964 turbo fuel / knock sensor questions
 

I am considering purchasing a 94 3.6 turbo which is on the market here in Thailand.

Its a magnificent example of the car with less than 15k miles on the clock and conditiion to match.

One of the things that has given me pause is that here in thailand it is now impossible to purchase 95 octane fuel with no alcohol content. I can get Shell V power 95 gasohol everywhere and 91 (non gasohol ) to which I could add a booster but good old fashioned 95 is a thing of the past.(

Are any of you running 95 gasohol in these cars and if so have you had any problems related to that? I dont mind changing fuel lines to more modern ones etc but I would rather not have to mess with really involved modifications.

On a related topic I downloaded Adrian Streathers excellent guide to the engine and related systems and noticed on p2 it says

"Note: Both the M30/69 and M64/50 turbocharged engines are designed to operate on 95 RON/ 85 MON fuels. However Porsche recommend that 98 RON fuel is used. The turbocharged engines are not fitted with knock regulation protection."

When I checked on Pelican parts there is indeed a knock sensor sold for the car so could someone please clarify. It makes no sense to me that a high performance engine of this quality would not have a knock sensor since it was certainly used in the 964 base models.

Advice from anyone with experience in this subject greatly appreciated.

Dennis

how about a custom chip from 911chips.com ?

there is a dip switch on the ECU to switch from a higher octane to a lower
it lowers boosted advance
at least on my 1991 there is one I assume there is one on the 1994

no knock sensor on my 1991 c2 turbo either

so from the 1991 Service Information Technik manual :

if you need to run the car on fuel with an octane rating below 95 RON
the ignition may be retarded by 2.3 degrees from a certain engine load
via a 2-pin code plug using jumper 944.612.525.01

Thanks to all for your quick responses.

If I purchase the car I will definitely consider the custom chip option and as a quick fix would try the boost retard jumper.

Can I assume that none of you would recommend putting gasohol in your cars?

Thanks
Dennis

Here in Texas we have 93 octane with up to 10% corn alcohol
No problems in my 91 964 c2 turbo

The car will run very well on Shell V-Power 95 octane with alcohol. Don't use any over the counter additives except for an occasional bottle of Techroline or Seafoam to clear out deposits, rust, and varnish from the fuel system.

Have fun,
Mark

The 965 doesn't have a "chip" or "ecu" (unless one's counting the Turbo Control Unit as an ecu). It's K-Lambda CIS and an electronic ignition module. It never came from the factory with a knock sensor either. It's a primitive engine management system, give what was available at the time.
The octane jumper is on the EZ 69 ignition module.

The Turbo 3.6 does not have a chip and the factory "octane jumper" does go on the EZ 69 ignition module.
I have the 944.612.525.01 jumper if anyone is interested.
Mike

Mike,

Has anyone tried this jumper with 91 ron fuel? Would be really interested to know how well it works

Thanks
Dennis

I tried the jumper and I could not tell any difference on the road. The dyno may tell a different story.

Mark

Dennis,
I never tried the jumper, mostly because I was able to get good fuel.
The jumper retards the ignition timing. With the significant power level increase occuring with increased boost, I think it would be difficult to feel the timing difference by seat of the pants.
Mike

I too live in Texas and all our fuel has at least 10% alchohol and I haven't ever had a problem. You should not have to retard with the 95 octane available to you. I've got a 91 Turbo now but with my previous 81 930 I did have occasional detonation problems on full boost. Since the engines are supposedly almost the same they must have done something to avoid detonation on the later cars as I've never heard it on my 91. ??

( -_- ) serious?

Guys, if you are having problems on 91. It's simple ( you need to have refinements made. )
Most fuels have up to 10% ethanol, most " modern engines " can withstand up to 15%.
In some parts of Japan they are now only offering 95 grade fuel. None of my clients have problems with Turbo applications in Japan, Taiwan, HK, Malaysia, Shanghai. All of which have tropical climates. Mind you Texas can get pretty darn warm, average summers being 70's a high of 110 F on the average. ( Depends ) As you go more south around like SanAntonoio it get's rather humid. Mind you I am all the way over here in California, I have a decade of testing in 120F+, and a decade of winter testing in Hokkaido Japan.

Anyways, good luck guys -

Ok, I give up. What refinements?