Is porting for power a myth?

Any form of normally aspirated power mods.
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Re: Is porting for power a myth?

Post by Ryan Rotary Performance » Wed Dec 05, 2018 9:31 am

I think this thread concludes that porting does make more power, albeit more difference on a 4 port than a 6 port engine :)

viewtopic.php?f=205&t=78656

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Re: Is porting for power a myth?

Post by ChrisHolmes » Wed Dec 05, 2018 1:50 pm

Less ports = more driveable power!
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Re: Is porting for power a myth?

Post by Ryan Rotary Performance » Wed Dec 05, 2018 2:22 pm

ChrisHolmes wrote:
Wed Dec 05, 2018 1:50 pm
Less ports = more driveable power!
I actually think the 4 Port, once its had our magic, is the better road car, only if coupled with the 6 speed box. We can also put the 4 port engine in the 6 Port Chassis with no issues.

The 6 Port engine on the other hand will make a better track car. (for now)

All this is subject to our 4 Port stage 2 modification which I think will see the 6 port become redundant come rebuild time for many.

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Re: Is porting for power a myth?

Post by warpc0il » Wed Dec 05, 2018 4:41 pm

Many builders choose the 4-port engine as the basis for FI installations.

Turbo or supercharging makes the original intake redundant and pressurisation means that you can flow more than enough air without the extra ports and their complexity. Most also keep the 5-speed 'box because they believe it to be stronger; at least for handling torque if not higher revs.
All replace the rear stationary bearing for the 231-specification part.
Some replace the flywheel and counterweight for 231-spec parts, but that's mainly because you can't get (most of) the performance clutch options in 192-fit.
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Re: Is porting for power a myth?

Post by PeteH » Wed Dec 05, 2018 6:05 pm

The 5 speed box is basically the RX-7 box (I think). Does that mean the 5 speed clutch is also the RX-7 clutch? If so, I don't understand the lack of high performance clutches. You'd have thought there would be some serious clutches out there for the tuned RX-7s...? What am I missing? :-k
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Re: Is porting for power a myth?

Post by warpc0il » Wed Dec 05, 2018 6:16 pm

The clutch has more to do with the engine/flywheel than the gearbox.

This means the Renesis 192 clutch is not the same as the RX7

The 5-speeds boxes are also more different than people think.

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Re: Is porting for power a myth?

Post by Szerelem » Sat Jan 05, 2019 11:59 am

Whats the consensus on japanese tuning options and ports, im sure its very similar to UK? Actually the mass depreciation in the UK lead to readily available engines which has given us some of the best rebuilders and researchers around in my opinion.

Anyway those in the know check out
seems the Fujita Engineering FEED car is already 219bhp straight away, but the weird thing is to my layman eyes i'm sure none of these cars are full bridged. Amemiya (Not in this video) but they claimed 250ps , 240+bhp which has to be balderdash....right?
I've always been curious about what they are doing internationally, knowledge is power etc. But as I say above, i think given any opportunity the rebuilds and specialists we have here in the UK are some of the best around.

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Re: Is porting for power a myth?

Post by warpc0il » Sat Jan 05, 2019 12:12 pm

Don't forget that the Japanese use a different calculation for power than the rest of the world, which is why the 4-port is rated at 210 in JDM but 192 everywhere else.

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Re: Is porting for power a myth?

Post by 13Black » Sat Jan 05, 2019 12:15 pm

And different dynos read differently and different operators will probably get somewhat different results and different days may produce different figures and....

Yeah can we all stop getting hung up on numbers thrown around that various dynos spit out - it's not what they're for, for good reason.
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Re: Is porting for power a myth?

Post by Szerelem » Sat Jan 05, 2019 3:24 pm

warpc0il wrote:
Sat Jan 05, 2019 12:12 pm
Don't forget that the Japanese use a different calculation for power than the rest of the world, which is why the 4-port is rated at 210 in JDM but 192 everywhere else.

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Really? Man thats crazy :-k

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Re: Is porting for power a myth?

Post by Szerelem » Sat Jan 05, 2019 3:27 pm

13Black wrote:
Sat Jan 05, 2019 12:15 pm
And different dynos read differently and different operators will probably get somewhat different results and different days may produce different figures and....

Yeah can we all stop getting hung up on numbers thrown around that various dynos spit out - it's not what they're for, for good reason.
It was just the quick example i could pull from memory, im actually 95% in the "how it feels" camp over the actual math, ive just always been curious to japanese tuning methods vs uk development. How they have approached porting the Renesis, as it seems there is still some kind of thin veil of mystery around it, although maybe its just the language barrier.

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Re: Is porting for power a myth?

Post by cib24 » Sat Jan 05, 2019 3:46 pm

Szerelem wrote:
13Black wrote:
Sat Jan 05, 2019 12:15 pm
And different dynos read differently and different operators will probably get somewhat different results and different days may produce different figures and....

Yeah can we all stop getting hung up on numbers thrown around that various dynos spit out - it's not what they're for, for good reason.
It was just the quick example i could pull from memory, im actually 95% in the "how it feels" camp over the actual math, ive just always been curious to japanese tuning methods vs uk development. How they have approached porting the Renesis, as it seems there is still some kind of thin veil of mystery around it, although maybe its just the language barrier.
No, there isn't any unique difference between how shops in Japan, Aus, NZ, USA or the UK port the renesis. If there was a way to extract more power without going to a peripheral exhaust port setup then it would have been figured out by now.

Just enjoy the Renesis for what it is but don't try to make any significant power out of it with porting. It doesn't really work.
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Re: Is porting for power a myth?

Post by Eddie_r32 » Sat Jan 05, 2019 3:53 pm

cib24 wrote:
Sat Jan 05, 2019 3:46 pm

Just enjoy the Renesis for what it is but don't try to make any significant power out of it with porting. It doesn't really work.
My full RRP bridge was worth every single penny
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Re: Is porting for power a myth?

Post by Szerelem » Sat Jan 05, 2019 4:13 pm

Thanks for the info,
I do enjoy my rx8 for what it is, great fun. :thumleft:
I wasn't posting looking for some miracle from the east porting bible, it was just a curiosity to see and compare their approach.

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Re: Is porting for power a myth?

Post by 13Black » Sat Jan 05, 2019 4:27 pm

Have to bear in mind that the grey one in the video has some kind of aftermarket ECU it seems, and a shorter diff. One of the white ones appears to be very standard but making good peak power, however the yellow one is quite down but still very stock it seems. No mention of how old and used they all are, how good their ignition is, if they're otherwise healthy etc. The rest of the Japanese is all Japanese to me so who knows what else they're divulging.

They only list the peak power too, which is somewhat useless as all you're displaying is how much power it produces across about 200 revs... which is about 1/20th of the range you're actually using.

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Re: Is porting for power a myth?

Post by delta0 » Mon Jan 07, 2019 8:33 am

Szerelem wrote:
Sat Jan 05, 2019 3:24 pm
warpc0il wrote:
Sat Jan 05, 2019 12:12 pm
Don't forget that the Japanese use a different calculation for power than the rest of the world, which is why the 4-port is rated at 210 in JDM but 192 everywhere else.

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Really? Man thats crazy :-k
They use JIS standard and we use DIN (~95 DIN = 105 JIS). That is why the 250ps is 228bhp here.
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Re: Is porting for power a myth?

Post by Dr. FrankenRex » Mon Jan 07, 2019 9:06 am

Who cares about power when your car BRAPS?!
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