Thats true. I call everything a debate. I was just tired and typing away. Im basically "overhaulin" over here right now, except im alone.
Finishing up 2 big builds and im worn out.
Bottom line, every chef has a different recipe for the same dish.
Remember... just because a few big names do something, doesnt mean its right or lasts very long at all.
My builds are meant to be as reliable as a bone stock s2k. And thus far all have proven to be just that.
There is one exception, but its due to the fact that the owner likes to tear it down and change it once a year..lol.

 

I havnt had experiance building a F20c yet, but for every B series, H series, even D series build I have done ARPs were always the way to go for boosting a nearly stock engine. (which I thought was the point of this thread) I know the F20c is a different animal and the OEM bolts are way better than say D series lol...just saying seems like these bitches keep heads from lifting??? I know aftermarket headgaskets are poop and they seem to go hand and hand with arps so thats probly why so many assosiated failures??
Anyway I know Im just doing ARP studs and a 2mm gasket to get a real boost fix while building a bottom end on the side. : ) We will c lol

 

If some of you would actually call ARP and talk to them about their standard studs for the S you'll find out that the power some of us are making on them isn't the safe thing to do.

 

Dude! we HAVE called. thats the thing! the tensile strength of the Chromoly Alloy stud compared to the heat treated oem bolts is much greater. and there are people still on 100% stock motors making 400+. so even if the 87 Alloy isnt quite 2x as strong, that still puts them in the ballpark of 700whp! how is that not sufficient for members on this site?

and in terms of safe hp on a turbo car, there are for more things to worry about failing when it comes to turbo issues with the S and reliable HP. i would think that the frequent issues would be a much larger concern.

 

Hmm, why so many ARP "failures" then? Or did a few people get a bad taste in their mouth and spread the word.

 

BTW PSI is the same everywhere. Here you are not measuring power but the actual pressure. The engine will still see 25 PSI of pressure no matter what turbo or what engine you have it on. Your thinking about CFMs.

 

Yes but 25 psi from a bigger turbo will still cause way more stress than that of a tiny turbo. Yes its a difference in CFM and that does make a difference. If I am wrong please let me know cause it seems pretty common sense.

If one turbo makes 10 hp per lb of boost but the other makes 30 hp per lb of boost, its obvious that the cylinder is seeing a lot more pressure with the bigger turbo. Volume plays more of a role than PSI in this matter. That's why I say its more of a power rating than boost pressure rating.

TeamValorracing - Yes I understand that the ARP tensile strength exceeds that of an OEM bolt but for whatever reason some ARP's arent doing so well as the OEM's. Just my thoughts.

I don't claim to be an experienced engine builder, but I do tend to listen to many of them along with taking some common sense into consideration. Who knows what the real reason is for 3mm HG's blowing and guess what? No one will ever know EXACTLY what caused the issues. The only thing everyone is basing failures on is it's track record.

Like it was explained to me, that 3 mm of metal between the head and the block now becomes the stress point in the cylinder so guess where pressure tries to escape. Maybe there are some underlying issues that people aren't seeing? uneven surfaces, debris, pitting on the deck or head surface, Under or over tq'ing the ARP's, wrong TQ sequence, wrong lub/oil, detonation, I mean the list goes on and on. It's practically an unarguable topic.

 

its nonsense dude. think about it. its like saying, "this grade 3 bolt is stronger and better than a grade 12.9."

i would link the failure to installation error. because pound for pound, alloy to carbon, tensile strength to tensile strength, the ARP will outperform an oem bolt in higher stress applications.

as far as 3mm failure. allow me to put it this way: the point of the gasket is to seal two pieces of metal together and not intrude on the surface combustion area right? well when you thicken up that space, suddenly that FRM wall stops, becomes a mixed metal thick space that now has to attempt to seal and hold combustion as well as the solid cyl wall. and that is just not possible. combustion is extreme, thats why we have solid cyl walls.

just run the oem gasket, build the motor the correct way for the hp you want. and if you are going way over oem compression with a substantial amount of boost, invest in some studs that will keep the head clamped to the block and not stretch and lift under extreme load.

 

EXACTLY! Let's end the debate lol. Run the stock HG and take everyone's recommendation throughout all the threads that cover this topic. Hell, my 3mm just blew 2 weeks ago so I said fk it, put in the stock HG and now things are perfect and troublefree Oh yeah, and I re-used the ARPs which are working just fine.

 

Cylinder pressure and manifold pressure are completely different. This is where people have a hard time understanding. Just because the intake manifold has a certain amount of pressure in it, does not mean the cylinder pressure is the same. A larger turbo will flow more air at the same manifold pressure. More air in the cylinder allows for potentially more cylinder pressure(basically what creates the energy the engine produces). So think of the headgasket as seeing cylinder pressure, not manifold pressure.

So think of it like this. Your tb and intake manifold gaskets see manifold pressure (this is why there are not multilayer steel) and the headgasket sees cylinder pressure ( much greater than manifold pressure)