THE DOCTOR

Oem Hitachi Bathurst sp twins ,rated at 650ps .
Dyno dynamic roller Dyno
19-20psi
Pump fuel
Fd motorsports U Type intercooler kit
Temps on power run 42 degrees c hold to 8500rpm
Air Fuel ratio 11.2
Power from wheels 318rwkw (430rwhp)
Amazing torque 649nm (479foot pound)

BLUE TII

iTrader: (9)

It looks like a 4th gear pull from the kmph on the bottom.

~55kmph to 235kmph
~34mph to 142mph
~2,000rpm to 8,000rpm.

The chart shows the 2ndary turbo transition at ~4,500rpm.

Nothing weird yet.


Now the weird.
You claim 479ft/lb torque
You claim 430hp

HP will always be higher than torque if your peak torque occurs after 5,250rpm and we can clearly see peak torque was indeed ~6,200rpm.

If you made 479ft/lb torque at 6,200rpm you made 565hp.

You didn't. You made 430hp as you should have with these turbos.

With your peak torque at 6,200rpm and 300kw (402hp) at 6,200rpm you made 340.5ft/lbs torque.

________________

These are definitely good hp#s for stock twins, but nothing we haven't seen before.

If you want to check the maths yourself-
Kilowatts to horsepower (hp) conversion calculator
Kilowatts to horsepower (hp) conversion calculator
Gear Ratio Speed Calculator
HORSEPOWER TO TORQUE CALCULATOR

THE DOCTOR

Special production hitachi twins
Bathurst sp

Larger a/r ratio compressor cover for high flow at high pressures
Compressors sizes
Std 41.6mmx57mm
Bathurst sp 47mmx 68mm

Turbine size
Std 45mmx50mm

Bathurst sp 51mmx56mm

Actuators pressures
Std 0.45 bar
Bathurst sp 0.85bar
Very responsive twins 2800 19psi to 8500rpm

THE DOCTOR

With your peak torque at 6,200rpm and 300kw (402hp) at 6,200rpm you made 340.5ft/lbs torque.

I've been tuning fd3s since 1999 and never Seen this sort of figure ever .
Normal max output from twin is 245rwkw(330rwhp)
Torque is 450nm (331foot pound)

My figures are correct 649nm 479f/p dyno dynamics reading is correct.

For hitachi twins on pump 98ron fuel its a world record
No water injector here .

And you can't calculator rpm by km on dyno if you don't know what diff ratios I have
Yes it's 4gear
I will be going to the 1/4mile track today to final prove these power /torque figures are
Authentic

BLUE TII

iTrader: (9)

For hitachi twins on pump 98ron fuel its a world record

They are just stock hybrid turbos, I don't see that it matters if you used complete Garrett CHRAs or Hitachi parts and custom cast compressor housings to make the hybrid.

As you found the stock exhaust side is the choke point.

So far Balljoint's 475rwhp is the most I have seen out of hybrid stock twins (he used external wastegate to get past the choke point of the stock exhaust sides).

BNR twins have been at 420rwhp for a decade or so.

THE DOCTOR

Actually your wrong about turbine housing being the choking Point , from my testing its been the turbine wheel .

Exhaust manifold pressure with the Bathurst sp twin I've got backpressure reduce by 16psi.
As for the highest power output for twin hitachi or the non reliable garret chra hybrid twins that use standard compressor cover .
Never seen more than 270rwkw in Australia .
I've tune
Knightsports twins
Revolution
Bnr
The standard comp cover are too restrictive doesn't allow for more flow high than 7000rpm at 16 psi
So the more boost u run with standard compressor with hi flow garret chra they just choke and reduce the peak power .

So don't know how your getting those power figure .

Anyway have you got any power dyno graphs?

BLUE TII

iTrader: (9)

Actually your wrong about turbine housing being the choking Point , from my testing its been the turbine wheel .

Exhaust manifold pressure with the Bathurst sp twin I've got backpressure reduce by 16psi.

Some hybrid manufacturers bore the turbo exhaust housing for higher flowing larger exhaust wheels.

Still no more peak power. Everyone seems to get stuck at ~420rwhp with bigger compressor wheels, compressor covers and bigger exhaust wheels but without an external wastegate.

Someone added external wastegate and boom 475rwhp.

I think the real restriction is the 0.60AR turbo exhaust housings for one and their orientation where the exhaust flow from the primary turbo is dead headed into the 2ndary turbo exhaust and then they must make two tight radius 90 degree turns (out of the turbos and then first bend in downpipe.

Dead head-ed flow merge is never desirable for flow.

My racing class mandates stock engine and stock turbos, but is free on manifold and turbo orientation, so I was thinking to move/rotate the rear 2ndary turbo.

Run two downpipes with a better flow out of the turbos and a more direct inlet path on the 2ndary turbo.

I don't know that I will gain anything on stock compressors- Mazda seems to have matched the restriction to the max stock compressor output well (400rwhp).


As for the highest power output for twin hitachi or the non reliable garret chra hybrid twins that use standard compressor cover .

BNR (the most common stock hybrid in the USA) does not use the stock compressor cover. They use complete Garret GT28 CHRA and they have their own cast compressor covers.


Never seen more than 270rwkw in Australia .
I've tune
Knightsports twins
Revolution
Bnr

The standard comp cover are too restrictive doesn't allow for more flow high than 7000rpm at 16 psi
So the more boost u run with standard compressor with hi flow garret chra they just choke and reduce the peak power .

Apparently BNR also found the 400rwhp choke point was the stock compressor covers since they make their own larger ones.

The chock point I am talking about is the next one which is the 420-430rwhp range and I believe it is the exhaust configuration and the 0.60ARs.


So don't know how your getting those power figure .

Anyway have you got any power dyno graphs?

470rwhp+ Balljoints parallel BNR hybrid twins with extenal wastegate-


429rwhp sequential BNR hybrids-
https://www.rx7club.com/attachments/...-2012-dyno-jpg

411rwhp non-sequential 100% stock turbos (not even hybrid with bigger comp wheels)
This guy ran a best of 10.87 at 128mph 1/4 mile on these stock stock twins too if you are doubting the dynos.
https://www.rx7club.com/attachments/...pdynosheet.jpg

THE DOCTOR

Here are my larger Bathurst special production cover beening machines
Bnrs are standard covers with hybrid garret cores , which I have seen a number times fail cause of the high oil temps the rotary products .

The new oem hitachi core made for high pressure are billet proof .
They have been improved with 360 thrust bearing plate and it uses a single bush
With piston ring.

As for bnr having big compressor ,I've only seen std covers which he
Cncs his name bnr on where the oem part number was.


If you have a picture post it up . But u will find you wrong again

As for your theory of two turbines directed at eachother beening a restriction .

Wrong again , If that was the case then how did I achieve 16psi pressure drop been engine and turbine housing .

Answer for u again is it was the large turbine wheels , all my upgrades are designed by hitachi engineers which pay lots money for , no guessing here like bnr .

Hitachi design and make all my

compressor wheels
Turbine wheels
Oem Higher pressure actuators
And larger special production a/r compressor covers



The hitachi engineers said the exhaust housing have some head room left .

Everything has its limits , but not yet for the exhaust housing .

External waste is no different to stock waste gate , it just regulate the exhaust gas velocity ,0 you only need to enlarge the hole , so u don't get over boosting at high Rpm .



Any way I love to see bnrs larger compressor cover.

THE DOCTOR

New improved hitachi high pressure chra , special order too.

Hitachi Japan quality .

THE DOCTOR

The high torque figures of 479foot/ pound from my dyno run is proof that the
Bathurst sp hitachi twins flow far superior than any other hybrid twin.

The reason is clear 16psi less backpressure from engine to turbo .

High torque means more exhaust flow which makes for high rotor chamber pressure .

Bnr uses standard oem covers and the outlet temps are very high .
I can see why they required water injection .

It's the same as running high fuel pressure to get move fuel flow from your injectors .

These power and torque figures were achieved with Australia bp 98ron fuel with a lower mon rating of 87 .

BLUE TII

iTrader: (9)

As for bnr having big compressor ,I've only seen std covers which he
Cncs his name bnr on where the oem part number was.

i believe you are correct there. I looked at recent pics on his FB (since his site is down) and they still appear to be the CNC machined stock covers. Earlier when his site was up I saw the molds for compressor covers and the custom cast compressor covers, but they must have been on his other applications.


As for your theory of two turbines directed at eachother beening a restriction .

Wrong again , If that was the case then how did I achieve 16psi pressure drop been engine and turbine housing .

Answer for u again is it was the large turbine wheels , all my upgrades are designed by hitachi engineers which pay lots money for , no guessing here like bnr .


Yes, I agree you will have incremental gains with the larger exhaust wheel, but as your HP shows you are at the choke point I am talking about with the stock exhaust housings/arrangement (420-430rwhp range).

The high torque figures of 479foot/ pound from my dyno run is proof that the
Bathurst sp hitachi twins flow far superior than any other hybrid twin.


That would be great if you made that torque, but you obviously didn't. The torque and horsepower numbers from that dyno sheet obviously do not correlate.

HP=TORQUE X RPM / 5252

You made 340ft/lbs torque.

If you made 479ft/lbs torque and "ony" 430rwhp your graph would look very very different. Torque would be crashing like off a cliff after 5,000rpm so torque could be higher than HP.

Here is the dyno of my EFR 7670-
See how bad the torque has to fall off for torque to equal HP? It is much worse if if you are making more torque than HP.

More torque than HP basically means the motor stopped making power at 5,000rpm.

http://www.rx8club.com/attachments/s...fc-rx7-13b.jpg

Narfle

iTrader: (16)

Easy fellas. I think you've both made your point.
I'd have those twins in a heartbeat.

BLUE TII

iTrader: (9)

Narfle Easy fellas. I think you've both made your point.
I'd have those twins in a heartbeat.

I don't think I am out of line on calling him out.

He is implying he has 3.1:1 rear end ratio, a 2ndary turbo transition at 3,700rpm and reved to only 6,000rpm while making 430hp @ 5,600rpm.

Because that is the only way he made 479ft/lbs torque and 430hp on that dyno plot.

edit- actually that doesn't even work because the ratio is wrong for peak hp of 430 at 5,600rpm then.

The dyno torque and hp really don't correlate on that dyno graph no matter what gearing.

cib24

First,
Great numbers but I have never seen a rotary dyno with higher torque than horsepower so I would agree with Blue TII's interpretation.

Second,
Putting the torque figures to one side, the power figures are fantastic for a set of hybrid twins with Hitachi quality. Shame they cost so damn much to buy.

Third,
Dynojet's used in the States are the most optimistic dyno's in existence. A Dyno Dynamics dyno common in Australia, UK and most of Europe reads about 15-20% lower than a Dyno Jet and correlates a lot more closely to manufacturer claims when dynoing a stock car (regardless of manufacturer). Therefore, doing some crude math to correct as if this car was dyno'd in America it would be reading over 500 hp which leads me to think the car in question is a world record holder for twins.

billyboy

The compressor covers of the BNRs have changed over the years - dimensions definitely aren't the same now as they were. Didn't seem to be the same machining marks required for chucking on the newer ones, so wouldn't be surprised they're cast....of course Bryan would be the one to know!

Someone forgot their passwords on multiple sites, hmm?

THE DOCTOR

It's not unusual to have the torque higher the Hp , here are some figures
That have torque higher than Hp.

The car has 3.9 diff so I hope this help you with your rpm calculations

But I Rev it to 8500rpm on dyno , I know this cause I tuned it using Apexi .

Anyway I amazed how much torque it made too, but all I know is the car pulls very strong
From 2800 to 8500.

I've been in high Hp cars and this feel lot strong , I know now I would rather have high torque car than high Hp on the street .

Nine Cars With More Torque Than Horsepower - Road & Track

BLUE TII

iTrader: (9)

Its great power from stock bolt on sequential twins.

What I have issue with is someone selling a very expensive product and misrepresenting it.

Big difference between the 358ft/lbs torque that he actually made (knowing it is 3.9:1 diff instead of 4.1:1 raises it from 340ft/lbs) and the 479ft/lbs he is saying he made.

There is no disputing the 358ft/lbs from that dyno.
Peak torque is shown at 180kmph.
It is making 300kw power there which is 402hp.
180kmph on 25" diameter tire in 4th gear with 3.9:1 rear is 5,900rpm.

402hp=(358 x 5,900rpm)/5252

HP=TORQUE X RPM / 5252

That is awesome power on stock twins.

That is not 479ft/lbs and 430hp. That graph would look VERY different. Torque would be **** after 5,000rpm.

--------------
Note I posted Balljoints 475rwhp parallel stock hybrid twins dyno that made 400ftlbs torque.

I posted another members completely stock twins that made 411rwhp and 375ft/lbs torque (torque was not shown on the graph, but calculate for 5,250rpm to see 375ft/lbs).
--------------

It's not unusual to have the torque higher the Hp , here are some figures
That have torque higher than Hp.


Yes, there is no problem with making more torque than hp on a rotary or other engine.

BUT when you do it will because your torque dropped hard after 5,000rpm!

Your dyno clearly shows peak torque happens at 5,900rpm.

The car has 3.9 diff so I hope this help you with your rpm calculations

Yes, thank you.


But I Rev it to 8500rpm on dyno , I know this cause I tuned it using Apexi .

Anyway I amazed how much torque it made too, but all I know is the car pulls very strong
From 2800 to 8500.

I've been in high Hp cars and this feel lot strong , I know now I would rather have high torque car than high Hp on the street .

high torque to hp has its advantages and disadvantages.

My EFR 7670 FC (dyno I linked) that made 420ft/lbs torque 420rwhp Dynojet had great low end and midrange power which was perfect for the "racing" in the parking lot/kart track/hillclimb I do.

But, it felt like a V8 on the top end with no torque since it dropped so hard after 5,000rpm. No difference in pull for the next gear shifting at 8,000rpm or 6,500rpm.

It made the same torque at the wheels at 100mph in 3rd, 4th or 5th gear!

I prefer the sequential powerband like you have where torque not only doesn't fall off a cliff at 5,000rpm, but actually increases. Makes the rotary pull awesome on the top end.

This is why I want to keep my FD sequential.

BLUE TII

iTrader: (9)

But I Rev it to 8500rpm on dyno , I know this cause I tuned it using Apexi .

If you have 3.9:1 rear the motor was only revved to 7,350rpm on that pull.

That is why I assumed 4.1:1 rear and revving to 7,800rpm and then 340ft/lbs torque.

If you revved closer to 8,500rpm (like 8,200rpm) then you have 4.3:1 rear end and then 325ft/lbs torque.

THE DOCTOR

The car will be going to many more dynos , I will be demonstrating to a number of big rotary shop here in Australia , next one is rotor master on his hub dyno.

I see what you mean now with your calculations .

But at the end of the day the car reved to 8500 rpm and the peak torque was is around 6500rpm .

I can road test what kms my car would be at 8500, I'll use a speed app on my phone to be accurate.

I'll take car to 2150rpm in 4gear and times it by 4 ,then you can re plot kms on my dyno sheet .

As another reference my injectors are running at 80percent , and my total injector flow at 42psi is 4800cc.

So Im consuming a rate of 3800cc which equals 585 Hp give or take a bit .

585hp x (0.8 losses through gear box 20%)= 468hp.

Sorry for bad gramma .

cib24

Cool news but dude. English man and better sentence structure please.

BLUE TII

iTrader: (9)

THE DOCTOR
The car will be going to many more dynos , I will be demonstrating to a number of big rotary shop here in Australia , next one is rotor master on his hub dyno.

See if you can get it on a Dynojet. I know not as common there as here, but its what everyone here is used to comparing number wise.

You will most likely make even more hp on the Dynojet as they have the most inflated hp numbers. They do load the turbo nicely with the inertia drum so it will get you good primary turbo boost/torque numbers as well.

Dynojet will be really good advertising for these twins.

7krayziboi

iTrader: (15)

Omg....

cib24

That will be difficult because Dynojets just dont exist outside of the US and Canada. The Dyno Dynamics is the most common everywhere else and to help US guys compare just add 15-20%. Think of it like the Mustang Dyno as the realism (or pessimism to Americans used to inflated dyno numbers) is similar.

BLUE TII

iTrader: (9)

Yeah, my friend 5 houses down has a Dyno Dynamics in his garage where we tune our cars (yes, tuning open dump external wastegate rotaries in residential).

DD is definitely the superior tuning tool, but its a pain to program it to get it to spool the turbo correctly in sweeps (load it as it does on the street). And as you say his reads 16% lower peak numbers than Dynojet consistently.

You can put it in 2R shoot-out mode or "comparison" mode and get Dynojet like peak numbers, except the low rpm is still weak since it doesn't spool a turbo with enough load.

My EFR 7670 did 369rwhp/350ftlbs on the DD.
Parked it drove to Dynojet next weekend and pulled off 419rwhp/419ftlbs.

BLUE TII

iTrader: (9)

Do they have DynaPack?

My car read exactly the same peak numbers on DynoJet and DynaPack, but again DynaPack did not load enough in low rpms to spool the turbo like on street or DynoJet.