Please keep it clean, friendly and on-topic people.

 

Sorry, I guess I get frusterated too easily with some people. I fixed it.

 

as long as it starts and i can drive it, then it's streetable. complaints about idling and loudness? then get a stock honda civic... geez.. i don't have to state the obvious here now do i?

 

You could also check out atkins racing. They build the motors, and can offer machining service for the rotors (3mm) seals...

 

Obviously as we have seen here, everyone's idea of "streetable" is different. Please don't compare a PP engine to Ted's car. He has a turbo anyways. He's probably far more streetable and faster!

"Streetable" in my opinion is an engine that can lug along at 2000-3000 rpm on the freeway at little to no throttle and not buck and backfire. A "streetable" car has better gas mileage than a Boeing 777. Depending on what part of the country/world you are in, a "streetable" car may have to pass emissions testing. A "streetable" car can be decently muffled. This is an impossibility with a peripheral port. As a general rule, by the time you muffle a bridge/peripheral port engine to the point where the noise level is tolerable, you have completely restricted the exhaust to the point that the engine makes less power than a smaller port with less overlap.

Can a peripheral port engine be physically driven on the street? Sure. If it has wheels and an engine, it can be driven. How "streetable" do you think a Formula 1 engine would be? Not very. Terrible gas mileage, loud, no low end power, etc... Could one be physically driven on the street? Yes. The problem is that too many inexperienced people get 2 very important things mixed up. Everybody always wants to drive a race car. The fact of the matter is that a race car is only practical on a race track. Period. So many people try for the compromise approach but still get it backwards. Instead of trying to build a streetable race car (which is unpractical and damn near impossible), you should be building a trackable street car. This is possible. But it still isn't a race car.

There is really only 1 truly practical way to go faster on the street and maintain all of the true qualities of a race car. That is quite simply with forced induction. You can get the power you want. You can get it over a broad rpm range. You can get decent gas mileage. You can keep a good idle. You can keep emissions passing ability if you need it. At the same time you still can get the power that you desire to go faster like a race car. You will also do it over a broad rpm range. Remember that different racing classes have different rules for engine combos. Some race classes allow no porting. Some allow forced induction. Some allow larger porting. The fastest cars are designed to work the best within their allowed environment. This is true with street cars as well. The fastest street cars are NOT those set up like race cars. A fast street car will blow away a race car on the street. The reverse is true on a race track.

Another thing to consider isn't only how strong your drivetrain is but also what your gear ratios are. Is anyone really dumb enough to use the stock transmission gear ratios with a peripheral port engine? Can it be done? Yes. Is it optimal? No. You are losing performance potential this way. Now you're building an engine and you can't even realize it's full potential because you skimped in other areas. Maybe that huge port job/ high rpm idea wasn't so good now.

Everyone quotes Rob Golden when it comes to peripheral ports. First of all, Rob believes that true dual exhausts are the only way to go. He even believes this on bridge and peripheral port engines. Do they work? again, yes. Do they work as good as other systems on a peripheral port? No! He also believes that a turbo style muffler is good enough for a bridge/peripheral port engine. Again, will they work? Yes. Will they work as good as other alternatives? No. A true dual exhaust and turbo style mufflers are fine for truly "streetable" engines with porting no larger than a decent streetport. Yes you see Mazdatrix and Racing Beat selling dual exhausts. They also only recommend "street porting" as the highest alternative for street driven cars. They try to cater to street driven cars the most which is why you will see a dual exhaust as an alternative. Show me even one race car with a true dual that has won a race. Since everyone always quotes Rob Golden in this area, find ANYONE else reputable that will agree with his point of view. You can't. Send an e-mail to Paul Yaw and see what he says about this entire thread topic, porting, exhausts, intakes, or otherwise.

The whole point is this. Yes you can physically drive a peripheral port engine on the street. However, if you are not willing to set up the car so that you are taking advantage of the engine's full performance potential, was it really worth it? Especially when you could have had more "streetability" with a smaller port and still hit the same power mark? I think not. In the end if you want 300 rwhp, it is far easier and cheaper to just use a small turbo. Is it really worth the time, effort, and compromise to daily drivability just to have that rough brap, brap, brap idle sound? Your intelligence and logic are in question if you say yes. Build a dedicated track car. You can have it all you want.

 

Ah, our resident PP expert chimes in...

Like he said, for a PP motor to work at it's most efficient, it needs an ungodly free-flowing exhaust.
If you're thinking about choking down the exhaust just to make it quiet - yeah, sure, you casn drive it on the street - but you're sacrificing a lot of the PP power potential to do so.

I agree - it depends on what your definition of "streetable" is...

I don't consider choking down a BP or a PP just to make it pass noise restrictions a "streetable" vehicle - I call it a "waste of time".

If a PP doesn't hit 300hp or comes close, there is something wrong.


-Ted

 

Whats so ungodly unstreetable about this car?
http://a-ds.serveftp.net/a-rf/video/021.wmv

On the streets...
http://a-ds.serveftp.net/a-rf/video/029.wmv

Nothing wrong with a p port, not even on the street, these things are more streetable than most of the smallblocks on the streets, they even make more manifold vacuum than most healthy smallblocks...
The key is strip the car down, and go light, which happens anyway when you lose the turbo/manifold/intercooler/ etc etc.... Its becoming the new trend in Japan, when I was there I saw a p port 20b, and another being built for a street driven FC, not to mention the Scoot 4 rotor pport.. If its a bit touch in the low revs , who cares, change the rear ratio and give it a bit more stick...max

 

Did you see the RPM's he was driving at?

It's not like everyone is going to be driving like that to go to Acme.. . .

For all I know that car may be streetable, but that video isn't nearly enough.

 

Throw enough money at anything, and you can make it "streetable".

I think you're getting away from the initial intent of the thread.

People are already complaining about my $10k number which I had throw out.
I don't even want to think how much it would cost to duplicate the Scoot 4 rotor.
Or even to swap rear end ratios to accomodate the new power band.

I mean, come on, I thought we were talking about 13B's here.
So all the 20B and 4 rotor talk is moot.

And those videos...
They only reinforce the poor low end power of a PP.
I mean the dyno one show the graph at the end, and although the show a poor shot of it at the end, if we extrapolate the graph out to a peak of 10kRPM, it makes very little power at under 3kRPM.
The driving video show the tach only going right of vertical, which means it's only running above 4kRPM (if it's stock) but I think it's a modified gauge face, which means it's most likely above 4kRPM...like 5kRPM minimum?

Hey, but you're right...keeping the vehicle light will somewhat overcome it's poor low-end torque capabilities.
I don't really consider that ARF FD to be "streetable" - by technicality, it will not pass any U.S. state exhaust noise laws.


-Ted

 

Its the thing to do in Japan, for highway racers and drifters. I doubt any of those drivers would use them for a DD, most of them probably take the bus or train during the day. Not to mention LOUD. You can hear the 7's coming long before anything else.
You just can't USE that kind of power on the street. In the video the guy was on an empty road, flooring it the whole time. Even just sitting he had his foot on the gas so it wouldn't die. Imagine trying to drive that in any sort of stop and go traffic, you can do it but its not worth it.
The turbo, in this instance, would be much more reliable and practical. Better gas milage, less wear and tear, and much greater engine longevity. PP cars are for people with money to take out on track days.

 

yea, but come on, that wasn't exactly your typical sunday drive. he had the camera rolling, his harness on, and he was wearing gloves. if you were to make a race-around-town video, what rpm would you be at?
i'll give you this, the video doesn't prove its streetability (as far as "low end torque"). and youre right, not everyone will be driving like that to go to Acme, but who would record themselves doing that?
so i agree, the car may be as streetable as a stockport or as hard to drive as some think, but that video doesnt prove either way.
looking at his tach, it looks like the redline is at 8. count the little lights (unreadable numbers). i got 0-8(redline) and then 9 (similar to an S5 N/A; and FDs i believe). looked stock.

and i believe that's unanimous!

 

So what happens when a PP fails? anyone? how does it fail?

 

It failes like any other motor only quicker becaues to use the pp for what its made for (to make power w/o turbo) you have use it at a higher rpm, which increases wear.. on everything

-Jacob

 

Oh I see. So its not that the actual structure of the PP fails, but more of everything really..

How do you reset the rpm limiter? when you run the engine at like 10k rpm what happens if a part breaks, I bet it could kill you!

 

which is why certain racing (or all?) requires scattershields and driveshaft loops. apparently an exploding clutch assembly is dangerous... i believe the RX7s actually have a safer region for the clutch assembly (further front). the RX8's is sort of behind the firewall (the firewall is recessed). i'm not sure how much more or less danger there is between the two.

 

Well that didn't prove much. Like I said, you CAN drive a Formula 1 car on the street. If you want to terrorize around the neighborhood all day then sure why not. Let's see how comfortable that car is in stop and go traffic. Let's see what his gas mileage is. The rotary is a terrible gas hog on a good day. Gas prices are damn near higher than they've ever been. And you guys want to drive around with even worse mileage? Why? do you really think there is a peripheral port anywhere in the world that can ultimately match forced induction? Name 1 advantage that a peripheral port has on the street to a turbo or supercharger. If you want to go fast, use common sense.

Spreading info about streetable peripheral ports is going to cause some poor ignorant kid to try to use a peripheral port engine in his totally stock car just because it is faster. I've already had to inform a new guy about this same topic. For street use and practicality, a street port or maybe a halfbridge like BDC would be the biggest way to go. On the halfbridge you'd better do it right and not get carried away. We've only seen it successfully done for street use on a turbo car. Gas mileage and emissions will still suffer though. If you want more power than this, time for forced induction or another rotor.

The most amazing thing though is the fact that me an TED finally actually agree on something!!!

 

read back what i said before

most PP runs carbon seals, when they let go usually there is no other engine damage.

of course a forced induction motor would be more ´friendly´ on the street for the average joe.
not everyone wants that though. can´t you guys accept that?

Most people drive large ported rotors because THEY like it and almost always know full well that a turbo 13b would give them more power and torque. Thats NOT always the point of the exercise though.

Like I said before, we all look at our cars differently..

Personally I´m currently doing a full turbo swap into my car and putting my N/A motor, which has some rather large ports mind you, into a first gen rx7... mainly because I could get a first gen lighter than ill ever get my S4.

 

[QUOTE=comradegiant] Even just sitting he had his foot on the gas so it wouldn't die. Imagine trying to drive that in any sort of stop and go traffic, you can do it but its not worth it.
QUOTE]I drive like that daily. I use my right foot to hold down the brake and modulate the gas. I have a vacume leak somewhere so idling isn't existant sometimes.

 

and i'm sure its annoying as hell for you. i had that, but it wasnt a vacuum leak. afm at wrong angle.
i never caught the guy keeping his foot on the pedal for it not to die. that should be irrelevant as its not unheard of for a pport to idle. if _his_ didnt, thats _his_ problem.
is this thread done??

 

What do you want a Cadillac...?...
That car is pretty ******* tame... I've driven things on the street that make lood like a tercel... There is no reason not to do it, all the bs about some kids might try it , no low end torque, gas mileage, I don't think anyone capable of building and tuning a peripheral port is gonna go in with rose tinted glasses that they think its gonna drive like a stock cutlass supreme on the street..Its gonna be a little be a little rough around the edges, but saying it can't and shouldn't be done cuz some poor kid might spend 15 grand doing it, is just kinda dumb and not a valid reason not to do it... What does the video prove, it proves it can be done, and it would be alot of fun... The s2000 has not low end torque niether does a celica gts does that mean its unstreetable... Hardly..
I've said this before , and I will say this again, efi tames a harsh motor like no other, I've seen a full bridge idle at calm 1100 rpm , and p port would not be much different, alot of what makes high overlap motors hard on the street was the tuning and the systems used to tune them, webers with no chokes, fixed advance distributors, or Holleys that love to blow power valves...
Lets not forget the earliest street drive rotaries were p ports as well... even the small displacement 10a's...
This discussion is all academic anyway, 99.9% of the people in this thread are never going to do it , it always cracks me up, that the nay sayers are the people that never would, haven't or just plain can't...I remember when I was told you couldn't run a large streetport on the street, then a turbo bridge port wouldn't work on the street, now a peripheral port doesn't work on the street, whatever....Max

 

You're missing the point. No one is saying it can't be run on the street. The people you are disagreeing with are saying there is no SENSE in running it on the street.

The scale of speed vs. practicality is tipped heavily in favor of forced induction.

 

Put a factor of ´k´ in there for the fun factor and you might see why some people choose to run a large bridge or peripheral port...

 

Speaking of these PP's, there is a FD in NZ that runs a quad rotar, home built out of two 13b, runs 2 ida style fuel injection, puts out 600 hp and cuts the quater in 10 seconds, also is street driven. Its what the individual wants, as long as they are happy!

 

I think this was my strongest point I was trying to make also.
It's obvious Maxthe7man does not agree.


-Ted

 

You guys seem to fight all the time about turbo or pp, why not use both?

I mean the only lag in a turbo is at lower RPMs, once the turbo starts making boost the power there are no problems. Not only that, but with a PP its gonna most likely be a track car anyways, so that means you'll be dragging it with 7k+ launches anyways. At this point the turbo is spooled, and your making the most of the PP

Im confused, am I getting this right, or is there something that I don't know about when combining these two ideas?