Gollum
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Posts posted by Gollum
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If you're going to actually use the engine at peak power regularly and chasing every HP, go 3". If you are just building a fun street car, go which which ever sounds better. 2.5 will sound brighter/higher pitched over tones while 3.0 will be deeper but as noted more prone to drone. If you get drone with any setup a well placed resonator in the middle of the longest straight piece will help wonders.
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Read every post about cylinder heads by BRAAP. The liner heads can flow just fine. The liners don't inhibit flow. And a mild step up from head to primaries isn't a big deal. People put the turbo manifold on the linered p79 regularly. Not THAT many cases of liners breaking and eating the turbo. I'd be willing to bet EGTs were a bit higher than they should have been with a proper tune.... if you're that paranoid, get 6 EGT sensors installed with a red light if any cylinder gets higher than expected norms.
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Even if it needs new floor boards. Even if it needs new rockers. Even if it needs replaced faux-rails. Even if it has no interior.
...This day in age. That's a steel. I got into these cars because they were cheap, but those days have sailed. Overall though, I think with some elbow grease that thin will turn out better off than many I've seen being daily driven!
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Oh wow, this is gonna get interesting. I'll be curious how this build pans out. There's so many points of escalation at that power level and there's never a clear path forward that others have paved. How much tire is right for the goals? What compound to use? How to handle the rear end setup to actually hook up that much power? What's the right amount of brakes?
None of those could I answer for anyone choosing that motor. Best of luck and I'll be following closely.
The purists are gonna love you.
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Most obvious choice:
http://www.thezstore.com/page/TZS/PROD/classic20c01/23-4042
Shouldn't be too expensive shipped to Holland.
Cutting the springs is only advisable in some circumstances. Some people say it's dangerous, but I've seen plenty of historical examples of racing teams doing it regularly in the 70's. So obviously any added "danger" was negligible compared to being on a track with other cars.
Just remember that lowering a car requires stiffer springs. Stiffer springs will require more force from a strut to achieve the same dampening rate. Wanting to adjust any of these factors will have impact on all the rest. Suspension design is always a balance of pros and cons and you have to realize you're giving something up if you want more of something else.
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This is such a great build thread, but I the thing I'm in love with the most is the steering rack/column and pedal combo. That's all fantastic and so much better than the OEM setup (and likely saves a few pounds over the hefty stamped steel column mount).
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Well you just dove right in, didn't you?
I look forward to following the build. Expect set backs, plan to fail. And then use those setbacks and failures to make improvements and refine the journey to the end goal.
Overall I'm pretty jealous of the state of the chassis. I used to think my 280Z was too far gone to care about making perfect again, but as I watch people like HomeBuiltByJeff I realize I'm quite fortunate, and your's is nearly perfect!
Now go make purists angry.
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Also for what it's worth, you'd be amazed how "smooth" a well performing suspension can be. Stiff might feel sporty, but remember that the goal is to maintain contact over the road surface, not skip over it. Also don't forget that spring rates are acting as a force between two points. Required spring rate to reach max travel target is subject to weight of wheel package as well as chassis weight. Then there's also suspension geometey which is a huge reason some chassis run wildly different rates. A 400# spring on a 240sx might feel soft but absolutely brutal on a s30.
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I'm super jelly about the historics. I wanted to go but already had a family camping trip on the books months ago. Apparently the wife would much rather camp next to a river than a race track.
I'm mildly worried that my suspension will be a bit rougher than I remember. We'll see how bad it is shortly. Worse case I'm going to find some OEM springs and cut if necessary. With as much weight as I've dropped I'd be riding pretty high I bet... Long run I think I've decided a full donor swap is necessary. I don't want to mess around modifying the stock bits to be better when I can spend that time engineering a drop in solution that's much closer to right all around.
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I believe the electromotive car tapped 2-6 cylinders... And must of us are still dreaming of even getting close to where they were in 1983....
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Compression ratios are rarely comparable from engine to engine when considering maximum boost for a given fuel.
I'd be interested what the IAT numbers were at the manifold though. I bet they weren't ever over 160... At the end of the day, detonation isn't encouraged by compression ratio, but the heat caused by compression. Without in chamber data of heat and various hot spots (which non of us have access to) you'll never predict maximum boost/compression combos. So we're left tuning and guessing based upon our own data combined with others experience.
Also, never underestimate what great quench pad design can do. I know in a lot of high performance drag application it's not uncommon to remove quench pads from the cylinder head, but you're talking about 80+psi engines pushing over 300hp/liter...
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Yeah I noticed this video recently as well. Not sure who the originator is.
I'd have put a bleed valve at the end of the (front) of the fuel/coolant rail. Overall though I'm glad to see people getting the information out. It's not an expensive mod, and I'd consider it VITAL for anyone who wants to push the limits of their tune, otherwise you're going to be needing to taper the ignition timing on 5 and 6 significantly, if you have the luxury to do so.
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Great info 240Z Turbo!
One thing I'd point out though, is that I generally prefer to look at NA power levels to gauge where an engine lands in it's recommended displacement window. Though the gtx3576r is suggested by garret to fit 2.0 to 4.5 liters, you need to figure out where your engine lands in that window to better solve which turbine AR to run. Like how the evo is a GREAT engine design, and wouldn't struggle to flow 200hp worth of air NA. By contrast, a 200hp NA L series is a pretty hot street setup, requiring basic head cleanup, a good intake, exhaust, and cam combo. Some nissan L heads can flow a LOT more with good port work, but that's not the majority of us here. So though 2.8 liters, it likely ends somewhere in the low to mid range of "NA Breath" for this turbo. But I agree, that .63ar is likely a touch small for the engine. I think we all agree this should be making closer to the same power as the other turbo though, so something seems off.
But once whatever is "off" is fixed, it's likely this compressor is going to land close to the last turbo before being turbine energy limited.
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Worth reading for the technical gems that are easy to pick up, even if it's not your engine platform:
https://www.perrin.com/blog/post/garrett-gtx-turbo-comparo-part-2
A great piece of it:
Quote23lbs/min under those conditions and as the turbine pressure raises it hit a wall. Basically adding more exhaust pressure will not do anything for the ultimate flow of the engine. On the 35R turbine map the .63AR housing hits a similar wall at 23lbs/min. This is why at the same boost levels as the 30R the engine wasn't flowing more air making more HP. But if we step up to the .82 there is an instant 5lbw/min of air flow gained from the turbine wheel. 5lbs/min is 50 engine HP worth of airflow so this should net close to 50 more Wheel HP. But of course at the expense of lag. In past tests .82 GT3582R would spool around 4500 RPM and with the GTX i think it will be the same. In the past we would say that when pushed the GT30R w/.63 made about, 400WHP, then .82 added 50WHP to that number, then a GT35R w/.63 added another 50 ish and then the .82 added even more.
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On 8/14/2018 at 6:36 PM, jgkurz said:
Adding more boost did not raise HP
Ah ha! My fault for assuming what this meant. I was assuming you meant that raising PSI lead to increased boost without more power, like an out of breath turbo on the right side of it's map.
If you were indeed inlet restricted (meaning the engine can't flow enough to push you right in the map, instead walking up a straight line not moving right) you'd still likely be able to target higher and higher boost levels, it'd just surge worse and worse. But as pointed out, you're pushing 400+ crank hp, which means you're AT LEAST around 35lb/min in flow, which isn't THAT close to the surge line...
This leads me to two potential culprits:1) You have a pretty healthy boost leak.
2) Your turbine's max flow can't spool the compressor any more
I'd see if you can find someone nearby that might let you borrow their turbine housing for a session. And also maybe try to find someone with a smoke test machine for tracking down any leaks.
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IF you can validate that you are in the surge area of the map, and having a hard time finding the sweet spot of the turbo, the "easy" fix is to go up a size on the turbine AR housing. Means less response, but it'll get the compressor flow further right and closer to the sweet spot as it comes on boost and (hopefully) supplying plenty of air as you move through the power band. But I think we all here agree, that turbo should make A LOT more power, indicating something is wrong with the setup.
But yeah, start with the easy stuff before going to extreme. Pressure sensors are cheap and loggable, which would allow you to pinpoint exactly where you're operating on the compressor map.
Another potential thing to consider: A larger compressor needs more turbine power to get the airflow out of it. It's potentially possible that your small turbine AR can't keep it flowing at the top. The problem I have with that theory here is that you're able to reach much higher boost targets when you want to. If you were choking the compressor because of lack of turbine energy available, you'd see boost drop off when setting pressure targets as high as 27.
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Do it!
I'm running a MN47. Currently with a turbo bottom end, but eventually when the head comes off for porting/revalve I'm going to build it with flat tops. I'm going to run as right of piston to deck clearance as possible too! I'll let the head builder choose the cam for the application, and get the geometer right for it as such.
But really, all in all, the head difference and port miss-match are all tiny differences in the grand scheme of things. With programmable EFI it's a bit of a moot point. Run what you want, and tune it how it likes. If it's detonation limited for half the RPM range, so what, now you know. Now you know if you need more cam to reduce dynamic compression or if you should add some meth.
My plan is dual fuel with E85. So now that I finally have my engine running with the new combo with MS3X, the next step in this build path would be building a custom intake with a second row of injectors. But. one thing a time. First I need to get my tune sorted and derivable.
Also consider this: the aftermarket HKS turbo setups existed before the 280ZX turbo was even a thing. What head where they putting those on?....
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Just another quick thought, is than an even cheaper way to test is to create a boost leak. Install a one way valve (so you don't alter vacuum areas of performance) post turbo and see what happens. This should force the turbo further right into it's map and give you an idea of what's going on. Obviously this isn't a forever solution, just a test method. Though people have created intake bypass systems before, in order to fit large compressors and prevent surging...
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My thoughts is that you're not even getting into the main island of efficiency of the compressor map. You're likely ridding the surge line, and the anti-surge ports of the compressor are making that fact hard to tell. This would correlate with max power being 22psi and more boost not adding power. Generally that's because you're on the OTHER end of the map with an undersized turbo, but in your case, adding pressure ratio is just pushing you further into the left side of the map. If you look at the map for the GTX3576r and the pressure ratio you're around (likely about 2.4-2.7) and follow the estimated airflow to make the above dyno'ed HP, you can't put the flow anywhere near the center of the map, if anything it's hard to even get it into the map at all! To make that HP at that PSI, unless the charge temp is insanely high (which I doubt considering your previous dyno with previous turbo) the calculated VE would have to be in the 60's... It's unlikely the engine is that low on VE, which means the only other variable that we can move is compressor efficiency, which must not even be reaching the 70's to explain the low power. Since we know this is a 600+hp monster compressor in the right application, we can only be left to assume you're not even waking the turbo up.
What's the specs on the motor? Seems like the easiest way to test this theory that it's the engine not swallowing enough air on the cold side (versus a turbine pressure issue as you'd been looking for) is to get a hold of some more aggressive cams to see if opening up the airflow a bit gets the turbo flowing more air.
This is also where talking to someone familiar with many turbos and various known applications comes in handy. Turbos don't just have a PSI they're designed around, but a Flow as well, and the right combination of both is required for a good fit for an engine. I can't say I'm anywhere near that level of an expert for any common engine, but I've read enough stories like this to know that it's never a "go bigger or smaller" conversation. It's always about the system approach and knowing how the turbo fits into the system.
That said, I'd love to be unhappy about 382whp
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She was bugging me so much this made the to-do list:
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I'd forgotten about that meetup! Thanks for the reminder of just how short Jesse is. By contrast I'm a hair under 6'. If I ever cage my 280z I think I'm going to have to cut into the B pillar to bury the main hoop as far out as possible.
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The only conversation I could find on the topic via Google is here:
https://www.raspberrypi.org/forums/viewtopic.php?t=14646&start=25
And some other talk about it here:
https://groups.google.com/forum/#!topic/loguino-users/WFDGp9oZgd4
I know Splunk won't be for everyone, especially as getting it set up is a bit of work, but that said it's certainly something anyone could follow along with a screen capture session to get started with. And I know we don't REALLY need another log viewing tool, but I'd argue that there's a lot of value in being able to bring some "big data analytics" to the table when it comes to digging into logs. While most log viewers are focused on drilling down into small point in time info, splunk would allow you to look at data correlations across large numbers of logs. I'm no splunk expert by any means, but hopefully I can continue building stuff useful for myself, while I share with the community.
Right now the log ingestion is a bit specific, and could easily break if anything doesn't mimick my setup. So some known basic requirements if you want this to work with my splunk app:
1) Logs should be stored in the default path of c:\users\$user\documents\tuner studio\$project name\Datalogs
The above $user and $project name will have to be different than mine but it's important the layout match.
2) I'm using the stock log format output. No custom field, using Tunerstudio free edition (plan to purchase in the next week or so). The field layout might differ in your firmware and/or tunerstudio version. Any changes to this will break the data lookups, as I've had to hard code the field extraction. Once I figure out how to automate that field extraction from the header row (which isn't a real header row.... grrrrrrr) then this requirement won't be an issue. Also, once you have your field extractor working, the dashboards should work regardless of what data you're logging (meaning it's JUST the field extractor that's hard coded, there's a few things I rely on, like "RPM" but it should all just work).
As far as release, I'm not quite there yet. I'll start a github repo and post some youtube videos once I get there.
But as a tease:
That represents less than a day of actual work from start to finish. One of the things I like about splunk is that it's relatively easy to build visualizations once you know the basics.
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Well, MS software might be more mature, but it's also quite stagnate. I was hoping that the open nature of RusEFI might help it gain ground quicker, and it looks like the project is doing pretty well, but it's not like the software(only) industry. There still needs to be buyers to get growth to happen to accelerate maturity.
But yeah, kit or pre-assembled, it's still a great deal to get into what looks like a great community.
But then alternatively, there's great propriety platforms that are very affordable these days. EMU Black comes to mind...
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If you're ever passing through Vacaville you can HAVE my old ECUs....
Keep up the neat work. Might not be applicable to most as aftermarket EFI is getting cheaper and cheaper, but it certainly fuels the learning/research data which ends up helping you and others that follow along, regardless of solution chosen. Before I scored a good deal on MS3X I was strongly considering ordering a RusEFI kit...
280z upto date wiring harness and fuse box...
in S30 Series - 240z, 260z, 280z
Posted
Because it was the 70's. They put carpet on everything!