@ these power levels it's about choices that follow with consequences! My tuner says other wise! heck even Mark said "I wish I had one". Even the stock crank can be machined for pennies! If you invest that kind of money why not play it safe! JMHO...tom

 

Why Does Porsche put a different crank & oil pump in the GT3? hmmm! before you say it, yes because it revs so high, but also for proper cooling & lubrication! these cars are the ones that Porsche knows are the work horses!!!! My machine shop that did my case, just got one in from a GT2 that spun 5&6! Why?

 

I heard knocking both times... when a bearing is spun, it sounds like a monkey with a cresent wrench inside your block. I thought that I had broken a rod both times. When the oil pan was removed we observed all rods and pistons in perfect working order. There was a gap between the rod and the crankshaft that was only a few thousanths but this is what caused the knocking.

 

What people dont understand is that the damage is cumulative! Both times my bearings went I was crusin, all of a sudden KABOOM! WTF......A again the rods weren't bent! When you dont have enough lubrication, metal on metal =KABOOM

 

Marty, DMK's stock internals were well tested as well ....up until the point it grenaded. This is a difference in philosophy, nothing more. If Todd is satisfied with a stock crank then that is his and the client's decision. Kevin, Tom and myself did not see the benefit in going 90% of the distance with this engine build, and not addressing the crank. I havent said that anyone needs to do this rather explained why we have chosen this path. My thoughts are that I can afford to build this engine correctly once...I cannot afford to do it over. It does make for an interesting debate as to why the street GT3 does not use the turbo crank if Porsche was fully confident in its abilities above the stock TT redline.... Again, the crank is no different than EBC vs Motronic, 1 file fits all vs multiple specific files, leaded vs unleaded, emissions compliant vs non emmisions compliant etc.... Different philosophies, nothing more. Be good, kevin

 

We are in no man's land after 7500 rpms... Ill be first to say. But Ill also say that its very expensive to do gt3rs crank and custom rods... so when we are doing these build outs... at 30,40,60, or even 80K a pop.... pennies count.
I would love to do a 4L or 3.8L at least with gt3rs crank and custom rods... but thats another $10 to say the least. I passed. I didnt have all that cash.
I rather put the money into the heads and cams.
just my opinion... in retrospect I wish I had the extra cash casue now I would be revving to 9K

 

Mark wants one to rev to 9k, not because he's necessarily worried about damage at 8.2k.

As far as "choices that follow with consequences", if I thought there would be any consequences with using the stock crank...I'd swap it.

My tuner could easily earn increased profit by recommending that his customers upgrade to a GT3RS crank...but since he doesn't believe it's needed, he doesn't recommend it.

As a matter of fact, Todd told me he feels the GT3RS crank can even possibly be a bad thing. Since the oil passages are drilled all the way through, at low rpms with a high torque engine...it can cause the rod to squish the oil out back through the oil hole, which can cause it to contact the bearing to the journal and...ouch! Of course, the GT3's won't have this problem since they don't make a lot of torque (respectively).

Instead of swapping the crank out on my car, Todd is bumping the pressure up on my oil pressure regulator to maintain better lubrication at high RPM.

Anyway, as has already been said...different tuning philosiphies.

 

+1. Todd Z. told me that I did not need GT3RS crank. I was prepared to pay the price if he recommended it, but he did not.

I am told that the the benefits of a GT3RS crank are not meaningful until north of 8k rpms -- I am well below that threshold.

As with Scott, I would have a GT3RS crank if I believed any adverse consequences would flow from using that stock crank.

Craig

 

Looks like I will have to stay above 8K rpms...
Scott, if you re-read mark's post ...he is concerned above 7500rpms..not 9K. Kevin

 

KPG,

You are the new 9K man!

We want video (digital) of this motor singing above 8K...soon.

You will have a great motor, I hope the assembly goes well.

MK

 

I simply don't know how many of us online are going to 8K... Im sure less then a handful... I sure would not keep it there for long... even if I had a gt3rs crank... it's just scary....

 

.............VRalexander has been reving to 7.8 to 8k for a very long time now. With no issues.

 

So i've heard...maxing out in 6th gear...and he has 10k+ miles... on stock crank

 

If you want to play in the 9-10K world and survive you need to do this. It isn't cheap, but you will have plenty of pressure and volumn and your motor can stay there all day long.