[greenstreak]

Bwahaha, sitting and reading while others do? You act like a turbo responds differently on a Spyder than it does elsewhere. There may be only a few people pushing any real power through a turbo setup on a Spyder but what leads you to believe that members here to not have as much or more experience than you on other platforms TMR2? Turbo and wastegate design is the same no matter what platform.

There is a point at which a wastegate will not be able to bypass enough exhuast gas past the turbine wheel to control boost. It is pretty basic info that the higher the boost you run the less the wastegate has to bypass. Eventually exhaust flow is high enough that the actual wastegate passage is just not large enough. You would run into the same problems at this point with a 38mm internal flapper as you would with a 38mm external wastegate. Either way when you reach the limit of what that valve can bypass your boost creeps higher....it is not a boost spike. A boost spike is caused by the pressure signal not opening the wastegate quickly enough and the boost is overshot and then when the wastegate does open boost comes back down to where it is set.
This is almost always related to a boost controller. EBCs are better at preventing boost spike because they can be adjusted by the gain setting to open that solenoid a little earlier where a MBC just opens once that spring pressure inside is overcome.

It is possible that the actuator is going south and reacting slowly but that would have manifested itself in other situation and not just this one wheel spinning corner that Mefarri has described.


Personally, I have run over 400whp on pump gas in my other car with an internal wastegate. I did switch to an external Tial because I wanted to be able to run a larger range of boost pressures. Not because I had any issues with spike or creep. I was limited to a range of about 14psi - 23 before the flapper would be blown open lowering my boost level. With the external I can and have run from 10psi to 30 psi.

 

[greenstreak]

Originally posted by morris
sorry I see this every day..I doubt those cars having those numbers on stock turbos dont have spikes...one of the fist mods people running stock turbos usually do is a wastegate....

My personal graph improved with the external WG..even though I hate the sound

I respect your statement because you do see a lot of cars through your dyno but I cannot agree with this. I rarely see upgraded wastegate on turbo cars that are going to be modded. I see maybe 15-20 turbo cars per week through our shop and it is rarely the case and when it is I feel that they wasted their money because it is cool to have an external. I have seen 350hp stock turbo stock wastegate DSMs come through the shop and their boost control is solid.

 

[MrZ-MR2]

Originally posted by morris
I doubt those cars having those numbers on stock turbos dont have spikes...

To talk about whether they do or they don't one needs first to define what spike is. Following definition of word "spike" in English they all have spikes, every single one of turbos in the world, regardless of what kind of wastegate is used. For me spike is rapid change in values that results in exceeding normal values and normal rate of change. What is "normal" is established through different methods and car is tuned for that. Any mechanical device can be killed if taken outside conditions it has been developed for.

 

[MrZ-MR2]

Originally posted by FriendOfSpyder
Internal wastegate with a manual boost controller and MAYBE i see a 1-1.5lb spike. But its tuned for that...

Bingo!

 

[mefarri]

Originally posted by TMRMR2+--><div class='quotetop'>QUOTE (TMRMR2)</div>

<!--QuoteBegin-MrZ-MR2

MKIII Supra: Internal wastegate 230hp 7.5psi
MKIV Supra: Internal wastegate 320hp 10-12 psi i dont recall
300ZX Turbo: Internal wastegate 300hp 9psi
3000GT Turbo: Internal wastegate 300hp 6-8psi
WRX: Internal wastegate 230hp 12-14psi
STi: Internal wastegate 300 12-14psi
Evo: Internal wastegate 300 18-20psi
Many HKS turbos: Internal wastegate All run better with external HKS wastegate.

:roll:

Draw your own conclusion what's flappin'.

Why is it APS, Greddy, HKS, Garrett, Turbo XS, Tial and many other tuners sell external wastegates? Oh, it must be because they are pretty. Or did you not make it to that chapter yet? You do know what happens to anyone of the above mention cars when you modify the exhuast/intake? Why is it when you put exhuast/intake on each one of the above mentioned cars that the boost spikes past the stock boost level? The wastegate is set to the set level isnt it? The stock boost solonoid is set to hold it there isnt it? But why is it the boost rises? Your Mr know it all Supra man, how many high HP supra guys,500hp+ are there running internal wastegates? How many WRX or EVO guys running 500hp+ with internal wastegates? How many turbo cars have you owned?

You remind me of the dude out on the stands yelling at Jordan, telling him how to dunk.

www.tmrmzine.com/mr2[/b]

hahahahahaha

 

[mefarri]

Originally posted by greenstreak
Bwahaha, sitting and reading while others do? You act like a turbo responds differently on a Spyder than it does elsewhere. There may be only a few people pushing any real power through a turbo setup on a Spyder but what leads you to believe that members here to not have as much or more experience than you on other platforms TMR2? Turbo and wastegate design is the same no matter what platform.

There is a point at which a wastegate will not be able to bypass enough exhuast gas past the turbine wheel to control boost. It is pretty basic info that the higher the boost you run the less the wastegate has to bypass. Eventually exhaust flow is high enough that the actual wastegate passage is just not large enough. You would run into the same problems at this point with a 38mm internal flapper as you would with a 38mm external wastegate. Either way when you reach the limit of what that valve can bypass your boost creeps higher....it is not a boost spike. A boost spike is caused by the pressure signal not opening the wastegate quickly enough and the boost is overshot and then when the wastegate does open boost comes back down to where it is set.
This is almost always related to a boost controller. EBCs are better at preventing boost spike because they can be adjusted by the gain setting to open that solenoid a little earlier where a MBC just opens once that spring pressure inside is overcome.

It is possible that the actuator is going south and reacting slowly but that would have manifested itself in other situation and not just this one wheel spinning corner that Mefarri has described.


Personally, I have run over 400whp on pump gas in my other car with an internal wastegate. I did switch to an external Tial because I wanted to be able to run a larger range of boost pressures. Not because I had any issues with spike or creep. I was limited to a range of about 14psi - 23 before the flapper would be blown open lowering my boost level. With the external I can and have run from 10psi to 30 psi.

That was my point the whole f*cking time. Jesus. I never said internal gates suck. I said mine was too small.

 

[greenstreak]

No, that is not what I was saying in that post. If yours was too small you would have seen BOOST CREEP prior to this scenerio.

 

[MrZ-MR2]

Originally posted by mefarri+--><div class='quotetop'>QUOTE (mefarri)</div>

<!--QuoteBegin-TMRMR2

blah blah blah

hahahahahaha[/b]

Where is that icon for azz kissin when you need one?

 

[TMRMR2]

Originally posted by MrZ-MR2+--><div class='quotetop'>QUOTE (MrZ-MR2)</div>

Originally posted by mefarri@
<!--QuoteBegin-TMRMR2

blah blah blah

hahahahahaha

Where is that icon for azz kissin when you need one?[/b]

Wait, did i just stick up for Mefarri?

WTF

 

[mefarri]

Originally posted by TMRMR2+--><div class='quotetop'>QUOTE (TMRMR2)</div>

Originally posted by MrZ-MR2+--><div class='quotetop'>QUOTE (MrZ-MR2)

<!--QuoteBegin-mefarri

@
<!--QuoteBegin-TMRMR2

blah blah blah

hahahahahaha

Where is that icon for azz kissin when you need one?[/b]

Wait, did i just stick up for Mefarri?

WTF

[/b][/quote]oh come on now. And because I think it's funny doesn't make me an ass kisser. You're all about absolutes.

 

[WTS]

Mefarri,

I forget which type you tuned on. If it was an inertial roller like a Dynojet 248x then it certainly couldnt load up the engine like the track or even many street conditions will.

Spinning tires at the base of a hill then suddenly grabbing will load up very quickly. Probably more so than from a standing start.

So, spike --> lean --> det --> damage. Have you torn the engine down yet? If not, how do you know its the ring lands?

I dont recall HPT saying they port the GT WG's either.Thye might, I just dont remember. But still, thats a creep not spike prevention mod.

 

[turbo_jimbo]

assuming it is a ring land problem, that means one thing and one thing only: detonation. if you detonated there is a possibility it cracked the ring lands. if you overboosted, the problem would be bent rods, or the like. cracked ring lands detonation issues not overboosting issues.

 

[mefarri]

Originally posted by WTS
Mefarri,

I forget which type you tuned on. If it was an inertial roller like a Dynojet 248x then it certainly couldnt load up the engine like the track or even many street conditions will.

Spinning tires at the base of a hill then suddenly grabbing will load up very quickly. Probably more so than from a standing start.

So, spike --> lean --> det --> damage. Have you torn the engine down yet? If not, how do you know its the ring lands?

I dont recall HPT saying they port the GT WG's either.Thye might, I just dont remember. But still, thats a creep not spike prevention mod.

No I'm currently still driving the car actually. I plan on tearing it down in a week or so. But here's what I told my friends that own Polk Performance and Don said It was ring lands : First, after the spike, I went back and my catch can was 3/4 full of oil which havdn't accumulated a drop before that. 2nd, I did a compression test when I got back cuz I was scared and cylinders 1 and 4 were perfect after 6 cranks at I think it was 180 but cylinders 2 and 3 after 6 cranks were well below at like 120 or something and it took more and more cranks to build up the pressure to 180ish. Third, I tried to leave one morning and the car was burning an insane amount of oil. So much so I couldn't see the car behind me so within and 1/8 of a mile I turned around and came home. It hasn't done that since then but it still burns oil at idle and some while driving until it gets warm. After telling Don all this he said yep you've lifted/cracked those ring lands. I thought maybe for a lil bit it might be something in the valvetrain like a leaking vlave guide or something. Does that make any sense? I also have some pictures of what came out of my catch can recently but they're at home where I'm not right now. I really want to 100% identify that it is the ring lands and not something else before I go pulling the motor out and droppin $1200 on parts.

 

[WTS]

Drain and strain the oil and then drop the pan and pick out chunks with a magnet. Then try to identify the pieces.

But the odds are the top compression ring on those two pistons are cracked/chunked, the rings damaged. The cylinder walls may even be scored.

I wouldnt keep driving on it because the damage will just spread as the oil distributes the sharp bits to all areas. Sure, the filter will pick them out and the oil pickup will keep the larger pieces from recirculating but they have to find they're way to the pan in the first place.

Big end rod and crank bearings being the next victims along with the crank itself.

The oil pump is a goner almost for sure.

As the damage continues , metal fragements will find they're way into all the oil galleys. The block will have to be stripped, hot tanked and cleaned really well.

 

[mefarri]

It's not that bad I guarantee you. It drives fine and I haven't boosted since. I asked it the walls would be scored and Don said he didn't think so and that I'd prob. just have to get it honed for the new pistons.

 

[WTS]

<div class='quotetop'>QUOTE </div>

It drives fine[/b]

Surely, you mean it still tracks straight and corners correctly because you also said...

<div class='quotetop'>QUOTE </div>

the car was burning an insane amount of oil. So much so I couldn't see the car behind me[/b]

Is this your only car?

Got bicycle?

 

[mefarri]

yea that was only that one day. Since then it just burns a little bit. So much so that it hasn't affected my oil level in over a week. And yea this is my only car. I think that one day was just a freak day. I'm sure it's hurt but not bad enough to be throwin metal shards all over the place.

 

[turbo_jimbo]

you wont know that until you pull the pan...

 

[mefarri]

yea we'll see I suppose. But does this sound like it could be anything else except the ring lands? Anything in the head maybe? It doesn't smoke when it's warmer outside.

 

[WTS]

If your not getting misfire PO30X codes then the plugs and valves are probably OK.

Anything that causes a cylinder to be down on compression should cause a misfire tho.

If you ARE getting misfires then it could be related to top and/or bottom end damage.

Its all just idle speculation until its torn down.