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Discussion Starter · #1 ·
1.5JZ VVTi build with the aim of maxing out the flow of stock head in order to compare versus 2JZ head using similar components.

Nice setup for midrange punch. Might do some headwork and change intake in future and see what it does, but happy with this for now.

261973


261970



261969


Summary of the important parts

Engine Type
1.5JZ VVTi
Single Turbo
10:1 Compression Ratio (Estimated 9:5:1 Dynamic Compression)

Engine Spec
Stock Head, Ports & Valves (1JZGTE VVTI)
BC 272 Camshafts with Titanium Springs & Retainers
2JZGE Block with Manley Turbo Tuff Rods & Manley 87mm Platinum Pistons
Stock Crank & Stock Main Caps
ARP Hardware for rods, mains, head, flywheel
Turbo & Intake
Precision 6875 Gen 2 DBB 0.96 A/R Open Housing
Stock 1JZ Inlet with 76 Hitachi DBW throttle

Fuel System
ASNU 1500 Injectors
PHR Triple Pump Hanger with 3 x 485 Pumps

Exhaust
4’’ SRD Downpipe & 4’’ Dual Box Whifbitz Catback S/S
Modified Walton 1JZ T4 Open Scroll Manifold
Turbosmart 60mm GenV Progate Wastegate with 1.3 Bar Spring (Recirc)

Driveline
Late Style R154 with PGS Dog engagement HD Gearset
Xtreme 230mm Rigid Twin Disc
A03B Diff (3.26) with OS Giken Superlock

ECU
Syvecs S7+
All the sensors.


261971
 

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Nice fabrication work in the engine bay!

I'd have expected the powerband to hold on through 8k at least with a turbo that size and cams like that. But I've seen fewer 1JZ-GTE VVTi's than any other JZ variant so it might just be my ignorance. Is that typical of a stock intake manifold on those? I know the plenum is a little smaller in volume than the pre-vvti engines.

I'm curious to see how this build holds together, too. I'd expect the R154 to explode 3rd gear at those power levels but 900ft-lbs of torque is pushing it on stock mains as well. Does the PPG dog gearset address the inherent gearset flex that makes 3rd gear so weak in stock form?
 

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Clean setup, looks great. I agree with Wreckless, get the mains done and plan on replacing the transmission.
 

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Discussion Starter · #4 ·
Nice fabrication work in the engine bay!

I'd have expected the powerband to hold on through 8k at least with a turbo that size and cams like that. But I've seen fewer 1JZ-GTE VVTi's than any other JZ variant so it might just be my ignorance. Is that typical of a stock intake manifold on those? I know the plenum is a little smaller in volume than the pre-vvti engines.

I'm curious to see how this build holds together, too. I'd expect the R154 to explode 3rd gear at those power levels but 900ft-lbs of torque is pushing it on stock mains as well. Does the PPG dog gearset address the inherent gearset flex that makes 3rd gear so weak in stock form?
Thanks!

The stock inlet plenum is smaller diameter and smaller volume then what you will find on a 2J for sure, plenum & runners are certainly more compact. I modified the plenum slightly to accept a 76mm DBW, as the factory throttle body has a tiny throttle blade in comparison and looked restrictive, plus always nice to have cruise control in the race car.

From what I can gather after experimenting with this setup, the biggest drawback of this head for making power at high rpm is the very small exhaust ports. Head is fairly efficient at getting the air into the cylinder, but then bottlenecks itself up top. With some fancy headwork I'm sure this could be remedied, but I wanted to establish a base using the stock head as there isn't much information about it on the interwebs being pushed to this sort of level.

So far I haven't had any catastrophic damages to report after 6 months other than a snapped solid prop, but I am willing to sacrifice the engine to the torque gods if they so wish it. Have already started my next weird 2J project engine, so starting to care less about this setup as time goes on.

As for the R154, I have lost count how many third gears I have stripped and countershafts broken in the past. The PGS dog gearset was the only solution within an R154 that I've tried so far that has given me confidence that the gears themselves won't strip. The gearset is very industrial, some would say chonky, and so far despite my efforts have not been able to break them. So time will tell I guess, I am just as interested to see how it holds up. Gearset does seem remarkably smooth given that there is no synchros and I can't think of anything better than rowing through the gears using a load cell to cut ignition whilst staying flat on the throttle.
 

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Other than the sheer size of the turbo, the engine itself isn’t much different than my own 1.5jz that makes 400whp on 94 pump gas. I’ve got the 264 cams. Obviously I haven’t gotten to require a dog box yet but I do have the same rear end. i only require one of those pumps too 😂
Im going to show this graph to my tuner this winter and see what we can do. I didn’t think you could make this kind of power at rpm’s this low on a 2JZ, like I'm making 400hp at 4000rpm and it’s holding all the way to 6500rpm And it’s very streetable. I’ll buy the dog box too, zero fucks given 😂

Have you gone to a dry sump at this point?
 

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Discussion Starter · #6 ·
Other than the sheer size of the turbo, the engine itself isn’t much different than my own 1.5jz that makes 400whp on 94 pump gas. I’ve got the 264 cams. Obviously I haven’t gotten to require a dog box yet but I do have the same rear end. i only require one of those pumps too 😂
Im going to show this graph to my tuner this winter and see what we can do. I didn’t think you could make this kind of power at rpm’s this low on a 2JZ, like I'm making 400hp at 4000rpm and it’s holding all the way to 6500rpm And it’s very streetable. I’ll buy the dog box too, zero fucks given 😂

Have you gone to a dry sump at this point?
Sorry for the late reply, just seen this.

VVTi helps bring the turbo on a little quicker than you might expect, lets me get away with a slightly bigger turbo without compromising too much on response. 6870 gen 2 precision turbo pairs really well with a steet driven 2JZ motor anyway as its responsive and can give out a decent range of power.

I don't have any plans to dry sump this setup as it dosen't really rev that high and so far have had no issues with oil pressure using stock pump.

My only addition to the oil system was a tomei sump baffle kit as I used to lose oil pressure under heavy breaking or going through a roundabout/tight turns too quickly. But haven't had those issues since, so happy to keep it on a wet sump.
 

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That is an incredible powerband. I don't think I've ever seen a Supra make 500rwhp at 4K RPM's no matter what size the turbo was. Nice job!
 
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