It's not "suck vs. blow". In N/A engines the air is "blown" into the engine too. The difference is that they're at the mercy of the local weather and altitude.

The TII manifold IS nicer from the perspective that it doesn't have as much surface area and the runners look shorter. The 6 port manifolds on the other hand allows the final turn to be more gradual since there isn't a turbo in the way.

It's basically the same problem as the primary ports of a stock carbureted intake manifold. They have to make a tight bend, so they intentionally left the port "short". You kinda wouldn't want to open up a TII manifold to mate up with a 6-port for the same reason you don't want to open up a carb intake manifold to match the (really tall) 12A primary ports.

 

murders the velocity?

 

You can't turn and diffuse at the same time.

 

Depends on how you define "superior". The NA design became, over the years, increasingly optimized for the stock power outputs. So it works fantastically for an engine with the same airflow capacity and porting as stock, designed to put the powerband in the same place as stock. The problem is, because of all those optimizations, it hinders any change from those parameters.

 

i thought the idea behind this thread was for people to post the highest hp made by a street port motor and perhaps what they did to make that power for the education of others on the forum.


now with that out of the way i feel the most important things to make power in there order of importance are

fuel +timing management
ehaust system(everything from headers to tail pipe is important)
the port(this can make or break a motor but is not the most important thing)
intake system(piping and airflow meter or lack there of)cold air is best
heat management

tuning will make or break any high hp combo and i have found the cars running my pipe that ignition timing will free up big increases in power gains of 4-7 hp were made from changing total timing advance with additional gains of 3-5 made from adjusting the lead to trail split especially at high rpm's (watch for detonation from too much advance)
incorrect fuel will just detonate or burn up the motor (most n/a tuners seem to runing 13's... ie 13.7...13.8 ect.....fuel air ratio) in my case pipe user's have to run 11.3-11.0

exhaust.....horse power waiting to be found the right system can add 20-30 hp the wrong system.... well you know.....so far my testing is saying im on to something with my system

port i wont say im a world athority on porting but i have been porting rotary engines over 20 years and developing ports for 6-port engines most of that time
.................................6-ports make power..........more people need to try them

intake SCCA puts limits on my guys so port and polish and thats it im working on a heat sheild gasket to try to dtop the intake heat plus tring some thermal barrier on the out side of the intake i think the modified stock intanke by yet give up anoughter 3-8 hp.... now if you dont have that restriction i say build a custom intake and a easy5-15 hp could be found maybe more .... try to eliminate the airflowmeter run a big bore cold air intake pull from behind headlight or duct from front valance panel

heat management .... coatings are your friends........ heat shields need to be used.....cold air intakes work ....if you want to get deep into it coatings in the motor show potential......

if you have no restrictions (big bore intake or ITB'S)and use all the tricks available(clipped rotors and coated any one?) i feel a race tuned 13b 6-port can build 240-260 whp(dyno jet)

 

Would you care to give us some of your timing specs that you have used with good success? I don't think that is giving away too much is it?

 

You're having fun here now aren't you!

Honestly I think you're very correct! With the power we're making on all out PP combos presently I see no reason why it cannot be applied to any other motor.
People spend too much time concentrating or porting when in reality there's only so much you can do with porting and yet there's a whole lot you can do elsewhere. Believe it or not we've gain close to 75hp with everything that's on the same motor without changing the present state the porting is at.
I've seen a street ported, four port 12A with all the goodies put down 255hp!!

 

please list your goodies chris

 

I would like to hear about those goodies also. I'm trying to achieve about 200rwhp with my 12a. Also we have to remember if you're using a race transmission, really light flywheel, and light wheels, that might be good for quite a few ponies to the ground.

 

Let me guess- race pullies, lightened and balanced rotors and rotating assy, direct fire/msd ignition, larger crankcase ventilation system, oil mods, electric fan, custome intake/fuel system, custom exhaust system. Did I leave anything out? Like you said about porting- there's only so many things you can do with the engine also. It's finding the right combination of parts and tune to make the horsepower is the tricky part.

 

Now, while I claim complete stupidity in building rotaries (or any motors for that matter...Im a transmission guy)

Wouldnt the intake testing be easy (relatively speaking) to exhaust testing?

I played with the flow bench a little bit at school...and the longer the runner was of course, the more velocity it had...but doesnt that also change where you would have the most efficiency and thus your peak power RPM? I can think of at least one quick and dirty way to lengthen runners to acheive that...

And what about plenum volume? I do know its a big issue on say a drag car...but for road race how important is it? If youre running ITB...i suppose the atmosphere would be your plenum...though that would be affected by the bell on the end of it.

Thoughts, knowledge?

I have a 6 port motor lying around that im waiting to dump money into, I cant wait to see how much I end up with...anything over 200 (Ill eat ramen for months on end if I have to...Ive done it before...) will make me plenty happy.

 

I have "heard" that every 10 degrees of oil temp over 180deg costs 10hp.

How many people build up kickass engines and then rely on the barely-sufficient oil coolers?

I've had okay success with the water-oil heat exchanger IF I could just keep the coolant temps down. The first run makes good power, afterwards though you can literally feel the power draining away.

I had plans to alter the coolant routing to give cold-water priority to the water heat exchanger simply because I have a hard time trusting an oil radiator hanging out where stuff can bash it and hole it up. Now I run one, just because I'm too lazy to adapt the water cooler to a 13B (12As very hard to find anymore), but I do have all the bits necessary to give the oil cooler its own separate water system. The plan was a pair of truck heater cores tucked up in a certain place where they get good airflow but are well protected.

Oh well...

 

really interesting about the 10hp loss at the above temperature. The highest that I do see my run at the track is around 90 degrees. I could duck my radiator better probably, and I too am still running the stock beehive.

 

Note I am speaking in Fahrenheit. 180F is 82C.

I would scream and shout if oil temps got over 110C. Although I am fairly sure I've gotten one of mine over the 120 mark... once. Shame shame!

The main limitation of the beehive in stock form is that the oil temps, by definition, cannot get any cooler than the water temp, and in practice run quite a bit hotter. How much hotter I can't say, but I've seen sustained coolant temps in the 220-230F range, so if my oil was only 250F (120-odd C) with a stock beehive, then I'd be really surprised.

That was the "event" where the 211k mile 12A in my silver car finally went kaput. It was just a wee bit hot

The airflow into the radiator is already really good. Look into getting it out of the engine bay.

 

Thread bump... just curious to see what *intake manifold* setups people are using.

I found that the primary throttle is way too small for a street port TII engine... so I'm ditching the Mazda throttle body setup!

 

well i've got the racing beat 2 piece manifold for my sidedraft ITB's ... I went to the dyno a couple of weeks back and only managed 2hp (150 hp) more than with my old holley setup and seemed to have lost my low end torque. I've been trying to tune things more and more and see how things go. I did manage to get the 3-4.5k range to pull harder. I know alot of the guys have said about 13.3-13.6 seem to be the good spot, but my engine seems to like 12.4's. Even on the dyno it made more power with those AFR. It could be my somewhat radical timing table from BDC. I should maybe post it to see what everyone says. BTW this is for 12 streetport.

 

So here it goes, all this is on a s4 GXL...
CAI
All emissions removed
Pineapple racing six port sleeves
Synapse FPR
Walboro 255
Mazdatrix 9lb aluminum flywheel
Ported TB
6 Puck stage 3 clutch
Custom fabbed header and 3 in. exhaust no cats
air pump delete
Modded air flow meter
AC delete
six ports operating properly
NOS wet Kit

O.k. so i'm expecting pretty close to 200 at the wheels before the nitrous. my 1/8 mile slips are pretty consistent with a car my weight making 200. the dyno tune comes next week. i'm hoping to make somewhere around 250 wit the nitrous.

 

I think you'll need a lot more to hit 200 whp, especially with an S4 engine and no VDI.

 

i had a simular set up back in the day and a 9.7 was my best at qualcomm. (car was pretty stripped) i think youll be around 150 or so (which is good for a s4 n/a)

 

really love this thread i am in need of good ideas.

 

Any idea on the power my set up will make

its a S4 13b 5 port with a street port
SDJ header with a borla xr-1 presilncer and ebay n1 out back
dual 40mm DHLA carbs on a Pierce(TWM) manifold
using a 12a dizzy with the DL ignition thingy(sorry I couldnt remember the whole acronym)

Crispeed just how bad is the TWM intake, I have been considering making my own but I am unsure on how to select the right proportions for the intake to actually make it better

EDIT: forgot to mention that I cannot find a good starting point for tuning the carbs

 

That should be a screamer, although I am not sure on your exhaust system. eBay isn't any brand I've heard of so I don't know what their mufflers are like. What's the inside look like? Louvered or perforated core? Any baffles? Does it have a good sized inlet/outlet but neck down to 1.5" in the middle like my Mind-Train presilencer did? (Horrible power but it was really really quiet...)

 

Its just an N1 knock off, strait through design perforated core no baffles and it is a 2 1/2 inlet with a 5in tip




It dosnt sound to bad but I am sure it is going to blow out sooner or later, then I will upgrade to a magnaflow out back. I also have been trying to decide wheter or not to step up on my exhaust size. I have seen a few people running 2 3/4 or even 3in but I am not sure if that is to large or not.

 

So...i dont know what kind of numbers mine is putting out, however my guess is in the 200 range if i'm lucky... Street port 89 motor using the pineapple racing templates, and then a little more. A webber 48 carb, full racing beat exhaust, 2 phenolic spacers, and a racingbeat 17lb flywheel. best part, motor was built and swapped by me.

All of this in my 85 gsl-se. I raced an s2k with exhaust and intake, and only lost by 2 cars, so i was pretty happy with my results.

 

seems kinda silly to quote myself, but does anyone have any suggestion on to step up my exhaust size.