Bill S.

Do you have your 60-130 times? Here's a video for my Ruf Turbo R (8.7 seconds) on a cold day with two people in the car, flat stretch, 91 octane.

This beats dynos, it's easy to do, and does not require hard, unpredictable starts.

Here's some published 60-130 times from Car & Driver magazine:

Enzo: 7.0
CGT: 7.3
F430: 9.5
F50: 9.6

I guess I'm a bit slower than an Enzo and CGT. What's your times?

Ruf Speedo

Woodster

I like it!!!!, I will report in the spring since my car is currently getting mods done.
we need a few guys in stock 993 twin turbos to report in their times to set our "baseline"
come on guys, hit those desolate roads...

TB993tt

Great work Bill and a good measure of real performance. Regarding speedo accuracy Do you have stock wheels and tyre sizes ?

Bill S.

Yes. OEM Bridgestone S-02s on stock wheels. I think these speedos are fairly accurate until you start going over 150 MPH or so.

Woodster

Use the digital speedo readout??

Bill S.

No. It updates too slow to get a good reading. The analog gauge is faster.

However, the digital does match the analog when you're accelerating much slower.

LAT

I do not have a C&D article on the Ruf CTR-2 but a Road & Track test in Feb 97 has the CTR-2 doing the 1/4 mile in 11.4 @ 133.7 and the 0-60 @ 3.6. Therefore I conclude that if the car can go from 60-133.7 in 7.8 seconds then it is probably around 7.5 to 130. Not bad for old air cooled technology.

Does anyone have anything to support this position.

Bill S.

I've also seen that R&T article. Your logic sounds valid. The Ruf CTR-2 is faster than a Turbo R.

R&T also tested a Turbo R. However, they didn't publish all the numbers. A call to the editor confirmed 0-60 in 3.3 seconds and 0-100 in 8.0 seconds. It seems the smaller turbos in the Turbo R may help a bit under 100 MPH, while the larger turbos in the CTR-2 help at higher speeds.

Note the following:

60-100 for R&T CTR-2 = 4.3 seconds
60-100 for R&T Turbo R (not published) = 4.7 seconds
60-100 for Turbo R (my measurement) = 4.3 seconds

I've driven in a CTR-2. That particular example felt slower than my Turbo R and had more turbo lag. Upon closer inspection, the car did not have the twin plugs and twin injectors. It seems Ruf may not have delivered all CTR-2s with that technology. The R&T example did have all of that.

LAT

My understanding is that both Porsche on the 993TT and Ruf on the CTR-2 did not use twin plug on their cars as they thought it had no added benefit because of the flat top pistons. Porsche already had the twin plug heads from the normally aspirated motors.
Before I go too far with this theory what year is your car and is it a twin plug?

Bill S.

My car is a 1996. Ruf does not use twin plug in the Turbo R, only earlier CTR-2s.

Twin plugs help avoid detonation with typical pump gas at higher boost levels. The 993 is more susceptible to detonation than the 996 because the spark is not in the center. Porsche should have used twin plugs in the 993 TT. They probably didn't for three reasons:

1. The cost would be too high.
2. The rated HP of the 993TT and 993TTS could be established with 93 (R+M)/2.
3. The 996 will soon replace the older 993 design.

I spoke with some Ruf technicians. They said they went away from twin plug in the 993 for a few similar reasons:

1. Porsche is not using it for the 996, so they cannot leverage-off the factory engineering.
2. The gas in most parts of the world is good enough for the Ruf HP ratings.
3. Ruf was having trouble getting twin-plug and twin injectors to work reliably.

Bottom line? A CTR-2 without twin plugs and twin injectors on US 91 (R+M)/2 is no faster than a Turbo R using the same gas.

However, if you use race gas (100 (R+M)/2), twin plugs offer little or no improvement, and a non twin-plug CTR-2 will be faster than a Turbo R.

BTW, the 996 is not immune to low octane fuel and will detonate. It's just a bit better than the 993. Detonation on US pump gas is a major limiting factor in increasing HP in 993TTs and 996TTs.

Note that Mercedes IS using twin plugs in their higher HP cars with 3 valves.

LAT

FYI
This is the scoop on the twin plugging of the Ctr-2, the following was provided by a RUF trained mechanic.

"The Ctr-2 was first developed with a Tag-Tronic control unit. This was a twin plug distributorless system. The system was extremely sophisticated. Maybe a little too sophisticated. The support that Ruf received from Tag was poor, And very expensive. Supposedly, Tag wanted something like to $10k to fit out a laptop with the software needed to service their system. So, as a result. Ruf retrofitted all of the Ctr-2's with Bosch Motronic systems. Most all of Ctr-2's I believe in fact have twin plug heads.

There might be a Ctr-2 out there that still has the Tag system on it. But, I really doubt it. The system is completely orphaned. About the only one that might be able to do any diagnostics someone in F-1.

There would be little advantage with twin plugs in the Ctr2. And, at this point be very difficult and probably very expensive. Your Ctr has twin knock sensors. So, Detonation is a non issue."

Bill S.

Thanks for doing the research. That's also what I heard. I forgot about the Tagtronic vendor problems.

Although detonation is a non-issue because of the knock sensors, it still means the CTR-2 is loosing power with lower octane fuel. So, with 91 (R+M)/2, I still believe a CTR-2 is no faster than a Ruf Turbo R. In other words, if R&T magazine tested a non-twin plug CTR-2 with pump gas, my guess is they would be hitting 125 MPH in the quarter, rather than 133.

LAT

Would the difference in weight and torque not also make a up some of the 8 MPH between the two cars. Have you ever had a chance to run up against a CTR-2?

Jean

Somewhere around 13.5 seconds if I am not mistaken. Thos times posted by Bill are amazing.

Bill S.

I don't believe a non-sport CTR-2 is any lighter than a stock 993TT. Also, a Turbo R has been tested at over 500 ft-lbs of torque, so it's very similar to the CTR-2.

I've driven in a single plug CTR-2 with pump gas, but have not run up against one. I recall the acceleration feeling the same as a Turbo R. It did not feel like a 133 MPH car.