hacker-pschorr

I can't find the info (part of KM's site has been taken down - long story I only know part of) but rules? What rules? More like a sh*t load of money poured into a project just to see what could be done. It's only a few years old, I think designed to run in PCA, not sure if there would be many cars around that would be able to run with it short of a 962.

Geo

Low mass components do not make hp. They simply allow the engine to rev up quicker. This will falsely show up as a hp gain on a inertial dyno.

UDPride

Anything is possible if you throw enough money at it.

All depends on how much value you place on the journey and not the destination because there really isnt a destination in 944NAs if you want to add lots of power unless the destination is an empty wallet.

Its like shoving a square peg into a round hole. Sure its possible if you try long and hard enough and wear the corners down. But why not simplify and just grab the round peg to begin with.

For the money you could throw at generating more horses in a 944NA, you could just go buy an 82 911SC with an NA flat-six that would run circles around most cars, be reliable, and retain some sensibility of equity if you were dead set against turbos.

Serge944

You cant make a direct connection between rotational components and hp gains.

Shaving a pound off the area on the outer diameter of the crankshaft will yield much higher gains than shaving a pound off the axis of rotation of the crankshaft.

What really surprises me is the fact people are so obsessed over wheel weight, yet they completely ignore tire weight, which has a much greater impact on the unsprung weight of a vehicle in motion.

Some tire weights vary more than the difference between a fuch and a phone dial. Maybe this should be taken into consideration before you go out and spend 3x more for a lighter rim.

Campeck

I know it doesn't CREATE HP. It just frees up some hp that the engine would need to otherwise turn that pound around its axis.
serge. I agree entirely. it probably depends on where the pound is. I told this to the guy and he said it didn't matter. and seeing as he is the guy that has a 180hp NA And tons of experience. Im willing to except that he is right. but still have my doubts.

Danno

"I know it doesn't CREATE HP. It just frees up some hp that the engine would need to otherwise turn that pound around its axis."

Yeah, but when you hook up that engine to 300lbs more of drivetrain components and 2500lbs of car that needs to be accelerated, that 1-2# savings don't really show up as increased performance. The amount of "tricked" HP that shows up on an inertial dyno from 20-30# of lightened internals is usually less than 5-hp. It doesn't even show up at all on a load dyno.

One of the reasons racecar engine have lightened internals is to lower the loads on the parts, which allows you to rev it to higher RPMs. But this requires redesigning the entire engine to match. Weight is also removed as part of the balancing as well. Lower weight pistons means you can use lighter rods, which places less of a strain on the crank, so you can take another 5# off that. Lightening the engine parts is just like lightening the rest of the car. The overall lower mass will result a faster accelerating car, even though its HP output is still the same.

Cubic dollars IS the secret to getting HP out of an NA motor. The highest HP I've ever seen from an NA engine is 221rwhp (260bhp) or about +100 over the normal NA's output. Here's the mods on this engine:

- 3.0L block
- 2.7L 944NA 2V head
- 13.0:1 high-comp JE pistons
- 3" exhaust dumping out behind front tyre
- 110-oct. race gas
- 10 hours dyno-time and custom GURU-tuned chip

The cost of parts is about $6k (includes cost of original engine & head), $2k for the rebuild, $2k for dyno-time and tuning for a total of about $10k. This engine was installed in a stripped out 944 racecar and it was one of the fastest on the track at Willow Springs POC event. In terms of straight-line speed, it was slightly faster than a TurboS because it weighed less, but didn't have as much torque or as wide of a powerband as the TurboS.

One of the major problems I saw with this motor was the protruding dome on the pistons and resultant crescent-shaped combustion chamber is not the best for high-speed burn. The ignition-advance values were simply obscene, indicating inefficient combustion. The 2V head and tri-Y headers are great for low-end/mid-range torque, but completely crappy for high-end HP where you typically run a racecar to its redline.

I can see areas of improvement that would get this engine up to about 300rwhp (350bhp) for +200hp over a 944NA:

$3000 fully D-ported 4v head with larger flat-head, narrow-stem valves, radiused contoured valve seats
$2000 solid-lifter conversion
$1500 custom cams optimised for solid-lifters and 6000-8000rpm range
$2000 twin adjustable cam-gear conversion
$2000 titanium con-rods to withstand 8000rpm operation
$1000 custom intake-manifold with large short runners
$500 big-bore throttle-body
$750 4-1 long-tube headers
$2000 standalone programmable EFI system
$2000 dyno and tuning time
-----------------------
$16750 total on top of the previous $8k engine ($2k tuning is the same)

Now this will be a race-only motor due to the narrow 6000-8000rpm powerband. To be streetable, you'd need to use a 968 head with VarioCam to spread out the powerband somewhat, so 4000-7000rpm would be more like it, but you'll miss out on some ultimate power by not being able to use the twin-cam adjustable gears to fine-tune the system.

It not that hard to armchair-design a high-HP 944NA engine. But when it comes down to putting your money down and actually building the thing, no one ever pulls the trigger...

Friendan

Is this thread for real?
If you "never" will have the time and money, then don't even BOTHER with this NA tuning business, unless you are out to prove to the world that it can be done, and you want to mortgage your house. Go and buy a 951, and deal with the "finicky"-ness if you want power. End of story, someone close the thread.

Geo

Nope. This is a popular misconception due to the proliferation of inertial dynos.

Low mass components will accelerate quicker. On an inertial dyno this will be read as more hp. However, it's not more hp, just quicker acceleration. Put the same engine on a brake dyno (which places enough load to keep a constant rpm) and you will find zero gain.

Tell me, if you take 200 lbs out of your car and it goes faster, did you gain hp? No, of course not. Same thing with the low mass engine components.

pete944

If you can pull that off and make it affordable you will be an extremely popular guy around here.

I won't say it can't be done (anything can be done) but I doubt if it could be done for under $25K and I seriously doubt that it could be a daily driver.
If you think a turbo is finicky, a 300 hp, 10K rpm NA motor would be an entirely new class of finicky.

Again, I think a 300hp street NA would be great but is a $25k engine in a $5k 18 year old car worth it?

Geo

I think 300 bhp would not be reasonably streetable. It would have to have such huge ports and aggressive cam that it would require a really high idle for one (probably 2k rpm or more) just to keep running. I think well over 200 bhp is possible without spending a fortune, but someone has to be bold enough to spend the dough and do it right.

Campeck

well. If it doesnt free up HP.
than like you said, It revs faster. meaning the engine is now lighter (parts of it) so it doesnt have to turn those parts. then with said lightening shouldn't the car accelerate quicker, since it doesn;t have to turn those heavy parts?

Scott at Team Harco

OK - it's time to kick start this thread with the only true answer to that age-old question of how to get more power from that little NA motor!






Just do what I plan to do....






It's really quite simple....







All need to do....








Is bolt on one of these....

RMills944

That brings up a whole new question - Can my 2.5L N/A turn this turbo?

Scott at Team Harco

Of course it can.

Just follow this simple procedure:

1) Jack up the rear of your car.
2) Support the rear with jack stands
3) wrap a long leather strap around the right rear tire
4) take the loose end of the strap and wrap it around the impeller of the turbo
5) get in your car and GUN IT!

Simple, no?

M758

Yeah, but that would make it into a supercharger... belt driven and all.


Back on topic....
... getting more power from a an NA motor is possible. When Porsche wanted more power from the 2.5L motor they did two things, 1 Turbo, 2 16v head. They also went to 2.7L and eventually to 3.0L.


Really anthing is possible for a price. Honda makes 240 hp from 2.0L in street motor. So at 120 hp per liter gets you the magic 300 hp.

Now... like others have stated doing this on paper is one thing. Making it happen in the real world is much harder. Given time, engineering knowlegde and a nearly unlimited budget I bet you can make really strong power from these motors. The issues are that the development costs are going to be very expensive and how much would a "production" version of these monster cost you to build?

Most folks now can't justifty spending $3000 on 944 NA when you can for that money get a turbo and get 300 hp without batting an eye.

Possilble --- Yes
Easy -- No
Cost effective -- hell no.

I would be an intersting project however.