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Discussion Starter · #1 ·
Does anyone know of any high compression, high RPM, NA builds? If so, I'd appreciate a link.

I've been watching Turismo Carretera vids on youtube today and love the sound of these things. They use the older Chevy, Dodge and Ford inline sixes, but built out and revving up to 8900RPM making like. 470-490hp out of a 3.2L all motor, no turbo.
 

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Brendan, aka @LRG SOUP has a very nice widebody NA with a high compression ITB build. It does sound glorious.
I witnessed it make 300whp on a Mustang dyno but the calibration was tweaked to duplicate Dynojet numbers, and I'm not entirely sure it was accurate.

His build thread is here:

If I had some money to burn, I've always loved the idea of an 2JZ-GE VVTi ITB high compression 3.0L running some huge ass cams. Based on dynos I've seen of 1100-1300hp 3.0L big turbo combinations built for E85, I suspect more than a few would be in the 350-400hp range NA with a nice header instead of the turbo.

With a top shelf cylinder head build and E85/race gas only compression, I've always suspected a 2JZ-GE could make 500hp NA, but the same overall expense toward a turbo build would easily make double or triple that, so it'd take a truly crazy person with the money to make it happen. Might be time to buy a couple more Powerball tickets, and hope that I could be that crazy person...
 
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Brendan, aka @LRG SOUP has a very nice widebody NA with a high compression ITB build. It does sound glorious.
I witnessed it make 300whp on a Mustang dyno but the calibration was tweaked to duplicate Dynojet numbers, and I'm not entirely sure it was accurate.

His build thread is here:

If I had some money to burn, I've always loved the idea of an 2JZ-GE VVTi ITB high compression 3.0L running some huge ass cams. Based on dynos I've seen of 1100-1300hp 3.0L big turbo combinations built for E85, I suspect more than a few would be in the 350-400hp range NA with a nice header instead of the turbo.

With a top shelf cylinder head build and E85/race gas only compression, I've always suspected a 2JZ-GE could make 500hp NA, but the same overall expense toward a turbo build would easily make double or triple that, so it'd take a truly crazy person with the money to make it happen. Might be time to buy a couple more Powerball tickets, and hope that I could be that crazy person...
Would a VVTi GTE head be a better choice? I thought I read the GTE heads flow more/better than the GE heads. Or does that not matter once you start doing extensive porting and head work? Possibly the GE head can be ported to outflow a GTE head?
 

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Discussion Starter · #4 ·
I would say, based on how the VVTi system is similar to the Honda VTC, the ability to change the cam centerlines throughout the RPM range will provide a lot more midrange power. Keeping it flowing up top would probably require a little bit of work, but probably not as much as you'd think.
 

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Would a VVTi GTE head be a better choice? I thought I read the GTE heads flow more/better than the GE heads. Or does that not matter once you start doing extensive porting and head work? Possibly the GE head can be ported to outflow a GTE head?
2JZ-GTE heads have a significant disadvantage on the exhaust side due to the port design. The ports aren't just oval but #1 and #6 are actually angled toward the back and the front of the motor, respectively. This was done for space savings to accommodate the complexity of the stock sequential twins.

Meanwhile, the 2JZ-GE heads have perfectly circular ports and none of the weird spacing or directional issues to address like the GTE heads. As a result, the NA heads flow more and many cylinder head builders, including Dave @ Headgames, have stated the GE is ultimately superior, though not by a huge margin.

I've given a wild NA build a lot of thought over the past few years.

I'd start with a 2JZ-GE VVTi not only for the VVTi benefits, but for the included cam/crank sensors and ignition system as well as a much wider selection of camshafts available because VVTi GE and VVTi GTE camshafts interchange. Tomei makes some very aggressive high-lift cams for the VVTi GTE that I've no reason to believe won't work in a VVTi GE. Based on other NA tuning done on later 4A-GE and 3S-GE engines, I think I'd start with the 290* intake and a 280* exhaust with the matching Tomei inner shim kit (or GSC conical springs and 1ZZ-FE shimless buckets) and sort out an ITB and header package from there.

VVTi control of the intake cam and careful tuning with an adjustable exhaust cam gear should make those big cams much friendlier to NA power by adding overlap where needed. Unfortunately due to the combustion chamber design and existing super thin HG there's no easy way to bump compression by milling the head a little. Custom pistons in the 11.0-11.5:1 range would help a lot toward making more HP, and with the big-ass cams involved you'd likely still be able to use pump premium.
Even with minimal cleanup sorts of headwork and stock valves, I suspect a combo like that could creep above the 300whp mark. But that's starting with a $2000-2500 investment in cams and valvetrain stuff, another $1000-3000 in ITB's, $1500-2000 in a standalone ECU and tuning, a $150 ebay to $2500+ custom header, etc etc; Insert the Toretto 'not a bad way to spend ten grand' quote here. Add in custom 11.5:1 pistons, rods, supporting build parts, and a top-shelf head porting and OS valves and that's creeping up toward a $15-20k engine package very quickly.

Figuring on the cheap end you get a basic ECUMaster or Link ECU for about $1k, put in the work to make the OBX ITB's work somehow ($750-1000), hope and pray the CX Racing equal length header fits well($750ish), and buy some less aggressive cams like the BC 272's that only need spring & retainer change ($1200ish) and that might be good enough for ~240-250whp with around a $5k total investment, plus or minus the additional misc parts and tuning of course. But it'd sound really cool.

All of which is a shitload of effort for basically the same HP that a ~$2500 complete w/ECU Chevy L33 Aluminum 5.3L can make only with a lot more torque, better fuel economy, more parts support, and less weight and better weight distro.
 

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Discussion Starter · #6 ·
Still going through that thread, thanks @Wreckless
I wouldn't go all out at the beginning. There's a machine shop that makes ITB adapter plates so you can use cheap motorcycle throttle bodies. Can't recall their name, my brother used their product to do this to a Miata though, and it wasn't that much. Can find a cheap Chinese header for a couple hundred, just have to wait forever for shipping, and then get a decent ECU that can controll VVTi, and see where it goes. Might make a nice bump, especially with the tuning, in the factory rev range.
If the above looks like a nice jump, then think about the cams and valvetrain and rods and pistons and stretch the RPMs out.
11.5:1 is very conservative. OEM K20 is 11.7:1, and most street cars use 12.5-13.7:1 pistons. My K24 has 14.1:1 slugs in it, dyno'd just shy of 300whp with an OEM intake manifold on it. Haven't dyno'd it yet with the new one, but you could see on the chart that it was being choked, so hopefully I can get another 20-30hp out of it now.
Speaking of LS swaps, saw a Corvette with a K-swap earlier today. Strange days.
 

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Still going through that thread, thanks @Wreckless
I wouldn't go all out at the beginning. There's a machine shop that makes ITB adapter plates so you can use cheap motorcycle throttle bodies. Can't recall their name, my brother used their product to do this to a Miata though, and it wasn't that much. Can find a cheap Chinese header for a couple hundred, just have to wait forever for shipping, and then get a decent ECU that can controll VVTi, and see where it goes. Might make a nice bump, especially with the tuning, in the factory rev range.
If the above looks like a nice jump, then think about the cams and valvetrain and rods and pistons and stretch the RPMs out.
11.5:1 is very conservative. OEM K20 is 11.7:1, and most street cars use 12.5-13.7:1 pistons. My K24 has 14.1:1 slugs in it, dyno'd just shy of 300whp with an OEM intake manifold on it. Haven't dyno'd it yet with the new one, but you could see on the chart that it was being choked, so hopefully I can get another 20-30hp out of it now.
Speaking of LS swaps, saw a Corvette with a K-swap earlier today. Strange days.

You're thinking Honda. Hate to say it, but Honda's K motors are light years ahead of a 2JZ for this sort of thing. The 2JZ is special because it holds together under lots of boost, and sounds great.
The 2JZ doesn't have Honda levels of combustion chamber heat dissipation to deal with high compression and pump gas, nor does it have that kind of cylinder head flow.

Arnout @ Suprasport Europe did the design work to basically make a custom 'K30' cylinder head for a 2JZ block, basically duplicating a K20 head for 6 cyls, keeping all the Honda iVTEC stuff and all. I don't know that he ever sold one though. If I were really serious about this sort of build, that's what I'd do.

As for DIY stuff, the biggest issue with ITB's on a 2JZ is injector placement. You basically have to keep a section of the lower intake manifold just past the injector bosses so you're not fucking up injector angle, etc. S54 M3 throttle bodies have surprisingly compatible port spacing for a 2JZ so that'd be the 'easy button' option there, just weld an adapter flange and port blend it to a lower 2JZ intake. Or just buy the OBX ITB kit for $750 and buckle up for some fucking-with to make it work. Better, faster results to go those ways vs 2 or 3 sets of motorcycle throttles and fucking all around with that. I did buy a two sets of Triumph T595 throttles based on the cylinder head side port design and top feed injector rails. Ended up being more work than it was worth, sold them for more than I paid and bought the E46 ITB's instead.

For a true cheap DIY ITB build I'd almost go 7M since the fuel rail and injector bosses are directly in the head, and cheap headers abound. Could mill the head down for more compression and adjust the camshaft zero with adjustable cam gears too. Only issue is bigger cams and setting up a crank sensor for decent engine management.
 

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Discussion Starter · #8 ·
Brother just sent me the link:
These use carbs, so no need to worry about the injectors. Just endlessly fucking with them to get them just right lol
After a quick search for sizing the GSXR carbs they seem kinda small, so probably not that great at higher RPM anyway.
But yeah, the combo 2JZ/S54 intake 'manifold' blend looks like it's probably the best bet for a cheaper setup.
Really too bad that Toyota didn't make an ITB NA 1JZ for the Soarer, perfect car name for a high RPM motor.
 

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Discussion Starter · #9 ·
Just finished up reading that thread. Really too bad no VVTi, and the compression seemed very low. Also not so sure about the cam, but didn't see a dyno sheet either, so who knows. What are the diameter of the Toyota ITBs he used?
 

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Brendan's build used AE111 Blacktop 4A-GE throttles, so ~49-50mm ITB's. They're known to be oversized for most 4A-GE needs, it was a sleeper move by Toyota to make them 'stock' for racing engines built off the AE111 engine. The good old days...

I agree that he could have gone higher on compression and more aggressive with cams, but running a CPS off the stock Non-VVTi GE exhaust camshaft location severely limits his cam options.
 

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I agree with what wreckless said above, but there is actually an easy way on a GE head to bump up the compression.
Compared to the GTE head, the GE head has a .028 ish recess on it, which is how it achieves proper squish with the paper thin headgasket.

So you could realistically still take .01 off of it (maybe even more) and bump up the compression and maybe maintain a bare minimum squish with the stock headgasket.
You will be approaching interference territory, especially with some aggressive cams, but for an all out n/a build that is not a deal breaker just make sure all the Timing belt components are quality parts.

There are numbers and you can do the actual calculations with the info from this thread.

I would still strap a turbo to it, good luck!
 

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Very interesting discussion and ideas in this thread.
I‘ve been chasing my Non Turbo project für almost 12 years now and am always open to new ideas.
I‘ve done some of the things mentioned here to my head already, although I did not go with ITBs but with a modded and ported stock intake instead due to legal reasons over here in Europe. I have not touched the bottom end as of yet.

One idea that I‘m toying around with since a couple of years is the idea of a 3,4L NA using the BC lightweight crank.
May I just ask why nobody (and there seem to be quite knowledgeable people around here) has ever mentioned a stroker crank in their ideal NA build menue?
I know there are many downsides like piston speed, rod angle etc and also limited ability to rev. Would a stroked high comp GE be just too much for a NA build even in an ideal world (money not a factor etc, just theoretically)?
Really interested to hear your opinions on this @Wreckless @signalpuke .

BR,
Herb
 

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Discussion Starter · #14 · (Edited)
If you're going all out, yeah, the stroker will help. It will push the entire power band to the left, and you'll run into restrictions a lot sooner in the RPM range from the head. It would probably be fine up to 8600, the stroke is only 94mm. K24 is 99mm and people spin them up there. The strokers for that motor are 106+mm and they're spinning them out past 10k. Comes down to how much you want to spend on rods, pistons, and sensors so you can find problems before they cause real damage, and how much you enjoy tearing the motor apart to check things. With all motor, you either throw money at the problem to make power, or you redesign your fuel system and run $50 per gallon nitrometh 'gas' lol.

Edit: Also, go bigger bore. It will assist a lot with the airflow. Not sure how wide you can go on the 2JZ, I did a quick search, and saw bore spacing was 92mm, so maybe 90mm? A 'big block' K-series build is 106+mm stroke, 90mm bore, for around 2.7L. A big reason we found a lot of the issues, and basically all the real information so fast on the K-series engines is because there was a huge trainwreck that had a bunch of K24s on board, and that resulted in them being $100-200 very early on (I think it was like 2006?). Racers bought tons of them and just tossed shit in them, spun them until they exploded, and/or boosted the piss out of them, etc.
I don't know the deck height of the 2JZ, but if you really want to go big, get an even bigger crank than what BC or whoever is selling, skip 94mm stroke and go as big as you can by notching the block for the rods. Quick check with an online calc shows that a 106x90mm motor is a tad over 4.0L displacement.
I posted the manufacturer's website address for all of these custom cranks coming from China in this thread:
Not saying it's possible to go that big, but it would be pretty sweet if you could. Can always email bwcrank and ask if they have CAD files for the block and see if they can make a crank that big work.
 

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Discussion Starter · #15 · (Edited)
Just saw this posted by 1320video. I have no idea what this is. Initial investigation was this was a 7.8L turbo diesel ford from a tractor, and then a Chevy/Buick engine bored and stroked out. It's some crazy shit from Brasil whatever it is.

Automotive tail & brake light Vehicle Motor vehicle Car White
 

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2JZ deck height is around 219mm from what I've calculated. A longer stroke would reduce R/S ratio to the point where you'll start having issues with rod angle and massive side loads on the bores. Possibly could do a deck plate like the Honda guys do to fit a longer rod in there with the long stroke. One other issues is the fitting that large a stroke crank in the block. Not sure if its physically possible to have that much stroke. Possibly with a custom offset ground crank with smaller rod journals and custom rods.

Also a 90mm bore without sleeveing the block with custom sleeves wouldn't work. I think the cylinder walls would be so thin at 90mm you would have issues keeping the bore round.
 
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