J81 JKR

Not sure where you are located but maybe you could find someone local who has had the 3.8 conversion and go for a drive? I've never been in a 964 other than standard 3.6 2/4 spec but I find it hard to imagine the £££££'s spent make your car significantly better than it was designed to be....

J81 JKR

....I'd rather spend money on a car that was built for speed rather than spend £££££s on performance upgrades for a (let's face it in the current climate) relatively sedate vehicle.

Brideyo

Its not like I need more speed I guess and I have 2 other cars that will always be quicker even if I go down the 3.8 route so maybe it's greed rather than necessity .
Gun to head right now id say leave as is and play with suspension. I'll not be doing many track days other than hopefully with this group and having flogged my other 964 I miss the interaction of this forum so that's the important part.
Cheers all David

dave964diver

We'll all I can say is after my rebuild with a 3.8 the difference is like day and night. It's probably the most expensive route you can take as it requires a bunch of other mods to make it worth the upgrade but I did mine due to necessity, my PC s were shagged.

320bhp and 300lbs of torque in an NA car with virtually instant throttle response is very different from stock.

ras62

320bhp and 300lbs of torque in an NA car with virtually instant throttle response is very different from stock.[/QUOTE]

Are those numbers the corrected figures at ideal conditions or are they what was measured at the crank and uncorrected. What was the at wheels figure?
I've seen very similar numbers on a freshly rebuilt 3.6RS just done by Wayne.

Captain Ahab Jr.

why not buy a motor bike, for the $$$'s you won't go faster

Bill Verburg

If you have the financial where withall go for it, the difference is nigh and day
here is rear wheel torque for 2 993s, same dyno, same cams, same valves, the 3.8 is a vram and the 3.6 is not


BTW 964 RS and Cup cams are the same as what is in a base 964, the 993RS cams are only slightly happier than the 993 or 964 base cams, you need to change the entire induction and engine management to use really happy cams, the SS cams are about as happy as you can use w/ stock intake and engine management

An alternative to 102mm p/c is to install a g50/21 or any of the g50/3x trans if you can find one, the results will be equally startling even a g50/20 will be somewhat better than stock 964 gearing

STUARTQ

So, Bill, I have a std 964 engine with a remap, supposedly pushing out 280bhp.
The engine has never had a rebuild and has done 145k miles, so it will need one sometime soon.
With money being no object, what would be your suggestion in order to get BHP and Torque up. I'm looking for my car to be competitive and pushing out 320 - 350bhp.

race911

Am I glad I have a 3.8 in my yellow car? Sure. Am I even more glad someone else paid for it, meaning I got it basically free? Doubly.

Now, here's the bottom line for me--purdy dyno charts or not. It means approximately 3 MPH trap speed on a ~75-~125 pull up the front straight at Thunderhill on a 2:00 lap v. what my stock class RSA (and that was stock down to still having the catalytic converter installed). Factor in the yellow car is regeared, and the RSA had the, uh, stock 5 speed I think it makes even less difference. (Full disclosure--RSA was on track about 100 lbs. less. But I've compared data, such as it was 10 years ago, with a full tank that brought the weight up to damn near equal to the yellow car.)

Anyway, here's some video where you can see for yourself what this Steve Weiner built ~315HP 3.8 does against a regeared and somewhat modified 997 GT3.

dave964diver

Are those numbers the corrected figures at ideal conditions or are they what was measured at the crank and uncorrected. What was the at wheels figure?
I've seen very similar numbers on a freshly rebuilt 3.6RS just done by Wayne.[/QUOTE]

Well wayne mapped it on Colin's Dyno. Think the torque figure provides the most seat of the pants difference. 300lbs of torque from a 3.6 would be some special tuning IMHO.

The real difference for me is the partial throttle pick up it's just immense. No effort at all so easy to drive quickly.

ALEX P

What an entertaining little video

I do however suspect that if it was you behind the wheel of the 997 then it would have looked slightly different!!

Bill Verburg

Drop it of at 9M for 3.8 - 4.0 treatment and a g50/30trans

J81 JKR

I did

kos11-12

You really want to get out of it 350 bhp, see Frank engine spec,
you may be able to do it in stages....
You can get about 300 bhp out of a 3,6 L , with a proper ECU and remap, but more if you put special cams and other bolt on parts , see KaiB engine & figures, I think his is 330 bhp with standard pistons....

Is the extra 20 bhp worth the money, is it really going to make a difference, or should you spend it on lighten the car...

dave964diver

No doubt but you won't see 300lb torque. But as you say get rid rediculously heavy seats aircon, power steering lwf assembly. Instantly quicker car.
To see real power gains in a 3.6 and this has been covered many times you need to increase the revs which means changing internals as the stock rods can't mange more than 7.2k. To increase the torque over the full spread of revs. Varioram. And to get the best from an after market ecu you need add ons. TPS piggy backed onto the system retro maf. It all costs.

So let's say 10k is your budget this will get you a motec package and possibly the full cost of a rebuild. But no change in internals.

10k will get you 3.8 PC and cams, plus possibly a full rebuild and a map from wayne.

For the motec to be fully utilized you need to change rods. Titanium valve retainers cams and possibly head work. There's another 3k this gets you 350bhp but still down on torque from the the 3.8

For the 3.8 to develop more power. Motec gets you to 350 with a very nice torque spread 5k.

To get to 380bhp on a 3.8 add another 3k for the above for rods valves and retainers.

Show me a 3.6 with big torque and and similar power for the same money.

Then there's all the other while you're in there stuff.

A remap by wayne is your cheapest bang for buck on a stock engine without a rebuild and provided your engine is healthy the next step up is motec.

There's a few threads on this but bottom line is what do you want to spend that number times 2 is a safe estimate before you even go there.