No HTwo O

Gandalthegray, thanks for posting this.

Do I understand this right? You are getting 408 WHP? Does this mean you are getting about 470 HP at the crank? I am figuring about a 15% loss. Correct??

gandalfthegray.

Yes, 408 Wheel HP & 437 Wheel TQ. I have always understood drivetrain loss to average 18%, but yes somewhere in the 470 - 495 flywheel HP.

There is a bit of a dip in the power curve that I want to try to sort out. At around 5100 RPM power falls around 25 HP or so then at around 6000 starts to climb again. Almost if the boost was dumped then starts to build back. IDK.

No HTwo O

^Thanks! That's a lot of ponies, for sure.

Are you running an auxiliary oil cooler?

TB993tt

My experience says you lose about 50hp max at peak through the 2WD drivetrain on these...

460hp looks about ball park for the mods....

Try some acceleration runs, data on the factory 450PS Turbo is in the link below, 60-150mph starting in 2nd gear took 18.5s, so you can test your hp from there

https://rennlist.com/forums/993-turb...o-s-450ps.html

gandalfthegray.

Due to the miserable winter weather it will have to wait for a bit, but I look forward to trying some runs in the spring. Trying to speculate the flywheel hp is hard as well, I agree. In my neck of the woods we don't really worry about the flywheel numbers anyway. It really only matters what's hitting the ground. Although it does sound better.

Yes, a Cargraphics unit.

Quadcammer

might kill a bit of the push though, no?

Greg H.

Is that Addison's old car with the UMW programming? If so, it's 460hp as TB said. I have the same. Can't trust chassis dynos is the lesson.

Greg H.

DM993tt

I run 275 hoosier R6 up front with neg 3deg of camber, erp monoballs and evo uprights, I don't experience much push.

gandalfthegray.

Greg, that's probably a fairly good guess. There have been some changes to the car which could add or subtract power since back in 2004. Have you ever dyno'd your car? I would be curious to see if your seeing a loss of power between 5100 rpm and 5900. I'm guessing you are. Addison's car and Pramm's both show the same power loss at the same rpm's. Now 6 years later I dyno the car and see the same power loss. One can argue the accuracy of the dynos but not the fact that both show power loss at certain rpm.

Quadcammer

back to the kiddie table with me

If you find your car on blocks without some front suspension components...it wasn't me or anything

TB993tt

On Motronic contol they all do that..... My understanding is that the boost ramps up for peak torque at around 4500rpm then the Motronic opens the wastegates and winds it back because it overboosts so it winds back hence the dip then once the new lower readings are seen it starts increasing the boost/timing again as the revs rise. It is accentuated on the 993tt because it seems to take time for the wastegates to be actuated and dump the boost and during that time the target numbers (from the ECU program) are overshot so it reduces the numbers even more hence your dip.
There isn't a lot you can do about it, even my custom engine dyno tuned Motronics have done it to some extent - I have the graphs somewhere....

JBL930

The only way around it would be to either fit 1.0bar actuators, or add more preload to your existing ones. Problem being then is that the ECU can't lower the boost below 1.0bar if it senses danger, it can only retard ignition or cut the spark completely. Stock wastegates are set to open 4mm at 0.5bar, you can wind them up a bit so they open 4mm at 0.8bar, the dip then wouldn't be so pronounced, but you are taking some of the ECU's control away

gandalfthegray.

TB and JB, what about using an electronic boost controller?

JBL930

Lot's of people run fixed boost set ups, it's a bit frowned upon though. A well mapped motronic set up is what you're after, one that will have full control over every aspect from CHT to IAT, air mass to ignition, so it will give you the right amount of boost for the right ambient temps, and that will lower boost or retard ingnition if IAT start to get too high.
A fixed boost engine will not have the longevity of a properly mapped motronic set up. It may well spew out better figures on a short chassis dyno pull, but at wide open throttle the fixed boost car may be running too hot and causing premature wear, and the ECU will be trying to pull ignition to save things. Where the well mapped motronic ECU will constantly vary boost and ignition to keep the IAT at a safe and optimum level.


ETA: If you're after a street car that does the odd traffic light blast, or a quater mile blast, then you can get away with a fixed high boost motor. If you're after an engine that will give you the same performance, even after Hours of abuse, then stick to the way porsche designed it, just get the best package and map, something like the RS Tuning stuff through Cargraphic, or RUF. Properly engineered, engine dyno tuned/proven packages

Spartan

So cars running a boost controller don't pull timing with higher IAT's or bad fuel? really?