DailyDriver2k5

Has anybody done this yet? I met a guy who does performance rotary motors for the past 15 years . He said there is so many trick and trades to the rotary that you can do without the use of turbos. Well he caught my intrest, he mentioned that you can bridge port the rotary. By doing this it gives N/a rotary motors some pretty impressive Hp gains. I suppose to talk to him more about this ,this afternoon at his shop.

Have any of you rotary heads done this? Seem credible, because i know if you port piston engines, you get a pretty impressive HP jump.

By the way, he showed me pictures in his wallet of his '80 RX7 1st gen with a twin turbo RX-7 motor in it, tubbed out and all, cars run's 7's in the 1/4 mile!

lurch519

with the older rotaries, it was pretty easy to extract major horsepower from these mods. for example, adding a header could add some serious horsepower. as to the renesis, i dont know. and yes, older rotaries can be quite nasty at the strip. i was at englishtown this last weekend for some nhra sport compact action, and the modified class had about 15 rotaries qualified in it, mostly starlets with tubbed out rears and rotoary motors. to qualify you had to be running somethign like 7.7 or better, and a nationaly record fell 4 times in 1 round of qualifying

silverwolf

2k5 i know your by UCf which car shop are you talking about around here?

ddub

Bridgeporting was invented to get around racing regulations. It is in fact the bastard child of a peripheral port.

Yes it is not as loud and intense as a p-port and you can street drive it a lot easier, but still not that great. If you're going to use the stock intake manifolds with a bridgeport than you're pretty much wasting the port since the stock ones will not do it justice.

And are you talking aux (1/3) bridge? Half bridge (really 2/3 in reality for n/a engine)? Or a full bridge? Each one is vastly different as far as setup, tuning, fuel, etc.

Hope you're not planning on using the stock ecu with this bridgeport. While it possible the car will drive and run like ****. Horrible gas mileage, not very good power, and pointless basically. Unless you're talking an aux (1/3) bridge, then that will only open when the aux ports open and at that point it isn't TOO bad, but a standalone is still very suggested.

I have built a bridgeported motor in the past. To do what I wanted it took a lot of prep, time, money for parts to go along with it, and in the end I was not that impressed. I could have gotten away with almost the same power by doing a nice/big streetport and using most of the same setup parts but being able to save some money in the long run.

Renesis_8

There is no need to port the Renesis, the intake is already a lot larger than old 13Bs, the restriction is in the exhaust as stated in many other threads. Maybe you can have a chat with the porting guy and see what he can do for you to increase the flow on the exhaust side.
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DailyDriver2k5

Its a shop in plant city...privately owned. This guy is known throughout the Tampa and some or Olrando area. Loui Fernando.....i believe is his name....I am going to see him this afternoon.

DailyDriver2k5

I'll ask him that question...i'll try and post his awnser tonight or early tomorrow.

DailyDriver2k5

You mentioned a streetport? What is that? And have you done this modification on your Renesis?

mysql101

I don't think you're going to find anything about the results "impressive" ... You can't look at his FI car's gains and think you're going to get anything similar. You'll get better results from just dropping a fuel management system on your car.


http://home.iprimus.com.au/bluey3/portsPage/ports.htm

godzilla

hey guys found this seems like porting is available on the renesis with good gains , interesting reading.
http://www.rotaryheads.com/dyno/rx8_...ort/index.html

Trekk

I dont know if it matters or not but.. In the before dyno it says MPH=126 and in the after dyno it says MPH=104.

ddub

That's guitarjunkie from the forum. And I'm sorry but if he dyno'd only in the 150's and 160's before, something was not quite right. Even after porting it only gets into the 170's? People dyno more than that stock.

F22C1

I see there is ~10rwhp, but at what price/cost?!?

I'm assuming this job isn't exactly cheap seeing how much labor is involved?

And why can't the exhaust be bridged ported?

godzilla

yeah i agree what your saying but dynos are only a tuning tool, cant really compare dyno figures unless you're using the same dyno, in saying that i was curious has anyone ported a renesis yet because there was huge gains on the previous 13b rotarys depending on the port job.

mysql101

Most of the work is getting the engine in and out of the car. If you can do that part, you should be able to get the actual porting done for about $300. If you can't.... the price goes up quite a bit. I'd assume $1300 range - but I'm just guessing.

ddub

You're forgetting the rest of it. Taking the engine apart, inspecting seals, replacing some of the seals depending on wear (I don't like to use used apex seals/springs or any of the o-rings when taking an engine apart/rebuilding). The labor and cost of parts goes up even more from there.

Most the time you're looking at over 1k easily for any tear down/port/reassembly. Most the time it's in the 2k range.

ddub

The reason there were such high gains from porting old style rotaries was because 1. the intake ports were much smaller stock than our renesis intake ports, and 2. the exhaust ports were peripheral rather than side and could flow WAY more.

The renesis is a bit trickier.

MazsportScott

Dont forget the fact that the height of the new seals are much shorter, if the bridgeports were of tradional size, the stock apex seals could easily fall into the intake port. This would require machining the rotors for different seals (which we do BTW) if not the decreased flow of the smaller bridgeports would start to offset the potential flow increase at high RPM.
So to actually do this properly:
R&R engine
Diss. and rebuild engine
Machine rotors for different seals
New internals, Ddub's correct, your looking at a stack of used parts, increasing the loads on them by 20% is a very bad idea if you expect it to last.
Portwork
Engine management so the engine can be tuned for the increased flow.
This is going to cost several thousand dollars if you are looking for somthing that will last. Just some thoughts on the subject, Scott

therm8

How about porting a supercharged 4port. There should be plenty of room where ports 5 and 6 would be. That's my plan when the engine needs rebuilding. (along with cleaning up the exhaust ports, or if someone comes up with a good template, porting out the exhaust too). Obviously a new intake manifold would be needed, but you could possibly use a 6 port manifold, and use a controller for the extra valves and let the 4 port's ecu control the rest.

rotarygod

I don't see you being able to use a 6 port manifold on a 4 port engine just by hogging out the runners. This is making the assumption that the 4 port housings do in fact have the same casting thickness as the 6 port engines. I have theorized in the past that they do but upon further study they do appear to be a little bit different. You can probably port them a little larger on the 4 port engines but don't expect anywhere near the port timing of the 6 port engines. You could probably keep the stock manifold just fine. Even the 4 port engines make more power than the last nonturbo 13B so they aren't that bad.

rotarygod

As strange as it sounds that's not necessarily true.

no dice

Keep in mind that guitarjunkies port job was done on a stock ecu. With aftermarket, i predict substantial increases...

rotarygod

All that and it still won't keep up with even a modest turbo system that wouldn't necessarily be any more expensive.

guitarjunkie28

me too... as soon as someone with an ems lets me port their motor.

any volunteers?

BaronVonBigmeat

Someone paid you to port their renesis, but couldn't cough up the cash for an EMS?