chu

iTrader: (72)

One thing I will say I don't like about the diverter valve is the design of the clamps that hold the flanges together, and the size of the o-rings. The bolts are small, appears weak, and simply doesnt seem to hold the flange to the bov with any force. Furthermore, the clamp doesnt seem to bring the flange and bov together. Its seems it fits into the slots just to prevent the flange from coming out. After bolting down the flange, I can still rotate it by hand. As mentioned by another post previously, I reused my TiAL o-ring instead of the one provided with the unit. The viton ring that TiAL uses are thicker and appears stronger. I would much rather see a redesign to use clamps similar to TiAL's design. Just my 2 cents.

I have not notice the fluttering issue going uphill in push mod. When I'm going uphill, 4th or 5th gear, and low rpm, and the car starts to build boost, the Synapse blows it off and my car doesnt buck like it used to. No fluttering at all. My boost gauge gause doens't go crazy, nor does the wideband. Don't know if that makes sense.

mrfred

iTrader: (50)

Shouldn't have to go looking for parts to be able to install a high end DV kit. I got my friend to buy one for his Evo, and he was completely annoyed by the lack of any fittings in the kit that would allow the quick release hose assembly to attach to the factory hard pressure line. I had forgotten about his for my install because there were some fittings lying around the shop that made it easy to adapt.

06MREvo

iTrader: (90)

^^^I agree with this...website shows fittings in a picture, with what I think is the evo kit but I didn't receive any fittings...seems some other members did receive fittings, not sure if they asked for them or not...

chu

iTrader: (72)

While I agree, it doesn't take much to get it to work. I ran the hard line the fitting, and cut a 1 inch piece of rubber vacuum tubing and fit that between the hard line and engine vacuum nipple. But I did get all the fittings with mine.

06MREvo

iTrader: (90)

I agree with everything you said in the 1st paragraph and everything makes sense in the 2nd paragraph...haha


^^Thats the same way I had mine setup till my fittings came in...

hmsevo9mr

iTrader: (11)

Once installed in push mode My booost jumped to over 30 psi when I was originally set to 26-27 psi. This thing is amazing and I would recommend this dv over any..[/QUOTE]

Isn't that a bad thing? if your tuned for 26-27 PSI and it jumps that high I thought that would be bad for the motor.

chu

iTrader: (72)

Isn't that a bad thing? if your tuned for 26-27 PSI and it jumps that high I thought that would be bad for the motor.[/QUOTE]

It means that the prior valve was leaking. When I swapped from the stock IX bov to the TiAl QR, my boost jumped 8 psi.

tim85851

iTrader: (23)

that means that the DV is holding boost better than whatever he was using before...
he should get a retune and possibly turn the boost down.

Synapse

iTrader: (1)

Just as a note is that this is a proven design that we have performed significant testing on. When designing any fastener or clamps you have to have some design intent going into it. This clamping methodology specifically compartmentalizes the loads on the flanging to two distinct variables, sealing and retention. The clamp and flange design are intended to operate sealing and retention as separate entities. Not only have these clamps been run on 10G loaded vibration test rigs, but well over 2 million pressurized cycles have been performed on them without any part failure or even signs of wear. The ability to rotate the DV for in situ installation actually works to dampen the harmonic frequencies applied to the loading of the DV in several degrees of freedom. If the flanging was tightly loaded, as you'll find with many untested designs on the market today, the result is galling of the Aluminum and improper loading of the seals that eventually lead to seal failure and leakage. There is plenty of time and money going into refinement of this product, and where there are serious deficits, they are quickly addressed for the benefit of everyone downstream. Some features may appear to be counter-intuitive, but I can assure you that there is quite a bit of thought and ACTUAL testing being done before going into production with this stuff.

Synapse

iTrader: (1)

Based on some recent research projects that we have, I've been looking at some data and realized why bucking even happens. I can understand the root cause of why this issue happens, I think I can even try to explain why Synchronic helps fix the problem. WARNING: Long post coming

chu

iTrader: (72)

Thanks for your quick reply. Keyword for me was "counter-intuitive." I don't doubt the design works. But it was definitely counter-intuitive when considering the clamp design of bovs we are used to seeing on the market.

Synapse

iTrader: (1)

To understand what really differentiates the Synchronic technology that is in the DV, we have to talk about reaction times. When connected straight to the intake manifold, Synchronic DV will react to a change in pressure in about ~25-30 milliseconds. The fastest a diaphragm BOV/DV reacts is about 200 ms, the slowest is 750 ms. This includes the piston units out there that have a brass or aluminum piston. Why is Synchronic so different, it is the geometry of our patented piston design that allows us to react so quickly. When used with a solenoid, Synchronic will actuate to full lift in as little as 15 ms.

Now, why do Evo's buck? The chart below is a trace of what surge looks like in raw data form plotted across time in milliseconds.

1- Blue- Intake manifold pressure, sourced after the throttle plate
2 - Orange - Air Speed - turbocharger inlet - equivalent to a MAF, very steppy because these $5k sensors only have a 50ms max resolution
3 - Red - Pre-Throttle, boost-only pressure



You can see that when the throttle plate closes (5), there is a significant pressure rise (4) in the intercooler piping. On this example, the base boost pressure is a mere 16 psi and spikes to as much as 21 psi. Take a close look at Air Speed (6) after the event. The airspeed hasn't changed because the momentum of the turbo, any turbo for that matter, cannot decelerate that quickly. There is still significant air mass being consumed by the turbo well over 200 ms after the throttle plate is already closed. This is airflow that the MAF is not only seeing, but calculating against and delivering fuel. So, even though, there really isn't any more aiflow going into the engine past the throttle plate, surge events force the MAF to read and subsequently deliver fuel against this data. The only solution is to have a very fast acting DV that can clip that pressure rise and airflow past the MAF.

Flutter, surge, or whatever you want to call it, is what is documented in (7) almost 400 ms after throttle closure. So, regardless of whether or not you hear flutter, the negative effects of a slow reacting DV are present.

Unfortunately, without any electronic controls to actuate the DV, you really can't get anything faster than 30 ms. Putting electronic control on non-synchronic DV's only improve them to about 150 ms reaction. Either way, Synchronic still enables fast reaction times, even in the absence of electronic control.

Equipment Used in Data:
DAQ - Motec @ 1000hz
Air Velocity - TSI Thermal Anemometer
Pressure transducer - MKS

mrfred

iTrader: (50)

I think that what you are describing is one of several scenarios where bucking can occur. The scenario that is much more apt to cause bucking on my Evo is very slight part throttle lift after mild acceleration at low boost levels.

I have a good idea of what is causing it, at least in push mode. During mild acceleration, light boost pressure builds up in the charge piping (and IC). When slight throttle lift occurs the vacuum change in the manifold is enough to induce the DV to open, and this in turn causes the pressure in the charge piping to drop which in turn causes the airflow into the manifold to drop, and the motor momentarily loses some power. After the charge piping pressure drops, the differential pressure across the DV drops, the DV closes, boost pressure increases in the manifold, and the motor surges momentarily. The charge pressure again rises high enough to open the DV, and the motor momentarily loses power again.

The problem is that the movement of the DV piston is too much in these scenarios. It needs to be able to bleed off the pressure in a more proportional manner. I called you guys many months ago to suggest that an angled skirt on the DV piston to help control flow at small openings might be helpful. I imagine that getting this to work could be a challenge though. With differential pressure acting on the valve, 99% of the time there is either a net open or net closing pressure, and rarely are the pressures balanced.

The interesting thing is that I get some of the same type of bucking in pull mode where charge pressure and manifold boost both act to hold the DV piston shut. In pull mode, I would expect that once the charge pressure drops from initial DV opening, the charge pressure closing force would diminish, and the valve would open further rather than close back up. Perhaps there is some effect of false MAF readings on timing and AFR.

Synapse

iTrader: (1)

That's good insight! And honestly, spending hours upon hours trying to tune something out mechanically, will drive you crazy, absolutely crazy, and leave you wondering if one setup is actually better than the other. It is fun work, but only for the OCD. And here's the problem, to get progressive lift, you need a decent amount of spring pre-load. But to get good reaction, you need low pre-load. There's no middle ground. The only answer is really electronic control, either via an output channel on a flashed ECU or on an AEM EMS. Once we have all of the data, we'll post a how to. We've learned something pretty big recently. If you run too light of spring, the DV can be induced to leak, but if you apply that ridiculously soft spring with electronic control, it works beautifully. So, the best of both worlds. But I want to be dead sure it works before making any recommendations.

Synapse

iTrader: (1)

Now, on to the boost connect topic. I know that there has been some complaints about boost connect, and I don't know if that is actual, conjecture, user error, or people just afraid of "potential" problems based on someone else's conclusions. The reason why we've standardized on boost connect are the following:

• The hoses don't expand or collapse under boost/vacuum
• You don't need a special tool to cut them = razor blade
• They are positively retained by connectors as long as they are pushed in all the way
• they are easy to cut to length
• they don't leak and minimize any questions regarding leaking
• they are very modular

We've performed plenty of testing with these connectors and hoses and haven't encountered big problems, unless they aren't installed correctly. We use these on everything, not to mention that we sample data in the millisecond range and they are consistent performers down to the millisecond every single time they are used. Granted there are going to be reject parts every now and then. But they have been very reliable on the whole. We've also taken the time to make sure to engineer the proper materials that will survive and perform in this environment.

There are a couple of big NoNo's when using these fittings and hoses. You need to give them some bend radius, they can't go very tight or they kink. Below are pics of an installation that I saw once, and obviously, they leaked in that situation.





You have to give them some slack. And when you do, they actually work to absorb a good amount of vibration in the system. Don't worry too much about hose length. They don't expand under boost so they get the signal to the devices very quickly. We've actually measured the delay, and it is negligible.





How to connect or transition to regular hose. There are several options, the easiest of which is just to slip the hose into the OE vacuum line as far as you can on the Evo. Yes, that actually works very, very well. The surface are friction between the two materials keeps them together.

1& 2 - We have female fittings that you can use to transition to any hose size you want

3 & 4 - We actually figured out that you can take our very small brass fittings that used to be on the BOV and screw them straight onto any boost connect line and then go on to hose.

For 5 & 6, we've tried to make everything modular and cross compatible so that no matter which version SB, DV or WG you have, you can still use the same lines that you already spent money on. Any of the boost connect line, including the PTFE lines will push onto any barb, or fitting in the product line.