I called Synapse directly and spoke with the engineer for an hour.
He is innovating, as the steel specificity of the metals used within the valve, in particular; have been the primary cause of wastegate failure, by known manufacturers, here in the USA.
It is all about the cost of nickel and reducing nickel content, from the valve metallurgy, by the foreign or US supplier. This lack of quality, is causing the low-nickel valves and wastegate seals to warp easier, and still meet ISO and ASTME specs. Hard to believe they can cut corners and still meet "specified materials", under any standard, yet it is being done to save a buck by contract component manufacturers and is a major problem, for us all.
Synapse said he re-designed the valve guides, so a returning wastegate valve cannot warp or bend leaving a gap, at the valve seal. His work sounded very thorough, removing the diaphragm, yet the added adjustability has not been reported as affordable or necessary, by anyone using it on an SR20, to the best of my knowledge. (obviously, getting screwed with a low-nickel valve and seal by a famous W/G manufacturer, is the last thing any of us would consider, while we re-build our entire turbine systems, or swap expensive manifolds, assuming problems being created from other items exists.
What if the "best known brand" of wastegate, is unwittingly using crap stainless?
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Why you think you need such a massive Wastegate is beyond me and here is why I feel this way; below is a link to one of the fastest, ultra-high hp engine builders in the USA. Tom uses ONE 42mm Innovative gate, to make 1500+ hp, on a very special street legal v-8. (Innovative has moved and there is a new site being built, so if you want to compare oranges, you might call Tom for the new number for Innovative, or whatever they call themselves now). {This company is NOT "INNOVATE", the crap electronics company, selling Cheap electronic engine controls}.
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Why anyone thinks they require a 50mm gate, unless they are breathing alcohol in a 500CI twin turbo-charged engine, is beyond me.
Read this article and then do some asking around by folks who understand physics of Turbine pressurization techniques.
I can understand needing to use a slightly larger gate, if your manifold is biased for the wastegate. If your manifold is biased for the manifold, then a smaller wastegate is in order; but do you know the difference and are you sure your engine requires such a huge vent, to control spooling; based on the size of your turbo and manifold?
Or are you guessing?
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High HP sr20 engines often use a 92mm full-stroker crank and riser-block, with a Cosworth Crank, (or alternative brands) and Cosworth race bearings. But the head gasket Tom makes, (see article), is far better than any layered steel gaskets you will find, even at Cosworth. Yet they will be happy to sell you the multi-layered steel gaskets, even though they might not hold up to your expensive internals, under massive boost. Then there is gasket thickness, to make it even more confusing.
The specified head gasket system discussed in the article linked below, requires machining of the head to make groves for special steel, perfect circle o-rings. I assume they are not cheap, either, but at 25-35 lbs. of boost, with a full bored T-4, you will be glad you made the investment. They sink into the copper and really cover your but, under massive head pressure.
Sealant or gasket coating choice is key, using this head gasket system and the article was nice enough to provide almost all the tricks and details.
Here is some of the information which confirms choice of the CORRECT gate size, is really important, or the spikes and lags, everyone always complains about, cannot be fully understood or controlled.
And I quote;
"The annoying thing about Tom Nelson is that he won't share his turbo specs beyond telling us they're 72mm, they are NOT ball-bearing style, and they're from Innovative Turbo Systems. We'll add that the exhaust trim and housing configuration are what most people-including Rick, Head of Innovative-consider pure race stuff, too serious for street or strip use under 1,000 hp. But Nelson swears that his happy customers can't be wrong." -end quote.
Here's the thread where I found these tricks, explaining how to build the sickest daily-driver v-8, ever designed. This article has several tricks you may want to consider, if you are seriously asking about this size wastegate and when it is required:
http://www.hotrod.com/projectbuild/h...ild/index.html
I can only assume, several of the tricks listed on this write-up, will conflict with the many versions of build techniques, we are being told to "try" to make high HP, from vendors selling stuff, they may not, in fact; use themselves.
The $5000.00 plenum, gag, is one of the more expensive mods, I have ever heard of, for a street rod, yet look at the results.
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Synapse, although revealing metallurgy issues, as being the primary cause of known manufacturer and /or wastegate failure, still requires extra money and many expensive hours of dyno time, since it is adjustable into six configurations.
Until I hear anyone successfully dyno-ing on-the-cheap, using a Synapse, (on a high quality AEM standalone or equivalent), the thought of endless hours of re-setting the synapse, no matter how much better adjustability is supposed to be, my original presumption of using a very high quality wastegate, properly sized for the exact flow dynamics of your engine, might be cheaper, in the long run, than tuning the synapse, endlessly. (So the $289.00 38mm gates with crappy steel valves and guides, just might be where our forum builders are having constant vacuum leaks, on the exhaust side, and not on the intake side, alone.
How can anyone require a gate larger than 42mm on any SR20 engine, when a sick-o twin turbo v-8 is just fine, with one 42mm gate?
What do the rest of you have to say on this matter and what do you think about the copper / steel o-ring head gasket system, using Time-Certs, Cosworth crank / bearings and GM / 1/2 inch ARP head and crank studs?
Is the head gasket system worth the expense if we can contain an extra 10-25 lbs. of boost?
(yah, I know carbon-fiber axles, three layered clutch plates and expensive balanced transmission internals become factors. Yet blown head gaskets are a recurring issue here.)
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Has anyone made consistent, high pressure boost, on a stock head, using just laminated steel gaskets?
If so, then how long has your engine made sick power, before the head gasket or wastegate became the issue?
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Maybe the head gasket system used by Tom, and choice of a high quality wastegate, would do us all better, for a longer lasting engine?
Will anyone who knows the exact steel composition of todays version of a brand new Tial and / or other "quality" wastegate manufacturers, please chime in here? What have our known suppliers got to say about low-nickel warping, or failing seals, on what used to be the standard of quality?
It sounds like we need to get to the bottom of who is selling crap and who is confusing the ordeal, just to waste our money on poorly designed or excessively expensive parts, which do not add up to quality or a long lasting engine design. Fake Tials are not the only problem, according to Synapse.
it is the guts which might be crap, in an official housing. True or not?
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We really need to get the bottom of the wastegate quality debate, properly defined by experts, so we do not make costly mistakes and continue to blow expensive engines, by choosing failed or sub-standard parts, (unless of course, you are sticking to a "low dollar build" and do not expect quality or longevity, in the first place).
Please pardon me for not directly answering your question, yet the details of choosing this new Synapse, seem a bit cloudy at this time, in my humble opinion.
We need to see the true cost of dyno-ing the Synapse, beyond the part cost alone, so it doesn't end up proving three times as much cash to tune it, just to get quality wastegate valves and seals. There are options, yet so few of the forum members share these details openly.
If anyone has the new Innovative engineering web-site, I would really appreciate the link, since they are obviously capable of manufacturing a very fine wastegate. I am very glad I own one.
Why don't forum vendors sell them or offer the o-rings and machining to build a stock head, (NOT a $900.00 VE Head), which is capable of increased boost pressure?
(VE guys should benefit from the same tricks, but they first have to spend the dosh on a $900.00 head, and then machine for steel rings, copper gaskets and high quality wastegate seals).
Can we make high quality HP using stock heads, spending hard-earned-money on improving the head gasket concept / the methods of fastening it to the block; instead of swapping to VE heads, and still having head gasket and wastegate leakage, causing problems anyways?
Will this mod, make stock heads meet the need for speed? Or will machining for copper and o-rings become cost prohibitive/ vs HP gains AND reliability?