I am starting to think about a rebuild on my Rturbo motor at some point in the future and I'm looking at getting the parts list together. I can get the Titanium connecting rods from RUF for around $4300 for the set. Also looking at the 3.8 Mahle pistons/sleeves (don't know if that's worth doing) along with a GT3RS oil pump and a GT3 crank. If I recall correctly, those were the main items mentioned by my engine guy. What else would be recommended for a 650 crank hp track motor? I would like to have a higher redline maybe around 7500 or so. What is needed to make the motor rev reliably to the 7.5-8K level? I do not NEED nor WANT more power than that as it's useless at the track. I never have or intend to take my car to the drag strip, nor am I concerned about stop light bragging rights or street racing. What I am concerned with is engine flexibility (higher RPM), durability and reliability when running 30+ minute sessions at the track. I'd like to keep the parts list under 15K ideally. Please refrain from posting info or suggestions related to exotic 1000hp builds as that is not what I'm looking for in this thread. Thanks for any input.

 

very interested in this thread! Want to do a very-similar build in next couple years.

 

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It not worried about the Ti connecting rods?? Light and strong but have read that just don't do well under high HP applications over a period of time.

 

Sorry...ur not worried about.

 

What is considered a high HP application? 650 crank? RUF uses Titanium rods them in their 650hp motors and their cars have proven themselves to be utterly reliable, as they would need to be, as production cars. For example, I have over 50 track hours on my 550 Rturbo motor without any issues (my motor has stock rods). That is why I'm considering them and also due the their lower weight. All GT3s come with Ti rods and there are no issues there. Maybe the Ti rods are not a good idea for 800hp car but that is not what I'm after. I'm looking at doing a 600-650 crank HP motor with a 7.5-8K redline. I really don't know much but just trying to gather info.

 

All titanium rods have a scheduled motor breakdown to check for stress. When a titanium rod lets loose there is NO warning. You cannot tell when they are ready to go without doing a tear down and checking the rods.

I wouldn't lose any sleep over rotating weight. yes, it helps, however there is a point where torque suffers. Besides you can take weight off rods, pistons, wrist pins, crank shaft and harmonic balancer.

You guys are going to ware me out. Hope it has been a small help ... bye.

 

I'm not trying to wear anyone out, just asking questions and trying to understand why RUF uses titanium rods in their 650 hp builds or why Porsche uses TI rods in the GT3 is they are so flawed and maintenance intensive when steel rods would be so much better. I'm not committed to anything yet. Part of a decision making process is looking at the pros and cons of all options. I hope that's not difficult to understand. I do appreciate your input.

 

So what rods would you recommend for my application with a goal or safely raising the redline of the motor as mentioned in my original post?

 

CJV and his comments in some distant thread is pretty well the source of my reading. I do love the idea of light weight TI rods myself but like you can't define a relative term like high horsepower. Best I can say is that if you have enough power to break factory rods you might be in the high HP spectrum! Pros and cons for sure and I certainly don't have anything conclusive to offer but interested in other comments. Iv got a set of pankl Ti laying around but I certainly would not put them in my car. Can't really afford one motor build much less two.

 

The titanium rod does have a life ..... just a lot shorter than a steel rod. If you decide to go with titanium then know in advance what the manufacturers suggest tear down and inspection is.

As for the why of using a lighter rod ..... response time. It takes less hp/torque to rotate less mass. With the rotating mass being equal the lighter rotating mass will get up to speed faster.

Take 5 grams per rod on a 996tt motor for an example. 5 grams times 6 rods times 4000 revolutions per minute calculates to a 120,000 less grams of rotating weight per minute. This transulates to a nice savings or work (hp) or more work produced with the same hp. Hope this helps.

Just keep in mind, reducing rotating weight by too much reduces torque. Furthermore, you can safely lose more weight in the harmonic balancer and crank and to a lesser degree with rods, pistons and wrist pins.

 

Great. That all makes sense. I just assumed that Ti rods were pretty much a must for a higher revving motor but that doesn't appear to necessarily be the case. Like I said, I'm just getting educated.. Thx

 

I like where this build is going but will say that Ti rods aren't the best idea for true long-term durability/dependability as has been said above, tracked GT3's have had rod failures from fatigue. End up with same issue as stock; worrying about the rods....
Personally will be going with steel rods, although still unsure what brand, when the mod budget allows me to do a rebuild/upgrade.
Cheers,

 

Ditch the Ti rods and go for a set of Carrillo's, there service life will be way better and there quality and strength is better then you need which is a good thing.

Spent the extra money on the valve train, that is one of the weak links if you want to rev this motor past about 7300rpm.

Seriously the Ti rods would be a mistake especially at over 2x the cost of a set of Carrillo's