BDC

I'm curious to see if it runs on the stock computer. I'm curious about both the positive and negative effects of overlap and how the computer is going to try and handle the idle. My guess is it won't work well and will require a standalone.

B

sauceyI986

Ports, ports,ports,ports the bridge port is nice but how expensive these engine are u break **** I rather not risk it. But I do see these engines producing 600hp later on the line.

Fate710

iTrader: (1)

I would say Bridgeported, a T04R, and some very good tuning, 600+hp wouldn't be hard.

But why risk all the headache when you can swap in a 13b-rew(almost bolt in), put on a GT35r kit and make 450rwhp on 15-17psi. Big Street port with a bigger turbo and you have over 750rwhp

bse50

How will the exhaust ports work with that kind of airflow?
Because dyno queens are useless. Many race rx7 don't even have 450rwhp yet they are pretty competitive. One of the 13b-msp advantages relies in the intake\exhaust configuration, it really makes a nice power curve that i wouldn't sacrifice just to dyno high numbers with a big turbo or with an engine swap for that purpose.

Brettus

iTrader: (2)

excellent point - might delve into this a little more .

Benjamz

+1 on that!

Example RE-Amemiya 3 rotor N/A 380whp, Unbeatable touge monster and time attack car. Well it is beatable but you need a super gt500 car to do it..lol

bse50

Glad you share it, i think that it's the time now, after 7 years, that somebody picks a couple of irons and seriously works on the exhaust ports and welds\modifies the water jackets (Extremely hard task)
I don't think that making them giant would help, it's always a trade between speed and volume. I don't even think that adding\advancing the exhaust port timing and duration could prove excessively useful but I may be wrong on that since i have never tried without having to worry about those damn jackets.
In a turbo car i'd like to have those ports open a couple of degrees earlier, in a NA set-up i'd keep the stock timing and work on the exhaust velocity more, coupled with a bridgeport you could probably see some limited power gain by rising the limiter up a bit, where it chokes in stock form.

Anyway most of those mods are useless in a street driven car, where the broader power curve the better. In a race car you pretty much always stay in the same rpm range (2000 or so rpms) so that's a completely different story and you need THAT range to be the as broad as possible.
Those considerations should also be parallel to the ones concerning weight and weight distribution. A 30whp difference can totally be made useless if the most powerful car is unbalanced. Talk about monsetr front mount turbos?

reddozen

iTrader: (1)

I'll never agree with the necessity of an REW swap. You're better off spending an extra 2~3000 and dropping in a 20b if you insist on a motor swap.

Also, focusing on the old engines is exactly why the RX8 is still the bastard child of the modern rotary world. I'm all in with bse50, we need to start experimenting with the Renesis motor more because the 16x will be based on the same tech. I don't see Mazda going back to the peripheral exhaust port.

I'm working on some other ideas myself, but it takes money, so I can only do so much, but I am trying to work on some solutions. Time will tell.

Fate710

iTrader: (1)

An extra 2K-3K to put in a 20b? Your insane. You can pick up a 13b-rew complete with all accessories and wiring for 1000 or under. You can use the stock RX8 transmission up to about 400ft/lb tq. So your only big expenses are the turbo kit itself, the ems, and that is pretty much it.

You can swap in a 13b-rew mated to the 6spd with a nice turbo kit and PFC for under 8000. Just have to find the best deals. That price is doing all the work yourself though.

BDC

Won't hit anywhere near that power with a TO4R. That's a 67mm compressor. Tops out around low 500's to the wheels when pushing it to high 20's boost.

450 at 15-17 on a GT35R? No, that won't happen either. 750rwhp won't happen on any turbo that's smaller than an 80mm.

Compared to piston engines, these engines consume GOBS of air to make their power (about 30-40% more). That's their major downside when considering their major upside being terrific weight/power ratio. It's also the single reason why we're forced to look at chamber cooling and higher fuel octanes due to heat output.

B

Fate710

iTrader: (1)

I've seen GT35R setups pull 450rwhp. I've also seen them push 500+ with e85.

I don't know alot about the rotary world, but I'm just going by the dyno graphs I've seen and the setups I've seen.

Not meaning to step on toes, just stating what I've seen.

bse50

That's not completely true.
A complete rew goes for around that money yes but...
A completely rebuilt\ported\modified one with new parts costs around 5\6000$, add the turbo, the intercooler and the ecu and you are going to drop another 4000$ easily. Add that the mounting locations are different and all the other bullshit and that swap is well over 10.000$ excluding labor\clutch\flywheel\ancillaries
For what? 450whp?
I'll take a right sized turbo over a complete swap and enjoy the good usable power that this engine can deliver and save the rest for when the engine goes pop because of some tuning mistake

reddozen

iTrader: (1)

exactly my point.
if you want 500+ reliable HP then that's 20b territory, otherwise, the Renesis should be more than capable of delivering the power you need for a lot cheaper than an engine swap.

REW swaps are good for showing off, sure, but not the best solution for more power IMO. Renesis or 20b and you should be able to do just about whatever you want from those 2.

J8635621

iTrader: (10)

Normally I stay out of turbo discussions as I really don't know too much, but I had to do a double take here. Stock transmissions go out with stock power lol. No way would it last under hard driving AND 400 ft/lb.

999miki

You probably donīt understand how bridgeport(and overall port timing) works

bse50

I'm sure that your definition of bridge port and the way it works will prove me wrong.
I'm looking forward to reading it.

999miki

Iīm having very nice concensus with Sean from A-spec about specific air consumption of rotary vs. piston engine. We settled that its no more than 17% higher in properly ported engine, so your exaggeration is ridiculous
And yes, I can explain it based on BSFC of rotaries vs. piston engines at given AFR. Also based on BMEP difference of all out N/A racing engines

bse50

Still i see no description though. There's a reason why I say so, pretty logical if you think about it.

999miki

If you think that bridgeporting IE opening ports early is only top end thing, you are way off Look at piston engines... Ever seen good powerful N/A engine opening intake after TDC? I guess no. For given power level, bridgeported engine will have much more area under the curve everywhere, at least from 2000 RPMs and so on... This is well know from very beginning of wankel engine developement. Also, engines with high VE% - properly done bridgeport, peripheral port... are more efficient at full load.
Of course, there is trade-off, low load sucks, fuel efficiency etc... If you ment that these mods are useless for street car, because of given trade-offs, then yes, but all around powerband? nothing can beat peripheral port

bse50

This thread is about bridgeports, right? You're talking about peripheral ports
I'm still not sure that a P-Port would be a better solution in an "overall" confrontation where real life conditions such as the power under the curve and emissions are taken into account.

The fact with the bridgeport is that it let's more air in that you will have to exhaust somehow. That's why it reduces\moves the powerband. Same reason why variable intakes are so successfull, they let more air in only when it's needed. With a bridgeport you'll have more air sucked in even at low rpm\low intake velocity and burning it properly would be a pity. Move a bit up the rpm scale and you'll have a sweet spot with the real limit being the exhaust ports since the intake ones can flow a lot more than the engine can ingest in stock form.

Still with we're discussing apples to oranges since you're going off topic with a P-Port and here we're discussing a bridgeported engine

Buy a couple of irons, a center plate, and start grinding the exhaust ports. Hit the water jackets, fill'em up\weld them and pray that they hold the temperatures and temperature deltas they're subject to! Nobody did that successfully to my knowledge, yet. I broke a couple of irons and gave up. Even warming them before welding led to ugly welds that simply would not be reliable!

999miki

jada jada doesnīt matter BP, PP its about timing... well area/degree relationship is different... I mentioned, that low load - read "90% of engine life in street car" sucks emissions, fuel economy... But not confuse facts - area under the curve - PP king

You mean shifts the powerband downward with more torque all around and spreads it in both directions of RPM scale?

We know that renesis exhaust ports can flow at least 260-280 BHP, with bridgeport, VE% goes up, this limiting flow is achieved at lower RPMs, but holds till redline, again, more power all around

****, I must go sleep

bse50

Where are the facts? If having more air in all the time was beneficial we wouldn't have variable intake ducts\apvs etc. Just our big ports there, always open.
Then you're throwing out numbers on how much this or that port can flow.
You said 260-280bhp (what a difference) for the exhaust ports. Well, the stock intake ports are good to levels above what you stated. What's the point in making them even larger?

Benjamz

P-port, B-port great stuff, so if the exhaust is such a problem on the renny then why don't we machine our own exhaust port inserts and make a new small exhaust ports on the rotor housing like the FD. It does not have to be that big, just big enough to help. The dam bolt holes and exhaust port templates are still molded in the renny rotor housing. We can make our own custom exhaust to take advantage of this new mod. So, if the exhaust is that big of a deal, would something like this work.

Sorry to change the subject.

bse50

Are you talking about making a peripheral\side exhaust port hybrid? It may like it may not work
The problem Ben is that you don't have much of a margin to work on the exhaust ports because of the aforementioned water jackets. Re-welding an iron is practically impossible or very hard\difficult anyway. That's where the porting limits reside. Custom sleeves could help, especially in a turbo'd engine. There's who runs sleeveless but the heat really stresses the irons. Definitely a big no if durability is a concern (and it is!)

999miki

You think that variable intakes are here for limiting amount of air at lower RPMs? Because by the way you typed it, it seems you do...
Variable intakes, different length runners for different durations of primary, secondary and auxilary ports are here for maximizing VE% at all engine speeds.... I really donīt understand what you meant by this...
Making ports even bigger would be very silly, but I didnīt mention such thing, you are twisting what I said
Opening intake ports early, highest VE% is attained. I donīt care about exhaust side, its not limiting factor for what bridgeporting give us in this aplication - stronger midrange...

Only fact is, that Mazdatrix had peripheral intake Renesis on the engine dyno and it was far more powerful everywhere then stock Renesis with all fancy intake tracks despite it was bad combination...