Turbo Locost
 

Hi,

Quick update of Turboed Locost:

Last 3 race weekends the Tullos EBC didn't control the boost at all. I was running with 7 psi spring on a wastegate and with 170 hp on the wheels instead of 208.

While troubleshooting Tullos EBC, I left out the wire to Solenoid completely and WG had same pressure on top and bottom of the diaphram.

It was very noticeable first time accelerating out, and Tullos showed 17 psi peaks. I thought 115000 miles was enough for the motor and used gas pedal as boostcontroller and had pretty fun time for a while.

Result was melted pistons on 2,3 and 4, 4 was worst.

In addition to this now broken engine, I have 99 motor which has spun bearing, so the crankshaft needs machining and one of the connecting rods needs to be replaced.

And the questions:
I have 99 block, can I use 96 crankshaft and rods on it with 99 pistons?
I could use 99 head (needs some attention) or 96 head which seems to be fine.

And for the better engine:
Is anybody running with Belfast setup yet?
What is the actual delivery time for is rods and pistons?

Is the normal failure mode of Electronic boost controller such that WG remains closed?

Thank you for your time

hrk

So you noticed that the turbo was over boosting and you stayed in it dude we are to much alike i believe that when any ebc fails the solenoid should fail open for safety but i dont know the particular solenoid you have. Congratulations on your adventures in high boost i hope you get back there with more fueling/cooling etc next time and mmore pooowwwah. The pistons and rods should be the same. Not to many actualy running the belfab stuff lead time is pretty long at 1 month + i believe ask hustler to be for sure.

If you're going to build an engine, search out some earlier 1.8 pistons that are lower compression than the 99s. The static compression on the 99s is 9.5:1 and if you do any surface work it goes up from there.

I know the link ebc/wg solenoid does NOT close if it's failed. That seems odd/wrong.

The solenoid MOST LIKELY fails open. That doesn't mean it CAN'T fail closed. It's a risk when you add an electronic solenoid into the system. You counter it by using an over boost shut down in your ECU. Of course, that's not an option if you don't have a programmable ecu. The Tullos assuredly has an overboost shutdown, but if it's broken.. well...

HRK, if you want me to call the stealership to get prices on anything, I will. I got retail prices for the pistons at $74 ea and $250 for the ring set. But I didn't ask wholesale.

Ben

Thanks for all comments,
I'll look if someone has earlier pistons available.

Most likely I will not build an engine like it should, just gather used parts together.
Any idea of crankshaft differences between 99 and 96?
Preferred place to get pston rings for turbo use? Thanks Ben for stock price, but 250 for set?

hrk

http://www.importperformanceparts.ne...portrings.html

http://www.importperformanceparts.ne...ngs_mazda.html

Thanks Braineack, will some of those work with stock 1.8 pistons?

hrk

cranks are the same

What are your mods that melted stuff at 17 psi? I run 18 every day and I hope this isn't my fate.

And internals are all the same spec from 94-2005. All they did was raise compression and weaken the con rods in the later years. My car is running 97 block, 99 head, 99 crank and oil pump, aftermarket rods and pistons.

And when your car feels like it has way more acceleration than normal, glancing at the boost gauge is an awesome idea. That and low oil pressure are two great reasons to stop whatever you are doing and get the car medical attention.

Mods:
Tuned for 9 psi boost, anything above that extrapolated.
Exhintake cam, otherwise stock motor with 115000 miles.

I was fully aware of boost levels and oil pressures (which were actually higher than normally towards the end of 20 minutes session because of the).

It ran fine for about 10 minutes if I bled off the gas pedal in higher speeds.

This is full track car and I have until 10 of August to fix the motor for next one. Since the engine had unknown history before me and I had put ~30 days on track and few hundred autocross runs on it, I decided that it was time to test what gives. Laying rubber well into third had something to do with it also. :)

hrk

I would say it did good to survive 30 days of track. That's gotta be equal to 100k street miles of hard boosting.

Only 8 of those days were with boost.

How about using just Tial wastegate spring to control boost? There are plenty of those for $30. Reliability should be good, no jamming solenoids or balls.
What are the downsides, besides losing the ability to lower boost? Spikes?
hrk

You can't lower boost. Even with an EBC. The WG spring will always determine minimum boost.

Yes, I know that I cannot lower boost below wastegate spring. But if I had no boost controller at all and run with 10 psi spring, as opposed to 7 psi spring and elaborate (suspect to fail) boost controller raising the boost up to 9 psi, would there be any ill effects except being able to control boost.

hrk