eclou

The mirrors could account for a couple of mph easily

Jean

That's maybe what the poster AAH is assuming

My version of the facts was that Woodster did 4 runs, he removed PSM and launched faster, went to 1.3 and 1.4 Bar in his last two runs (with same results of 191mph). You are certainly right that octane will help with higher boost, especially at the high temps they were running, how much, who knows, I honestly would doubt this is what made the car go 6mph faster, nor the mirrors

His quartermile run had a trap speed of 5 mph faster and 1 second better than what he ran in the Texas Mile.

It is not about the tuner, I don't believe in magic, I am only surprised by how effiicient this 996 platform is, for me this was a true learning. Heat soak was there big time in 6th gear (over 150Hp drop), the same as in the Rt12 though based on the performance seen.

TB993tt

+1

Woodster

The difference from Saturday to Sunday (184 vs 190.7) was threefold:

Saturday == MS103 (99 octane), lower boost, PSM ON!
Sunday == MS109 (103 oct), allows higher boost, PSM OFF !!!

Boost difference of .1 bar == 25 to 30 hp approx.
Having PSM off makes a big difference!

MK

Red9

To all that have helped get these nimbers and the real data in the public arena for examination. TB,Jean for persisting(insisting?) on questioning . For those that have been prepared to post data for examination and scrutiny - in this most recent case-Woodster for sharing his experiences as they happened( and numerous others) we should all be saying a huge thankyou.

M-Phibian

No surprise, but it looks to me like all of the HP claims and acceleration numbers correlate quite accurately:

Let's summarize:

A RWD RT-12 went 11.0 @ 133.9 mph in the 1/4 mile. Woodtster's (Marty's) AWD car went 11.0 @ 134.4 in the 1/4 mile.

According to my calculations, it would require app. 586 all-wheel hp for Marty's AWD car (with more drivetrain loss) to trap 134.4 mph with him in it. He made 623 rear-wheel on Protomotive's Dynapack, which converts to app. 578 all-wheel hp on an AWD dyno. That's a "true" 710 BHP, as claimed.
*For the sake of comparison; my car, when it was at that same 700 BHP level, had essentially the same bolt-on kit that Marty has now and went 136 MPH in the 1/4 mile with RWD and less weight. So our power was almost identical.

Now...the RWD (and lighter) RT-12, with driver, would need app. 575 rwhp to trap 133.9 mph. Using the same 12.5 % drivetrain loss that we used for Marty's car, that puts the crank HP of the RT-12 at 668 BHP. Since everyone here claims that RUF under-rates there engines...this seems right on.

Now, Marty's car also went 2.5 mph faster than the RT-12 in the standing mile….despite having the disadvantage of being heavier and less aerodynamic. This seems to align perfectly with what we've seen already of the direct correlation between wheel HP and MPH at the end of the 1/4 mile run.

Nope, no magic here. It's simple to see that Marty's inexpensive, bolt-on 3.6L engine makes more "real" power than the 3.8L RT-12 engine…no matter how you slice it.

Congratulations, Marty!!


Scott aka "Divexxxtreme"
Protomotive RWD PE950R 996TT
830 rwhp/780 rwtq @ 1.41 BAR
Best 1/4 Mile ET/MPH: 10.45/148 (on street tires)
60-130: 4.90 (2 shifts)
100-200 kph: 4.23

KPG

Scott, why would you use the same 12.5% loss factor on both cars when one is AWD and on is RWD?
Marty had a great run in TX and now we are seeing the goalposts start to shift once again. Apparently , now the TX mile is questionable due to a 20 ft downhill run over a mile.... that is about .003% neg slope. Give me a break.

M-Phibian

Kevin,

Marty’s car was dynoed in RWD on Todd’s Dynapack. So I had to use 12.5% to convert his RWD dyno numbers (623 rwhp) to crank HP; which is app. 710 BHP. I then used 18.5% to figure his AWHP numbers from 710 BHP…which is 578 AWHP. Almost exactly how much power he would need to put to the ground to trap 134.4 mph at his weight.

It all correlates perfectly.

LOL…I know. The faster our cars become, the more desperate for excuses some of these guys seem to get.

KPG

Now that makes better sense

TB993tt

You 6Speedonline guys can high five your 710hp all you want

but if you check out the data a page or so back, the full weight 4WD cars tested by Sport Auto had the following results:

RS Tuning 569PS 100-300kph in 20.9s
Krono 996tt 650PS 100-300kph in 20.7s
Gemballa 750PS 100-300kph in 17.6s

Woodster XXXPS 100-300kph in 22.2s

This run doubtlessly started out in the high 600hp level but averaged for the run it was no more than 600hp

Trivialising the Ruf RT12 is fun and what is said is probably true and relevant to many markets but the difference bewteen the RT12 and others is that the RT12 can run at its top speed ~219mph for a long time and the engine is expected to last the length of its warranty period......

This is taking nothing away from Woodster's achievements - what Todd K has produced has certainly altered my understanding of big power possibilities somewhat

M-Phibian

Those are great times!

But I'm talking about the RT-12's top speed in the standing mile being less than Marty's car. Either the RT-12 does not make 650 HP, or Marty's car...being heavier and less aerodynamic, makes more than 650 HP. You can't have it both ways.


Ah..I see. So again....if the lighter and more aerodynamic RT-12 has a lower standing mile mph than Marty's car does...what does that make it's average HP? Under 550 hp? As I said; you can not have it both ways. Sorry.

Marty's car, as great as it is, is not making "big power". It's only making 700 HP from a simple bolt-on kit on stock internals. It's only considered a mid-range HP Porsche here in the US.

M-Phibian

By the way, does anyone have the 0-250 kph times for the Gemballa GTR 750?

I only have data on my car up to 250 kph (not 300 kph, unfortunately), and I'd like to compare the numbers past 200 kph. My car went 0-200 KPH in 8.4 and 0-250kph in about 12.0 flat.

Thanks.

TB993tt

I just love 6 bling hp - RS Tuning, Manthey and Ruf charge north of $150K for ~680 Porsche hp yet that is "simple bolt-on" , "mid range" hp..... lovin it

Stummel

how about that?

100-300 km/h in 15.1s and 936m
2 shifts at 215 and 264 km/h.

100-200 km/h in 4.75 s and 199m

And finally praise the holy Autobahn:
300-340 km/h in 6.7 s and 598m

PS: it is a narrow body car with passenger

Jean

There was no need for all this, the debate was being kept at a quite techincal level and the learnings are for all. Red9 Thanks for your comments, you like many of us appreciate the value of data.

Without challenging and getting into the numbers deeply, we would not know 10% of what we know today. There are still many uknowns that we need to understand better, and our tuners included are benefiting from these debates.

As far as the comparison vs the Rt12, yes I agree that Woodster's car seems to be putting more HP to the ground, but I also know that there is a boost controller on board, and that the success of the run is dependent on it, whereas the Rt12 does the run the way it is driven daily, with boost that goes up and down between circa 1.1 and 1.4 Bar to keep the engine safe and with substantial internal work, and therefore comes with a warranty....There is merit to both directions I guess, depending on what each one's objective (and budget) is.

I have no doubt that if RUF (or many other tuners) wanted to have a go at a 1 mile event, they could build an engine in a couple of days that would blow the Rt12 numbers away as well, but would not come with a warranty.

The Gemballa GTR750 was a car that was built in 2001-2002, back then, no US or European tuner knew 10% of what they know today, it was already using GT3 head, GT3 oil pump, titanium crank and many other things that people 5 years later think are breaking ground. And how many tuners out there can sucessfully program a Motronic to go with those heads even today, 5 years later?

The worse part for us is that it was not even a Porsche tuner who built it!! But an aircooled engine builder who happened to know about Motronic as well.

That car had fixed boost control, GT Ball bearing turbos back in 2002, and special pressure sensing intake setup, and achieved those times without even trying to beat any records, just picked and tested by a magazine at 1.4 Bar and no race fuel. It ran 4WD, and had LOUSY aerodynamics with one of those painfully ugly Gemballa wings in the back. The downforce created by that wing must be in excess of 3-400lbs at 180mph, and a CD of at least 0.37....let's add those 400lbs to the car's full stock weight and drag and do the math of the HP/Weight ratio. If that car was running 1.6 Bar, no wing and special fuel and setup it would have probably seen 17 seconds to 300kph.

The value of this debate to me was that Woodster's car was able to maintain the performance for much longer than I thought while running 1.3-1.4 Bar. What I get from this is that the 996 Platform is an efficient one that can keep heat soak at bay for much longer than initially thought.

This does not make these cars reliable, and they will break if they are driven this way for too long, whereas an RT12 is likely to last for longer as a result of the engine self protection by pulling and boost when needed.

As far as Woodster's HP estimates, based on these runs, the car is putting consistent 650-670HP in 4th gear, drops to 630-650HP in 5th gear and then to around 500 in 6th gear!! The temps in Texas certainly were a major contributor to this drop, a temperature of 40F out there would have made a very substantial difference I am sure.

I don't know what the Rt12 is doing with heat soak but it should be similar judging by the acceleration numbers in 6th gear. These numbers are all calculated based on long Gs, aerodynamics, rolling radius, RPMs etc.. and have been tested against many stock cars with excellent accuracy to factory numbers. Yes it does mean that the RT12 is putting less than that in reality.

Peace!