As I'm buying parts for my build, I was originally planning to just get the regular ARP headstuds. But then I noticed the L19s. At around $220, they're a good bit more expensive than the regular ones, but is it worth the cost? Are there people making big power on the regular ones? If it's worth it, I'd rather do things right the first time around, but I don't want to waste my money if it's just a bunch of hype.

 

Its mainly a preference. I dont see any problem using the regular arp studs. There just as good. Me personally I wouldnt pay the extra money to get them!!

 

there is another thread in here about them, If you are not making 700+ the regular ARP's are good enough. That was the general consensus

 

Pretty much what he just said. The standard ARPs are fine for tons of power, anything over 700 or 800 I'd go with the L19's. They're a different material steel I think, and basically will never stretch they're so strong.

 

There is a lot of conflicting information and opinions on the regular ARP headstuds. Some say they are good for 700whp some say they are no better than the stock bolts. Do some reading and make your own determination.

 

The standard ARP head studs are all you need.

 

I personally experienced head lift due to the regular ARP studs in my car. Every cylinder got some blow out... Luckily it was very mild and just pushed a tad bit of coolant and didn't damage anything. I was also on 41PSI on a 6262 full build AMS 2.0 etc etc over 700AWHP. After contacting AMS and ARP i was told by both places that at my level of cylinder pressure the L19s were required. I installed them and haven't had a problem again with head lift.

So IMO the 700WHP rule is a pretty good rule. If you ever plan on getting to or close that level just go ahead and spend the extra and get the L19s.

 

I actually contacted David Buschur about this because I wasn't sure which head studs to use. He said the standard ARP head studs will be fine for up to 40+ psi.

I guess if you plan on exceeding 40 psi you should get the L19's.

 

I posted a thread about this a few days ago and I've decided that the arp headstuds will be good enough for my 600whp and 35psi of boost...I'd probably bend one of my eagle h beam rods before lifting the head

 

Boost pressure has nothing to do with determining when you need a different head stud. It's the cylinder pressure. IIRC, cylinder pressure for normal combustion is in the neighborhood of 2000+ psi...so you're going to tell me 40psi of boost is a determining factor?

Obviously cylinder pressures are going to be directly related to mass airflow, which is related to boost pressure, but there are too many other variables involved to pinpoint a certain boost pressure as the limit.

 

That's true. But if one plans on pushing past 50 psi to achieve a goal of 800hp the standard ARP head studs won't cut it and the L19's will be needed.

I would have explained it the way you did but I'm typing on my iPhone.

 

+1 well said

Everyone seems to associate boost with when they need to change the headstuds, which is not the case... i.e. a bigger turbo will make a lot more power (cylinder pressure) at lower boosts than a smaller turbo.

 

yes. Cyl pressure is the main factor. If you are using Meth/E85 you are using more volume/earlier timing = more cyl pressure.

 

All it takes is one tuning mistake to lift a head!

The L19 studs could mean the differance between just fixing the tuning mistake and having to replace a head gasket.

One time at the track I swapped in an older tune forgetting that I had also made a base fuel pressure change. The result was a huge knock spike in the middle of a 1/4 mile pass. Oops! luckily no damage was done, (L19s and a FelPro 1153-1) I just fixed the base fuel pressure and made another pass.

Well worth the extra $$.

John-

 

good thread.

I've also been wondering the difference. Thanks for the info!