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Discussion Starter #1
Seen some supras, AMS mitsi evo, and NBF mitsi 3000gt running 3bar or 3.5bar boost+ , how is it possible to run so much boost, is it just the fuel is 110 octane+ and they last less than 5 miles a fully forged engine? or can they last a few thousand miles?

What boost can the RB26 handle [forged engine], 3 or 4 bar? most japanese vids ive seen of gtr dyno's ~2.4bar seems there max?
 

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ive got a couple of DVD's from the states of a day that dusty womack holds every year and there are many many supra's running the GT62 tubbys flat out on a 3.2 motor, there puting down about 1600whp, it is pretty good to watch
tell you what, drop me a p.m with yir addy and ill post you it, can make it do the rounds ;)
 

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The RB is prone to lifting its head if you run too much boost and therefore create too much in cylinder pressure.

The RB will run revs better than these engines. So in theory they will run better horsepower.

Lastly, much of this has been driven by USA development (big market). So if Skyline GTR's had been sold off the shelf there the playing field would have been very different.

DaveG
 

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Discussion Starter #6
thanks for the info :thumbsup:

The RB is prone to lifting its head if you run too much boost and therefore create too much in cylinder pressure.

The RB will run revs better than these engines. So in theory they will run better horsepower.

Lastly, much of this has been driven by USA development (big market). So if Skyline GTR's had been sold off the shelf there the playing field would have been very different.

DaveG
 

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2jz-fse heads would make me drool
 

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I have in my head HT's wastegate pressure was well into the 30psi range, high boost I wouldn't dare guess - but given the power it has pumped out I would say quite a lot. We have EVOs in NZ which have run 50+psi, methanol helps...
 

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Discussion Starter #10
shame there cant be a low cost mass made adaptor made to fit the 2jz to the r34's getrag 6speed....
 

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no adapter needed for the transmission, just the transfer case. Actually, won't an R34 tranny+transfer case bolt right up to a 2JZ? The problem is, where does the front propshaft go to? Need a place for the front diff to go.
 

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Discussion Starter #14
I have in my head HT's wastegate pressure was well into the 30psi range, high boost I wouldn't dare guess - but given the power it has pumped out I would say quite a lot. We have EVOs in NZ which have run 50+psi, methanol helps...
do you/anyone know how long those evo's last at 50psi? 5km 50km 5000km etc?
 

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The one I had in mind only had engine problem at any meet I saw when it had a boost control issue and spiked to 60+psi and lifted the head. Other than that, I am unaware of it doing anything untoward though I am not sure of the maintenance in the background. They definitely don't seem to be rebuild every meet type deals.
 

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I think you will find they mean pressure ratio on all of them, not boost.

BARO is 14.7 (1 bar) at sea level. So in a perfect enviorment that would mean 1bar boost is baro pressure + boost pressure (29.4psi) actual manifold pressure

44.1psi = 2bar/pressure ratio of 3
58.8psi = 3bar /Pressure ratio of 4

Now you can check the compressor maps of garrett, and you will see on many of their turbos its impossible to run more than 3bar boost due to the lack or pressure ratio.....the compressor on many of garrett turbos cannot take that kind of boost levels.
 

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I understand pressure ratio, I can't see anyone showing any sign of being confused - hence the use of boost when referring to these numbers. The guys I were referring to were running 3+bar of *boost* at times, ie... pressure ratio of 4+.
 

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Garrett turbocahrgers dont need silly pressure ratios to make good power, I do not see the fascination with stupid amounts of boost. Air flow is more important not pressure ratio.
 

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The more air you can get into the engine the better, so once you have made the entire engine (and attached bits) setup as optimal as possible the more air you can force into set optimal setup the better. If you can make really good power out of a setup of 20psi, and can keep improving the power at 30psi, 40psi, and 50psi without breaking things etc.... then wouldn't it make sense to do so? The cars weren't making good power, they were making completely insane power!

Also increasing boost has a much bigger effect on torque than just optimising the basic setup, and as they say - torque wins races! Its worth mentioning that the GTR I was referring to is the worlds fastest GTR, and the EVO was the worlds fastest EVO when it was last campaigning... so the high boost levels are clearly justified.
 
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