pzull

My buddy just faxed me his dyno right after his tuning session. It used an SC as base but had following conversions:
1) 3.4 liter
2) 9 compression ratio
3) Twin turbo chargers from 993TT
4) Autronic SMC ECU
5) Custom Equal length headers (very very short...almost straigght from exhaust port to turbo)
6) Magnaflow straight thru mufflers
7) SARD BOV
8) 993TT injectors
9) Turbokraft IC

Max boost at 0.55bar

He says drives beautifully with full boost at about 2,700rpm but also alot of torque below that because of high CR. Car is also stripped out lightweight

He's one happy smug ****

schnele

Nice numbers with such low boost, even at the flywheel. I rough guess would mean the car in a normally aspirated mode would make 300FWHP.

pzull

He was going for tractability similar to an NA. He's a little whimpy these days having been a wild track freak with a fire breathing lag monster years ago.....now he drives it a daily driver

I can't remember other mods he's put in like what cams, etc. He had aquamist before but he didnt mention if he installed it this time. I think he didnt as he was bitching about the hassle of filling it up

ProtoCab

Very impressive. Must be a joy to drive!

slownrusty

Nice numbers and obviously lots of room for more power at only 0.55bar. If you don't mind me asking where in "Tropical Asia" are you?

Yasin

BReyes

Good to see he has mellowed out.

Give him my regards,

RarlyL8

You can't post a thread like this without PICTURES!

Geoffrey

I notice that the dyno operator put in a 20% drivetrain loss in the Dynapack software. Based on my testing with an engine dyno and the Dynapack chassis dyno, 20% is high so this graph appears inflated and is not RWHP, but a converted FWHP based on a 20% drivetrain loss.

pzull

That's what I told him; that it looks more like a C4 drivetrain loss. 2 wheel should be 13-15% loss? I also told him to just get power at the wheels. But my main point in posting the graph is to show the shape of torque curve: very NA looking.

Geoff, some dynos I've come across auto-calculates drivetrain loss on the zero throttle overrun stage of the dyno-run. Any idea how accurate these calculations are?

We live in different countries but I will get to see the car in 2 weeks and will shoot some pics

BReyes, you know him?

Kevin

pzull have the operator set the TCF to 1.00 and run it straight up.. That way there is no guessing to your numbers.. It is what it is.. If you run it at 1.00 it will be very accurate as the actual number that is produced. Geoffrey can chime in as to what he uses on his Dyna Pack runs.. The gearbox/drivetrain loss is not consistant. It's not a steady 10, 15 or whatever.. As the gearbox warms up the number changes.. If you want a good number to take to the bank, run it at 1.00

Geoffrey

I always leave the TCF at 1 which means the graph will produce accurate RWHP numbers. When I first did my turbo engine it produced 521 on a DTS engine dyno. I then installed it in the car and ran it on a Dynapack and it produced 444hp to the wheels. This is with a gearbox temp in the 135 degree range. If you do the calculation, it is a 15% drivetrain loss with my G50/50. I feel confident that if I maintain the same testing parameters ie ramp rate for the run, gearbox temp, dyno sensor placement, etc. I can get repeatable numbers that are reasonably accurate. There is no way they are the same as an engine dyno, however, I feel they are good for comparison. Will a 4spd have a different drivetrain loss? Probably, but I don't know what it is for sure. I've been using 15% and it seems in the range of what is reasonable. For instance, a 2001 Cup car produces 335rwhp on the Dynapack.

Other dynos that calculate the drivetrain loss during coast down are interesting. I've only used the Dyno Dynamics which seems to do a good job at estimating the HP based on Porsche's published HP and TQ numbers. I don't know enough about it to comment other than that I've seen stock cars produce caluclated FWHP numbers that are 2-3hp different than the factory's. Considering that Porsche has always been conservative with the published numbers and that the cars may vary some from car-to-car, it really is hard to say.

On the other hand, I recently did a stock 996GT2 engine (no mufflers or cats) with MoTeC and it produced 460hp@.6 bar of boost to the wheels. This is considerably more than the factory car. I went back and retested a stock GT2 that had only a performance muffler on it and it produced 404rwhp which is a little more than stock and about what I'd expect to see from a stock GT2 engine in that configuration. So, I don't know...

Red9

Update??