JJayB

[QUOTE=TB993tt;6920144]
So create whatever myths you like about Ruf's CTR2's power outputs but in the end it was/is limited by intercooling and was never meant to be raced, it was and is an iconic ~520-580PS (depending on IAT) legend

Toby,
The Yellow CTR2 Sport previously owned by Bedoir, had boost activated water injection that sprayed H20 on the intercoolers! One way to keep IAT down. The 580PS claim would be close to 600 hp SAE.
The Bedoirs did a lot of development work for RUF in the states which included complete data logging video and many variations of gearing.
I noted that the water injection was absent in the pictures posted recently on another thread.

biiig-hp

This is all pretty interesting . I’d like to chime in on the topic of intercooler temps and turbo efficiency. I have to agree with tuner1 In regards to turbo’s and IC temps. From personal experience and from what I’ve seen in the drag racing world on the dyno, Turbo choice make a huge difference in regards to intake temp. As well as head flow. If the turbo is out of its efficiency range it will make heat, and a lot of it. Eg. You can run two different turbo’s on the same motor, one at let’s say 11 psi and make 600 hp. And then run a much smaller turbo that’s capable of making the same number but over spinning at say 22psi. The power curve will look nothing alike but I can guarantee you the smaller turbo will make more heat. Same goes for heads that do not flow enough. You will be able to force the air through but again it will make more heat. There is no easy way around it. These 600hp plus motors need to be built by people that know what they’re doing for the purpose that the owner wishes to use it in.

And I do not agree that the only way to make 600+ reliable hp is with a secan and only a secan. I could be wrong though. I did a few 0-300km runs a few years back and my IC temps (from what I recall) were not over 10c higher than ambient. Yes the older EVO cars made 620ish hp but they had a lot to contend with considering the 25mm restrictors and turbo technology from 1995. I think there have been a lot of advances made in turbos as well as different cam profiles and ecu systems that make these cars run faster and cooler.

Tuner1

TB993tt: 80C is very high. The intercooler(s) would be burning hot to the touch. Personally I would back out of the throttle if my IAT ever reached 60C.
An interesting test would be -- On a 30C day, what is the very maximum IAT one could register on a bone stock 993TT?


Yes, I would likely trade my 993TT for a similar condition CTR with all the option boxes checked What a great car. Are you saying the power would roll back from 520 to 469 from an overly rich mixture and the DME pulling timing?

TB993tt

Fair point, I didn't know that

TB993tt

All good stuff and interesting. The CTR uses massive KKK26s with external wastgates (which make a glorious fluttering bird like sound when dumping ) so I am pretty sure two of those big lads are comfortably in their efficiency zone for ~500PS
I understand what you are saying and of course big power can be made without Secan - Jussi on here ran ~700hp and for long enough to go to 190+mph - I guess I mean for Porsche like hp (well old Porsche like) the sort of hp which is still there in the middle of and at the end of an endurance race requires the Secan for the 993 air cooled engine (the water cooled are a different matter). The air cooled engines will warp and bend if the heat is not managed effectively (if the engine is used hard) - anyone else on here had to buy a full new set of heads ? (apart from JC on his GT2 ?)
10DegC above at the end of a 0-300kph run is not possible from my experience with 993tt .......

TB993tt

Fortunately if you have a properly programmed 993tt Motronic you don't have to back off the throttle - see my engine dyno data below, at 80DegC the Motronic gives you 87% of boost and 6 Degrees timing retard cutting your power by ? maybe 100hp ? If it gets any hotter the ignition will cut out fully.

I don't know what protection system the CTR's hybrid pressure sensing Motronic set up used but suspect it was the richness of mixture - it certainly smelt like it !

Jean

LAT, Vincent, thanks, I have been around

The RUF CTR2 Sport of Beddor runs a boost controller, it was an atypical (non RUF like) setup that was customized for their hillclimb/road racing, short and quick full power laps or a few miles of uphill racing mainly. This is the same as other US tuning setups (like protomotive, MODE, etc..) where you can run high boost and make a lot of power, however you do not enter the professional racing/Club racing/Endurance racing world with such setups (like mine). The car was very fast from what I have seen on videos, good drivers, and great aerodynamics too...

We know for a fact that RUF has not built Motronic var. boost 580PS engines before LAT's despite literature out there about it (CTR2 were only 520PS), and in fact they went through painstaking testing and failure before they were able to put it together as it should. They are not using EVO heads (it is single plug), nor Secan intercoolers or alike, which is what RS had to do to have reliable 580PS on TB's car. The CTR2 520 was about 100kgs+ lighter from memory, which contributes to the high trap speed recorded in a quartermile.

A 0-300kph run, hillclimb special or quartermile car is very different from racing requirements for a 993TT, they are in fact two very different ballgames, 50HP drops is VERY conservative for any 993TT running 600HP+ after 10 laps at racing pace without Secan/twin plug/ state of the art tuning.. A high speed run has 100s of cubic meters of airflow being forced through the IC, whereas in racing you spend 90% of your time on full boost in 2-3-4th gears at low speeds, IATs will skyrocket, heads will melt.

Tuner1, looking forward to se emore about your car, performance, engine etc..

biiig-hp

I don't know much about that car's internals, so we don't know if the heat is being made by the turbo's or most likely head design. I don't think Ruf is one to mess with over sized valves or porting and polishing. I don't think he used the motorsport heads either.

I still think there are better turbo choices these days.

I'll look for the data log for my 0-300 runs, if not i'll do a few more runs again.

biiig-hp

No arguments from me. the only thing I’ll challenge is the fact that the secan is the only way to make reliable 550+ hp that could be used as a DE car.. I will not argue about the secan being the best out there because I'm sure it is. but I just think that it could be done without going to such extreme costs in the IC department.

Jean, I'm not looking to start an argument with you or Toby as you guys have forgotten more about these cars than most people will ever know, I just think that we have a lot of new options when it comes to building our motors these days.

biiig-hp

I did but but it was from a lean condition that I never cought in time.

TB993tt

So I presume you had ditched the Motronic knock control ?

biiig-hp

Motec.

LAT

I can assure you that Ruf does not give away horsepower, he sells it.

My 520 HP CTR-2 was upgraded to a 580 HP version after changing a lot of internal parts and money. The engine was running at 582 HP on the engine dyno nothing more. I have been in the dyno rooms many times over the years. BTW they have two engine dynos one for air cooled and one for water cooled.
Developing my engine was a work in progress for way too long as they attempted to create a motor that would hold together at 300+ kph Autobahn runs. I did melt it down once at 306 kph, GPS steady speed. Ruf rebuilt it again and then one of their test drivers cooked it and it was rebuilt a third time. Always trying different turbo and mapping combinations to be able to produce 580 HP that could be held at WOT on the Autobahn. The side intercoolers were an additional challenge to maintaining power as they heat soaked quickly and are made of normal oem type cores. I am certain a better IC set up would of helped.

I am certain that 993TT can be built with 700+ HP all day but don't try to use them in the same manner as the car above or I gaurantee you will fry the engine regardless of the type of turbo or IC used.

M2C, 520-530HP is the safe limit for a WOT Autobahn burner in a 993TT configuration that one could use as a daily driver. Thus my RS Tuning 993TT, although it presently lives in speed challenged Canada.

Tuner1

Does anyone know this car? Associated with Black Forest Racing?

Tuner1

Very interesting. No doubt the learning curve is very steep when trying to build radical engine packages.

I can only dream of living in a land that would permit steady state 300km/h driving without ending up in jail. At least there are plenty of track days that I can attend to test the durability of my car. As Jean pointed out, back-to-back WOT pulls in lower gears (less flow over the IC) can be even harder on the engine than high speed runs.

In my car I have three boost settings at my finger tips that give me approx 510hp, 620hp and 725hp, and most of the time, even on the track, the 510hp setting will be enough to stay ahead of the pack without running the car too hard!