Can the 2JZGE rev up to 10k?
06-04-08, 01:54 AM
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Can the 2JZGE rev up to 10k?
I always liked that about the R34. I know it had less displacement than a GTE, but it was a high revving engine. I know BMW also made some decently high revving 3 liter engines as well. Maybe 10k is too much, but is there any way to raise the rev limit past 6800?
06-04-08, 02:37 AM
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Even if you could, wouldn't you be well passed your peak power? The 2jz isn't like an M3. The old E46 had its peak power hit at 7900 RPM and the new E92 hits at a whopping 8300 RPM! Now on the otherhand, the 2jz's peak HP hits at a much more subtle 6000 RPM; unless you could tweek that too. They're beasts to tune, but the jz's aren't high revving engines.
Last edited by Brendon; 06-04-08 at 02:46 AM.
06-04-08, 06:18 AM
#6
Even if you could, wouldn't you be well passed your peak power? The 2jz isn't like an M3. The old E46 had its peak power hit at 7900 RPM and the new E92 hits at a whopping 8300 RPM! Now on the otherhand, the 2jz's peak HP hits at a much more subtle 6000 RPM; unless you could tweek that too. They're beasts to tune, but the jz's aren't high revving engines.
with the work required to get a 2jzge to rev that high the powerband would also be changed and it wouldnt be making peak power at 6k anymore.
06-04-08, 06:22 AM
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it would take a lot of internal engine work.
if i were to do that id go with a GTE setup.
but if u like being NA then i think a NA build would be nice to see on a SC
if i were to do that id go with a GTE setup.
but if u like being NA then i think a NA build would be nice to see on a SC
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06-04-08, 07:51 AM
#8
You can raise the rev limit with a standalone engine computer; but, if you are not supporting that mod with super aggressive cams and a top end and bottom end that are both sturdy and light, you will neither be making power nor be spinning that motor for more than a few weeks.
I have talked with a Supraforums member through PM rather extensively about his various set ups. He said that he set the rev limiter on his stock GTE to 8000rpm and ran that way for 20k miles. However, without cams, even his 72mm turbo -making over 600 to the wheels- was not enough to justify revving out to that degree often since the power fell off earlier than that. When he rebuilt his bottom end, he said he was surprised to see everything in as good of shape as it was.
That being said, I agree with the above poster who said the 2JZ is a monster motor, just not a high revving beast. There are well prescribed paths with which you can embrace the 6800rpm rev limiter and absolutely run circles around 99% of the cars on the road. If you want a high revving motor, you may need to look elsewhere.
Your easiest option to rev close to that limit would be with a 1JZ, due to its shorter stroke. In general, motors with a shorter stroke will be more easily revved. However, the 1JZ did come with shorter connecting rods than the 2JZ, which probably nerfs any high revving advantage that the 1JZ might have. Regardless, I would venture to say that a 1JZ would rev harder longer than a 2JZ (GE or GTE) in stock form.
A ultimate option for a high revving beast of a JZ motor might be to investigate the possible cross-compatibility of the engine internals. A hybrid set up with a 1JZ crank (for 2.5L of displacement and the short stroke) with the 2JZ rods (longer to yield a rod ratio more favorable to revving) and the 2JZ block (taller to accomodate the longer 2JZ rods). I believe this set up has been coined the 3JZ (in some ways similar, but -at the same time- different from the 1.5JZ). I am relatively certain it has never been tested, even for measurements let alone in motion on a dyno. But, I am relatively certain that this is the only possible way to rev to 10k using the JZ motors without extreme measures (ie. titanium componentry...if you don't consider this "3JZ" to require extreme enough measures).
I have talked with a Supraforums member through PM rather extensively about his various set ups. He said that he set the rev limiter on his stock GTE to 8000rpm and ran that way for 20k miles. However, without cams, even his 72mm turbo -making over 600 to the wheels- was not enough to justify revving out to that degree often since the power fell off earlier than that. When he rebuilt his bottom end, he said he was surprised to see everything in as good of shape as it was.
That being said, I agree with the above poster who said the 2JZ is a monster motor, just not a high revving beast. There are well prescribed paths with which you can embrace the 6800rpm rev limiter and absolutely run circles around 99% of the cars on the road. If you want a high revving motor, you may need to look elsewhere.
Your easiest option to rev close to that limit would be with a 1JZ, due to its shorter stroke. In general, motors with a shorter stroke will be more easily revved. However, the 1JZ did come with shorter connecting rods than the 2JZ, which probably nerfs any high revving advantage that the 1JZ might have. Regardless, I would venture to say that a 1JZ would rev harder longer than a 2JZ (GE or GTE) in stock form.
A ultimate option for a high revving beast of a JZ motor might be to investigate the possible cross-compatibility of the engine internals. A hybrid set up with a 1JZ crank (for 2.5L of displacement and the short stroke) with the 2JZ rods (longer to yield a rod ratio more favorable to revving) and the 2JZ block (taller to accomodate the longer 2JZ rods). I believe this set up has been coined the 3JZ (in some ways similar, but -at the same time- different from the 1.5JZ). I am relatively certain it has never been tested, even for measurements let alone in motion on a dyno. But, I am relatively certain that this is the only possible way to rev to 10k using the JZ motors without extreme measures (ie. titanium componentry...if you don't consider this "3JZ" to require extreme enough measures).
06-04-08, 05:49 PM
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Like DX3 said, the cams, springs and retainers should move you up, but I also read for the 1jz in the supra forums awhile back that all you need is bottom end fasteners and you should be able to add 1k to your revs... I cant back that up though but its a start in your research.
06-04-08, 06:32 PM
#13
the reason the r34 can rev to 10,000rpm is because the stroke of the motor is a lot shorter NOT because of the less displacement. the stroke of the motor will dictate piston speeds and the higher the piston speeds the higher the overall wear and tear of the engine.
after talking to my boss' friend who worked for McLaren racing back the day. he said that, and i pretty much quote, "F1 racing engines dont exceed 25mps for piston speeds, neither should yours."
the stroke of the 2jz is 85mm. for the 2jz to reach the 25mps mark you have to rev 8300rpm. so basically you can rev to that but after that the engine wear will exponentially deteriorate faster.
the stroke of the 1jz is in the 60's i think. i remember doing the math back in the day and you can rev about 11,000rpm.
none of this can be done in stock form but can be a guide line.
i would just get a 1jz and work with that. yes the torque in low rpm on those sux but it revs to 7200 stock. doing valve springs, retainers, and cams can help it rev to 10,000rpm.
as far as stock motor: if you do a NA-T the stock redline should be more then enough for you.
after talking to my boss' friend who worked for McLaren racing back the day. he said that, and i pretty much quote, "F1 racing engines dont exceed 25mps for piston speeds, neither should yours."
the stroke of the 2jz is 85mm. for the 2jz to reach the 25mps mark you have to rev 8300rpm. so basically you can rev to that but after that the engine wear will exponentially deteriorate faster.
the stroke of the 1jz is in the 60's i think. i remember doing the math back in the day and you can rev about 11,000rpm.
none of this can be done in stock form but can be a guide line.
i would just get a 1jz and work with that. yes the torque in low rpm on those sux but it revs to 7200 stock. doing valve springs, retainers, and cams can help it rev to 10,000rpm.
as far as stock motor: if you do a NA-T the stock redline should be more then enough for you.
06-04-08, 09:32 PM
#14
stock GEs are supposed to be able to rev to 8500ish with the correct cams and turbo on the stock head with just valvesprings and retainers
Some real misinformation in this thread. Why do you want to rev so high? Just to brag about it? Who cares how high you have to rev? The point is to have a fat powerband.
Oh and the stroke of the 1jz is a 71.5mm and the bore of all JZs is 86mm
5sp jzz30 has it right. With an NA-T, the redline isn't going to be on your wishlist unless you're just wanting to brag about your redline (which is really lame); it makes the power. And as he said, there's no point in revving any higher than that in this car. It can make the power you need below that. You aren't on the budget to need anything that would need that kind of redline anyway. (like the ridiculous turbo in the picture above)
Let the drifter wannabes and RB26 fanboys cluck about their redlines all they want: they still don't make as much power and still run around with a super peaky powerband (stock turbos are ridiculously laggy in a stock RB26)
Some real misinformation in this thread. Why do you want to rev so high? Just to brag about it? Who cares how high you have to rev? The point is to have a fat powerband.
Oh and the stroke of the 1jz is a 71.5mm and the bore of all JZs is 86mm
5sp jzz30 has it right. With an NA-T, the redline isn't going to be on your wishlist unless you're just wanting to brag about your redline (which is really lame); it makes the power. And as he said, there's no point in revving any higher than that in this car. It can make the power you need below that. You aren't on the budget to need anything that would need that kind of redline anyway. (like the ridiculous turbo in the picture above)
Let the drifter wannabes and RB26 fanboys cluck about their redlines all they want: they still don't make as much power and still run around with a super peaky powerband (stock turbos are ridiculously laggy in a stock RB26)
Last edited by Bean; 06-04-08 at 09:36 PM.
