Might sound ridiculus but I'm dead serious about pulling this off. The local rotary guru was telling me that anybody can bolt a big turbo to a rotary and run 12's but it takes alot to build a fast N/A rotary. So here's what i have to work with. I have an '81 GS thats about as base as it gets. The engine and drivetrain are in fantastic condition but not really important. Sufficient suspension and tire upgrades will be made of course. I also have a 6 port 13B completely dissasmbled and ready to be rebuilt. It came out of a S4 and its basically just the housings and everything that goes in it. My goal is to use this motor and and the FB and build a sub 13 second car in N/A form. Heres what I need to know.

Carb or EFI? Carbs seem to produce nice results and will help greatly seeing as how I want to keep it as simple as possible not to mention its cheaper.

What ignition setup? If I'm running computerless it seems a distributer is the way to go. However what are the other options?

Street port or bridge? See here is my biggest decision. I want the car to be streetable. But a porting job will be very necessary if I plan on getting some power out of this motor. Will a street port be good enough for 200-220hp?

Do I need a better drivetrain? I was considering a GSL-SE drivetrain but if the current drivetrain will be more than sufficient for my needs I don't feel it will be necessary to replace it.

I've got expert help on hand so it getting done right isn't any problem. If all goes as planned I'll have a 2000lb (car tipped scale at 2280lbs with nothing removed) FB with a 220hp 6 port 13B. The car will have to be streetable and very cost effective. Suggestions please.

 

You're definitely going to need a bridge port / half bridge if you're looking for 200-220 rwhp. More and more people are daily driving these engines, they're pretty streetable depending on the specific port, tuning, and of course your idea of what's streetable.

I don't any experience with carbs, but a simple and cost effective EFI solution is to run a Haltech F10 with a dizzy. But if you're looking to extract all the power possible from your engine, the couple hundred extra dollars for a Microtech, Haltech, Wolf, Tec3, etc. may be worth it. You just can't fine tune timing with a dizzy like you can with a standalone (obviously). I would look for a used standalone, you'll see one for sale once in a while on the forums.

 

With a light car like a semi stripped down first gen, it won't take much power to get you to your goal. You can get 200 rwhp with just a street port. The reason you never see people (2nd gens) doing it is because most still use the stock ecu's that have air flow meters. Kahren got 187 rwhp out of his totally stock block 6 port engine with nothing more than a Haltech and a homemade intake manifold. Not even a set of headers. He did it properly. A bridgeport will definitely get you there.

For a cheap alternative you should check out the Megasquirt ecu. I have one. There are other rotary people who use it as well such as Jeff20B and Bill Shurvington. I have less than $200 into mine and the car runs great. I only have it running fuel at the moment but you can make it do ignition as well.

For a simple and fairly cheap intake system that flows very well, i'd do the Holley manifold from Racing Beat along with an efi throttlebody. I have a very cheap source for these tb's. Just $75. You'll need to make a fuel rail but that's easy. Here you go.

http://www.auto-nomics.com/cgi-bin/s...rt=10850-002-D

 

Sounds like EFI is the way to go. However I really don't want to bother with fuel injection and I'm cruising towards a carb setup so its ultra simple and no electronics. A friend of mine pulled sub 12's in his TII powered GSL-SE. It was making 230rwhp and was factory wieght. I believe his best was a 12.48 in that car.

 

What kind of stuff does your friend have on his TII GSL-SE. I have the same swap in my car and its almost running, i want to compare so i can see what kinds of times ill be running.

I dont know where you live but BDC(brian cain) on this forum is a great engine builder and great guy in texas.

 

His GSL-SE is long gone. The motor was basically stock with a few tweaks. But the guy is amazing when it comes to building motors. Maybe thats why he beat Ari in pheonix. He pulled a 12.48 in his GSL-SE pushing 230 rwhp. Now I'm trying to talk him into porting my 6 port for my GS.

 

In my opinion I would get rid of the 6port plates and get a set of 4port turbo plates. Get a mild bridge port done on it, mild meaning do not cut into the water seal, and I'd do it on all 4 sides. Run a Holley 600cfm carb with MSD ignition. To me that will be the cheapest and easiest way to meet your goal. I did this setup in a friends datsun 1200 with full interior and on steet tires it runs consistent 13.3 in the 1/4 spinning them through 3rd gear. Also did the setup in a RX2 owner never ran down the strip but was strong as hell. EFI is great but you can make the power with a carb if you know what your doing or if you know someone to properly setup a Holley carb for a rotary. Some people buy the Racing Beat carbs but I can't justify buying a $500+ carb if I spent that much I'd go efi then. But I spend $150 on a brand new carb and set it up myself.

 

check this man ken sheepers has a 10sec N/A 1st gen...... making a 13 sec 1st gen is nutting thats easy, i would use F.I if u plann to use a turbo later on, a 600CFM or higher (adjustable) monster J port ill give u around 300HP with everything els done to it, lighter rotors, lighter e shaft, ect ect, and a 4.44 gear ratio i say ull be running 12s in a light 1st gen

 

Man did you read his post? He wants to make it streetable. Yeah I'd drive a huge J-port, hell I'd drive a PP motor on the street if I could get away with it, but how long do you think that motor will last before it starts leaking coolant and yes it will. Have you even built a J-port motor? Probably not and if your going to ask if I have I'll save the time and and answer yes to that. A good reliable mild bridge port will get you what you want. And 300HP from a J-port you better be an excellent tuner to pull that number. If 1/4 mile racing is what your looking into I wouldn't waste time with those 4.44 shoot for 4.88 gears with 24.5in to 26in slicks. And upgrade to turboII transmission.

 

TII transmission eh? I happen to have one I can spare. But the trans in this FB is pretty smooth so I'll keep it unless I stumble upon the '81 GSL I originally owned (and sold for $100 dammit!) that had a GSL-SE drivetrain in it. The engine is being built from the ground up to run 10k+ rpms. I'm going to use a S4 EFI lower intake manifold with port actuators then get a side draft manifold for whatever setup I decide on. But no detail will be overlooked. The manifold is going to be smoothed out and polished (internally) and anything else that needs to be smoothed out. Anyways what is the stock gear ratio for a '81 GS anyways?

 

How about putting it in a Datzun 510? or a Spitfire? You should be even faster?

 

Sounds neat but I already have the car and I already know how to work on it. Plus I don't think I'll have any luck finding one here seeing as how I haven't seen enough of them to know what they look like.

 

well a bridge port motor suppose to last 50,000 miles i dont know how much problems will happen till then but to me that number says 5 summers for me

 

Longevity on a bridge depends on the size of the bridge port. If it dosen't compromise the water seal then it will last long but if you cut into the water seal and are relying on sealant to keep it from leaking well it will eventually leak. Every motor has it's purpose and you have to build it for that purpose. You can build a huge bridge port but be prepared for the up keep and maintenace for that motor.

 

Go with a semi bridge carbed engine and run a quadra jet carb from a chev, you can get an adapter to fit it on a holly carb manifold. The carbs have massive secondaries with small primarys, run it mechanical and then well crusing low rmp you will still get good gas milage

 

do you have a link to Kahren's car? i'd like to learn more about this.

 

We are putting together a half-bridge 13B with a dual weber soon and putting that into a 79'. I would be more then happy to keep you posted as to the performance results of the car.

 

So, are you guys saying that if you have EFI (like in a stock 13B from an SE), then are you saying to keep the injectors and just add a Haltech and maybe exhaust to reach 200 hp?

 

You're probably going to need at least a large street port, a good tune, and a well designed full exhaust to reach 200 rwhp.

 

Ok... what about going with all that you mentioned except the street port... any idea what hp that would yield? My engine is still good <fingers crossed> and I'd hate to pull it.

 

With 4.44 gears I bet my car will hit high 13's



Mods in sig

 

this would be possible with a 4.3 rear end, lightening, proper porting, proper tuning, etc. hell, look at Jesus car!

 

Well, as stated above, Kahren made 187 rwhp with a standalone, a great tune, and a custom intake manifold. That plus a well tuned exhaust will probably get you close. But you'd either have to fabricate your own intake manifold (and do all the R&D to find proper runner lengths, sizes, etc.) or pay someone with experience to build one for you. At that point, you might as well pull the engine and port it. Ports are really the key to making power in a rotary.

...There's always nitrous. (Puts on flame suit)

 

i have a friend that has a daily driven 12 sec all motor fb ,he runs holley 650 on a bridge ported 13b 4-port the car weighs about 1,900lbs. with nitto drag radials, works well

 

I wanna see this intake manifold on Kahren's car now! I want pictures, write up, the full spread! I WANT IT NEEEEOOOOOOOOOW, DADDAY!!!