According to Rob the 993tt should have the same limits that the 996 does. I would tend to agree. I don't want to discount Stephens experances. He has had his hands in lots of motors. Other than those ah em marks he had at the shootout he seem like a straight shooter.

Last dyno pull I had 502whp and 504 wtq on a awd mustang dyno. I am addicated to the power. If I vent the block it will be major$$$. It maybe time to run 1 bar (instead of 1.2) and break it down this winter. I thinking of gathering parts now. GT3 crank, carrilllo rod, 3.8 kit and RS cams seems like a good place to start. I am also thinking of doing the same turbos that you have.

In the mean time I will continue to admire your build.

Kudos to Kevin, looks like he got bitten by the same bug as you!

 

Never spoke of a bottle. Why would you suggest that?

Kevin you need to look at the motor in two different halfs. One half is above the piston and one half below. While I agree that a water cooled motor benifits from greater bore stablity due to controlled temps the benifits below the piston do not translate. Both motors are oil lubricated and cooled below the piston.

Connecting rod and bolts are hardended at XX degrees. You cannot remove the heat treating of said components by introducing temps below that level. While I would agree that higher oil temps (above oils operating range of 250+ mineral and 270+ synthetic) does increase wear.

Stephens findings are interesting. I would like to know more details.

Stephen has earned my respect from the conversations I have had in person and the way he presents himself online. I trust his opinion and experances.

Kevin you and I have butted heads far to often. We need to get past this as we could both learn a lot from each other. You have to understand that I have had my hands in LOTS of motors. Just because they are not porsches does not discount my experances. In the future I would like factual based answers. I always give a strong factual case for my POV.

You on the other hand have not always given me the same courtesy. I feel like this all started after I elected not to buy your turbos and go to another turbo house for my upgrade. I was able to do what you said I could not.

Lets wipe the slate clean. I have a lot to offer. You and I share the same entusiasm. Lets put it to productive use.

 

K24,

When I made the statements above I was talking about the stock rods. I don't know where the Carillo rods would take the breaking point to.

Again, I don't have any personel experience with this motor. Someone must have tried it. Kevin or Stephen, have either of you built a 993tt motor using the Carillo rods? If so did these rods bend or break and if so what torque or power range were you using? I believe this is the information K24 is looking to assemble.

 

I have done a lot of 993 motors with Pauter and Carllios. We have yet to break one of those. Keep in mind that if you use one of these rods you need to profile the oil pump...always.

Tom,
You have to take into consideration that the temp of the cylinders and pistons are still going to be far greater than that of the 996. The heat coming from the cam housing out to the case will carry more heat then the 996TT. The 996TT has the same type of channeling, but rather than trying to cool the assembly, its primary purpose is to lubricate. The oil is naturally cooled by the water passing over the cylinders etc. The friction becomes less and efficiency goes up.

Bolts stretch for many reasons. The out ward torque and trust will be affected by the overall power. Let me see if I can explain the difference n wear. When on the dyno with a stock car the sweep takes for ever. When the car becomes modified that same car rips through the dyno. Things are pushed ut harder and faster, even if that RPM limit is the same. The end result is that stock bolt can not handle it. It slowly pulls apart. The rest is history.

Obviously huge power will cause downward movements and

Thanks for the kind words BTW!

 

Make sure in your engine build that you replace all factory hardware with ARP or raceware. Its the best insuranc you can buy for your motor. And yes from allmost all the porsche motors ive delt with the rod bolts breaking loose caused the damage.I would listen to stephen and CJV all have alot of great info to give up. Allways use carillo H-beam rods and CP pistons.

 

Thank you Steven, Chad and mpwrmodena for the informative response. I have turned the boost back to 1 bar (grrrrr) and will start collecting parts for the tune up.

Rods, RS cams, ARP hardware and look into better head sealing.


I would like to retain stock pistons. Do you see any problem with that Stephen?

 

Not at all. The factory pistons are pretty good from the get go.

 

Kevin will the Carillo rod bolts stretch or how about ARP bolts?

 

Thanks Kevin I will do that upgrade on the rods when I order them.

Not to beat a dead horse. But I am still having some trouble understanding something. So far all of the refrences have still been to HP and not torque.

Stephen and Kevin if you could both reply to this in a scientific manner I would be greatful.

If the limits are say 550hp (993tt) and one car hits that number at 6,200 rpms and the other car hit it at 5,200 rpms (because of higher torque at that RPM) how can the ill effects be the same?

Lets say the 5,200 rpm car has a peak torque of 450 and the 6,200 rpm car has a peak torque of 400 how can the damaging forces be the same?

FWIW this has been the foundation of my safety. Keep peak torque levels at approx levels of a stock K24 setup but carry them further out the RPM band to create more HP.

THIA

 

Those were fun days!!! I remember going, "Kevin, let's go bigger etc..." and then after talking to Joan you were "Take it easy fella your rods will already be in bad shape" lol...

 

Any ETA on your beast Alex???

 

Actually Kevin, one of the biggest problems with the 996tt motor is excessive thrust bearing wear. We discovered what causes the problem and came up with a fix that works extremely well. In addition ....... the fix is cheap as long as you implement it before the wear starts to occur.

With the exception of one board member/tuner who asked if we had experienced any wear problems here, I don't believe anyone else is even aware of this problem.

 

I'd guess the hotter air cooled cylinder head would be more likely to give combustion cylinder pressure spikes vs the water cooled head (borderlind detonation). Also the shorter duration cam of the 4 valve head may extract more torque from each combustion.

 

Chad,
Would you mind sharing your information for curing the excessive thrust bearing wear? When my motor was recently torn down, excessive wear of the thrust bearing was observed along with excessive crank end play. My motor (GT2) had 6400 miles at the tear down, 5000 of which were at Stage IV (502 RWHP & 503 RWTQ). Thanks for any information you can provide.
Cleve

 

I have more info in that thrust. I have been told by very good powers in the Porsche world because of the movement in the drive train Porsche built that spec in. They call for almost a 6 thousands clearance on the max wear. They also said that removing that play will cause worse damage as it relies on this play.

Doing some research shows different models of Porsches with similar drive train movement (not 911) can carry up to 10 times that amount of movement. Most are on the lower end of scale according to the book. I think the confusion is looking at the older Porsche turbo specs. They are far tighter than that..