01coccobet

Since I think it is not connected with the X51 spec,I thought to open-up a trd regarding it.

This mysterious engine is keeping me up at night.

I've only few info regarding it…..

It should be a performance kit from motorsport for MY '94 and '95.

Should be something like the 964 RS 3.8 engine,

it is a 3746cc with 220kW/299hp at 6100 rpm,365Nm/269lb ft at 5250 rpm and usual compression ratio of 11,3:1.

It should have manual valve clearance adjustment(like 964 RS),one CAT instead of the std 2 CATs,a special intake plenum(not sure about it).

Now I still don't know how to identify this from stds

It has a sticker on the manifold,but could fall off,no idea of the sticker under the hood,nor the engine number or if it could be upgraded after the purchase of the car.

Anybody here could light the shade?

Here are few pictures

Bill Verburg

George posted the correct info in the other thread for the X51 update to the M64.05 engines, these were built for MY'94(R series) and MY'95(S series)

all street 993 have only 1 cat mounted transversely under the rear bumper, OBD1 cars have a central mixing chamber w/ 1 O sensor, OBD2 cars have a dividing wall between the 2 sides and 4 O sensors

the only 993 w/ mechanical lifters were the 993Cup, 993RSR, 993GT2evo

964 3.8RS used a special aluminum resonance manifold and itb's
964 3.8RS intake and itb's



and will look like this in a street car


like this in a race car

SC2993

According to Adrian Streathers book the 221kw engine was only for Varioram engines from 1996 to 1998, this car does not appear to be Varioram. Non-Varioram would be 210kw (285hp) for model years 1994-1995. Both of these were Porsche TEquipment options and available to all markets as part of an engine modification to 3.8 litres. This engine kit can be fitted to 993's with manual or Tiptronic transmissions. The sticker under the hood would show #573 "210kw retrofit kit for 993 M64/05/06". Do you have the engine serial number for this car?

01coccobet

Bill,I'm not sure that OBD2 Cat are divided in RoW cars(see my pictures),
anyway thank you for the plenum pictures,very interesting.
Are there any pictures of stickers,CAT,or other stuff to figure out how to distinguish?
Was it possible to retrofit?

Bill Verburg

That's because there are no OBD2 RoW cars except the turbos, all n/s RoW street cars are OBD1 w/ the single O sensor and the mixing chamber design cat.

the 2 cat designs are easily distinguished
1 O sensor in the middle OBD1
2 O sensors offset from the middle OBD2

The Cups were also OBD1 but often ran w/ a gutted cat

I have to look up for the RSRs but the GT2 evo used an aftermarket efi solution, no cats on either of these anyway.

01coccobet

I often use an OBD2 reader and sw,
so I thought it was OBD2.

Bill Verburg

Sometime in '95 they switched from the round OBD1 plug to the trapezoidal OBD2 plug, the electronics are still the same 55 pin OBD1 Motronic 2.2 as was previously used

An OBD 2 reader can read some of the OBD1 info

01coccobet

I will count my DME pins.