Is porting for power a myth?

Any form of normally aspirated power mods.
User avatar
13Black
Club Member
Club Member
Posts: 4634
Joined: Sun Jan 10, 2016 10:14 pm
RX-8: 231
Colour: Velocity Red
Location: Leicestershire
Has thanked: 524 times
Been thanked: 803 times
Contact:

Re: Is porting for power a myth?

Post by 13Black » Mon Nov 12, 2018 9:35 am

Mister kopite (Ian?), I think what Pete is trying to say is: any gains, big, small, coming alive, driveability, whatever... CAN be measured on a dyno.
There's no difference between the two - to make a car a better drive through porting, that will equate to a direct measurable difference on a dyno.

If a 15% increase is all it takes to transform the car, then that's fine. But the car won't pull any better then the dyno says it does.
I often see people say that it's fine that A Car is only making x more peak horsepowers, but it's driveability etc is more important.... which I think what what they mean is, the power in the midrange has increased as well, maybe by an even larger increment than the peak figure has, which is fantastic as well, but still measurable. There's no feeling necessary when you have measuring tools.

Not sure if that clarification was needed, so completely disregard if already understood :thumleft:
Last edited by 13Black on Mon Nov 12, 2018 10:09 am, edited 1 time in total.
-= Rotormelon Money Pit Build of Tasteless Questionable Bodgery =-
Experimelon 183whp rebuild | Rotary Revs D585s | PZ Suspension | Hawk & Yellowstuff pads | Extra steering lock | Custom exhaust | Added rearward flames of glory | Unnecessarily repurposed ball gags
-= Clicky click for build thread =-

User avatar
Conan
Club Member
Club Member
Posts: 6194
Joined: Tue Jun 28, 2011 9:22 pm
RX-8: 231
Colour: Brilliant Black
Location: Cotswolds
Has thanked: 56 times
Been thanked: 733 times

Re: Is porting for power a myth?

Post by Conan » Mon Nov 12, 2018 9:40 am

:) And a happy Monday to everyone.
I don’t disagree with Nick (13 Black) but people describe and explain things differently.
People also see and comprehend things differently.
I understand what people are saying ( well most anyway :) )
I will use the following example to try and explain what I am saying and ambiguities

Rotary Revs do an excellent lightening and balancing service : :thumleft:
Does this increase HP :)
Does it measure on a dyno
Does it Revs quicker
Does this increase excelleration
Does it make the car faster
Does it give you a faster lap time
Does it make rev matching a dream and quicker and smoother
Does it give you a million more smiles per mile :) :thumleft:
Arguments on the back of a postage stamp and discussion below ;)
Pete
Speed is not always about maximum HP
Last edited by Conan on Mon Nov 12, 2018 11:27 am, edited 3 times in total.
Events Coordinator. 2014 to 2017

I’m an expert in nothing....I have made mistakes in everything

User avatar
kopite72
Club Member
Club Member
Posts: 11349
Joined: Wed Dec 28, 2011 8:30 am
RX-8: R3
Colour: Diamond Grey
Location: Cork Ireland
Has thanked: 434 times
Been thanked: 824 times

Re: Is porting for power a myth?

Post by kopite72 » Mon Nov 12, 2018 9:56 am

Disregarded :lol: don't worry I totally understand what Pete is saying, all I'm saying is that Porting can and does transform the car.

No it may not add heaps of power but it makes the car infinately more enjoyable to drive and that to me is more important than some numbers on a printout
R3 GONE, FUN WHILE I HAD HER BUT NOW LOVING MY 25TH ANNIVERSARY MX5.... MODS INBOUND 8)

User avatar
geofftl1000r
Club Member
Club Member
Posts: 556
Joined: Mon Nov 27, 2017 9:31 pm
RX-8: 40th Anniversary
Colour: Metropolitan Grey
Location: Redhill
Has thanked: 186 times
Been thanked: 119 times

Re: Is porting for power a myth?

Post by geofftl1000r » Mon Nov 12, 2018 12:20 pm

I would guess not many people take a sick car to the dyno before having work done to compare how much of an improvement a fresh engine has over a sick one.
I read lots on hear about lack of torque for overtaking and general driving around but this has not been my experience but then I've never driven a ported engine to have a comparison.
Maybe we need a time stamp on the rpm scale of the dyno sheets so that you can compare the spin up times for lightened components but then you'd need standard weight wheels/tyres to compare.
40th Anniversary RX8
R3 Wheels: PZ Coilovers: RRP 'Red' Coils: RRP Engine mounts (softer ones): RRP COFS: RRP Blue Pulleys: Silicon hoses in blue: Goodridge brake lines: HEL clutch line: Racing Beat ARB's: SS Braided oil lines: Mishimoto radiator (oem fans)

User avatar
Conan
Club Member
Club Member
Posts: 6194
Joined: Tue Jun 28, 2011 9:22 pm
RX-8: 231
Colour: Brilliant Black
Location: Cotswolds
Has thanked: 56 times
Been thanked: 733 times

Re: Is porting for power a myth?

Post by Conan » Mon Nov 12, 2018 12:35 pm

Hub dyno :)
There are maths equations that wizards like Nerdstrike are clever enough to use for lightening rotating mass.
Pete
Events Coordinator. 2014 to 2017

I’m an expert in nothing....I have made mistakes in everything

PeteH
Former Member
Former Member
Posts: 5848
Joined: Mon Apr 11, 2016 1:26 pm
RX-8: 231
Colour: Custom
Location: West Sussex
Has thanked: 177 times
Been thanked: 786 times

Re: Is porting for power a myth?

Post by PeteH » Mon Nov 12, 2018 12:38 pm

Most dynos don't work like that (and RR's certainly doesn't). They control the sweep rate of the rpm, so that all runs are always done at an rpm increase rate which is decided by the operator. This is one major reason why all dynos give different values; the operator can choose almost any sweep rate he likes. If you put a very fast sweep rate in, or you have a large powertrain inertia, then your recorded power will be low. If you do steady state runs (holding the revs constant at each test point), then you get the best possible result on the dyno. But this method takes ages, and can cause your car to get very hot. Dynos can measure powertrain inertia, but this also takes time, so most operators don't bother.

User avatar
warpc0il
Spin Doctor
Spin Doctor
Posts: 25571
Joined: Sat Sep 06, 2008 10:56 pm
RX-8: 231
Colour: Lightning Yellow
Location: Groomsport, Co Down, NI
Has thanked: 456 times
Been thanked: 1825 times
Contact:

Re: Is porting for power a myth?

Post by warpc0il » Mon Nov 12, 2018 2:31 pm

Increasing the sweep rate higher than it would be possible for the car to accelerate can also cause issues with algorithms in the PCM.

For example the PCM has built-in hysterisis to prevent the intake valves from flapping around the trigger points.

If the sweep rate is set too high the SSV etc will open too late to meet the demand and you get big dips in the power curve - which couldn't occur on the road.

Sent from my SM-G800F using Tapatalk

Dave
The Spin Doctor ™
uǝǝɹɔs ɹnoʎ ʇɹǝʌuı ǝsɐǝld :ɹoɹɹǝ

User avatar
ChrisHolmes
Committee Member
Committee Member
Posts: 19051
Joined: Sun Jan 29, 2006 10:04 pm
RX-8: 231
Colour: Velocity Red
Location: Cheltenham
Has thanked: 5273 times
Been thanked: 2398 times

Re: Is porting for power a myth?

Post by ChrisHolmes » Mon Nov 12, 2018 6:57 pm

geofftl1000r wrote:
Mon Nov 12, 2018 12:20 pm
I would guess not many people take a sick car to the dyno before having work done to compare how much of an improvement a fresh engine has over a sick one.
I read lots on hear about lack of torque for overtaking and general driving around but this has not been my experience but then I've never driven a ported engine to have a comparison.
Maybe we need a time stamp on the rpm scale of the dyno sheets so that you can compare the spin up times for lightened components but then you'd need standard weight wheels/tyres to compare.
The nearest we have for this is my engine which was dynode at RR last year 14/10/2017 with 169.7whp and then it ran out of breath a couple of months later and was replaced by a rebuilt street ported spare engine using all the same inlet and exhaust system on 06/11/2018 and produced 172.8whp so a gain of 3.1hp from the rebuild with all new seals and a street port.
Bridge Ported 231
Light weight Flywheel
Tein MonoSports with EDFC Active
Racing Beat F&R ARBs
Racing Brake 4 Pot Front Calipers
Racing Brake two piece slotted & drilled discs
LED Rear Lights
LED 3rd Brake light with blink effect
MazdaSpeed skirts
Safety Devices Full cage
Royal Steering wheel
Short shifter
Mishimoto Catch Tank

User avatar
warpc0il
Spin Doctor
Spin Doctor
Posts: 25571
Joined: Sat Sep 06, 2008 10:56 pm
RX-8: 231
Colour: Lightning Yellow
Location: Groomsport, Co Down, NI
Has thanked: 456 times
Been thanked: 1825 times
Contact:

Re: Is porting for power a myth?

Post by warpc0il » Mon Nov 12, 2018 7:41 pm

Have you got the full printouts to compare, rather than just the headline figures?

What were the atmospheric conditions (temperature, pressure and humidity) on these two different days?

Were you wearing the same colour socks both times?
These users thanked the author warpc0il for the post:
nightfire10 (Mon Nov 12, 2018 7:55 pm)
Dave
The Spin Doctor ™
uǝǝɹɔs ɹnoʎ ʇɹǝʌuı ǝsɐǝld :ɹoɹɹǝ

User avatar
ChrisHolmes
Committee Member
Committee Member
Posts: 19051
Joined: Sun Jan 29, 2006 10:04 pm
RX-8: 231
Colour: Velocity Red
Location: Cheltenham
Has thanked: 5273 times
Been thanked: 2398 times

Re: Is porting for power a myth?

Post by ChrisHolmes » Mon Nov 12, 2018 7:56 pm

Here you go Dave,

viewtopic.php?f=136&t=78524#p1185866

Josh adjusted the swizzleometer and jiggle rate so I presume that covered any possible variation.
Oh and we were both wearing black!
Bridge Ported 231
Light weight Flywheel
Tein MonoSports with EDFC Active
Racing Beat F&R ARBs
Racing Brake 4 Pot Front Calipers
Racing Brake two piece slotted & drilled discs
LED Rear Lights
LED 3rd Brake light with blink effect
MazdaSpeed skirts
Safety Devices Full cage
Royal Steering wheel
Short shifter
Mishimoto Catch Tank

User avatar
Lemon
Forum Moderator
Forum Moderator
Posts: 1434
Joined: Wed Nov 30, 2016 4:08 pm
RX-8: 231
Colour: Winning Blue
Location: Wiltshire
Has thanked: 31 times
Been thanked: 173 times

Re: Is porting for power a myth?

Post by Lemon » Mon Nov 12, 2018 8:27 pm

ChrisHolmes wrote:
geofftl1000r wrote:
Mon Nov 12, 2018 12:20 pm
I would guess not many people take a sick car to the dyno before having work done to compare how much of an improvement a fresh engine has over a sick one.
I read lots on hear about lack of torque for overtaking and general driving around but this has not been my experience but then I've never driven a ported engine to have a comparison.
Maybe we need a time stamp on the rpm scale of the dyno sheets so that you can compare the spin up times for lightened components but then you'd need standard weight wheels/tyres to compare.
The nearest we have for this is my engine which was dynode at RR last year 14/10/2017 with 169.7whp and then it ran out of breath a couple of months later and was replaced by a rebuilt street ported spare engine using all the same inlet and exhaust system on 06/11/2018 and produced 172.8whp so a gain of 3.1hp from the rebuild with all new seals and a street port.
And my 192 which put down 147 at the hubs with low compression on the rear rotor and ate a bearing a month later.

Sent from my Nokia 6.1 using Tapatalk

Thanks, Stu

User avatar
geofftl1000r
Club Member
Club Member
Posts: 556
Joined: Mon Nov 27, 2017 9:31 pm
RX-8: 40th Anniversary
Colour: Metropolitan Grey
Location: Redhill
Has thanked: 186 times
Been thanked: 119 times

Re: Is porting for power a myth?

Post by geofftl1000r » Mon Nov 12, 2018 9:48 pm

Hmmm maybe I shouldn't have told Jessica I put her car on the dyno as they seem to die shortly after!
40th Anniversary RX8
R3 Wheels: PZ Coilovers: RRP 'Red' Coils: RRP Engine mounts (softer ones): RRP COFS: RRP Blue Pulleys: Silicon hoses in blue: Goodridge brake lines: HEL clutch line: Racing Beat ARB's: SS Braided oil lines: Mishimoto radiator (oem fans)

User avatar
Lemon
Forum Moderator
Forum Moderator
Posts: 1434
Joined: Wed Nov 30, 2016 4:08 pm
RX-8: 231
Colour: Winning Blue
Location: Wiltshire
Has thanked: 31 times
Been thanked: 173 times

Re: Is porting for power a myth?

Post by Lemon » Mon Nov 12, 2018 9:54 pm

geofftl1000r wrote:Hmmm maybe I shouldn't have told Jessica I put her car on the dyno as they seem to die shortly after!
Mine was well on the way when the Dyno sesh was done, had been having cold start issues for a good while.

Sent from my Nokia 6.1 using Tapatalk

Thanks, Stu

User avatar
13Black
Club Member
Club Member
Posts: 4634
Joined: Sun Jan 10, 2016 10:14 pm
RX-8: 231
Colour: Velocity Red
Location: Leicestershire
Has thanked: 524 times
Been thanked: 803 times
Contact:

Re: Is porting for power a myth?

Post by 13Black » Mon Nov 12, 2018 10:16 pm

[2017 RR Dyno Might Survivor] 1 year on.

You don't know maaaan, you weren't there! :guns: :duel:
-= Rotormelon Money Pit Build of Tasteless Questionable Bodgery =-
Experimelon 183whp rebuild | Rotary Revs D585s | PZ Suspension | Hawk & Yellowstuff pads | Extra steering lock | Custom exhaust | Added rearward flames of glory | Unnecessarily repurposed ball gags
-= Clicky click for build thread =-

RobinPZ72
Former Member
Former Member
Posts: 1390
Joined: Sat May 19, 2018 4:55 pm
Has thanked: 67 times
Been thanked: 32 times

Re: Is porting for power a myth?

Post by RobinPZ72 » Mon Nov 12, 2018 11:33 pm

Anyhoo I honestly think porting can be done to be effective an fairly reliable too, however things can go wrong and if they don't we're not trying hard enough!

If my car was working well and being competitive with similar specs the last thing I'd be doing is a dyno! Get yourself a good OB2 reader and a app or software that allows data export and as long the proper vehicle profile is added it's as close as you'll ever needed it! unless you are actually racing and have a budget to get the best kit possible!
These users thanked the author RobinPZ72 for the post:
ChrisHolmes (Tue Nov 13, 2018 9:51 am)

cib24
Former Member
Former Member
Posts: 933
Joined: Sat Feb 23, 2013 4:38 pm
Location: London
Has thanked: 4 times
Been thanked: 74 times

Re: Is porting for power a myth?

Post by cib24 » Tue Nov 13, 2018 12:21 pm

The FD:OC had a Dyno day on the 4th of November and after collecting all of the results I painstakingly extrapolated the PDFs into Excel for direct comparisons. This is the type of data analysis that needs to be done among the RX-8 community to see the real benefits (or lack thereof) of porting the Renesis and observing the power under the curve.

https://fdoc.co.uk/forum/threads/fd-oc- ... v-18.1905/
These users thanked the author cib24 for the post (total 2):
RobinPZ72 (Tue Nov 13, 2018 12:31 pm) • warpc0il (Tue Nov 13, 2018 1:03 pm)
1999 Mazda RX-7 Type RS

Mods - Apexi PFC @ 1.00-1.06 bar, AEM WI 250cc/min, Knight Sports DP, RE-A 80mm cat, Fujitsubo exhaust, Greddy SMIC, Koyo N-Flow, Ohlins DFVs, poly bushings, Dixcel FP 17" discs , 17"x8" BBS RG-R, Nankang NS-2R, Project Mu pads.

398 Bhp (340 Whp) @ 6,036 RPM, 350-360 lb/ft (299-307 Wlb/ft) @ 2,900 - 6,100 RPM. - 12 Nov 17

My Build Thread

User avatar
kopite72
Club Member
Club Member
Posts: 11349
Joined: Wed Dec 28, 2011 8:30 am
RX-8: R3
Colour: Diamond Grey
Location: Cork Ireland
Has thanked: 434 times
Been thanked: 824 times

Re: Is porting for power a myth?

Post by kopite72 » Tue Nov 13, 2018 12:50 pm

Wow that's a serious collation of data, nicely done. Enjoyed reading that, some nice numbers there too. Thanks for posting it
R3 GONE, FUN WHILE I HAD HER BUT NOW LOVING MY 25TH ANNIVERSARY MX5.... MODS INBOUND 8)

User avatar
13Black
Club Member
Club Member
Posts: 4634
Joined: Sun Jan 10, 2016 10:14 pm
RX-8: 231
Colour: Velocity Red
Location: Leicestershire
Has thanked: 524 times
Been thanked: 803 times
Contact:

Re: Is porting for power a myth?

Post by 13Black » Tue Nov 13, 2018 12:59 pm

I have a similar collection of figures on a spreadsheet from the MAP and Horsham days. Resolution not as good, but manual entry, so.

Might make it more readable and upload it here if I ever get time.
-= Rotormelon Money Pit Build of Tasteless Questionable Bodgery =-
Experimelon 183whp rebuild | Rotary Revs D585s | PZ Suspension | Hawk & Yellowstuff pads | Extra steering lock | Custom exhaust | Added rearward flames of glory | Unnecessarily repurposed ball gags
-= Clicky click for build thread =-

cib24
Former Member
Former Member
Posts: 933
Joined: Sat Feb 23, 2013 4:38 pm
Location: London
Has thanked: 4 times
Been thanked: 74 times

Re: Is porting for power a myth?

Post by cib24 » Tue Nov 13, 2018 1:01 pm

13Black wrote:I have a similar collection of figures on a spreadsheet from the MAP and Horsham days. Resolution not as good, but manual entry, so.

Might make it more readable and upload it here if I ever get time.
Yeah, I had to do manual entry eyeballing every 125 RPM. Fortunately, the PDF printouts were quite detailed so I was able to eyeball with reasonable accuracy.
1999 Mazda RX-7 Type RS

Mods - Apexi PFC @ 1.00-1.06 bar, AEM WI 250cc/min, Knight Sports DP, RE-A 80mm cat, Fujitsubo exhaust, Greddy SMIC, Koyo N-Flow, Ohlins DFVs, poly bushings, Dixcel FP 17" discs , 17"x8" BBS RG-R, Nankang NS-2R, Project Mu pads.

398 Bhp (340 Whp) @ 6,036 RPM, 350-360 lb/ft (299-307 Wlb/ft) @ 2,900 - 6,100 RPM. - 12 Nov 17

My Build Thread

PeteH
Former Member
Former Member
Posts: 5848
Joined: Mon Apr 11, 2016 1:26 pm
RX-8: 231
Colour: Custom
Location: West Sussex
Has thanked: 177 times
Been thanked: 786 times

Re: Is porting for power a myth?

Post by PeteH » Tue Nov 13, 2018 1:29 pm

Yep, nice analysis. I think this sort of thing is easier when the changes are big, and FD's certainly come with an impressive spread of differences these days (250whp to +500whp.....)

I think the difficulty with the RX-8 is that any mods we do are "within the noise" of the normal variability of the engines as they wear. In other words, a stock 231 RX-8 could be any where from 160 to 185whp, but doing mods can add anywhere from 0 to 25whp. So if your street port motor makes 180whp, is that because it's a 160whp motor with a 20whp upgrade, or is it a 180whp motor with a pointless street port?

I think we can be sure of a couple of things:
- A stock 231 is very unlikely to make more than 185 to 190whp.
- The best Bridgeport motors make 210 to 215whp, so we can assume a good bridge will add about 25whp.
- My motor has had everything done to it except porting, and makes 203whp, so the best of all other mods together (exhaust, coils, map, intake) will add 15 to 20whp.
- The best street port result I have seen is 13Black's, at about 185whp, and his car has a custom catless exhaust and 585 coils. So does a street port add power? Impossible to say, but it's not much. Anyone seen a better street port result?

If I get time (and I probably won't) I will collate the results from all three dyno days so far. But note that 350Matt already did some collation here:
viewtopic.php?f=24&t=74460&hilit=dyno+d ... 5#p1112424

User avatar
13Black
Club Member
Club Member
Posts: 4634
Joined: Sun Jan 10, 2016 10:14 pm
RX-8: 231
Colour: Velocity Red
Location: Leicestershire
Has thanked: 524 times
Been thanked: 803 times
Contact:

Re: Is porting for power a myth?

Post by 13Black » Tue Nov 13, 2018 1:41 pm

CUSTOM exhaust.

Bahahaha. If that's how we want to describe it, sure. Might be able to flog it for extra JDM ¥¥¥ that way.
It's only the standard 2.5" main pipework that goes to twin 2" tips. Welded back up the morning of the dyno day. With a wonky ghetto decat with even worse welding.

Gene pulled up one of their street ports of similar spec to overlay on mine, theirs had a couple more hp, but nothing to shout about, and as you say, within the noise surely.

Brix's factory R3 made very slightly more than mine on the day also.

Some street ports not making good power might have something else letting it down, like coils, sensors, whatever. Or maybe just not a very well executed porting - uneven, too much here, not enough there, too polished, bla.

Similarly, some standard engines could have the fuelling 'off' due to a sensor and running coincidentally quite nicely leaned off, who knows.

Not to sound like I'm making excuses to make the results fit what I want etc. Classic amateur statistician. But to be sure any result is accurate it'd be (probably too idealistic, but) nice to ensure that things are behaving as they should.
-= Rotormelon Money Pit Build of Tasteless Questionable Bodgery =-
Experimelon 183whp rebuild | Rotary Revs D585s | PZ Suspension | Hawk & Yellowstuff pads | Extra steering lock | Custom exhaust | Added rearward flames of glory | Unnecessarily repurposed ball gags
-= Clicky click for build thread =-

User avatar
warpc0il
Spin Doctor
Spin Doctor
Posts: 25571
Joined: Sat Sep 06, 2008 10:56 pm
RX-8: 231
Colour: Lightning Yellow
Location: Groomsport, Co Down, NI
Has thanked: 456 times
Been thanked: 1825 times
Contact:

Re: Is porting for power a myth?

Post by warpc0il » Tue Nov 13, 2018 1:51 pm

I'm a Six-Sigma Black Belt and none of the tools that I have to hand have been able to prove significant benefits from street ports, based on limited data available.

However, if/when my engine needs a rebuild I'll still be getting the ports at least "tidied-up".

Sent from my SM-G800F using Tapatalk

Dave
The Spin Doctor ™
uǝǝɹɔs ɹnoʎ ʇɹǝʌuı ǝsɐǝld :ɹoɹɹǝ

cib24
Former Member
Former Member
Posts: 933
Joined: Sat Feb 23, 2013 4:38 pm
Location: London
Has thanked: 4 times
Been thanked: 74 times

Re: Is porting for power a myth?

Post by cib24 » Tue Nov 13, 2018 1:54 pm

In any case, whether the cars dyno all over the place or not it would be useful to see how these particular cars are developing their power just so you can see if the porting is actually shifting the power band or not.

The RX-8 had huge ports from the factory and whilst I had a half bridge street port on mine, I very much doubt it was the porting that was really contributing to the extra power I observed when chasing down guys like Casey at the track. I think it was more to do with my Racing Beat header, Racing Beat Mid Pipe and Racing Beat cat-back as well as brand new coils.

As REC mentioned in their Youtube video, the intake ports flow well enough but it's the exhaust port that needs better flow. Add a good remap on top of that (which from what I can see RX-8 owners have yet to see a good tuner) to optimise power across the rev range, and you should see some benefits. The question is how much and what shape does it make for you?
1999 Mazda RX-7 Type RS

Mods - Apexi PFC @ 1.00-1.06 bar, AEM WI 250cc/min, Knight Sports DP, RE-A 80mm cat, Fujitsubo exhaust, Greddy SMIC, Koyo N-Flow, Ohlins DFVs, poly bushings, Dixcel FP 17" discs , 17"x8" BBS RG-R, Nankang NS-2R, Project Mu pads.

398 Bhp (340 Whp) @ 6,036 RPM, 350-360 lb/ft (299-307 Wlb/ft) @ 2,900 - 6,100 RPM. - 12 Nov 17

My Build Thread

cib24
Former Member
Former Member
Posts: 933
Joined: Sat Feb 23, 2013 4:38 pm
Location: London
Has thanked: 4 times
Been thanked: 74 times

Re: Is porting for power a myth?

Post by cib24 » Tue Nov 13, 2018 1:56 pm

warpc0il wrote:
Tue Nov 13, 2018 1:51 pm
I'm a Six-Sigma Black Belt and none of the tools that I have to hand have been able to prove significant benefits from street ports, based on limited data available.

However, if/when my engine needs a rebuild I'll still be getting the ports at least "tidied-up".

Sent from my SM-G800F using Tapatalk
Humble brag ;)
1999 Mazda RX-7 Type RS

Mods - Apexi PFC @ 1.00-1.06 bar, AEM WI 250cc/min, Knight Sports DP, RE-A 80mm cat, Fujitsubo exhaust, Greddy SMIC, Koyo N-Flow, Ohlins DFVs, poly bushings, Dixcel FP 17" discs , 17"x8" BBS RG-R, Nankang NS-2R, Project Mu pads.

398 Bhp (340 Whp) @ 6,036 RPM, 350-360 lb/ft (299-307 Wlb/ft) @ 2,900 - 6,100 RPM. - 12 Nov 17

My Build Thread

User avatar
13Black
Club Member
Club Member
Posts: 4634
Joined: Sun Jan 10, 2016 10:14 pm
RX-8: 231
Colour: Velocity Red
Location: Leicestershire
Has thanked: 524 times
Been thanked: 803 times
Contact:

Re: Is porting for power a myth?

Post by 13Black » Tue Nov 13, 2018 2:09 pm

It's not a definitive metric but airflow traces should directly correlate to power produced... all things being equal... which could tell us something.

Even if it's one engine ingesting 180g/s with another ingesting 220g/s, but both producing the same power - suggests the latter is not doing something properly with the potential chemical energy at its disposal, be it exhaust restriction, ignition problems, injector issue, sticking rear brakes(!) etc.
These users thanked the author 13Black for the post:
ChrisHolmes (Tue Nov 13, 2018 5:13 pm)
-= Rotormelon Money Pit Build of Tasteless Questionable Bodgery =-
Experimelon 183whp rebuild | Rotary Revs D585s | PZ Suspension | Hawk & Yellowstuff pads | Extra steering lock | Custom exhaust | Added rearward flames of glory | Unnecessarily repurposed ball gags
-= Clicky click for build thread =-

Post Reply

Return to “Naturally Aspirated”