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Discussion Starter · #1 · (Edited)
I am going to start this off saying I think reason forum venues are lacking now is that anytime in the past someone posted a question they immediately got attacked saying "use the search you (insert explicit here). So instead, why don't we start inviting such questions...

This topic used to bring about heated debates back in the day and always brough forth great information for everyone. I feel now that there is more offerings and more aggressive cam profiles than yesterday (Last 22+ years). All our options evolve around Tomei, Titan, Kelford, HKS, GSC, BC, JUN etc. I'd love to hear more about Tomei Cams as I can't dig up too much information regarding Tomei's. So, let's keep this informative based on real world experiences, dyno graphs, etc.

Another reason for this is a lot of the dyno graphs posted in search function posts are deleted or not showing up anymore. Not to mention what better way to bring life back into the forums for some of the newer folks who may not know much about the Cam offerings.

Fire away!
 

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If the goal is longevity you want the slowest ramp profile, least aggressive lobe, lowest lift possible and matching weakest valve spring.

Its possible to make 1000hp with a low lift, gentle camshaft profile. Power comes from the turbo, not the cam, for the most part.
This is a basic knowledge for achieving high mileage. It applies to all engines, whether 2jz, RB, LS, SR, anything.
 

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Discussion Starter · #4 ·
Found interesting video of Tomei and the 1JZ/2JZ Poncam. Their 260 cam. I am trying to compare to the HKS 264.

 

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my rule of thumb is always go with the lowest lift cam hks make and match it to whatever spring they sell for it.
I didn't realize that was an option

how can you go with anything else?

I just didn't outright say that at first because I didn't realize HKS was still an option.

Real HKS? Any original company like JWT HKS their low lift stuff is factory reliable. I've witness enough sets of 272 duration near factory lift profiles perform well to 8,000rpm with light springs on a wide variety of engines over 20 years. I wonder if you can order the old profiles if you wanted. They may have a specific tone or note.
 

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Discussion Starter · #6 ·
If the goal is longevity you want the slowest ramp profile, least aggressive lobe, lowest lift possible and matching weakest valve spring.

Its possible to make 1000hp with a low lift, gentle camshaft profile. Power comes from the turbo, not the cam, for the most part.
This is a basic knowledge for achieving high mileage. It applies to all engines, whether 2jz, RB, LS, SR, anything.
Cool beans, Let’s keep this stuff rolling. This coincides with what I might be looking for if I decide to touch the cams for a single turbo OEM ECU build. I have seen quite a few of these done on the OEM ECU. I’d love to hear/see more information running these smaller cams that way. So the HKS 264s, Tomei 260s, JUN 256s and 264s and Kelfords 248s are all the ones I am interested in.

I’ll try and take some time tomorrow with what information I did dig up and also reach back in our history/search to bring some pertinent info that still exists.
 

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More duration adds more airflow/hp at higher RPM's. Duration is tricky because you never really know what it's advertising until you read the fine print. Duration can be measured from valve closed to valve at 1mm lift or valve at .050" lift or any number of things like that. With the fine print, you might find out that one brand's '264' is actually longer duration than another brand's '272' - that actually happened with the Non-vvti 1JZ-GTE cams between BC's 264's and the old man Crower 272's for the same engine. So read the fine print!
Also, more duration will affect the low RPM efficiency, fuel mileage, and idle characteristics in generally negative ways. Many folks love a good camshaft 'chop' so there's a tendency to over-cam cars just for the idle noise. This sacrifices MPG in a big way as well as idle stability and general driveability. But the heart wants what it wants!

More lift adds more airflow/HP everywhere. Lift is a much more direct and consistent measurement as that distance is how far the valve will open when it's at its most open/peak lift position.

The 'modern' profiles largely do better due to increased lift. There's a lot of ways to do this - shimless buckets and conical valve springs and all the stuff that goes into supporting high lift cams. As @Kingtal0n already explained, higher lift = higher ramp rates and higher ramp rates are almost always harsher on the entire valvetrain from the springs to the valve seats to the valves themselves and even the cylinder head itself. So there's a tradeoff with high lift that comes at the expense of valvetrain life.
Some of the camshaft wear issues were addressed by going billet on the cams themselves, as found on GSC and some Kelfords now, but that came at the cost of a very specific and incredibly necessary camshaft break-in process that absolutely must be observed to prevent cam and valvetrain damage. When starting a fresh engine, it's a bitch to have to balance your preferred bottom-end break in process against an incredibly necessary cam break in.

Tomei's ProCams use a neat concept where they reduced the base circle 3mm on the cam itself, which allows for a lot more lift without needing to grind the head for lobe clearance, and also efficiently allows for a shim-under-bucket setup they provide. The downside is that by cutting the base circle 3mm, the only valvetrain kit that works with those cams is the bespoke Tomei spring/retainer/bucket setup designed to match them. I've seen pictures of a few foreign builds that used the ProCams but I haven't seen anything good to compare them to other current options. Personally I love the idea of a high lift '260' or '270' profile in a VVTi engine for a truly 'have your cake and eat it too' sort of option. I've also pondered what a 2JZ-GE might do if the head was milled down to achieve 11.5:1 compression and a set of those Tomei 290's were dropped in to match a decent header and ITB's, but I digress :)

Meanwhile, older Japanese cam profiles like the enduring HKS 264, 272, etc were set up for maximizing reliable HP on Japanese RON 100 pump premium fuel. So they used intake valve opening/closing timing to reduce dynamic compression a little, which translated into a bit more lag vs stock cams. So this lag was not added because HKS didn't know what they were doing, they were just tuning those parts to meet different goals. The cam cards are available and a tuner that knows what they're doing can adjust an intake cam's cam gear to eliminate that lag if they wanted to, but that adds a bit of lope in most cases from what I understand. Or you can skip the BS entirely and go to a VVTi head the VVTi HKS 264 intake cam and tune the VVTi accordingly on the proper standalone to 'have your cake and eat it too' in that regard.

When shopping as a layman, the 'easy button' answer is that most 'advertised duration' vs ideal power band on most Japanese-made cams will break out about like this:
(I learned this from some old school 4A-GE guys, and so far it's stood the test of time with JZ engines and others)

260/264 - 3k-6500rpm
270/272 - 4k-7500rpm
280 - 5k-8500rpm
288/290 - 5500-9500rpm
304 - 6k-10k+ rpm (I know TRD made a handful of 304* cams for the 7M, but I've never seen any 304* cams for the JZ engines)

Similarly, on lift with a 2JZ, lift will go about like this:
~9.1mm or less or 7krpm rev limit = OK for healthy stock valvetrain, fresh or upgraded springs recommended. (many OEM valve springs are just old and fatiguing these days)
9.3-9.5mm lift or 7500rpm limit = upgraded springs strongly recommended, Ti retainers recommended, stock buckets OK.
9.5-10.0mm lift or 8000rpm = upgraded springs required, Ti retainers required, shimless buckets or shim-under buckets strongly recommended
10.1-10.5mm lift or 8250rpm = upgraded springs required, Ti retainers required, shimless or shim-under buckets absolutely required
10.5mm+ or 8500rpm+ = high-lift friendly spring set (Such as GSC's conical spring set) required, Ti retainers, shimless buckets, etc all required. "Full monty" on top shelf valvetrain parts.

Obviously not all cams have the same ramp rate for a given lift, so this is a 'rough guide' and should not be considered more valid than a specific cam maker's or engine builder's recommendation for supporting parts for a specific cam.
Always believe that list of required support parts provided by a vendor or engine builder! Always err on the side of caution.

The one exception to that is that stock shims and buckets have been run to 8k+rpm under HKS cams on many setups without incident. But again, that's HKS's conservative ramp rates and relatively low lift keeping things in check. More lift will require shimless buckets at a much lower threshold.

There's also a balance to strike with low lift, long duration cams like the HKS 280 and the RPM intended by the user. By the 280's conservative lift measurements it doesn't 'require' a valve spring upgrade, but by keeping the valve open longer, you will see valve float occur sooner with a 280 than a 264 of the same lift, all things being identical. So very long duration cams with low lift that are intending to run high RPM should apply the valvetrain reinforcement appropriate for that RPM range and HP level, and not just think 'low lift = stock parts'. So if you're running HKS 280's and intending to run an 8200rpm rev limiter, I'd go full ham on all the valvetrain upgrades for that high lift/high RPM profile.

When selecting a valvespring combo for your cams, be mindful of valve seat pressure. The higher the seat pressure, the more boost and RPM it can take before floating, but higher seat pressure will also beat up your valve seats much faster than an OEM setup. Back to the higher lift results in shorter longevity overall.


TL;DR
More lift = more power everywhere, reliability trade-offs affecting camshaft, valve, and cylinder head life, more expensive/fancier valvetrain parts required.
More duration = more power in high revs, less MPG, generally more reliable and easier on valvetrain parts. Stock valvetrain parts work to a much higher HP threshold.

Newer cams aim for more lift, older cams aimed for more duration. Don't over-cam your build. Read the fine print and the cam cards when comparing camshafts. Believe the camshaft maker / engine builder when they say it requires certain support parts to run a given cam! Same for camshaft break-in procedures on billet camshafts!
 

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Discussion Starter · #8 ·
I knew this thread would grab your attention, Jeff! Thanks for all that info!

I really want to learn more about the Tomei's offerings and hope some of their users see this thread.

Kingtalon, I was unaware that HKS has changed their profiles?
 

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Discussion Starter · #9 ·
Oh, and Jeff you are not the only one that wants to see an all-out NA build...

Here is what I am seeing from manufacturers site as far as advertised information. I chose to use profiles for drop in stock motor, or small single ecu cams.

VC = Valve Clearance (cold conditions)
IN = Intake
EX = Exhaust
CL = Center Line


HKS
264 Duration
9.0 Lift
115 Degrees valve timing

JUN
256 Duration
9.3 Lift
0.20 IN VC
0.30 EX VC
---------------------
264 Duration

9.3 Lift
0.20 IN VC
0.30 EX VC

Tomei Poncam

260 Duration
8.90 Cam lift IN / 8.70 Valve lift IN
9.10 Cam lift EX / 8.80 Valve lift EX
0.20 VC IN
0.30 VC EX
110.0 CL IN
115.0 CL EX
36.0 Base Circle

I am really liking how Tomei throws it all out there and as Jeff has mention this isn't even bringing in their Procam line up. If you go off what KingTalon is suggesting, then the Tomei's Poncams are the ticket for stock twins or small single ran by the OEM ECU.

I still am curious to know if HKS has changed their cam profiles as I have to admit I have been in and out of the game since then and haven't stayed on top of things such as cam profiles. My latest engine was built with the knowledge of the builder and his recommendation for my goals/build.
 
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AFK
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older Japanese cam profiles like the enduring HKS 264, 272, etc were set up for maximizing reliable HP on Japanese RON 100 pump premium fuel. So they used intake valve opening/closing timing to reduce dynamic compression a little, which translated into a bit more lag vs stock cams.
I always thought that slow opening and closing was intentional for longevity, and as technology improved with valvetrain components and cam design software, the company simply redesigned a more aggressive profiles because they could get away with it now that the lobe shape and high rpm character was more easily modelled in the software that they used to design the cam lobe. I wasn't aware and not sure that they were aiming to kill Dynamic CR, but either way, those "old lobes" may have a characteristic tone some people would prefer, if they exist still.






There's also a balance to strike with low lift, long duration cams like the HKS 280 and the RPM intended by the user. By the 280's conservative lift measurements it doesn't 'require' a valve spring upgrade, but by keeping the valve open longer, you will see valve float occur sooner with a 280 than a 264 of the same lift, all things being identical.
Hmm I was pretty sure the slow opening and closing is going to reduce valve float, not increase it. The valve 'float' is usually a valve bouncing off the seat due to rapid closing, so if you close it more slowly and carefully.... I am getting this from circle track cars that repeatedly spin 6k to 9krpm on and off the throttle, they used a very looong opening and closing ramps with loooong duration cams and low lift to maintain valvetrain stability at continuous high rpm. I used a circle track grind in my LS in fact. But I don't run high RPM like them crazys do- I just wanted the gentle ramp profile. You can get a low lift with an aggressive ramp, or a low lift with a gentle ramp, Its part of the decision. But I wouldn't see how a slow ramp would initiate a valve float condition? Unless you meant using long duration low lift with stock springs vs upgraded springs on a shorter duration lobe, upgrade spring should easily win because it will close the valve more forcefully but there is some consideration of harmonics, specific rpms which destabilize a single spring system resonating can cause loss of valve control completely, which is how you can buy a very stiff powerful spring and still float the valves at specific rpms and why I always say to match the spring with the lobe manufacturer recommendation because they probably tested and tuned the harmonic features ensuring there is no harmonic initiated valve float at intended operating ranges.
Also it isn't really the effects of valve float we are worried about mostly, yes its annoying and can be power limiting when it happens but the true scaryness is the potential loss of contact mechanically with a valve or lifter series of force applications intended to be well controlled sequences, for example if a valve bouncing causes loss of contact between a lifter and it's lobe interface parts, whether pushrod or shim or rocker arm, there is a dangerous potential for breaking and bending parts, dropping valves, abusing guides/seats, catastrophic stuff can happen.


imo don't use more spring pressure than needed to make the engine run well. You want a low pressure to preserve parts and reduce wear, best to match the spring to cam by manufacturer recommendation and go for the lowest lift and lightest spring.

...Unless winning a race matters, like if you are building an actual racing car don't do it this way lol. Race cars get the highest lift and longest duration they can handle, along with trans-brakes and triple plates and 2000hp and frequently rebuilt and torn down for inspection. I would expect every 8k to 15k miles tear down the head and inspect for wear and replace as needed. Most of the valve springs in that category will need to be replaced anyways with such low mileage. It is common for powerful racing springs that tolerate high lift to only last 20% to 30% as long as a weak more "normal" spring for regular low lift like OEM lift.

I just assume most novices are looking for highest mileage and not actually building a race car. Its a completely different mind set for every part, in racing I would require inspection intervals and we can get away with more aggressive driving and parts usage such as trans-brakes because you know you will just be changing the part anyways before it can wear out completely, your next trans is all setup in advance, the next engine is ready to go on the shelf. At least this is where you want to be for racing, first rule of the engine is always assume the engine block needs to be replaced and can't be rebuilt at any given instant. Racing is supposed to be hard on parts, push them to the max, ftw not try and get them to life forever 300k miles
 

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Discussion Starter · #12 ·
Assume you mean me Steve? I started this thread just to get some conversation going and to gain knowledge about all the cam profile offerings that are out there compared to "yesterday". Back in the day it came down to HKS and GSC with BC sprinkled in the mix.

As for me, I don't even know if I will ever get cams for my current car, but I went with GSC S2 on my built motor at the recommendation of my builder. If I did ever want to do cams for my stock 94, it will be for a stock ECU ran small single turbo with longevity in mind for a street/cruise/car show build. Right now, it's looking like HKS 264 or Tomei 260, but I am in by no means rushing to buy. I mainly brought this up as I stated above originally and to invoke some life around here.
 

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Now thats a great reply, great detail.

I have yet to find anyone who has run the new tomei high lift poncams yet. I do really like the idea behind them and their potential performance, so much so I might test them myself. My only worry with an under shim design is that we add a new weakness to the 2J valvetrain.

RB engines have a similar under shim design, and it's fairly common with RB engines to spit a shim out after harsh gear cuts or ignition cut limiter bashing. Obviously you can tune around that and be aware of it and normally be ok, but 2J factory valvetrain can take a beating normally and carry on like nothing happened. So it would be a shame to lose that side of things, but I guess the upside is that you dont need to machine your head to fit the cams etc.

I'll report back with data if I get a set for my next build later this year.
 

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Use a harder steel.

You seem to be conflating things, and it may be causing some confusion you're having. In a boosted engine you want to run higher rated springs in general if you're pushing a lot of pressure through it.
Good primer on cam shaft, or, valve control, design.
I'm not confused about anything. We've been using the same formula for hundreds of cars over 20 years and seen 200k 300k miles from engines using low lift Offerings from tomei, greddy, hks, and similar.
It is common knowledge among engineers that high pressure in any system is unwanted if unneeded, goes for blood pressure, fuel pressure, oil pressure, etc... nothing should be higher than necessary and that goes for valve spring pressure the same.

It was said well enough here
higher lift = higher ramp rates and higher ramp rates are almost always harsher on the entire valvetrain from the springs to the valve seats to the valves themselves and even the cylinder head itself. So there's a tradeoff with high lift that comes at the expense of valvetrain life.
a higher lift or faster ramps needs more pressure on the spring to help snap the valve shut and hold it shut, by inspection this has to be true due to energetic investments in a valve mass. Its more force involved and force results with stress. Furthermore there is harmonics to consider which goes beyond stiffness and material science, or 'hardness'. Valve guides maybe bronze, they can't be made hard afaik so it's pointless to make some part harder if it's just going to wear out the guide faster and require service even sooner with the harder parts. It isn't really about performance, its about longevity. Performance takes a back seat when longevity is important, just logically. You choose one or the other upfront

The valve seat is another potentially delicate situation, possible to abuse. You can't just stick a harder material somewhere and expect everything else to just deal with it, there is a need for parts materials to match properly and surface wear specific patterns that the stiffness or hardness or anyone of the many ways you can measure a piece of metal needs to be set properly. The whole thing is like an orchestra with each player having practiced with the other for rehearsal in the lab for a million miles, even if they cause poor performance together the efficiency and reliability outweights some percentage of a downside to performance, our opinion is how much performance is worth how much reliability. I personally feel 200k is pretty good but I like to think I could get 300k miles from a 800-1000rwhp stock OEM engine from any popular manufacturer. The cam itself isn't a wear concern or 'hardness' concern as its lifespan is significantly longer than the engine to which it is attached a cam might go 1 million miles or more. Mechanical parts are not supposed to appreciably wear but the valvetrain is full of potential maintenance items regardless of their hardness.
 

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Discussion Starter · #17 ·
Loving the discussion fellas and thank you for contributing, even if it brings a little heated healthy debate.
 

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I'm not confused about anything.
...
a higher lift or faster ramps needs more pressure on the spring to help snap the valve shut and hold it shut
Then why bring up all this other stuff when I explicitly said boosted engine. I don't care what the cams are doing, if you're running high psi through the motor you need stiffer valve springs in general, doesn't matter what motor. Same thing with higher RPM.
You're not using a higher psi spring to keep the valve shut, you're using it to keep the valve from floating and then crashing down on the seat.
Go lighter with the valvetrain when you can, so the valve motion stays consistent with the cam master design the cam lobe was ground against. If the motor doesn't have cam phasing, and you're using the OEM gears, use the recommendations that Wreckless provided above per your RPM use case. If you have adjustable gears, then create your own overlap setup that fits your turbo and power band goals, or save yourself all that headache and use a VVTi head.
When it comes to cam longevity, use a harder steel. For the head, treat it if needed, new seals, seats, etc. For the valvetrain, go as light as possible, and use inconel if needed. There isn't really much more to discuss unless there has been some breakthrough outside of electronic or pneumatic valve control the last decade that I'm not aware of. Wreckless pretty much summed it up.
 

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Then why bring up all this other stuff when I explicitly said boosted engine. I don't care what the cams are doing, if you're running high psi through the motor you need stiffer valve springs in general, doesn't matter what motor. Same thing with higher RPM.
none of the cam companies that offer matched springs for low lift, with low seat/open pressure, will hinder the ability of an engine to make power using boost. They would never be able to sell a low lift spring/cam combo if that was the case. I personally don't deal with natural aspiration, ever. Everything I do is boost for 20+ years. The low lift and light spring offerings are fine for 1000hp. Its like you've never actually owned a high power engine with a reliable valvetrain before.


You're not using a higher psi spring to keep the valve shut, you're using it to keep the valve from floating and then crashing down on the seat.
LOL thats the same thing. haha you make me laugh gj

Go lighter with the valvetrain when you can, so the valve motion stays consistent with the cam master design the cam lobe was ground against.
I never said not to go lighter. You never said it either. You said go HARDER. Harder <> Lighter. Get the word play right
 

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Loving the discussion fellas and thank you for contributing, even if it brings a little heated healthy debate.
I appreciate you reading
The valvetrain is an insane amount of engineering to setup and major manufacturers make mistakes all the time with regards to longevity items, for example Chevrolet z06 heads from certain late model years all have some known issues and need complete replacement even with 7k miles it can drop a valve. And this is a V8 company making 'performance' engines for 50+ years or whatever. How could they make such a mistake?
That type of mistake happens when you try something new or modify the way something is made in mass. Anyway you can make a material or engineering mistakes when designing something new or implementing something new. In this respect, anytime you do valve work at all you enter new territory. Because unlike assembly line procedures will vary, and results will vary. Even if I just replace 1 lifter in an engine it can establish some new or unexpected type of wear and ruin the engine with metal debris.
Another example lets say I went lighter with some piece of the valvetrain hardware, but there is a critical oversight in the design that nobody will catch for 100k miles. Or perhaps that batch of parts something is wrong with it. You are taking a gamble anytime you swap something out, even if the new part is desirable or lighter or whatever. Its a RISK. My job as a engine tuning setup expert is to identify and eliminate risks. I've successfully setup hundreds of daily drivers that use turbos and the key is change as little as possible, use mostly OEM used parts with established well wear patterns that will work together the same way they always did. Even if there is something better available, it would introduce an unwanted risk if you actually intend to drive the vehicle 200k miles or whatever, you don't want the slight benefit weighted against the potential for catastrophic engine failure. Not worth.
Identify the risks


I guess what I'm saying is, the only real way to 'build' a high mileage valvetrain is to use parts that will known reach high mileage and already on their way. Which is like saying not to build anything at all- just use the stock stuff. Its a question for each engine of how far stock stuff will go in terms of power while holding onto reliability. For Natural aspiration we really have no choice, we have to port everything perfectly and use the perfect cam for area under the curve to match the type of racing, lighten every part, tune the exhaust perfectly empirical testing length individual runners for max flow work, perfect intake port resonance for matched area under the curve of VE from the camshaft, yes all of that is super important for N/A applications.... but for turbo the situation is quite different. Turbo can make 5x the power using poorly matched ports, poorly timed valve events, awful merge collectors, insufficient pipe contours, questionable tuning, all the while maintaining a majority of OEM components and being as reliable as any untouched engine should be.
That leads to the question of 'why no improve the flow of the turbo engine also...' and this is actually a long discussion about boost pressure and the shape of a compressor map. But hey Ill see if I can summarize quickly.
If you look at a compressor map and draw a kind of cone


Notice the faster the boost can rise to meet the inner left line of the red cone, to sort of stay near the inside left center of the compressor map, it follows an increasing area of efficiency for each successive adiabatic island for the flow rate to translate as it maintains some max boost pressure and moves off to the right side at peak output.
Next notice the turbo overall flows more volumetric rate once the pressure ratio rises above a certain magnitude. In this case, it takes nearly 3.0 pressure ratio reach the max flow capability of compressor. You paid for a compressor that flows XYZ But it can only do so at 3.0 Pressure ratio and beyond.

So now imagine we make the engine flow rate better, add a good cam, port work, exhaust tubular tuning, bigger downpipe, higher lift, what happens?
The boost required to make the same power as before, will decrease.
If we used to use 3.0 pressure ratio and now we only use 2.0 pressure ratio, how much power can the turbo support at 2.0?
Looks like the turbo lost 20 to 25% of it's capacity at 2.0 pressure ratio. Now you have to upgrade the turbo and increase the boost back to 3.0 to take advantage of all the modified valvetrain hardware.
By increasing the size of the turbo in this manner it will take more energy to spool and the engine displacement being the same means it will spool more slowly. It will make more power of course, but if the original valvetrain supported your power goals at 3.0 then by making the engine flow better all you've done is reduce the capability of the turbo and make the engine response suffer, and subsequent turbo will be larger which also hinders spool.
It was better off with the reduced flow rate of the original engine with no upgrades. Therefore turbo size interplay with valvetrain setup is always together, you can't size one correctly without considering the effect it will have on the other due to difference in pressure ratio and flow rate on a compressor map it will have.

Thus the cam/head/flow potential of the engine should allow a turbocharger to reach 3.0 pressure ratio (or whatever it is for your turbo selected) In order take advantage of the entire compressor map and stay left while translating to high flow as it runs into the larger areas of each island while moving off to the right edge of the map where you'd like to wind up for daily driver size turbos. For racing, nitrous, aux injections, t-brakes, 2-steps, drag specific stuff, you would want to be in the center island which dramatically increases the size of the turbo even further, but it has nitrous so the spooling isnt an issue. It just always needs nitrous, its not a daily driver.

And... all of this is kind of funny to me, being that we are discussing the 2jz , which is one of the best most incredible turbo-valvetrain platforms available of all time. You could do almost if not 1000hp with a stock cam and spin to 8,000rpm using springs similar to stock. From the point of view of any other engine out there just about- you would do well to go a little deeper into the valvetrain consideration. But for a 2jz its kind of crazy to me, to take something practically given to you that is super reliable & functions well at any power feasible for a street car (1000hp is meh feasible) and try to slap in a bunch of new parts some of which carry unknown various risks in an effort to make an engine flow ~5% better when the result is going to reduced compressor flow capability by lowering boost pressure at specific output or increased turbo wheel mass to maintain that output at lower boost, both which subtract from the area under the curve for typical daily drivers. rofl?
 
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