zbomb

Yes, definitely odd. Check the dyno thread.

PM me you zip and I’ll let you know if I k ow of any good dyno shops in your area. NJ/NY has a bunch.

Based on what’s been posted, this is what the FSI 4.0’s make, actually it’s among the highest that’s been posted. The exception being the one that the LN guy with the many, many words posted. We have never seen an owner post one even close so take that FWIW.

GC996

Fwiw, here are the various FSI rebuild options.

https://flat6innovations.com/

In addition to bore size, it seems to be headwork, cam, induction, exhaust and software as the incremental inprovements in performance by engine rebuild type.

If i was to take a WAG on breakdown of performance from conversations with industry professionals, here are back of the envelope estimates. But I have not yet done a rebuild and dyno to confirm.

1. Headers, cats, plenum, tb and software ~15-25
2. 4.0 to 4.3 = ~30-50
3. Heads = ~ 20-30
4. ​​​​​​Cam = ~20

There is your estimated 100 hp gain. If the rebuild was Stage 1 is for the street, by default it leaves quite a few performance enhancements on the table which may not matter to the 996 owner. No need to pay for 100 hp and all the extra work needed and cost if you dont want or need it. Obviously personal preferences come into play.

Haven't looked at the Hartech program yet, but it would follow a similar logic.

No magic exists with the 3.4 or 3.6 M96. You gotta figure 100 hp gain max with the full monty listed above. Maybe someone figures out how to get a bit more out of the M96. Sure, if you want more than that then you gotta get a Turbo or do an LS swap or Honda swap. Comes down to personal preferences.

50 extra hp in my 996 on the track would be fantastic. 100 hp extra would be utopia. Doubt I will need any more than that.

zbomb

No need to rely on back of envelope estimates. Power numbers are here for an array of options from stock to bolt on to rebuilds and swaps.

Actual results from users, videos and for sale threads that have been shared, it’s a beautiful thing.

Happy reading 👍

https://rennlist.com/forums/996-foru...s-allowed.html

GarrettSR5

lol

sdematt

I'm surprised the torque curve looks like oceans waves instead of a single sand dune...

bdronsick

M96 is pretty darn durable as-is. I've had several, some well over 100K trouble free miles. I never did buy the doom-gloom "hype"

wdb

There are a few ways of looking at it though.

First of all, the M96/7 is far from the only engine in this class of car to have the sword of Damocles hung over it by the commentating mob. BMW S54, S65 spring to my mind but there are others. I had an S54 engine from miles 78K through 97K, during which time it should have shredded the rod bearings and sheared off the VANOS bolts, destroying both top and bottom ends, according to the doomsayers. I just took it easy warming up and never shied away from the 8K redline. So the M96 is scary, sure. So are a bunch of other engines in this class of car. If that kind of thing keeps you up at night, buy a Honda S2000 (although I hear stories of valve guides...) or an Acura NSX.

Another way of looking at it, which is what did with the targa, is that it's a 20+ year old car that: a) has 100K miles; b) has never been apart; and c) has known weak points. I don't think it's doom/gloom to be willing to pay for peace of mind in a car with those bones, that I intend to drive a whole lot before I pass on in my will.

bdronsick

Yes definitely other experiences out there. Some guys bought 996/997 (even DFI) at low miles and had catastrophic failures

Heck even post-Mezger 991 GT’s dropped like flies for several model years!

(early 991 GT DFI still riskier than M96/97 IMHO)

Like everything I guess YMMV

SRMPDX

Yeah the torque line is weird maybe something weird with the dyno? Since HP is just a calculation of torque and RPM both lines should be similarly wavey, but the HP line is much smoother

Compared to my pretty much stock, tuned 3.4L dyno chart mine is a much smoother tq curve, but my peak torque right around 5000 RPM is less than this 4.0 has at ~2800. My peak is about 252 lb-ft vs the 4.0s 285. That would make a very real difference in performance.

zbomb

Could you post the graph and your mods in this thread ?

https://rennlist.com/forums/996-foru...s-allowed.html

sdematt

@SRMPDX Who did your tune?

wdb

Not that prices are drifting up that much lately, but this does still seem to be the place to discuss interesting cars for sale. Here's an LN-engined cab on Cars & Bids, sounds tastily modified:

https://carsandbids.com/auctions/Kdz...rera-cabriolet

wdb

No sale at $29.6K. I wonder how they got a reserve that high.

wdb

What's up with this car? Seems like a great spec but the last two owners both kept it for a year then put it up for sale.

https://bringatrailer.com/listing/20...upe-6-speed-2/

gbarron

Hmmm...I wonder if this is a game of "hot potato" due to bore scoring issues? LH exhaust tip looks to be well scrubbed for pictures.