I have a few questions about my newly turbo'd b18b1. I have looked and cannot find a definitive answer. My setup is a t3/t04e Turbonetics with a .63 exhaust side. I'm not sure of the trim. I got it in a used kit. I have 750cc rc injectors, walbro 255 fuel pump, 2.5 inch downpipe to a 3 inch thermal exhaust. The used kit came with a chipped ecu with either a basemap or tune on it. I haven't figured out if it was ever tuned. The kit came off a b18b1. Basically, I want to know how many psi can I run before I need head studs? I plan on getting some soon as my hp goal is as close to 300hp as I can get. I just want to bring the pressure up to make sure all is good before I head to the tuner. I have gone up to 7 psi but too afraid of blowing a head gasket to go any higher. Also want to know if anyone has install ARP headstuds without changing the head gasket by installing one head stud at a time and only torquing them to factory spec until all studs have been installed then torquing them to ARP specs?

 

If your not sure if its tuned properly then don't hit boost at all! Especially if you don't have a wideband in the car to moniter afrs. If your goal is 300whp then put some ARP headstuds in (the right way with new OEM head gasket) then take it straight to a competent tuner.

 

I do have a wideband gauge. It is also an open loop setup. No factory o2. At idle, it is between 15.2 and 16. That's the only time it runs lean. I never go wot so I cannot tell you what it runs then. At 5 inches of vacuum, it's around 12.3. This car is my dd. I have to drive it for a little without a tune for financial reasons. That also why I was asking about the head stud install. I don't have spare money for a new head gasket.

 

Get it tuned or you'll be investing in more than just head studs. Also, PSI doesn't dictate anything - its all about power creation and how well its tuned. Head studs are easy peace of mind and you can install those whenever your little heart desires

 

Okay, I should have guessed most of this was coming. I was just curious if anyone was running a low boost setup, between 8 and 10 psi, without headstuds. I am not beating on the car and when it does see boost, it's only for a second. I will be having my car tuned soon, although I might have to wait until spring.

 

Low boost 8-10psi means absolutely nothing to us...again, its power (torque, more specifically) that breaks parts. As a guess, you would probably be in the mid, maybe upper 200hp range. Head studs are not required at this power level, but again are good peace of mind.

If youre running around untuned, DO NOT get into boost, even for a second. Get it tuned...dont wait until spring. If you must wait to tune, start building a back up engine now - you'll need it

 

On my first setup I was running 12-14 psi max on a TUNED bone stock GSR. Never had any head lifting issues. Only thing that did happen was my oil dip stick tube would pop out due to me not having proper crankcase ventilation system. I was advised long ago, once you go 15 psi and upwards thats when headstuds would be required. Dont quote me ont that though. Just like Schister66 said, you need to get TUNED ASAP. You may not have a running car sooner or later if you keep driving it the way it is.

 

Okay. That was the information I was looking for. I stay put of boost 90 percent of the time. If I wait until spring, I will find a way to store the car for winter. Another question I have is about my exhaust. When I sent my car to a local exhaust shop to have a downpipe made, I asked for a 3 inch to match up to my thermal r&d exhaust. Went to pick it up and they decided to make the downpipe 2.5 inch. Will having 2.5 inch downpipe into a 3 inch exhaust hurt my potential power?

 

Yes, but not much at your power level. With a 3" dp, it may have spooled a bit quicker and made a hint more power up top, but for ~300whp, it wont make a drastic difference.

I'll say it one more time so that it sinks in - PSI doesn't mean anything ... power (torque) is what breaks parts and since we know that Torque = Cylinder Pressure, you can figure out that at a certain torque level (aka cylinder pressure level), the head begins to lift. This is why saying "I ran 15psi and it was fine" is an irrelevant statement.

 

Exactly. 15 psi could mean 200whp or 400whp depending on size of turbo. 15 psi out of a straight t3 60 trim is not the same as 15 psi from a gt35r. This is why it doesn't make sense to ask "how much psi can I run safely".

 

No, no, no... this just won't do. The question does have an answer actually.

Q: How much boost can I safely run on stock head studs?

A: All of it.

I think the horse was dead a long time ago...

As far as head studs being replaced one by one is concerned - YES, it is doable but NOT preferred. I have done this multiple times on OTHER people's cars that are cheap asses / broke. You run into having the possibility of issues but I do a specific method without failure yet.

It's basic but effective.

1.) Start in the normal order of head bolt removal and remove only ONE.
2.) Spray a little brake parts cleaner into the hole.
3.) Use a shop vacuum with a hose taped to the end to suck out all junk from hole.
4.) Lube threads of head stud and install into hole.
5.) ***User preference / Optional*** - Torque head stud into block 10 - 15 ft lbs.
6.) Install nut on stud and torque to factory head BOLT specs.
7.) Continue with Steps 1 through 6 for the remaining head bolts.
8.) Start in factory torquing order and split the remaining stud torque into 2 equal steps. (Some people may prefer to just jump straight to the final number but I am paranoid.)
9.) Double check all your work.

 

Minor tickle - you aren't supposed to torque the stud itself into the block. According to ARP's specs, it should be "hand tight". If you call them and ask what "hand tight" means, the answer is bottom it out, then back it out a quarter turn.

 

Clearly there is a lot I don't know or understand. People saying it makes no sense to ask how much psi can I run safely may not make sense to you but for someone that has very little knowledge of a boosted vehicle, it seemed like a viable question. I came here to learn, not made fun of. I will take everyone's advice and drive it as little as possible. If I have to drive it and I stay out of boost will I be safe?

 

Safe is a relative term.
If you want to learn, go read the FAQ sticky at the top of this forum.

 

Yes, stay out of boost and it will be fine. But for your engine's sake, get tuned soon or limit your driving as much as possible.

The annoying "how many psi can i run" question is the oldest one in the book - those of us who have been here for a number of years (see Join Date on Profile) have seen countless posts asking about "what psi is safe" and "how many psi can i run" and what we're trying to point out is that you're asking the wrong question. Its not a matter of psi because the power an engine makes varies depending on the turbo you're using - bigger turbochargers make more power than a smaller turbos at the same boost levels; therefore, running 14 psi on a small turbo makes much less power (and causes less internal stress) than 14 psi on a really big turbo. The factor you're comparing (PSI) is the same across both, but means entirely different things. What you need to consider is the power level.

 

Thank you, finally a decent answer. I don't post very much here because of all the bashing and unnecessary comments that people make. If you don't like things that I say, you do not have to answer. The biggest reason I ask about driving is the closest reputable tuner to me is 3 hours and I have no access to a truck and trailer. I have to drive it to the tuner so I needed to make sure as long as I behave and stay away from boost, I have a decent possibility of making it there in one piece.

 

Ya know, there's a really easy way to stay out of boost - disconnect the charge piping. Done. Problem solved.

 

I built my first turbo setup when i was 19 in practically the middle-o-nowhere (grand forks, north dakota) and had to drive nearly 5 hours to get tuned. I built the setup, drove it carefully to get all the bugs worked out, and then made the 350 mile trek to the tuner - all at a blistering 55mph. I got tuned and drove home all in the same day (295whp/192wtq on a log and 60 trim @9psi, stock GSR). If you skip the important part of the setup - i.e. Tuning - that setup won't last and when it does run, it wont run well.

Work the kinks out of your setup (so as to not waste your time and money at the dyno), save some money, schedule a tuning appointment, take a day off work, and get it tuned properly

 

I dont get why people wont do this... Its so easy and so much more safe for their engine.

 

Did you read the part where I said USER PREFERENCE / OPTIONAL??? Everyone has their own ideas and I even stated as such. I am well aware of what ARP recommends as I called them myself about this very subject. I have even talked to people like Benson, Lasky, Darton MID, Golden Eagle, etc... each has their own views. In my experience not bottoming them out causes a soft stud of sorts. You get the same phenomenon when over torqing a bolt right before it shears. I have always torqued them and never had an issue. However, I have seen some people develop cracks over years of abuse. It all comes down to build - Is it sleeved? If so what brand / process? How much cylinder pressure / heat will there be? Many avenues to explore... so again, personal preference as stated.

 

I did read it, I also always prefer to follow manufacturer recommendations. Unless you have tools and solid proof that their way is wrong? Didn't think so. In my engineering experience, bottoming them out causes a lopsided pinch at the union point, whereas installing them to spec creates a proper sandwich.

 

The whole backing off a 1/4 turn drive me nuts from an engineering point of view because your affecting the friction consistency. The bolt can turn in the threads or not spin, with the inherent problems of loading the head studs with the torque wrench method. With that said I only torque them down like 5lbs. I have personally seen a block someone mess up a block by over torquing them. The oem method of seating them backing off and then re-torquing to a certain preload then add so many degrees ensures a proper strain value. Which is a much better way to ensure each bolt is pulling with roughly the same load.

 

Without tuning the car literally everything else is pointless. No tune, no point.

 

Did you actually read my rebuttal? I am in agreement with you as well as stating my observations from experience. Again, it is personal preference. We all know engimaneers aren't always right and it gets proven time and time again but I am not saying it applies to this subject, but if you really are an engineer then you understand exactly what I am saying. For instance if we ran Wiseco PTW recommendations on our engines most people would have contact issues. It has been proven multiple times. I hope you understand I am siding with you and against you at the same time. Then again, mmMMMmmm sandwich...