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What you have to remember is that HKS turbos are desighned to give their best at a fair bit more pressure then 15 psi, closer to 22 psi would suit them better and then they would realy start to show what they can do

Garrett/HKS these days there really isnt any difference.

What you would apply to one, you would apply to all.

Was a bit different 5-6 years ago while Garrett were all over the place, but not-so now.

Turbos are virtually identical

zaneafsdkfaskd however its spelt.. i cant see it atm so i cant spell it.

do u build motors for a living??? yes?? no?? shut up. u dont build shit otherwise u wouldnt be sayin the bullshit u say

i have never seen a rod let go (under normal circumstances) due to power increases. 17psi is rubbish.

increasing boost by 5 psi is about what?? 40kpa? not even? in a combustion chamber thats sittin in the 1500kpa+ 40ish isnt goinna do shit. so listen to everyone else and shut up and LISTEN.

rods are rated @ hp not boost.. and stock rods are rated to roughly 100hp each. u should make around 600hp with stock rods. whether ur doing it with 5psi or 25psi.

Yeah I think both of you make fair points.. But in what ive discovered boost will f**k an engine.

Rb20s have strong bottom ends, which id say is why you could run alot more boost.

To much boost will cause detonation, but thats only if you dont have supporting mods.. I.e if you smashing 20psi through it with a SMIC your engine is f**ked.. if your running all the cooling avaliable and making big power and no detonation you will be fine.. up to 280 is about the max for any engine (RB range, minus 26s) after that the bottom end, rings, and so on are not strong enough from factory to keep up with the power for a extended period of time.

So in all you are both right.. so I guess you guys should shush now.

All I will say is Supporting mods, Supporting mods, Supporting mods......

Dont' slap this here biggun turbo on the side of a completly stock engine setup.... I mean, stock injectors, stock cooler, stock fuel system, etc.

Stock bottom ends are fine. Mavric has run up to 22psi with his RB25 with an old school T3/T4 hybrid. He was making 280kw atw.

zaneafsdkfaskd however its spelt.. i cant see it atm so i cant spell it.

do u build motors for a living??? yes?? no?? shut up. u dont build shit otherwise u wouldnt be sayin the bullshit u say

i have never seen a rod let go (under normal circumstances) due to power increases. 17psi is rubbish.

increasing boost by 5 psi is about what?? 40kpa? not even? in a combustion chamber thats sittin in the 1500kpa+ 40ish isnt goinna do shit. so listen to everyone else and shut up and LISTEN.

rods are rated @ hp not boost.. and stock rods are rated to roughly 100hp each. u should make around 600hp with stock rods. whether ur doing it with 5psi or 25psi.

Did I hit a soft spot? Mi scuzi.... :rofl:

No need to get upset now and have a teary. If you go a problem with me, PM me, I'll be more than happy to fix you up, as I said, stop high-jacking the thread.

Start your own thread if you want to argue about boost levels.

MORE BOOST = MORE DAMAGE full stop! :)

Cheers :D

dude ur the dick here. u dont build motors. u just guess. u can get more hp via other means which will break rods instead of upping the boost.

Detonation due to higher boost levels means ur not cooling it down properly like someone said.. SMIC or inefficent front mounts.

u could run 40psi and make 150kw and u wont break anything. or run 10psi and make 400kw and break everything.

its simple

Mate what don't you understand? I seriously don't know how else to explain it to you, I am beginning to think your retarded....

This is the simplest way I can put it, don't give me a bullshit answer, just 'A' or 'B':

What car do you think will last longer, a car running 25 PSI (A), or a car running 10 PSI (B).

Now you may say, "yes, but with supporting mods and good tune blah blah blah you can run 25 PSI safely"

Ok, fine, have it your way, even if the car does have the supporting mods to handle 25 PSI, do you think it will last longer on 25 PSI or 10 PSI.

Don't forget, ANSWER THE QUESTION, A or B?

Seriously, it's not that hard understand. :D

If you answered A, I should slap you senseless with my dick. If you answered B, I am glad that what I've said finally got through that retarded head of yours. :)

u can get more hp via other means which will break rods instead of upping the boost.

I know, I never said you can't increase HP via other means... You answered the question yourself. Simple premises, and I'll define them for you... Ready?

Premis 1: In the sentence above, you expressly admit that more HP will increase the likelihood of engine damage.

Premis 2: We all know for a fact that winding up the boost increases horse power.

Conclusion: If you wind up the boost, you will increase horsepower, and thus, increase the likelihood of engine damage.

Was that simple enough for you? :)

pick a turbocharger that has a compressor map that dictates your power requirements

then theres no need for guess work or picking random PSI figures from thin air

select the power you want

--> select the turbocharger that suits your power

---> based on its compressor map, pick the PSI the map dictates for given XYZ airflow cfm

At the end of the day you need to run the right turbo at the right boost pressure to get the right result. Here’s an a or b question for you, which engine will last longer

A: Stock rb25 with a T88 running 14psi making a shite load of power? or,

B Stock rb25 with a small as buggery turbo running 30psi making no power?

The point here is that the tiny amount of extra pressure ure adding to the cylinders from an extra 5 or even 10psi of boost (going from 15psi or whatever really) makes a very tiny difference, like will the car last 10 years or 10 years and 2 days.

High revs, shortens engine life, detonation shortens engine life, an extra 3% (at most) of pressure on the rods/pistons does not meaningfully shorten engine life.

zafeniak,

Why bother asking a question?

So far you have listed a few snippets of info from a thread, posted your views and then told every1 else they are wrong when they disagree. Quite simply if we are all wrong why bother posing a question to us in the first place. If you want to run standard boost and try and find other ways to create power thats your call. Personally ill go with the tried tested and proven method of winding up boost with adequate supporting mods.

Quite simply your showing your arrogance and ignorance in regards to engine building and modification in general. Not to mention a complete lack of respect to pretty much everyone. It would seem you dont actually have a huge grasp on the workings of an engine, and as such rather then listening to the advice of others WHO ALREADY RUN INCREASED BOOST SUCCESFULLY, you choose to insult them all systematically.

Enjoy my D#ckface of the day award. You've earned it.

Mate what don't you understand? I seriously don't know how else to explain it to you, I am beginning to think your retarded....

I'm pretty sure everyone on here is thinking the same thing about you dude.

Read what everyone is telling you, no shit increasing boost increases horsepower (unless the turbo is out of its efficiency rating, then it is just making unnecessary heat and not making more power). However your argument started saying that you wouldnt run more than something like 15 or 16psi through a stock bottem end (cant remember the exact amount you said because i cant be bothered looking back). With your argument, what turbo are you talking about? I'm pretty sure your aware that a boost pressure on one turbo is completely different to a boost pressure on another turbo because a bigger turbo has more airflow, its airflow at a given pressure that makes more power (look at the example in the above post regarding a T88 and a stock turbo).

So on something like a 2535 or a highflow turbo, pushing 19psi on a RB25, if its still in its efficiency rating, might make something like 240kw@wheels. Everyone knows aslong as the tune is good and you have supporting mods that this kind of power output on a stock RB25 bottom end is fine.

Now on something like a GT3037 pushing 19psi will make closer to 320+kw@wheels, obviously this on a stock bottem end is dangerous and yes it will most likely let go.

See whats different here, its not the bloody boost pressure that kills a bottem end, its the power output due to stress on the conrods, bearings, pistons etc.

Your argument is pointless and you have no proof to backup anything you say, there are far to many variables.

The point here everyone is making, is it is horsepower that kills an engine, not boost pressure!! And yes i can even predict what your going to say back to this "Increasing boost makes more horspower, you even said it yourself." So via your theory, putting a highflowing exhaust on a car makes more horsepower, you saying that highflowing exhausts kill engines? Running water-air intercoolers drops the intake temperature, thus creating more horsepower, you saying water-air intercoolers kill engines?

Seriously man, what the hell don't you understand??

Hell ill even throw some maths into this to prove that a couple of psi of boost pressure has no affect on cylinder pressures of an overall engine.

Pre-igntion cylinder pressures are calculated by multiping the cylinder pressure at bottom dead center (one atm on our lovely planet under normal conditions) by the compression ratio (say 9.1 to make things easy) to the power of the ratio of specific heats of the working fluids (wether the car is running a methanol setup, or C16 race fuel or normal petrol). Air is about 1.41 so lets use this.

So we have: Cylinder Pressure = (1bar) x (9^1.41) = 22.155bar which you can calculate yourself to about 300+psi.

Obviously there are variables that effect this such as cam timing, boost pressure (which is what we are discussing here) etc.

However if i remember correctly, most common cars run around a minimum of 11bar cylinder pressure.

Obviously some cars will give much higher readings then this if running huge compression ratios and big boost and race fuel.

So can you see that adding something like 5psi of boost is going to do sweet fark all on cylinder pressures, its the amount of energy that the cylinder can produce once the spark plug detonates the charge which drives the conrod back down that determines the amount of power it makes. If this energy is to great then something is going to let go.

Ok im done, thanks for listening.

Edited by PM-R33

Its not about how much boost your run, its about how the boost is delivered.

Zaf, you seem to know everything so you go and do what you think, and stop annoying us with these bothersome threads?

Also, if you think running high amounts of boost is going to bend or break a rod, then you are a retard. Air compresses quite well. Its the power\speed of the explosion that buggers rods.

I'm running 22psi from a GT3076 (aka HKS3037) on my RB25 and my rods are fine. (for 18months now)

Just admit it - you thought if you had too much air\fuel mixture pressure in the cylinder the rods would bend. They aren't made from chalk you know..

You could load 100psi with an air compressor into a RB25 cylinder and it would be fine. Spark the plug and then you're in trouble.. The power of the explosion would blow the block apart.

By the way - I'm running over 420rwhp - thats pretty much 500hp at the engine. Standard engine..

Everytime you rpely, you never answer my questions,

WHy do 90% or the people here run 17 PSI or below?

Running a T88 at 20PSI is still in its efficiency range, but what do you think will happen to the turbo???

finally, why don't you PM me with your address tough boi so I can smack my turbo over your retarded head :D

I know you said 10 PSI, and I replied, that 20 PSI on a T88 would still be in the turbos efficiency range, and then I asked you a question, but what do you think will happen to the engine runnign 20 PSI with a T88"?

nothing would happen to a T88 running 20psi because theyre maps r good for over 30psi...

fairly stupid question. as for y does 90% run 17psiu or less... because 90% have stockish turbos or highflows which are not very efficent above 17psi. a GT2835 doesnt come into full stride till around 24-25psi so if ur running less.. then ur missing out.

everyone can see how stupid u and your arguments are.

Take a page from the pros and listen to us.

ok just so we get this straight about how stupid u really are...

a T88 kit for an RB26dett starts @ 6k

if u have 6k to spend on a 1000hp+ turbo kit then u have plenty to do the motor

Further more, who in their right mind would put a T88 kit on a stock motor? u must be stupid to do something like that or even suggest like u have.

and just to add to that.. if u were stupid enough to do that, ull find that @ around 15psi ur engine would shit itself... not 25psi because u wouldnt get that far.

Ontop of ur stupidity, do u know what happens to a turbo when its run outside its efficeny range?? do u even know what that means?? im going to wait for ur response on that one.

yes it creates more heat.. but the BOOM part.. im sure ur thinkin of the wrong part going boom...

first thing thats gonna happen is ur intake temps r gonna soar like crazy.. try 100deg+

2ndly.. because of ur intake temps being sooo high, ull detonate causing a huge spike in cylinder pressure and it'll uncontrollable.. they will reach well over 3000kpa of pressure and all of a sudden, ull have rods smashin through the block

Like i said before. I BUILD ENGINES FOR A LIVING. I SEE WANKERS WITH UR THINKING EVERY SINGLE DAY.

Listen to the ppl who deal with this stuff every day.

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