Jump to content
SAU Community

Recommended Posts

Why does big boost have such a bad stigma?

Its my understanding that it's not like the "boost" is anything scary in and of itself. Its combustion pressures that blow your engine up, not "boost". Some people think that because person A is running more boost with a turbo than person B with another turbo, yet theyre making the same power on the same engine, that person A more likely to scatter their engine, which is false, no? The byproduct of high boost is more air, and thus fuel, in the engine, plain and simple. Am I wrong with this logic?

You are correct in a sense. But the more you compress air the hotter it gets so leaves less room for error in the event of a slight lean out etc

It also comes from the dark ages of horribly inefficient turbos the just blew hot air at anymore than a hand full of boost.

I always think back to the millions of dollars car manufacturers put into things. Etc why doesn't ford use a tiny little turbo and 40psi instead of a gt35 to make 240 kws etc

Less boost means a more relaxed engine in general. Efficiency is key. I'm sure we would all like a lazy 7psi to make 500hp but the reality is we can so it's always a balance between response and power on our small engines

yet theyre making the same power on the same engine, that person A more likely to scatter their engine, which is false, no? The byproduct of high boost is more air, and thus fuel, in the engine, plain and simple. Am I wrong with this logic?

If the only thing that was different was boost you'd be perfectly correct, the issue is the higher the boost pressure the hotter the intake gas, also the higher the EGTs and hence everything is just generally hotter. Heat is the enemy as it makes detonation easier, so you need to do fancy stuff like very efficient intercoolers, water/meth injection, exotic fuels like alcohol to be able to run this kind of boost whilst still running some margin of error from detonation.

When running this close to the limit you would want to start trimming individual cylinders by using individual EGT probes etc, it starts to get expensive very fast. I doubt many (if any at all) of the guys running 35psi are just simply running an intercooler and 98 octane fuel.

Why does big boost have such a bad stigma?

Its my understanding that it's not like the "boost" is anything scary in and of itself. Its combustion pressures that blow your engine up, not "boost". Some people think that because person A is running more boost with a turbo than person B with another turbo, yet theyre making the same power on the same engine, that person A more likely to scatter their engine, which is false, no? The byproduct of high boost is more air, and thus fuel, in the engine, plain and simple. Am I wrong with this logic?

You are correct.

If the only thing that was different was boost you'd be perfectly correct, the issue is the higher the boost pressure the hotter the intake gas, also the higher the EGTs and hence everything is just generally hotter. Heat is the enemy as it makes detonation easier, so you need to do fancy stuff like very efficient intercoolers, water/meth injection, exotic fuels like alcohol to be able to run this kind of boost whilst still running some margin of error from detonation.

When running this close to the limit you would want to start trimming individual cylinders by using individual EGT probes etc, it starts to get expensive very fast. I doubt many (if any at all) of the guys running 35psi are just simply running an intercooler and 98 octane fuel.

Then it would behoove one to run a cheap simple mod like an BAT (boosted air temperature) sensor in the intake.

Here is a question...where teh hell do you find a 3 5/8" V band for theses thing?

can find 3", 3 1/2", and 4" easy.......3 5/8".....

or do you simply use a 3 1/2" unit?

Powertune have them in stock to go with the precision turbo's.

  • 3 months later...

PJ....that R34 with the stock bottom end and stock cams....what was the power at the hubs? Im presuming the dyno run is showing corrected power at the fly? Im in the UK and I want to run a single on my Forged RB26 in my R32 GTR (Stock head and cams). Im going with a T3/T4 topmount manifold and was looking at the 6262.....I want 500BHP at the hubs at no more than 25PSI.......is this gonna be do-able with the 6262? Im looking for spool compariable to uprated twins but with the ability to crack 500BHp at the wheels. What do you reccomend guys??? Exact turbo specs please?

Oh.......why all the reference to 4 Cylinder Nissan engines and even worse Toyota engines??? Surely you guys must be all running 6 cylinder RB's in the main???? Just find it a little strange as in the UK where im from there isnt a lot of skyline interest in 4 cylinder mills....its all RB26/26/30 etc.......

Cheers

Andy

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • A 1.5 way is a 2 way. It is just a 2 way with a less aggressive ramp on overrun.
    • The ABS and/or TCS being missing/broken will not cause the engine to misbehave. It just casues CEL to come on and annoy you. The CEL is useless if it is always on, so you have to do the things you have to do to get rid of it, so it can be useful. Being a Stag ECU, then yes, it will not expect TCS to be present. But it will expect ABS to be present and working. You will need to either make the ABS CU talk to the ECU (don't ask me what that will take on an NA R34), and make sure the hardware is working....or, you just need to blank it out in Nistune. Do not persist with the stock ECU. You will just have problems. Gte it Nistuned. Start from there. DO YOU HAVE A BOOST SENSOR? The ECU's boost sensor that it. It is connected to the loom at the rear of the coil cover. Usually rides on the firewall on an R34, but is usually bolted down to a bracket along with all the other crap at the back of the coil cover when a Neo is dropped into another car. If you do not have it, the ECU will shit the bed. So, do you have one?
    • So sadly the fuel pump etc was not it. The pump and filter is new and it is still cutting around 4000 rpm. A read something about ABS/TCS (engine is from stagea and ECU too so no TCS) and i dont know for 100% that my car has ABS. It has ABS "cube" in engine bay but i dont think it works(or at least from my braking experience). Can be something like that?  I will be driving the car next week to Nistune tuner to properly see what is wrong...  
    • the Tomei LSD fluid with lsd kit. frustrated that it was shaking the car to crap and affecting everything else negatively, I pulled the diff last night, and removed the lsd carrier, could not find anything wrong, however it seem to be 100 locked up acceleration, and deacceleration, wondering if they sent me a 2 way not a 1.5??  either way I installed the stock open carrier back in place. test drove everything smooth as butter again. no shake, shutter, random, what felt like clutch slip and grab or drive shaft play, etc. something differently wrong in side the lsd. I might bother taking it apart (if possible) to figure out what's going on inside this carrier, as bought too long ago to return.  only draw back is its back to a one wheel wonder.
×
×
  • Create New...