I'm also looking at a top end rebuild in the near future and I plan to stick with 3.6 but with just an extra twist. I don't know much about our engines but isn't there a "base" package from 9M that brings you close to 300hp without dipping into your kids college funds. Geoffrey, am I right??

 

Ritter (CWay),

I did no go 3.8L. Steve Weiner and Jeff Gamroth did the complete re-build keeping the 3.6 displacement. It's "blueprinted", new P&C set, RS cams, various small upgrades and ECU re-mapping. We also changed over to the plastic intake setup, and went with a cat-bypass and cup pipe. Engine pulled 291bhp and mid-260's torque on their engine dyno, and is built for longevity (mine is still primarily a street car).

I think the most "quantifiable" aspect to the re-gearing work , for me anyway (and which Bill hinted at), is the changed character of the car (shift points, frequency of shifts, etc.). The car has an RS flywheel and clutch assembly, and now there is an almost linear character to how the car pulls and accelerates from 1st gear, all the way through 5th and into triple digit speeds. Granted, I've lost some top end, but it just seems to Go, Go, Go!

Feel free to PM me if you have any specific questions.

Take care,

Dave

 

Thanks for the info but what are those "small upgrades" besides ECU?? Was the chip an "RS" one??

 

Sounds like unless you NEED a total rebuild, when you might as well put in bigger pistons etc.(but possibly not), the 3.8 convert is high cost/low return IF your 3.6 is otherwise in good shape- like mine is. The money would be better spent on race tires etc. and towards a GT3!

Thanks- this is why I'm here- to pick your collective brains and offer what little I can in return.

 

964 RS cams = same as stock

 

He was probably talking about 993 RS camshafts.

The 964 RS cams are not the same as regular 964 cams, they don't have the power steering drive on the 4-5-6 camshaft.

 

CWay: By "small upgrades" I was referring to items such as RS motor mounts, Cup airbox, etc., as well as the replacement of a host of hoses, fittings, etc. simply due to age and wear - nothing too extraordinary, I'm afraid. The ECU mapping is Steve's proprietary work. I know he worked at it a bit, so it's not a stock RS or Cup mapping.

Colin: I am not aware of the specifics of duration, lift, etc. I know WebCam was involved in the process (as opposed to our having purchased OE items). I am still running the power steering rack, FWIW.

Take care,

Dave

 

I was talking in terms of performance specs!

 

Thanks for clarifying Dave.

And since I have the manual rack, would there be any advantages in going with euro RS cams??

 

I just did my 993 cup car, bumped it to 3.8 RSR... New P&Cs and a little head work.... $20K... included some other minor things...

I would do the gear box first. I swore my 964RS was a 3.8.. The gear box and a little less weight is the ticket. The 3.8 RS motor in my hotrod is a torque monster... The most fun to slam the peddal of any thing I have...Almost as fast as the 997 GT3... Rolling at 40 mph dead even...

If you have the $$ do the gear box and the 3.8... you will have a weapon that will not be stopped. You will never regret it. You will own the best of the aircooled cars, with the best power an aircooled engine can reliably give... Go for it.

Good luck.

 

CWay -

Colin or Geoffrey could perhaps chime in on the cam question, as I am, obviously, not the cam-meister. All I can suggest is to take a moment to seriously consider how you are using the car. For example, although some would certainly love it, I don't know that putting a highly aggressive cam in a daily driver makes long-term sense.

Just my $.02...

Take care,

Dave

 

Andial did my 3.8 conversion & I love the way my car drives (runs). I also thought it was noticeable, but I as of yet have not Dyno it for the "real numbers", only because I haven't found a AWD Dyno. But I think it was well worth it ($) for what it's worth!
Happy New Year!

 

Geoffrey:

Thankfully, Mahle has addressed these issues with a revised 3.8 RSR set (109mm) that has the correct offsets on ALL 6 pistons and the proper valve reliefs for most cams. Even though the Mahle pistons are heavy (compared to the equivalent JE, Omega, CP, Pankl, or Wussner) they last FAR longer than any 2618 piston and run quieter as well. Both configurations of 3.8 RSR P/C's are still out there so one must be careful about where you buy them and what you get.

FWIW, I don't recommend the thin-wall (107mm) versions any longer due to cylinder distortion over time and resulting higher than average leakdown figures. Its worth the effort to spend a few extra $$ to machine the case and install the thick-wall (109mm) versions that are far more durable.



Like anything else, its all about what one's priorities are,...

 

Hi Steve, Yes, thankfully Jeff Gamroth was able to design a revised Mahle piston for general consumption, but it is still a very heavy piston (+500grams) in comparison to a proper race piston (-400grams). Mahle does not have a blank they can produce a lightweight racing piston from. But they have fixed the other issues.

The issue of longevity is THE reason that I went with stock Mahle P&C in my racing engine. However, I think that some of the newer cylinder technology and piston designs from some of the manufacturers allow for tighter clearances than in the past and with the different construction will accept a 2618 piston with reasonable longevity. But I agree, running JE pistons in a Mahle cylinder is not necessarily a wise thing to do if you care about noise and longevity (and piston cracking in the older blanks).

 

I looked into the 3.8 option when I recently rebuilt my 3.6 engine, but my mechanic talked me out of it based on the bang for the buck ratio. My rebuild was approx $16K without doing a 3.8. To go to 3.8 would have added a minimum of $5K to that and would have become a very slippery slope of money. I'm told that its not just a matter of buying P&C's. There is more that is needed to take advantage of the 3.8, which leads to more money being spent...

I especially would not do it if I already had a strong top/bottom end. Why waste money tearing into a solid engine? In my case, my engine needed a rebuild anyway, but I still couldn't justify a 3.8 in my mind.