I've got a 1988 GTU S4 N/A. I want to push between 280-350rwhp on an N/A setup, or even 300hp at the crank.

Let me know what everyone thinks.

Current upgrades:
5-Lug rotors and wheels with 4 piston front calipers
Cone filter intake


What I've got in mind__________________________________________________


Engine and Exhaust:
AEM Dryflow air filter
RB Header
RB True dual Exhaust or REV TII
Weber Carburetor (not sure on the specifics of this one, have to research it)
Mild or Large Streetport
550cc primary injectors
720cc secondary injectors
Rtek 1.7 or 2.1 ECU
Emissions removal
Throttle body mod(???)
MSD 6A ignition coil(s)
FD3S dual belt alternator

Tires and Wheels:
Kosei K1 TS 17" wheels (14.4 lbs each)
Hankook tires- Ventus V12 evo K110 (215/45ZR17) front and rear

Drivetrain:
Lightweight flywheel
Carbon Fiber driveshaft
S4 or S5 Turbo II transmission
Exedy Stage 2 Clutch
Short throw shifter

Suspension:
KYB AGX adjustable struts with Eibach sport springs
Cusco upper strut tower bar front and rear
Cusco rear lower strut bar
Cusco front and rear sway bar

Brakes:
Need advice.

 

Full bridge or pport and supporting mods 10krpms for those numbers. rtek won't work for something like this. and just from ur list you don't any idea what your trying to jump into.

 

D shaped or square peripheral ports, some exhaust porting, custom intake, custome fuel rails, custom intake manifold, custom header, Standalone ems.

dyno tune

custom headers and custom exhaust

dyno tune

and then just keep on going.

 

Where are you getting the Carbon fiber driveshaft?????

Not going to break 200 without some serious work if this is a street car

 

You're right I have no clue but gave it some guess work, I can build a piston engine from the ground up, but I've only recently begun to delve into the Rotary world. Which is why I'm asking for opinions.

 

With a s4 six port block not possible.
Get a FD block or cosmo block,swap to 9.7.1 rotors,peripheral port,custom intake manifold,custom exhaust system and ems.Know you just built a real loud pain in the *** almost impossible to drive on the street car.

 

For a pport wouldn't matter what irons were used, ports are gonna get filled with devcon.

 

a built 20b n/a would be the easiest way IMO.

 

This car will be my daily for some time so I want it to be Street level modification until I can do a full build. Obviously this is my first rotary build, as you can see from the list above. I'm assuming that instead of Rtek, I should try more along the lines of a Haltech setup.

This sounds fun. Why does everything need to be custom?

Precision Shaft Technologies make Carbon Fiber Driveshafts, it'll cost about $1,000 but it will also shave 30lbs of rotational mass from the car.

 

A Cosmo 20B swap is what I've had in mind for the longest. I'm looking at spending $4,000-5,000 to get that done though and plan on doing that for my second build.

 

What isn't possible? There's some pretty loud Honda's out here with 5" fart cans, would you say louder or quieter than those. cause you can hear them from about 1/2-3/4 mile away.

Why would they get filled with epoxy.

 

Yeah..you have no idea what you're asking. Do some research on porting(the different types and their horsepower limits)

You won't make more than 180hp with a "street" port on a 2 rotor engine.


If you want 300 horsepower for the street then a turbocharger is the obvious choice.

 

If this is gonna be a daily, look at streetport or small bridge porting(200whp can be obtained with a little work). The power lvls you want out of a n/a require some aggressive porting that cut engine life pretty significant and all the power will be form 7k rpms on up. And everything from intake to exhaust is generally custom cause the intake and exhaust are tailored to what the engine wants. Dont compare a honda to a rotary ever... a full bridgeport or pport doesnt have alot of vacuum at id'le or low rpms so its under i high load making exhaust loud(over105db generally) and is very sensitive to restrictions so free flowing(header/straightpipe to straighthrough muffler) is generally your only option. As for the irons being filled with epoxy on a pport, ill let this pic do the talking...

 

How do you expect an RTek ecu to work with a webber carb?!

Research bridge and pp porting... And start there because that would be your best bet at ever reaching close to your power goal.

 

Ok I've made a decision and thanks to Corey, a better list.

Also I don't compare any Honda to even a blown 12A, if I had to choose between those I'd take the 12A. I was using the exhaust sound of a Honda that drives around here because it's the loudest thing out here. But 105db's is pretty damn loud.

Anyway here's Corey's list

Engine and Exhaust:
S4 13bt
S5 turbo and ported wastegate
Racing Beat 3inch downpipe + cat delete
Racing Beat 3 inch catback
Mild or Large Streetport(Fun but not totally needed)
550cc primary injectors
720cc secondary injectors
Rtek 1.7
Emissions removal
Throttle body mod(???)
FD3S dual belt alternator
Aeromotive FPR
Walbro Fuel pump

Drivetrain:
Lightweight flywheel
S4 or S5 Turbo II transmission
TII rear end
Exedy,Spec,act clutches are all good.


Suspension:
Strut bars are ok, They help a little. Get the Infini stock strut bar
Cusco rear lower strut bar
Sway bars aren't really needed to upgrade
Ksport coilovers. They're cheap and good. You won't know the difference between a $2K set of something and Ksports.

Brakes:
Get some good pads and that's it. Stock 4 piston brakes are awesome. A good pad will make them great.

 

How are you going to shave 30lbs off of a driveshaft that doesn't weigh 30lbs stock?

For a streetable engine, you'll be hard pressed to get more than 180RWHP out of a two-rotor NA.

 

Yeah, I screwed up on that, that was their "up to" weight reduction. I have to call them or fill out an order for a custom shaft for an FC.

 

LOL, I'm getting flamed for being a retard but at the same time I'm getting valuable knowledge on something I don't know much about.

 

I do appreciate all the info you guys are giving me though. Thanks alot

 

What all would I have to do to obtain 200whp with an N/A setup?

 

You should focus on the engine rebuild. I would keep the ports stock for now and focus on obtaining the right seal clearances and end play. Once the engine is running I would start working on the rest of your list.

 

KLZE Mx-6 V6 J-spec with a bunch of head work

Edit: oh, you want to keep it a rotary? umm... lol

 

We all know that but he is starting with a S4 NA engine that is way i suggested a better block.S4 has the weakest dowel pin land,9.4.1 rotors,regular engine bearings(not high flow or multi windows)no set screws,crappy oil pump,skinny tension bolts,lower oil pressure regulators just to mention a few so for me is not good candidate for a PP project cause all this stuff has to be upgraded,now with a good FD core you can build a budget PP motor keeping mostly all the internals.

 

You're looking at 200 tops. For what you want you need a peripheral port or a turbo. Peripheral port setups are extremely expensive and have other drawbacks so most go turbo.

 

From what little I know [having never attempted this]:
*S5 rotors
*S5 Intake [plus a couple RPM switches and solenoids to activate the 5/6th ports and VDI]
*At least Rtek 2.0
*Wideband to tune it
*a good exhaust system [maybe true-dual Racing Beat?]