Porsche 964 power output

[Markh]

Just trying to find out some rough figures for power outputs for standard and tuned 964's (allowing for rolling road discrepancies) what is a good figure



Many thanks

[Jay964rs]

My old 1990 964 C2 made 298bhp after a rebuild and chip wizards map.
Good solid power.

[McSwerve II]

My old C4 with 160k on the clock made 260 bhp with sports exhaust.
I loved it.

http://www.pistonheads.com/gassing/topic.asp?t=259...

[BillyB]

Standard is 250bhp. As above, not unheard of them to produce a good bit more (up to 290 ish) with a free-flowing exhaust and a remap.

[charge]

My mate had a Motec 964 ( which was standard, but with the restrictive inlet removed) and saw 315 on the dyno
Are you interested in turbo power also?

[Slippydiff]

The standard injectors won't flow enough fuel for more than 290-300hp (and at those Hp figures they're maxed out on their duty cycle)

Anyone claiming more than 290hp from nothing more than a remap and decat needs to taking a closer look at the rolling road they're using . . . . . There's one company whose RR is optimistic to the tune of 12-14hp. Remove those "phantom horses" and you end up with more realistic outputs for a mapped/de-catted 964 engine.

[charge]

As pointed out, the car was converted Motec management, which included the removal of the restrictive inlet metering unit, and run on other parameters for metering fuel including the lambda and knock control. The injectors could very well have been replaced for all I know. The point was the potential with a less restrictive inlet on an otherwise standard engine. I am sure with a proper exhaust and ITB's there was more to be had. I think the 3.8 rsr engine as built by CTR dev. In the 993 Richard has a hand in racing is knocking on the door of 400 bhp! This is what can be achieved with a N/A 964 lump if you have a BIG pot of money and a st hot builder. And the understanding it probably will not last more than 30-40,000 miles between re-builds at best if used hard!

[paul284pt]

charge said:

My mate had a Motec 964 ( which was standard, but with the restrictive inlet removed) and saw 315 on the dyno
Are you interested in turbo power also?

Hi,

I think you mean a Motec M84 which definitely isn't standard. The 964 came with a Motronic. The Motec is favoured when upgrading the power or rebuilding as there's so many more options over the limited Motronic unit.

As stated previously, standard power is 250bhp. With de-cat, secondary muffler delete, chips etc. it's possible to get it up a little, 270 - 290bhp if you add in a lightweight RS flywheel and clutch. The low-down power delivery is much improved.

However with a 3.8 build, Motec M84, ITB's, light-weight steel connecting rods, RSR cams etc. a possible 350 - 370bhp is available. To go much more than this you're really talking about a higher revving race engine, possibly a 4 litre.

Cheers,
Paul

[johnycarrera]

paul284pt said:

With de-cat, secondary muffler delete, chips etc. it's possible to get it up a little, 270 - 290bhp if you add in a lightweight RS flywheel and clutch.
Paul

First I've heard a clutch and flywheel adding power!

[paul284pt]

The lightweight flywheel and clutch helps the engine by reducing the spinning mass making the engine more responsive and helping to deliver the power. A C2 loses about 30bhp between the flywheel and the rear wheels, the C4 loses approx. 100bhp in transmission. It's at the rear wheels where you want the power, an RS lightweight flywheel and clutch is a major upgrade and one that will put a smile on your face.

Cheers,
Paul

[johnycarrera]

Cool, didn't mean to be cheeky, semantics I guess, I have the GT2 version, doesn't add any power whatsoever but agree its a worthwhile upgrade

[ras62]

[quote=paul284pt]

Hi,

I think you mean a Motec M84 which definitely isn't standard. The 964 came with a Motronic. The Motec is favoured when upgrading the power or rebuilding as there's so many more options over the limited Motronic unit.

There is nothing limited about the Motronic DME. What is limited are the number of people able to alter the code, btw Motec is always fitted with uprated injectors which as Slippy has already pointed out are a handicap when chasing over 300bhp..

[charge]

ras62]aul284pt said:

Hi,

I think you mean a Motec M84 which definitely isn't standard. The 964 came with a Motronic. The Motec is favoured when upgrading the power or rebuilding as there's so many more options over the limited Motronic unit.

There is nothing limited about the Motronic DME. What is limited are the number of people able to alter the code, btw Motec is always fitted with uprated injectors which as Slippy has already pointed out are a handicap when chasing over 300bhp..

I have pointed out the var was converted to motec? Cant get my head round anyone not understanding that statement?
And as for a limiting factor on the Motronic, have you considered the 2x1.5 inch hole ( approximate, before any clever alec give sizes to the mm) the inlet air is sucked through, known as the air flow metre?

[ras62]

Charge, I was replying to Paul284 comment on the Motronic not about you mates car...btw the restrictive air flow meter is actually not really that restrictive at all.

[Ian_UK1]

johnycarrera said:

First I've heard a clutch and flywheel adding power!

So it may please you to discover that they do! Not at steady-state (i.e. constant rpm) but when the engine is accelerating. All the energy (or power, depending on what you're measuring) that is normally spent spinning-up a hugely heavy flywheel from idle speed to max rpm (and it's a lot) is, instead, sent to the wheels to accelerate the car. This results in measurably better acceleration in 1st and sometimes 2nd gear - the effect reducing with each higher gear.

Reducing the flywheel's rotational inertia (which does NOT necessarily mean a reduction in the flywheel's weight, the same effect an be gained by moving it's mass towards the centre of rotation - think of an ice skater pulling-in her arms and rotating a lot faster) gives very similar results to lightening the car - it's just achieving the same effect by different means.

There's an excellent write-up here, in Pistonheads' very own technical forum:

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Ian

ETA: IIRC, the main difference in performance between the 997.1 GT3 and GT3 RS was gained from the low-inertia flywheel fitted to the RS.

Edited by Ian_UK1 on Monday 28th October 08:58

[melv]

My old '89 C4 was 258, then 292 with Geoff Everett AMD remap, rechip and bigger air intake....

[johnycarrera]

It certainly does please me that a light flywheel makes an engine produce more power, I genuinely didn't think it had anything to do with the output of the "engine", happy to be corrected

[Markh]

Thank you all so much for your contributions, just wanted to get a good bench mark, picking mine up tomorrow after MoTec/varioRam conversion

[thegoose]

johnycarrera said:

It certainly does please me that a light flywheel makes an engine produce more power, I genuinely didn't think it had anything to do with the output of the "engine", happy to be corrected

It doesn't add power, but Ian's description of how it can improve performance is correct.

As I understand it the power output of an engine is the same even with no flywheel attached (as in a dyno bench test), what's important is using as much of this as possible (reliably) to accelerate the car along the road as quickly as possible (or not, if you'd prefer additional smoothness from a DMF).

[BillyB]

Markh said:

Thank you all so much for your contributions, just wanted to get a good bench mark, picking mine up tomorrow after MoTec/varioRam conversion

That sounds like an interesting project!