"think" I know??? ^^^

i've owned a couple evo's and my brother in law owns an evo shop, EVERY customer is advised to use headstuds when boosting 30psi.. You're gonna have to do more then qoute a few threads

It's good advice period

 

Yes think you know, yes headstuds are advised* but not necessary when the car most likely won't see over 500 hp, i don't care about you or your brothers shop, there are many shops around that will advise its not a necessary step, so its a matter of opinion. Your basically giving the aura that if someone runs 30 psi they will lift the head due to the stock headstuds, i myself won't waste time on searching for you so you may do it at your own will, i've owned a couple of evos too and diy everything from tuning trannies etc, check my profile ive been here quite a while longer.

its good advice yes, but so is installing an exedy hd, wiseco pistons, manley rods, but these are not necessary for a stock turbo e85 evo.

so as ive stated do your own research and you'll find both yes and no across these forums from the top tuners down to the hobo next door.
goodday

 

You said do my own research before giving said advice... What is that crap?

It's a new evom screen name - I've been on this forum since 2005 and i know more then you about evos.. blah blah

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So before YOU start giving your opinion on stuff listen to the next jerk off who wants to contradict your posts and be a know-it-all

 

you know what i'll just keep this on topic, i won't fight over who knows more or who can do what, i do my own work to my car , and based on my personal opinion from reading countless threads on here , more than others, research headstuds and come to your own conclusion, if you feel they are necessary buy them and have them installed, are they added insurance? yes they are . But are they necessary for a stock turbod e 85 car?? i say no.

good day

 

A lot of people read these forums looking for good advice ie. added assurance (Head studs)

Bad advice would be more like.. "no headstuds necessary for that 450 foot pounds of torque you plan on making"

 

Upgraded headstuds are NOT necessary for that. Sure it would be nice. Required? No. Necessary? No.

 

actually i recommend against them. the only time i swap them out is if someone is having the head taken off for any reason, or if they want the studs replaced and are willing to pay to have the head removed and done with a new gasket.

and i own an evo only shop, so i think its safe to say i have experience with evos

i've seen melted pistons, broken ring lands, rods thrown, thermostats fail, waterpump freeze plugs blow, but never once a failed headstud. even the freeze plug blown was because of a failed thermostat, not "lifting the head" because he was running 30psi. how many E85/meth/racegas cars have you tuned with stock headstuds? i'm sure its safe to say i've tuned more then you, and guess what, still no failed headstuds.

i'm actually in the process of testing the tensile strength of the stock bolts, and an ARP stud (hopefully a few others as well). we will let the instron machine tell us how much of a difference it makes

 

On topic E85 is AWESOME stuff! Use it, Love it, its a poor mans race gas! I was one of if not the first in the area to do it, and I love it, Im currently back on the 93, but 1/4 tank way from being back on the corn. I switched back to 93 because non of the local tracks have e85 close and I wasnt into carrying around a 55gal jug to do a track day, so I guess I would say the only bad thing I have found is NONE OF THE TRACKS HAVE IT!

Off topic: Please discuss why head studs are better?
The ONLY time I would put head studs on a car are after the head has to come off for some other reason (porting, upgrading, engine build etc), and why do i recommend it then, because it makes it easier to get the head lined up when it goes back on.

Do you know what is the Alloy, the hardness the, the Tensile yield strength of the stock VS the ARP head studs?

Why are they better?

This is one of the arguments that drives me CRAZY! Below are my opinions, and thoughts on the matter with some data. Am I wrong, maybe, but i have seen a lot of motors blow, and never once have I seen a head stud failure, I have seen a head gasket failure, never due to lifting a head off. You are far more likely to launch a rod out the side of the block or melt a piston, then blow the freaking head off the car because your head bolt failed or stretched.

I did a little research. While ARP does not come out and say it, the head studs are either 4130, 4340 or 8740, or their special ARP2000. Just looking at numbers alone...

Tensile Yield Strength - all numbers come from Machine Design 3rd edition - Robert L. Norton
4130 min 52,000psi - max 212,000psi
4340 min 61,000psi - max 230,000psi
8740 min 60,000psi - max 133,000psi
The minimum values are in the fully annealed state, so its pretty safe to say they can be omitted.

ARP Materials Info Taken from - http://www.arp-bolts.com/Tech/TechMetals.html
ARP 2000 min 215,000psi - max 220,000psi
8740 (with APR HT) - min 180,000psi - max 220,000psi
L19 min 230,000psi - max 260,000psi

Lets assume the Stock Head bolts are equivalent to a grade 8 bolt - I'm sure they are much better but thats a good base line to work from.
Grade 8 bolt min 130,000psi - max 150,000psi - From http://www.tessco.com/yts/customerservice/techsupport/whitepapers/pdf/bolt_grade.pdf

Best case scenario for the ARP bolt to stock is that the stock bolt is in fact Grade 8 quality - your max "insurance factor" is Stock Bolt Grade 8 VS ARP L19 bolt

Grade 8 - 150,000psi VS L19 - 260,000psi you have a 73% increase in strength.

Lets talk more about reality - which as Kevin mentions earlier, we are going to have some testing done to put this argument to rest once and for all.

The arp head studs are probably the ARP2000 material and the Stock studs are probably 4130 material, if you look at the case, your Insurance factor is only 3.7%

Now think about a bolt , have you ever broken one? where does it break? The shank??? NO the threads. That being said, what is the weakest link in a bolt, again the answer is the threads. So look at the stock head bolt closely it has one set of thread at the bottom where it screws into the block and under the head is a nice little stress reducing radius form the head of the bolt to the shank. Now take a look at the ARP head STUD... it has 2 sets of thread, one at the bottom that screws into the block and the other at the top where you screw a nut on to the stud. 2 sets of threads, 2 weak links.

Now lets look at the block, it is made from some sort of cast Iron, not sure of the exact type, but again there is a best and a worse case in this circumstance.

According to Machine Design 3rd edition - Robert L. Norton
We have to look at Ultimate Tensile Strength because this is case iron which by nature is VERY brittle and will fracture with yield rather than deform.

standard Cast Iron - min is 22,000psi and max is 62,000psi

There are specialty cast irons that are ductile which the block could be made of, again I do not know the material it is made of only that it is made from some sort of cast iron.

ductile cast irons have a Tensile yield strength
ductile - min 47,000psi max 120,000psi

So the best case for the block would be ductile and 120,000psi which is still 25% less than a standard grade 8 bolt. This means you will pull the thread out of the block before you will break the bolt. Does this always happen, NO, look at the turbo bolts, the bolts break in the cast iron housings all the time, there are a lot of other factors involved heat, oxidation etc, but you get the idea. Also, there is a torsional force associated with removing a bolt which is not present when talking about lifting the head. If you think just of lifting the head, pure tension loading, the threads in the block will pull out before the Grade 8 bolt will break, so what is the purpose of a stronger head stud again?????

Also, head gaskets are a one time use item anyway. You torque everything down, the material sets, compresses, and that is how it is to remain. When you replace head studs you remove move the stock bolt, unseating the head gasket then re-torque the gasket with the head stud, to me this sounds riskier then just leaving the stock head bolt in there. And the small amount of "insurance" you might gain by using ARP head studs is not worth the cost to remove the head, replace the gasket for no reason. Again Ill restate, PUT THEM IN IF YOU HAVE A REASON TO TAKE THE HEAD OFF IN THE FIRST PLACE!

Now, I just did all this in a matter of 20mins or so, and Im sure I have missed some details, but and bring on the comments from all the material specialist etc out there..... I didnt look at everything, I do not know the exact loading, and I am not a materials expert, I took 2 classes about materials in school then worked in a failure lab, and I just took a quick look at the basics in this case, but thats how I feel about head studs. When we get around to doing some actual testing in the lab we will have some measured real life results!

 

The answer is yes. As said you would need to upgrade your pump and get some bigger injectors. Remember you will use about 30% more fuel so you need at a min 30% bigger injectors to keep up.

The biggest gains you will get will be from more timing, but you will not see the huge gains that evos see with the turbo.

 

Its amazing change from pump/race gas. Q16 is 75 for 5 gallons here and e85 is 2.39/gal. The benefits are better with the corn, and you get a cleaner engine. And also 12k on 30 psi and stock headstuds. i have apr headstuds sitting around just havent installed them.

 

E85 is definitely the way to go! The only thing that sucks, is that hardly any gas stations have it.

My friend installed a map switching box that he built, so when I can't find an e85 station, I just fill it up with 91 flip the switch and revert back to my 91 tune.

 

I am too lazy but plan on running e85 here pretty soon, unlike many others i've done the research and agree with kevin , in that if the head has never been taken off you don't really need headstuds, sadly im just too lazy to start the project.

I know of two stations on in keller/ north richland hills, and one near midlothian i think?

 

wheres the keller one at?

 

Where's the one near midlothian? I'm moving back to midlothian on wednesday, and need to fill up the car when I get there.

 

There is an e85 station on highway 26 in NRH, and a station that is operated by classic chevrolet off of 121 in grapevine (next to the hummer dealership). I have used multiple e85 notification sites and have yet to find a location in Keller. There is a nice location in Crowley though that is just down the road from MSRC.