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-   -   PFC Tuning for lower Octane. (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/pfc-tuning-lower-octane-535945/)

chopstix 05-02-06 04:00 AM

PFC Tuning for lower Octane.
 
Im currently in Tokyo but will be shipping my car back to Australia in a few months where 98 RON Octane is the highest rating you can buy. Most/All tuners in Japan tune for 100 RON.

Does this mean the tune should be less aggressive? ie richer maps/retarded timing etc.

Mods will be;

CatBack
Metalit High Flow Cat
Down Pipe
13 psi boost/stock sequential turbos
SBC boost controller
Trust SMIC
Amemiya Intake

DaiOni 05-02-06 05:28 AM

I don't think they will tune your car for 13psi with that setup.

willjs7 05-02-06 06:48 AM

ur gonna need more like 10-11 psi , u wont have the fuel for 13.

DaiOni 05-02-06 07:15 AM

it should be doable on .8bar - get them to set a low boost tune as well

chopstix 05-02-06 07:20 AM

ok...0.8 bar it is then.

Thanks for the feedback.

rynberg 05-02-06 10:29 AM

What the hell are you guys talking about? He's got the mods to support 13 psi!

To answer the original question, yes, if the Japanese tuners actually tuned for 100 without a good safety margin, then yes, you will want to run slightly richer AFRs and retard the timing a degree or two.

DaleClark 05-02-06 12:42 PM

Also, octane is tested differently - this was a big one when the PFC first came to the US. Their octane rating system is different than ours, and may be different than Australia's. I'd ask some Aussies about it - importing hi-po Japanese cars is so commonplace, I'm sure you could find a good answer.

Dale

DaiOni 05-02-06 09:00 PM


Originally Posted by rynberg
What the hell are you guys talking about? He's got the mods to support 13 psi!

why would you tune for 13psi when you can get the same results at 11.6psi? As a rule, they're not going to push the 320rwps mark.

rynberg 05-03-06 02:35 AM

Huh? You are going to make more power at 13 than 11.6 psi! I don't know where you're coming from here?


Originally Posted by DaiOni
why would you tune for 13psi when you can get the same results at 11.6psi? As a rule, they're not going to push the 320rwps mark.


DaiOni 05-03-06 05:29 AM

like I said - they will be shooting for 320rwps. With his mods they should do it with 11.6psi

DaiOni 05-03-06 05:51 AM

...they won't go over 320rwps or thereabouts with the factory fuel pump.

rynberg 05-03-06 11:00 AM


Originally Posted by DaiOni
like I said - they will be shooting for 320rwps. With his mods they should do it with 11.6psi

You are not going to hit 320 with a hi-flow cat and stock motor/turbos at less than 12 psi.

xblazinlv 05-03-06 01:20 PM

Wow some people in this thread said some really stupid things.

You can easily run 13 PSI on 98 octane, but if they did tune the car for 100 octane you will need to take out a bit of timing.

airborne 05-03-06 01:25 PM

Yeah I was running 14.5psi on 94 octane and am now down to 93 octane with no ill effects on a steve kan tune. stupid sunoco.

SiKoPaThX 05-03-06 02:02 PM

98 RON is not the same as 98 octane here guys.

xblazinlv 05-03-06 02:08 PM

98 RON is a high-octane unleaded fuel that maximizes engine power and performance, as well as producing less pollution.

BP is currently the only reseller of 98 RON petrol in WA and markets the product under the BP Ultimate brand name.

98 RON is promoted as providing excellent fuel economy, has a sulphur content which is 10 times lower than the national standard for unleaded fuels, and has low levels of benzene, sulphur and lower aromatics.
98 RON is used by some imported and high performance vehicles
http://www.fuelwatch.wa.gov.au/info/dsp_fuel_types.cfm



Still higher than US 91 octane gas, which the west coast guys are stuck with, and I'm sure plenty of them run 13 PSI on pump gas. He should have no problem pulling timing and re-tuning for 13 psi on 98 RON.

Gadd 05-03-06 03:47 PM

FYI on octane. There are two basic ways gas is tested for octane, research octane RON or motor octane MON. Europe, Japan, Australia use RON which can be 10 points higher than MON for the same gas. The US uses an average of the two. But sence your going from Japan to Australia, you'll be working with the same numbers.

DaiOni 05-03-06 08:15 PM


Originally Posted by rynberg
You are not going to hit 320 with a hi-flow cat and stock motor/turbos at less than 12 psi.

rubbish, I made 321ps on .8bar.

DaiOni 05-03-06 08:20 PM

...that's with a restrictive kakimoto exhaust, HKS dp, SMB metal substrate cat, trust fmic, apexi intakes, upgraded plugs, stillway pulley kit, PFC, *japanese high octane fuel*, stillway tuning @ .8bar.

rynberg 05-03-06 08:28 PM


Originally Posted by DaiOni
rubbish, I made 321ps on .8bar.

Not legitimately you didn't (unless your car is an absolute freak like Boostn7's was). Was the 0.8 bar measured on the PFC or a separate boost gauge?

Most people are lucky to get 320 with 13-14 psi with a midpipe. Your slightly better fuel nets you some hp, but you ain't making 320 at <12 psi on a stock motor with a cat, hi-flow or not.

neit_jnf 05-03-06 08:32 PM

I made 315 with stock cat at .86bar

DaiOni 05-03-06 09:01 PM

perhaps a dyno discrepancy.

DaiOni 05-03-06 09:04 PM

and fwiw, reads .8bar on my defi boost gauge, and on my profec b, and thereabouts on the PFC.

chopstix 05-05-06 05:49 AM

Thanks for your input guys. I will ask the tuner about it next week.

Ill keep u posted.


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