SleeperZ

You are correct a lower temperature thermostat will not help. If all components are in good shape as you say, you must have a big air bubble in the cylinder head. I've not had that problem with Z engines, but I warped a Honda head real badly by not bleeding the coolant system well.

Seems to me you want a high stall behind a turbo, not low. You'd be a dog off the line with a diesel torque converter.

The first and last time I had something pressure tested, the shop gouged the inside fins badly. It wasn't a radiator, it was an IC, but I was PO'd. I'd just run some Simple Green through it, rinse well and install it. If there are leaks, it will become obvious quickly.

Looks to me you linked the thumbnails instead of the full size pictures.

Sweet! I'm drooling, just waiting for install details and results!!

Take off the caps. They are there to protect the pintle - just take care when you install them, and don't smack the tips on the manifold.

Yes, boost leaks can do that, now that you mention it. You can always try to spray flammable stuff around your pipes and listen for the idle speed to change. That may or may not find boost leaks. I had some leaks at first, and ended up checking all the connections, and repairing some. I had a big leak on the outlet of my DSM BOV - I didn't consider that a problem until I heard the valves are supposed to leak a little bit at idle. I also found that my air regulator had blown out it's bimetal strip (the long bit with the electrical connector). Since I repaired those two leaks, my car was much quieter under boost.

The comparison of turbo vs. compression is just an equivalence. If you were not running an intercooler, you would have the internal temperature rise associated with such a compression ratio, but with intercooling you get the air volume without the temperature rise, making MAD POWA YO!

You need at least 16:1 or 17:1 compression to generate enough heat to ignite the fuel. A spark will not ignite diesel. You would also have a hard time pumping diesel through the EFI system, it's very viscous compared to gasoline, and it would not vaporize once out of the injector. Diesel fuel is nothing like high octane gasoline - it's basically a light oil, similar to kerosene or home heating oil. It's flammability is called "Cetane", the lower the number the more resistant it is to ignition, and has nothing to do with how controlled the burn is, or "Octane".

I use it for the fuel vapor cannister, so it vents only under throttle tip-in, to make sure the vapors go into the engine. AFAIK, that's it's purpose on an FI car. If no one knows for sure, I can venture to the garage, I know the FSM is buried somewhere there...

Don't let off the throttle j/k, thought I 'd throw that at ya. I'd try to confirm with an a/f meter or something if it is hitting rich - has your AFM had the tension changed? Not sure what else to check.

And I'm not saying the gauges are completely useless, I have one myself, and it seems to be consistent as well. I've just seen enough data to know they cannot be relied upon as a precision instrument. The fact that it is an oxygen sensor implies it cannot reliably measure degrees of richness because there is close to zero oxygen in any "rich" mixture. The wideband "oxygen" sensors use a different technology, and do not simply measure an oxygen level.

ZmeFly - Don't try to calibrate that voltage curve. It will vary from O2 sensor to O2 sensor, and it will vary with temperature as well. If you have ever seen a graph of the voltage vs. mixture, it is not even CLOSE to linear. Seriously, anywhere richer than 13:1 can read from 0.7V to 1V, and anything leaner than stoich will be close to zero. There is a reason for the price and popularity of wideband O2 gauges.

Brad, I am not contesting twin turbos cannot be made to have good spool characteristics. In order for equal flowing twins to spool the same as a single, the inertia of one twin must be 1/4 the inertia of the single. If the single has 2.5x the inertia of one of the twins, then the twins will be much slower spooling. I get my numbers from "Maximum Boost" by Corky Bell.

You can measure the output of the O2 sensor using a digital multimeter (set on volts). An analog type has too little input impedance and will not make an accurate measurement. 0V = lean about 0.5V = stoich >0.8V = rich Ands that's as accurate as the O2 sensor gets.

Given the conditions you assume, same airflow and efficiency, I believe the single will spool faster. I am assuming you are running parallel twins, each driven by three cylinders. In order to spool a turbo with half the exhaust flow, you need a much lighter turbine to equal the spool characteristics of a single with full exhaust flow. And I'm not talking a turbine with half the inertia, I'm talking twins with 1/4 the inertia of the single.

Ditto, FPR cannot pass the fuel volume at idle.

If the downpipes or wastegates will not swap, it's very easy to swap the turbine housings - even if they have different downpipes, the housings will swap. Then you can keep the coolant cooled center section. If I'm talking out of my ass, let me down easy

There is an edit function for your own posts...

Magnets will not affect fuel injectors in the least. As a matter of fact, there are no magnets in injectors, so they cannot become de-magnitized. There is an iron rod attached to the pintle that is attracted to an electromagnetic coil when current flow is active.

The pumps I was plumbing in parallel were high pressure Bosch pumps. I don't know why they didn't play together, but judging by my fuel pressure gauge, there was no doubt they didn't like being plumbed inlet to inlet, outlet to outlet. Most likely they were starving for fuel, and separate inlets may have solved it. FWIW, the Porsche turbos use two high pressure pumps in series, just like the pump I was using. Of course, one pump is serving me just fine right now, but under higher boost pressure, plumbing pumps in series is a good solution for compensating for the high boost, maintaining fuel flow.

Bill, I commend you on your ability to walk away on a 'deal' that might not be all it seems. If you think the owner was lying about one thing, it probably wasn't all he way lying about. God knows what you might find once the engine is opened up. And attention to detail is necessary to perform a good engine build - if the builder wasn't paying attention to plug wires and block prep, there could be MANY things inside that weren't paid the proper attention.

My bone stock L28ET makes 128 hp/liter.

Your current pressure sounds normal now. I've never seen my pressure at idle as high as 20-25 psi. Always in the 10-15 range, with my mechanical Autometer pressure gauge.

All I can think of is you had a misaligned gasket to begin with. Faulty parts.