Bill S.

I just picked up my car today from Beverly Hills Porsche where the Ruf tech completed a 993 Turbo R Engine Conversion. The car went in with the Porsche 450 HP Powerkit Plus, which I had for 3 years. I thought I would try to express the "feeling" of the Turbo R for everyone while it's still fresh in my mind (car had 91 octane):

1. I was suprised when the car was idling. My wife thought is sounded like a speed boat. You could feel the engine shaking, and hear the exhaust popping irregularly.

2. When I accelerated in first gear, the pull felt a bit stronger. However, it happened so fast that it was hard to tell if it was much different.

3. In second gear, the pull felt quit a bit stronger. The car came alive around 4000 RPM (the 450 kit came alive around 4500 RPM). The power seemed to trail-off a bit around 6500. However, it still pulled strong to 7200 (the new redline).

4. Third and fourth gear were quit a surprise. The car pulled much stronger in these gears. It felt like it had a much bigger engine. No peaks or valleys from 3000 RPM to 7000 RPM. Quit a difference from the 450 HP kit. In third and fourth gear, I would say that the pull I felt with the 450 HP kit at 5500 RPM was equal to the pull I felt with the Turbo R at 4500 RPM. Above 4500 RPM it feels like a giant engine.

5. If you step on it in fifth gear at about 4500 RPM, the car has an incredible pull. Much more than I had with the 450 kit.

6. When driving in the mountains, it was noticeable that boost came on much faster. I used to downshift to second when I wanted more boost. Now I could stay in third. The boost comes on much faster. Again, the car felt like it had a bigger engine.

In summary, I would say that the Turbo R really shines in third gear and higher. When I took my wife for a ride, she though first and second felt about the same. However, when we shifted into third and even fourth, she could not believe that the car was still pulling as strong as it was in second. I think this is because we are on the high torque curve for a longer time, giving us more opportunity to enjoy the stronger pull. The car just feels "fatter". I don't know how else to explain it. It's like a stock 993 TT with a 50% bigger engine. It's very smooth. The 450 HP kit did not feel "fat". It always had that "slingshot" feeling. The Turbo R feels like your driving a 993 TT with a 4.5-liter engine. It makes you really think twice about flooring it on the highway for more than a few seconds in fourth or fifth. At 60 MPH, high speeds just come up way too fast.

P.S. A 996 R Turbo with tiptronics was also completed. The Service Advisor thought the 993 Turbo R acceleration felt stronger ("like a bat outta h***"). We were curious how the 996 R Turbo with a manual would feel. Maybe I'll hear someday.

JJayB

Bill
Sounds like you are pleased with the Ruf mods.
Did Ruf make make any transmission or gear changes with your car?

I read in European car magazine that a 996 GT2 and another tuner car rated at 540 hp, was timed at 3.2 seconds for the 50-75 mph in third gear. I would think your times would be comparable or better. See you at Willow Springs.

Jim

Bill S.

Jim,

The Turbo R is faster than I thought it would be. I am pleased with the Ruf engineering and installation (i.e., no scratches, all parts perfectly aligned, etc). They didn't touch the transmission. Only added cams, cam gears, catalytics, ECU, air filter, large oil cooler (with fan on driver's side behind front bumper next to A/C radiator), turbos (stock turbos with hot and cold sides enlarged with larger turbines), 5 BAR regulator, and new plugs. I was curious about your 50-75 mph in third. Since this is easy to check, I tested it with my wife using a stop watch and me saying "Start" ... "Stop". I started in third at 30 MPH and said "Start" when we hit 50 and "Stop" when we hit 75. We did this 4 times. We got 2.03, 2.07. 2.04, and 1.94 sec. We also started at 50 with no running start. She started the time when I hit the gas. With this I got 2.2 sec. This 50 to 75 in third is a particularly good test because it occurs in an RPM range when most 993 TTs are not yet pulling. In third, I feel the Turbo R start to pull around 3500 RPM and it really kicks at 4500 RPM. It's really exciting to feel the car pull all the way to 7200. I'll need to talk to Ruf to see if this is a good thing to do. Maybe it's OK with the new cams.

Ruf-Racer

Bill,

Congratulations!Did Ali do the work? I am a bit puzzled about your observations since my Ruf on pump gas has a 'deadband' in the 5500 region.It goes away with 103 gas and the Ruf takes on an entirely different character as the ECU learns it is time to run hard. BTW, I do strech to 7300 on certain turns to avoid a gear change but generally make a habit of shifting at 5500!Enjoy that machine.

Roland <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

ADOGNY

Bill,

What did your original 450HP kit consist of? I just got a new ECU from Cargraphic and plugged it in for the first time yesterday. Couldnt notice much in first gear (too short), but in second the boost came on much faster and harder than before. I pretty much had the same results in third thru sixth, and it got up to high speeds in a much shorter distance. I had to let off when the Digital read 181MPH - does anyone know how accurate that really is?

Anyway, I was extremely happy with the increase so far from the ECU upgrade and was wondering what you car had in addition to that. Toby tells me the bug will bite me soon, and I think it already did after that one drive! Thanks!

Adam <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Ruf-Racer

Adam,

My experience is that the digital & analog speedometers are very nonlinear above 90-100 mph. On my car I would say 185 digital is closer to 175 GPS indicated. Two hundred actual would translate to about 220 digital indicated.At 205 the digital & analog are way off!Come to think of it I have never looked but I do have tape!At my next event @ Battle Mountain Nevada I hope to gather calibrated data including a 100-150--&gt;&gt;200 time!BTW,Bill the ABS quits above 330kph and the panel lights glow brightly!Did you change your top gear?


Roland

TB993tt

Bill
Congratulations on making a great car even greater.
Did the Ruf techs use head sealing rings ? and are the cams still using the hydraulics ie self adjusting ?
It is interesting what you say about the power tailing off at the top, 'cos 911 & Porsche World got hold of a dyno printout (much to Alois's disapproval) and it indeed showed power tailing off after 6000rpm. My experience however is different, I got the chance to ride in a Turbo R and noted fairly modest (relative term) mid range boost but a real charge from 6000 to 7000 rpm. Maybe that was an early car or had slightly different spec <img src="confused.gif" border="0">

Bill S.

Here's answers to some questions:

1. I did not change my top gear. Without this, the car will only do 195 MPH at 7200 RPM in sixth. Since I use the car mainly for cross country trips and ocassional track (like Willow Springs) I preferred acceleration over top speed. However, I can see how the Turbo R could give quit a rush as it continues to pull very strong up to and past 150 MPH.

2. I do notice a dead spot at 5500 to 6000 with 91 octane (I also hear a short "tick" from the engine). When I added 11 gallons of 100 octane to the tank, the dead spot went away and no "tick".

3. My 450 HP kit is from the Porsche factory. It consists of an ECU, GT2 turbos, Turbo S oil cooler, and dual pipe exhaust tips. I enjoyed the kit for almost three years. The Turbo R, however, is faster. The torque curves published on this board show why. Maybe I'll enjoy the Turbo R for another three years or more. The 450 kit felt very fast for the street. The Turbo R feels too fast for the street. I can see why Roland likes to use the car for high-speed runs. The long and powerful pulls are very entertaining.

4. Ruf technician Christian Treiber did the conversion. He comes highly recommended by Ali Acarsoy. Christian mentioned he did about 40 Turbo R conversions. He completed the conversion in about 4 days.

Bill S.

Here's a few more answers/comments about the Turbo R after a 230-mile drive through the mountains and desert with a 2000 Viper RT/10 (460 HP):

1. The Turbo R acceleration at 75 degrees and 3000 feet felt about the same as it did at 98 degrees and 200 feet.

2. From a rolling start to 120 MPH, the Turbo R is about 7 car lengths ahead of the Viper. With the 450 HP kit, the car was about 3 car lengths ahead (we had the same drivers).

3. Contrary to what I initially thought, the Turbo R does not have any power loss above 6500 RPM. It seems the car had to "learn" a bit about the gas it was using, and maybe my driving style. Now the car pulls strong with no noticeable peaks or dips from 3500 to 7200. Also no "ticks" from the engine. The tank still had some 100 octane in it, so it was definitely over 91 octane during this trip, but not much. I would guess the ECU had to listen to the knock sensors for a while to decide the best timing, fuel, boost, etc. Roland has also experienced this "learning" behavior.

4. The car still uses the hydraulic lifters. The cam timing is 1.6 mm.

5. Ruf does not change the head gasket. I think because Porsche designed the 993 TT piston to travel 5 mm further into the combustion chamber, the seals no longer have the stress seen in previous turbos. Maybe Ruf thought this was OK.

6. I only saw the rear wheels break loose under two conditions. Once in first gear at 6000 (from a rolling start), and nearly every time after the 1-2 shift. In both cases, only a small patch of rubber was left on the road (less than 1 foot long). This was on dry asphalt with the SO2s.

7. On the curves, third gear is much more usable. In this gear, the speeds usually are within the 3500 to 4500 RPM range. With the 450 HP kit, I would find myself having to shift down to second very often. I need to do this much less often with the Turbo R.

As an aside, although the Turbo R easily pulls the Viper on the straights, it requires quit a bit of concentration to keep it behind on the curves. I think the Viper's faster throttle response, very wide torque curve, and more confident steering feel make up for its 30-40 HP deficiency in the curves.

Ruf-Racer

Bill,

Prior to an open road event I like to go out and play. I run many rolling starts through the gears to get the ECU educated!Once I have the ECU educated the performance goes from good to 'fierce', a huge difference.Running pure 103 we can break the tires loose if we wish,but we don't!As you gain confidence you will learn when to let it rip and learn to jump on it earlier and earlier.Careful on the track at first! I have been sideways at Spring Mountain out of ten several times by being too heavy too early!

Enjoy,

R
<img src="graemlins/jumper.gif" border="0" alt="[jumper]" /> <img src="graemlins/jumper.gif" border="0" alt="[jumper]" />

TB993tt

Gents
This talk about ECU "learning" is surely not correct
Yes it will adapt to the grade of fuel, but not to the way you drive.

Ruf-Racer

TB993TT,

My Ruf always runs better after running hard.If I do some city driving the idle characteristics change and performance is diminished.A few runs through the gears or a quick trip to Las Vegas does change the nature of the beast!High octane fuel of course makes a radical difference as well!

Cheers,

R

Bill S.

I think saying it learns your driving style is incorrect. I think it's more accurate to say it requires you to drive it hard so it can obtimize the engine's timing, fuel, boost, and other parameters for the entire RPM range for maximum acceleration. If you don't drive it hard, it doesn't have enough information to do this. For example, if you never accelerate hard, it doesn't know how much to push these parameters because the knock sensor is never activated. This is called an adaptive feedback system. Although I don't know the details of this software, I can imagine it uses engine load and rate of acceleration before it starts really fine-tuning the curves from the knock sensor. It seems the Ruf car might be very aggressive in this respect, increasing the boost considerably if no knock is detected. Maybe this is why I felt a very noticeable performance increase from 91 to about 94 octane, while Roland sees even more with 103. Steve Weiner knows what the stock 993 TT engine does. Maybe he can shed some light on what Ruf might be doing or is capable of doing with the computing power of this ECU. Computer's can be pretty smart. If you can think of something to do to increase performance, it's likely that you can program the computer to do it for you. Personally, as a former programmer of systems like this, I would increase boost as much as I could, without sacrificing engine longevity. Ruf, theoretically, could set boost to 1.3 Bar or higher for short times if the oil temperature, manifold temperature, and knock sensor activity history make it safe to do so.

TB993tt

My theory on why the Ruf turbo R engine may need a good thrashing to keep the ECU giving maximum power:
From Bill's answer above, the Ruf conversion leaves the head gasket alone and therefore can only run moderate boost levels between 4000 to 5500rpm (for moderate read up to 1.2 bar)At this level of boost, a properly configured tt will not be near detonation -so I'm saying the boost is limited by the head sealing rather than the onset of knock/detonation. The Ruf cars start coming on the boost over 5500rpm (I have actually held a boost guage on a turbo R and witnessed this with up to 1.1 bar @ 6000rpm) so the ECU only starts working on the knock onset above 5500rpm on boost. If you drive around using full throttle but not passing 5500rpm then the ECU may "forget" what knock is - until you start giving it full load (ie 3rd/4th/5th/6th gear) runs above 5500rpm.
My engine is set up differently with GT2EVO head sealing and the ECU gives big boost (up to 1.6bar) at 4500rpm, therefore the ECU is working the timing very early on.
What do you think guys <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />

Bill S.

TB993tt,

Your logic sounds good if it's unlikely to get detonation under 5500 with the levels of boost Ruf is using. Then there would be no need to use the knock sensor at this RPM. However, we don't know for sure. Ruf could be using the knock sensor in this range also to determine boost, fuel, and timing. I do recall hearing a "tick" in this range with 91, which would mean they are using the feedback. I'll listen the next time I'm using 91. You car, however, sounds like a totally different animal. Running the high boost you quote would require much more changes than we have in the Turbo R. I assume your engine has quit a bit of cooling, breathing, and strengthening modifications. Also, maybe several enhancements to prevent detonation, like twin plug and very high octane fuel? I don't think Andial's 3.8-liter or even Ruf's CTR2 goes this high with the boost.