zguy36

I have seen your header that you have pics of on your webpage. That thing is beautiful. Have you had any problems with the heat wrap that you are using? I haven't decided which route I want to go, heat wrap or ceramic coating. Both will cost me about the same, or maybe I'll do both!

You are a brave man investing any money into an xs-power turbo.

Hmm.... I figured more people would find this information useful, but I guess it isn't useful to know the cfm of air your engine consumes. technicalninja, I have seen VE described two ways, one way as how you described it to me and another in the way I described it earlier. If you would like, I could just change the term to something else to describe the value I am using in my calculations. I guess it could be called pressure independent VE for lack of a better term. yo2001 Most of the hyrbid turbos that I have seen, at least when they are mild upgrades only change the compressor side and leave the turbine side. If you want a large exhaust side too, then that would defeat the purpose of combining two differnet turbos into a hybrid. I know this isn't only the case, but in this case, the pressure independent VE of the engine wouldn't change. I'm not exactly sure what you were asking about the 16g example, but yes, with the larger turbo, using my equations, the lbs/min would increase, provided you enter all the correct values into the spreadsheet. The pressure independent VE would not change though. The smaller, more inefficient turbo will be heating the air more and provide less dense air charge. The difference does not lie in the efficiency of the engine, but instead the efficiency of the turbo. This is a good point though, and I am going to have to do some more thinking on the subject to make my speadsheet directly comparable between turbos. As it sits now, it will only tell you how much air is being processed in your engine. What you can do with that is still left undecided. vbmenu_register("postmenu_", true);

The VE of your engine will not change unless you make a modification that will change the breathing characteristics of your engine. One of the most popular turbo upgrades is changing from the stock t3 to a t3/t4 hybrid. Since you are not chaging the exhaust side, you aren't changing the VE of the engine. If you do change the exhaust side, your VE will change, one of the major reasons you get a power increase with a bigger turbo. Don't confuse turbocharging an engine with increasing your VE. If you are familiar with tuning a megasquirt, think about the VE tables that are used. They rarely go above 100%, and if they do it is probably because you have another parameter set wrong. VE is the percent air going into the engine compared to displacement. The proper way to look at this is not thinking that more pressure increases your VE. More pressure does put in a ton more air, but the efficiency of your engine stays the same. VE is the amount going in compared to the amount that would go in at that same pressure if the engine were 100% efficient. This calculator will tell you the exact amount of air flowing through your engine as it currently is. How it will perform with with a larger turbo, is still something that cannot be directly calculated. This calculator is however, tenfold better than the method used to calculate airflow that uses displacement, engine rpm, and a guessed VE

If someone wants to send me a datalog of a boost run and the parameters of their engine, I can enter all of the values into the spreadsheet and post the results. The spreadsheet is currently filled with values from an RX-7, hence the big injectors and high RPM.

Yes, this is basically what this calculator is doing, calculating the VE of your engine. Instead of having a graph of VE, you get a graph of lbs/min so you can use this calculator to pick turbo sizes. Any engine parameter does not matter, as the calculations are not dependent on anything other than what I stated. This calculates the amount of air flowing through the engine, based on fuel consuption and air fuel ratio.

Enter your values into the shaded regions. This is set up so that you can take values from a data log (you have to have a standalone to work this spreadsheet). The values of importance are injector size, ambient air temp, base fuel pressure, number of injectors, and the a/f column and the injector duty % column. A lot of the other junk such as RPM is so that you will have something to graph your airflow values against.

The stock ecu is extremely limiting. You can make it work, but it won't give you results that will make you happy. I just finished a megasquirt II install and have been very happy with the results. I would imagine similar results with any standalone.

My last post on this subject was booted because I "don't play nice". Anyway, I appologize for being an *** and hope that this is some good information. I added an excel spreadsheet to the downloads section that will calculate the airflow of your engine based on real parameters that eliminates any guesswork at all. Yes, that's right, you don't have to guess the VE of your engine, you can directly calculate it for any RPM! http://forums.hybridz.org/showthread.php?p=613687#post613687

I had mine dump on the old stock setup and there weren't any driveability issues. It did make it more prone to shoot fire between shifts too. I didn't realize how rich it was actually going though till I bought the wideband. 9:1 between shifts.... Not really a big issue, just a little added fuel cost

The problem is that if you solid mount anything, it is going to transfer the vibrations directly, which can lead to fatigue. You are correct in saying that with only half the diff mounted, that this is worse. This concentrates all the vibrations to one spot instead of two. Here is the key for fixing the matter. Steel has an infinite fatigue life. A general rule of thumb is that steel will never break due to fatigue if the stresses that it experiences are less than half of its ultimate strength. (static breaking strength) Figuring out how much stress your parts are experiencing, now that is a different story. Your cracks were starting at bolt holes (I am assuming, I couldn't really see them in the pics) which are giant stress concentrations. The solution, if it breaks, beef it up!

We can't all afford turbo blue! I can't even get 94 at the pump here in Idaho, the best they sell is 91

Are you forgetting about the u-joints? You can hard mount the differential without having any adverse effects on the engine. The engine can still torque over because the u-joints allow the movement of the engine.

I used one off of a DSM and it worked great as well. It didn't work however when I upgraded to a larger intercooler. With the larger mass of pressurized air in the NPR intercooler, the DSM blowoff valve didn't have enough flow capability.

This hose feeds all of your idle control stuff. My opinion of old stock nissan idle control is pretty poor. I am pretty sure all the components were worn out and not performing properly, but when I took them all of, the car idled better than ever. I drive mine in a temperature range of 20-110 degrees and haven't had much of a problem. When it is really cold outside, you just have to be a little careful to not let the engine die for about two minutes, then it idles great. In my opinion, take all that crap off and plug the hose.

I agree with Clifton that you should not be having detonation problems at such a low boost level, and your timing is pretty conservative too. With colder intake temps, your chance of detonation should go down, not get worse. I think there is some other factor that is causing you to have problems. I can run 15psi on 85 octane when it is <30degrees outside, but can't even dream of that when it is any warmer.

I've had some luck with a copper head gasket. If you are opening up your motor a lot, then they are worth the little extra money as they can be cleaned up and re-used. As for a stocker, don't mess with it, order up a new one. They are designed to crush when bolted down so that they fill any imperfections in the block and head. Once crushed, they don't uncrush and won't recrush when bolted back down again.

dapiper, That sounds like a lot of ignition advance! What kind of horsepower number are you making with that much advance? It seems like you might be better to back your timing off and run a lot more boost.

Put the BOV nearest to the throttle body. The purpose of the BOV is to prevent pressure waves from bouncing back and forth between the throttle plate and the turbo, which is bad when the pressure wave bounces back into the turbo. If you put the BOV near the throttle body, when the throttle goes shut, there is a pressure relief right by the shut throttle body. If you put the BOV near the turbo, there is enough momentum in the air flow that pressure will build against the throttle plate and bounce back towards the turbo and reliev pressure there. I don't know if there is much of a noticible difference between the two ways to do this, but mounting the BOV nearer to the throttle plate will prevent any pressure surges.

It's hard to give you a reply since we can't really see what you are working with. Just make your bracket so that the wastegate will open all the way when there is pressure applied to the diaphram and closes tightly when there is no pressure. That is all that really matters when installing the actuator.

Moby, I have had the best luck gluing the o-ring in with JB-quick, or JB-weld. The quick sets up a ton faster so you can see right away if it is going to work or not. Just be very careful to not get any of the glue on the sealing surface of the o-ring and that the o-ring is seated perfectly flat in the bottom of the fitting or else it won't seal for beans. Here's another interesting though for these types of controllers. I traded my ball and spring controller last year for a rising rate fuel pressure regulator ($10 traded for $60 and couldn't find a suitable ball to build another one. I took a grabber screw and carefully ground all of the threads off of it and left about half an inch of the shank. These have a really nice tapered underside to the head of the screw which was the perfect diameter and seated great against the o-ring. The shank stuck through the fitting and acts as a guide for it to slide and not pop out of position. Since the top of the screw is flat, it is perfect for the spring to seat against. Just more ideas for these cheap controllers. For the bleed, I am not sure exactly what size you need for proper function. All that I did was take my knife and put a small slit in the hose ~1/4" long. That way it seals when there is no pressure and releases pressure when it needs to.

I am not currently set up to make multiples of these, at least not in stainless steel. I am using borrowed tools (tig, mill, band saw) I could be enticed to make tool purchases with a good offer though

The small bleed after the MBC is CRUCIAL to proper operation and consistent boost. I have been building these things for years and have had great luck with them. Right now, mine is set at 15psi. I get 15psi at 3200rpm in 1st, 2nd, 3rd, 4th, 5th and that holds clear till redline. No spikes, no drops, just consistent boost. My design does have internal threads, but they don't go full length inside the controller, so the spring does not touch them. The bleed valve greatly effects your results. Without one, whatever your boost spikes to is what your controller is set to. When pressure finally pushes past the ball and spring, it opens the wastegate fully open. Fully open is too far open for your wastegate as it will oscillate until it settles at the correct openining for your desired boost level. Well, when the boost starts to drop with the wastegate wide open, the ball and spring controller shuts and traps the pressure on the wastegate and it remains open, dropping your boost level below your desired. A small slit on the hose, or a small bleed after the controller will bleed off this pressure and allow the wastegate to shut again. Keep in mind, these oscilations happen very quickly and are very small motions, so they aren't detectable when your controller is working properly. Another note for consistent boost controllers. When I first started building these things for my friends, I had the ball seat metal to metal inside of the controller. I figured that this was a good enough seal for the ball to seat against, but was wrong. If the ball doesn't have a perfect seal against its seat, then you will also get inconsistent boost. I modified mine so that the ball seats against a rubber o-ring and had much better luck.

just takin the piss.... Sarcasm! :shock: :shock: