prime

Does anyone have a fairly decent reliable do-it-yourself method for scalloped/bevelled rotors? I've been looking around for a machine shop that offers the service, but I can't find it anywhere, I can't get in touch with CLR Motorsports, and it doesn't show up as an option on the Racing Beat website.

I have an N/A, I'd like to keep it N/A. From what I've heard, no one has really broken the 300 horsepower barrier on an N/A without a J-Bridge or the like, and I know a guy with a PP port who's making 260 to the wheels of a PP Port.

I've been wondering what the effect of scalloped rotors, which some claim has equal effect as a Bridgeport on an engine, would do in an engine thats also running a full bridge or half bridge port. In all honesty I'll probably do a thin bridge on the primaries, and go moderately large for the secondaries and auxillary port bridges. The origional ports will be taking the form of an aggressive street port, though likely conforming to the safety margins of a template.

One of my buddies suggested, instead of getting a stand alone engine management system, getting a Weber Carb, and the Distributor and Cap out of an 85 GSL-SE, as a much simpler and cheaper option for the bridgeport effort. His idea has merit in my mind, feel free to chip in your opinions on that as well.

Ultimately the intended purpose of this machine, is to be a streetable drift machine. The only comfort I need is a stereo system, which will be firmly bolted down in inconspicuous locations to discourage thieves. I'll electrify the door handles too...hehehe. Can't complain about it if you're trying to steal my car *******!

Anyways yes, information on Scalloped/Bevelled Rotors....COMMENSE!

Also if anyone has a set to sell for a reasonable price...I'm interested.....

AGreen

iTrader: (11)

Maybe you could contact the guy here that had it done on his 20b.

Link gets blurred out. I guess Rx7 club has beef with R0tarycarclub.com

diabolical1

iTrader: (3)

it can be done, if you know what you're doing on a conceptual level. i made a 2-dimensional rotor so that i could use it as a template. i even went as far as mocking up an actual rotor, but never made any cuts. so it can be done at home, just keep in mind that you will NEED to have the assembly balanced afterwards and that's probably not something you can do at home!

what's the issue with getting in touch with Carlos? i can usually get through whenever i call (though it's been a long time since i last called him.)

opinion here, so beware ... honestly, if this is your way of trying to break 300, i'd say you need to look elsewhere. what is your motivation for that number other than "no one has really broken" it? i suppose this is the part where you're supposed to say "just because no one's done it, it doesn't mean it can't be done ..." and you'd be right ... to a point.

that said ... what is NOT my opinion is the fact that your information is not correct. 300 has been broken N/A at least on one occasion that i'm aware of.

as for everything else that you touched upon, carburetor or EFI is totally up to you and who will be tuning your engine. generally speaking, i'm sure you can build a potent setup with either one. for me, if i'm faced with the choice, i will choose EFI all the time! i don't claim to know anything about drifting or setting up a car for it, so i leave my commentary right here.

i've recently learned to have a new respect for the 6-port blocks, so i'm not knocking them, but it sounds like you're planning your setup around one and i just want you to weigh your goals versus your realistic options.

diabolical1

iTrader: (3)

oh yeah, and before someone reads my post and thinks i was implying it can be done at home, simply at will, let me clear that up. i was merely saying that it can be done. i happen to like experiemting with things like this, but i'm not making a blanket recommendation for everyone to go out and start hacking up rotors.

farberio

iTrader: (7)

Interesting bevel, it almost looks like he cut into the dish! Also I fixed your link so its click able

.

prime

I don't have breaking the 300 barrier as one of my goals really, though I'd be happy to make better than 300 horsepower. If I could get to 250+ I'd be perfectly happy to drift my car with it, I've seen Turbo II's bone stock do some amazing things with that level of power, and I think I'd be satisfied with it.

When I say I want to see what happens with a bridgeport and scalloped rotors, I don't mean I expect a godlike setup, I'm literally -just curious-, I want to know what effect it'll produce. I've heard you can get that nice brap brap with scalloped rotors too, I'd like to know what that brap brap is gonna sound like on scallops and a bridgeport. Cheers.

j9fd3s

iTrader: (3)

you could streetport a 4 port block, throw an RB holley on it, and with the right exhaust, be at right around 195-200whp

the weber might add 5hp, maybe a little more.

i'm not sure what the scallops would do, it like the bridgeport, depends on the size/shape/timing.

so the weber. the weber IS simple, if you think of it like an ECU, there is an idle map, and then there is maybe a 3x3 map for everything else. there's no coolant or air temp correction (well its YOU). so tuning it is much much quicker than an ECU.

the problem with the weber is that to change things you need to change parts, and you need to buy these parts and wait for them to show up. these parts add up in cost as well. so the carb might be simpler, and it might be cheaper, but by the time you buy all the jets and venturi's* and air filters and fuel pumps and regulators and stuff, you'd be looking at about $1000 us. $500 in jets? yes.

*actually to make this cheaper, on a 48IDA/13B run a 43mm venturi, and F8 e tube.

prime

When I ordered it, I'd just tell racing beat its intended purpose is to run a bridgeport. I'm sure they could give me a basic workable setup for a bridgeport that I could work off of, thats what I was informed at least. Additionally, the buddy who gave me this suggestion owns a -huge- formerly rotary only tuning shop. I'm sure he could set me up with any minor modifications I need to make to my weber under the table. I know the fuel pump will need to be scaled back to a much lower pressure, but as he pointed out, thats dime a dozen with most old muscle cars. A trip to the junkers would likely sort me, especially if it fits in my pocket. *cough* Because junkers have fair pricing.... *Cough*

Also yeah, thanks for the tip at the bottom, helpful piece of advice.

Oh also, my engine is a 6 port, so yeah. Not to sure how that would factor into your calculations, aside from I should be making better than 200 horsepower on a bridged 6 port.

farberio

iTrader: (7)

A bridge in addition to bevels is going to open the ports pretty early. Be aware that there is more to power then just making the ports bigger.

prime

I am aware, I'm hoping the combination will equate to an aggressive full bridge, or perhaps a J-Port. Thats why I mentioned how large I intend to cut the bridges and where. If I can cut a small bridge and get the effect of a medium sized bridge on my primary, cut a medium bridge and get the effect of a large bridge on my secondary, and cut a large bridge on my aux and get the effect of a -very- large bridge, I'd be happy. I'm wanting to get more without cutting into the housings as much, and risking cutting through to the water jacket.

I want to make them work with eachother to my best advantage, I'm well aware that if I just try cutting out huge ports and ignore flow issues and such I'm going to hurt a lot more than help myself. I don't want an awesome top end with an insane idle, I want drift power, and my intuition says that this could work well.

Derekcat

iTrader: (8)

That's very interesting about the rotors.. I've never heard results of it though..

Anyway, about the quote: I think the key words there are "much simpler".. I really don't understand why anyone still runs a carb on a FI car outside of race cars [fewer things to go wrong, no care for fuel economy or full range performance..]

j9fd3s

iTrader: (3)

peejay has run a bunch of different combo's over the last couple of years, he is doing rallycross, so he's actually looking for powerband that is WIDE and not tall.

anyways, the best combo he's had was a 4 port with a half bridgeport, intake is an S4 NA.

he's done a 6 port half bridge, and its not as good.

prime

Btw thank you guys for posting the writeup on the 20B with bevelled rotors, its really appericiated. My dream is to convert my car to a Bridged 20B GT40RR setup, I'd like to get into really competative drifting, and even if I move on to other cars in the future, there's one I intend to keep to highlight all the good memories. Helps that its my favorite, and the RX7 should've been a 3 rotor anyways! Lol.

There is nothing like hearing that crowd roar, aye?

j9fd3s

iTrader: (3)

actually HIGGI is really happy with his car, and its primarily drift.