zguy36

Kevin, Great attempt at coming up with an equation, but you just don't have enough tools to get this done. Looking through your equations, I can see that you had your inputs and your results and tried really hard to fudge the numbers in between. What you need to do, in order to continue building your equations, is manipulate your variables. Each variable plays a role in the equation and should vary your answer accordingly. Pick one variable and change it keeping all others the same, then look at your result and see if it changed how you thought it should. Using this method, your equation has quite a few holes in it. To run this equation for turbocharged engines, you are going to have to add a lot more variables into the equation, which is exactly why you don't see catch all equations floating around. There are too many factors to deal with and it gets too tough to find the math to cover it. For example, take two identical engines running 15psi of boost. Lets put small turbo on one and a large turbo on the other. Even though they are running the same boost pressure, the larger turbo will most likely make more power at the same boost level. The turbocharger has a huge effect on the actual horsepower output of an engine, but is very very difficult to model as a whole system with an engine.

I am not sure if it was this site, or the megasquirt forum, but I saw some opening curves comparing a high impedance and low impedance injetors. There wasn't really much of an difference to speak of, so I wouldn't get too stuck on staying with the high impedance. Your megasquirt will run a dual stage fuel map, so you can have your smaller injectors for idle and run large injectors for everywhere else. (That is not called sequential injection as you stated) If you do this with the squirt, you will have to run high impedance injectors though, as the squirt cannot drive that many low impedance. I have also tossed around the idea of using a single throttle body injector for this two stage setup along with the biggest injectors that you can still idle well with. This would save a lot of plumbing by only adding one injector instead of six.

Thanks Clifton!

Has anyone tried the professional products damper pulley from Motorsport Auto? I recently received one of these (actually ordered two months ago) and am noticing big differences between the stock one and this. First major difference is that the belt groove is much narrower. Second is that the pulley is smaller diameter (about 14%) difference. My question is, has anyone had any cooling problems with installing this pulley? The smaller diameter is going to make the water pump and the alternator turn slower. Alternator won't be a problem, but my car is already marginal for the cooling system. Any input would be appreciated. Thanks. Jeremy

Check in the downloads section. I have a spreadsheet that will calculate the airflow through your engine based on fuel consumption and air/fuel ratios. With guessing a VE of a certain percentage, you may as well be guessing your airflow.

So you are saying that the only changes that have been done it to increase the downpipe size to go with an external wastegate? I am having a hard time believing that such a small upgrade would give 80hp increase, without any other mods or tuning changes.

With a 1/4 mile run, I usually do not see temps that are any more than 30 degrees over ambient temperature. This is with about 19psi of boost.

#3 looks like a turd! Nice work on the downpipe, I'd love to see you make your goals.

I blew a steel o-ring with copper head gasket. The gasket shoved right out past the o-ring and the o-ring fell into the combustion chamber. This was all on stock turbo pistons. I swapped to the steel hks gasket and am still using those same pistons.

What were your peak EGT's during those runs? I just installed a pyro and am wondering what is considered unsafe. Great numbers by the way.

Phil, I was running into some really similar problems to what you are describing. I chased the ignition gremlins for a long time before I figured it out. I also had the same symptoms, when you decrease gap, problem gets better. I bought a hotter coil, but still couldn't get the problem to go away. Turns out, it wasn't an ignition problem at all. My problem was a setting on the megasquirt for decel fuel cut was set too sensitive. At high rpm, high power load, I was getting more noise in the signals into the megasquirt and it was briefly triggering a fuel cut, which translated to really bad misses. Take a look at your datalogs and see if you are getting sudden decreases in pulsewidth. Why my problems with this got better by dinking with the ignitino system, I do not know, but I'm not complaining that it is fixed. Jeremy

I recently installed at garrett gt40 turbo to my l28. This turbo has roughly 1000 miles on it now, and now has .040" thrust bearing wear. I am using the stock oil feed line, which worked great on my t3/t4 hybrid. Any ideas as to why I am getting such excessive wear? There is little to no radial play, only axial. I would think that lack of oil would wear both bearings. Let me know your thoughts on this. Thanks. Jeremy

I am not really sure what you are asking.... You change your fuel setup to put in the correct amount of fuel, no matter what systen you are running. You need a wideband sensor to to this correctly. Playing around with the stock system is difficult to do. I scrapped it a while back and have no regrets. The full tunability of a standalone is truly the best way to go. A megasquirt is cheap to, so money isn't so much of an issue.

your wastegate is stuck open, or your blow off valve isn't adjusted tight enough.

looks like they are proud of their products.... the prices are crazy

Remote mounted turbos are for cars that can't fit them under the hood. They aren't as efficient or good for as much power as an under hood mount. Do a search on this site and you will see lots of posts on this.

I've been running stock pistons from an 83 turbo, with 20+ psi of boost. i've also detonated enough to blow a steel o-ringed copper head gasket and to break spark plugs. I just took the engine apart for a rebuild (bad bearings) and the pistongs looked as good as new. I am running ceramic coatings on them as well. When they finally go bad, I'm melting these suckers down and making body armor from them!

I had the same problem with my 73z. The linkage that pushes the master cylinder had come loose and tightened the adjustment. This pushed the slave cylinder slightly out, which in turn causes the clutch to not fully engage. I was also fighting thrust bearing problems in the engine as well. If your slave cylinder is tough to put in, then this is your problem with the slipping clutch. To fix it, check that asjustment and see if it is way out.

that search found no hits for me..... the act clutch holds more torque than the ebay one anyway.

Pretty weird answering some old stuff, but thanks for doing it. I would have missed this thread otherwise and it had some good info. I am in the process of a rebuild due to a bad thrust bearing. I was running a SPEC pressure plate with a stock disk.

Before you blast me with the search hate, I'll let you know that I have! This isn't a question for nissan engines, but this is always a good source for knowledge. A friend of mine got a bit carried away with the porting on his rx7 rotary and ran into a water jacket. Don't ask me why, but he continued until the hole was about one square inch. I have heard of people using a filler of some sort for cylinder heads for this same purpose. Do you guys know the name of this stuff? And also if it will work for a hole that big? Thanks for the help. -jeremy-

Can you hear the miss, or just see it on the light? Maybe your light sucks?

I don't think there is a difference between turbo head bolts and non-turbo head bolts. At least they have the same part numbers at the dealer.

If it is just like the Tial parts, then run these to test them. If they break, you can directly replace it with parts that are known to be good. Not a bad deal if you ask me. Cheap is always the way to go, as long as it holds together!

I've seen that car on this site before... don't remember where though. I'm getting very leary of cars for sale on ebay. Could be the latest scam or something. Who's gonna try and gouge money out of a church?