1jz dont lack peak torque. They lack low end torque. With bigger numbers there hp and tq numbersd are usually pretty close to each other.
A new manual transmission is in town... The 'V154' !
- Thread starter SupraClaou
- Start date
Hp is a function of torque and rpm. 1jz doesn't rev that much higher than a 2jz, and hp can be comparable.. so the torque must be there
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The lack of stroke on the 1jz makes the low end torque not there. hp and tq numbers are not comparible to 2jz.
I was referring to peak torque, I was actually agreeing with you haha. But 280 in a 1j is pretty comparable to 280 in the Japanese 2js.. not too far from the 320 in American 2js.
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All JZ engines are under horse powered on factory paper numbers....
1JZ stock jdm spec on paper 280fwhp, though it is consider around 300fwhp
2JZ stock jdm spec on paper 280fwhp, though it is consider around 340fwhp
2JZ stock export spec on paper 320fwhp, though it is consider around 360fwhp
that is one of the reason that a Supra with only BPU mods will gain more than 400+fwhp !
1JZ stock jdm spec on paper 280fwhp, though it is consider around 300fwhp
2JZ stock jdm spec on paper 280fwhp, though it is consider around 340fwhp
2JZ stock export spec on paper 320fwhp, though it is consider around 360fwhp
that is one of the reason that a Supra with only BPU mods will gain more than 400+fwhp !
toyotanos;2002572 said:
Please explain more in details why a straight-cut, dog engagement gearset will be better? Has anyone proven this transmission with good success? I'm very interested in a beefy transmission so spending the money isn't my concern. However, doing it right the first time is.
Helical cut gears are weaker. The only reason there used is for noise. Dog boxes with straight cut gears are very noisy.
Helical gears introduce lateral loads that try to literally blow the case apart... Dog box is a different type of engagement for the gears. Easier with pics and too much to type: http://www.carbibles.com/transmission_bible.html
We got a company here in Australia that pretty much specialise in gearbox. But they are expensive as fuck..
Go to toyota obviously http://www.ppgearbox.com.au/page.asp?productid=42
Go to toyota obviously http://www.ppgearbox.com.au/page.asp?productid=42
SupraClaou;2002985 said:
A number of changes occurred in 1994 actually.
The R154 was first used in production in February, 1986; for the most part it stayed the same until 1994. In early 94 the shifter type changed to an externally mounted type with a shaft and a tripod mount. In early-mid 94, the 2nd gear synchro hub keys changed from a snapring-spring style to small coil springs, one month later many of the shaft locking balls were changed out for stronger pins and the counter shaft changed from a retaining nut to a select-fit snap-ring; in addition the shift forks were changed (No.3 was combined with the reverse head and the shape of the reverse arm was changed as well). 2 months following that, a synchro was added to reverse and 2nd gear changed from a single to a double-ring synchro instead.
Not much changed after that and the transmission stayed relatively the same from 1995-2004. The thrust washer was the same from 1986-2004.
(Not all-inclusive list of changes by the way, and there were a few different shifter types over the years).
Jeff
Poodles;2003923 said:
Thanks Hvyman and Poodles. That was very educational.
This brings me up to my biggest concern. The R154 been a stout transmission for its stock purpose and levels beyond that. But once pushing the r154 to levels past 700 rwtq. it becomes a questionable topic. Yes, it has held but then again its not the ideal transmission. I say that before somebody jumps my throat. Most r154s have a 100K plus miles on them. THey've already been beaten down. There's fatigue in parts and/or slightly chipped gears doesn't make it the ideal transmission to put down a 700-1000 rwhp setup when you have the funds to invest properly in your drivetrain.
I've considered several options...
Option 1:
Rebuilding a R154 with all the upgrades and obtaining another R154 with similar upgrades just in case. How feasible will this route be. It makes no sense to me to swap a transmission knowing that down the road it will fail. After each swap and rebuild, you could of invested in the baddest tranny/diff combo and be done with it. So to me this option isn't that practical unless your more on a budget.
Option 2: Changing out the Gears (cost of 4500 plus labor)to take the abuse. Granted, it's not proven and was rated only at 600. This is very alarming to me because spending 4500 on internals, i should then have one hell of a transmission! I don't feel that it will take the abuse needed for 700-1000 rwhp build.
Option 3: Buy a v160/v161 and change out the diff setup like Sean did at Titan but that would be ridiculously expensive. I think that be an extreme route to go. Plus a huge downside that transmission is becoming scarce and demand is driving the prices of v160/v161 through the roof. lol Plus, it is showing signs of problematic errors(yes, driver error is a big contributor) but still it isn't the holy grail as everybody as made it to be. By that statement, it does indeed break; granted it can hold ridiculously amounts of power stock.
Or
Option 4: Utilize a T56 or a Nissan transmission and build that badboy up. I personally feel this is the route to go for the MK3 crowd.
All im trying to say is there needs to be a backup plan to overcome the lack of abundance of r154s. I'm just curious where everyone stands on this topic.
If you shift them easy and do not leave hard and they are freshly rebuilt AND your drive line is ideal (tight, no slop anywhere whatsoever, no worn out parts, correct angles) they tend to hold roll in power well. I have broken one sub 400WHP with aggressive driving and seen them break locally due to worn out mounts/slop. I had one a few years ago with 1-2-4-5-R in excellent shape and third gear was literally a pulley. They are not an ideal transmission for what many people use them for but in good circumstances they tend to hold together pretty well. There are not many options that tend to hold together north of 700 in drag conditions.
I would really consider going auto over a dog box for a street car. You can find many videos of other cars with these types of transmissions online... Hardly an enjoyable experience for a street car. A T56 Magnum/TR6060, V160, 350Z trans etc can be done for the same or less money, would likely hold just as well and be leaps and bounds better to drive.
I would really consider going auto over a dog box for a street car. You can find many videos of other cars with these types of transmissions online... Hardly an enjoyable experience for a street car. A T56 Magnum/TR6060, V160, 350Z trans etc can be done for the same or less money, would likely hold just as well and be leaps and bounds better to drive.
I still hate the title of this thread but have now found a wealth of information in the posts. For that I thank all of you.
Quin;2004321 said:
I agree with the T56, V160, 350z Trans would be leaps and bounds better. I don't discredit the r154- it's one hell of an amazing transmission especially when you consider how well it performs from 80s technology. However, I think the T56 or the 350z would be a best option as a long term perspective. Especially, once you consider that the R154 and the V160 are becoming harder to find. Then also taking into effect the mileage that has been through these transmissions as well. I know friends that have upwards of 80K on their v160.
I'm leaning more towards the T56- I feel you can built it up to hold a substantial amount of torque. Plus, it offers an array of clutch options that is a huge benefit. No reason to spend 2500 on a triple OS Giken when you can get one new around 1K- 1500 range. There's a guy locally that has done the swap. I would like to see a kit be produced that helps out the MK3 community. I don't mind investing my additional funds for this swap. Hopefully, it be one hell of a sturdier transmission but i'm okay if the project is a bust BUT at least we know. I would love to go with both options of the T56 and the Nissan tranny and see which outperforms the other. Have a cost analysis and see how each one operates under pressure. Let's put these transmissions to the test
. You'll see a write up from me soon in next few months. I hope by mid to later part of summer...
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I still think that with the correct and proper parts like clutch kit, trans.shifter, trans./engine mountings, trans. oil, gear changes and operation
without misusing......and a stock and healthy R154 could hold around 1000 HP on the street (no strip or drag racing) and highway!
And this is what I am going to test adding some tricks to it...
Some very important tips for big HP guys using the robust R transmission :
- Keep the car weight as low as possible, a 3300-3400 lbs is ideal and possible for a daily mk3 with A/C, power everything,etc.
- As you know torque is what will kill the R154, so we can get around 1000 hp with moderate torque numbers like 700lbs using big 76mm turbos instead of 67mm and 800lbs.
(unfortunately a 7M will produce more torque than a JZ engine cause of the higher stroke. 7M could hit 700lbs of torque with only 800hp)
- Using the stock oem driveshaft with the center bearing. This way the shock vibrations to the drivetrain/trans will be less than a one piece shaft
- Keep the revs of the engine under 8500 rpms, cause the R154 can't handle more than that...gears won't engage past that point.
And then it might hold, this is what I think and these are my thoughts. In no way I do not think this is a 100% safe way to do that...
So , it is still a risk at that power level ;-)
without misusing......and a stock and healthy R154 could hold around 1000 HP on the street (no strip or drag racing) and highway!
And this is what I am going to test adding some tricks to it...
Some very important tips for big HP guys using the robust R transmission :
- Keep the car weight as low as possible, a 3300-3400 lbs is ideal and possible for a daily mk3 with A/C, power everything,etc.
- As you know torque is what will kill the R154, so we can get around 1000 hp with moderate torque numbers like 700lbs using big 76mm turbos instead of 67mm and 800lbs.
(unfortunately a 7M will produce more torque than a JZ engine cause of the higher stroke. 7M could hit 700lbs of torque with only 800hp)
- Using the stock oem driveshaft with the center bearing. This way the shock vibrations to the drivetrain/trans will be less than a one piece shaft
- Keep the revs of the engine under 8500 rpms, cause the R154 can't handle more than that...gears won't engage past that point.
And then it might hold, this is what I think and these are my thoughts. In no way I do not think this is a 100% safe way to do that...
So , it is still a risk at that power level ;-)
V160's are going to get more rare because the FR-S/BRZ/GT86 guys are switching to them.
Had this discussion with others on that forum, there's tons of options, you just have to get the parts to make them work. I'll just leave this here: http://www.tremec.com/menu.php?m=94
Had this discussion with others on that forum, there's tons of options, you just have to get the parts to make them work. I'll just leave this here: http://www.tremec.com/menu.php?m=94
1986.5supra_kid;2004703 said:
That car runs the same basic Aisin trans as the 6-speed Miata and the S2000. They all have a few issues once you start pushing power (there are already people over 500HP on the damn boxer 2.0 motor with forced induction!) and they're fragging the transmissions. V160 doesn't take much to bolt in and handles the power great.