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-   -   300rwkw/18psi,bathurst sp ht12 twins on pump98 (https://www.rx7club.com/new-member-rx-7-technical-256/300rwkw-18psi-bathurst-sp-ht12-twins-pump98-936875/)

THE DOCTOR 01-04-11 01:36 AM

300rwkw/18psi,bathurst sp ht12 twins on pump98
 
hi guys

its taken me 1 year to complete my project , manufacturing the Bathurst sp covers
and larger sp compressor wheel onto brand new set of Hitachi twins.

back in 1995 Mazda Australia released a rx7 Bathurst sp these cars went on to win the 12hour endurance production race in 1996.

there where 38 street cars released they had the standard ht10 on them.

but the race cars had a special set of twin turbo s put together by Hitachi engineers which had larger a/r compressor covers and larger compressor wheels and the exhaust housing and turbine wheel were the same.

because of the larger a/r cover and comp wheel these allowed for more flow at higher rpm allowing the stock engine to rpm to 8000rpm instead of 7000rpm from standard comp covers.

i have had the cover manufactured to same specs as the original one with some added improvements.

and had adaptors made so they can fit to a new set of ht12 and i made factory fit high cracking presuure actuators so i could run factory boost control to 18 psi.

factory actuators cracking pressure were too low which were only good for 15 psi.

i had tested them on the same dyno back to back on the the same car with pump 98 octane fuel.

standard twins max on 15psi/7000rpm made 238rwkw(65 degrees f)

Bathurst sp ht12 on 15psi 7800rpm made 258rwkw (room temps degrees 84 f)

when i ran the Bathurst sp ht12 on 18psi they really came alive and it made
297rwkw /7800 (room temp were 92 degrees f )

mar3 01-06-11 03:55 PM

Hmmm....the pics didn't survive the deletion from the Introduce Yourself board. You're going to have to put 'em in one more time, it appears.

:cool:

dgeesaman 01-06-11 04:59 PM

I remember someone sold a set of brand new "bathurst" twin turbos here a few years ago. They were really interesting.

David

THE DOCTOR 01-07-11 12:20 AM

6 Attachment(s)

Originally Posted by THE DOCTOR (Post 10397041)
hi guys

its taken me 1 year to complete my project , manufacturing the Bathurst sp covers
and larger sp compressor wheel onto brand new set of Hitachi twins.

back in 1995 Mazda Australia released a rx7 Bathurst sp these cars went on to win the 12hour endurance production race in 1996.

there where 38 street cars released they had the standard ht10 on them.

but the race cars had a special set of twin turbo s put together by Hitachi engineers which had larger a/r compressor covers and larger compressor wheels and the exhaust housing and turbine wheel were the same.

because of the larger a/r cover and comp wheel these allowed for more flow at higher rpm allowing the stock engine to rpm to 8000rpm instead of 7000rpm from standard comp covers.

i have had the cover manufactured to same specs as the original one with some added improvements.

and had adaptors made so they can fit to a new set of ht12 and i made factory fit high cracking presuure actuators so i could run factory boost control to 18 psi.

factory actuators cracking pressure were too low which were only good for 15 psi.

i had tested them on the same dyno back to back on the the same car with pump 98 octane fuel.

standard twins max on 15psi/7000rpm made 238rwkw(65 degrees f)

Bathurst sp ht12 on 15psi 7800rpm made 258rwkw (room temps degrees 84 f)

when i ran the Bathurst sp ht12 on 18psi they really came alive and it made
297rwkw /7800 (room temp were 92 degrees f )

and here is some pics of my premium u type inter-cooler kit that i got manufactured.

its comes with 2 piece carbon fibre ducting ,ast stainless steel bracket, silicon hoses and hose clamps.

vrx8 01-07-11 10:30 AM

that looks pretty F*&%ing bad ass, great job

dgeesaman 01-07-11 01:03 PM

If you're using factory boost control, what ECU are you running?

What injectors are you using?

THE DOCTOR 01-07-11 05:47 PM

mod list of my car to achieve the 297rwkw:

apexi pfc ecu
sard 280 l fuel pump
primary injectors 550cc ,secondary injectors 850cc high flowed to 1200cc
autoexe intake
3inch exhaust turbo back.
my premium u type inter-cooler kit that i make.(limited number of sets to be sold)
special type Bathurst sp ht12 Hitachi twins that i make too.(limited number of sets to be sold)
these twins come brand new in the original Hitachi box.
pump mobile/bp 98 ron fuel ,18 psi and i tuned the car myself .

the rest of the engine/car is untouched and stock standard .

dgeesaman 01-07-11 06:49 PM

Nice.

No cooling system upgrades?

THE DOCTOR 01-08-11 03:08 AM

2 Attachment(s)

Originally Posted by dgeesaman (Post 10403350)
Nice.

No cooling system upgrades?

sorry i forgot i have a arc 36mm radiator its no necessary because the spirit r comes
with a 26mm but i put it for piece of mine.

and also i have put a hks la clutch kit .

WannaFD 01-08-11 02:22 PM

Looks like an awesome set-up. Any scans of a dyno graph, would like to see the power delivery

THE DOCTOR 01-15-11 07:03 PM

1 Attachment(s)
go to the drag strip soon

diabolical1 01-15-11 11:40 PM

excellent! that must be quite the little firecracker you've got there. you should be proud of your work.

WannaFD 01-16-11 10:13 AM

Thats some really nice power delivery and vary consistent boost all the way to redline. Must be really fun to drive around

yvonne4248 05-02-12 09:30 PM

What did that set you back. We have a street SP that's been sitting 12y however it had a single turbo installed but I can't tell if the SP had a special suspension or shocks and as its Been sitting. For 12y you might be the expert to suggest modifications and extra checks this model might benefit from. I have see a list of recommended changes a new owner need to make immediately but do they all apply to this model
Best regards. Yvonne. WA

charliev 05-04-12 12:57 PM

very nice!

FD_Nick 05-06-12 12:36 AM

Very nice/unique setup. I like the intercooler setup too.


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