could easily tell that the injected engine was a pussycat drivability wise but the carb car was an obnoxious, unpleasant bitch except at full throttle.

Which jibes with my experiences with peripheral port engines. And why when I started playing with bridge ported engines (saves a lot of time compared to fabricating everything) I never went to a carb, it was injection all the way. AWESOME drivability.

Oh wait, look what I found!


Versus...


For further reference, here's one of my bridge engines on the street...

j9fd3s

iTrader: (3)

lmao, Pj yours is so quiet. if you derattled whatever it is in the suspension that is clunking, its like stock

rcpython59

Yes I will be planning on the glc if I can find one in my area,but I might compromise and do some custom body work.

And thanks for that wi link,faith in a sub 10 car is restored,I shall not be embarrassed,(nor beat) by anybody at my local track with the exception of nationals and some street bikes. The numbers on that link help put some stuff in perspective.

One topic I haven't brought up yet,how can I get a bp quiet enough for street use without restricting too much? How much are cats gonna cost me that will put up with turbo and a pretty viscious anti lag?

peejay

It's the 3rd link. The rod ends last maybe two days before they start to clunk. I change 'em every couple years.

j9fd3s

iTrader: (3)

i doubt Mazda sold many GLC's in your area, and then people threw them away, they kept the Rx7's though. good luck!

you need lots of mufflers... they need to flow enough, while also being durable enough to not come apart behind the engine

a bushing on one end would fix that, but its a race car...