It's Inevitable Part: Double Quadrahelix
07-12-2008, 06:44 PM
#1
Boost Czar
Thread Starter
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,488
Total Cats: 4,077
It's Inevitable Part: Double Quadrahelix
Prologue: A few months back I PM paul and ask him if he ever had issues shaving down the screws on his butterfly valve when he ported it. Said all was well for years, so i decided to go at it as well.
Inevitability: Car runs great for 5 months driving over 100 miles a week to work, averaging something like 25mpg.
A few days before I have a scheduled dyno tuning hour, I stop at a stoplight and notice my idle is smooth at 1500RPM. hmm. try to blip the throttle, turn the a/c on/off...nothing, steady at 1500RPM. Light turns green. Sounds of death and lack of power. shut it off.
pull over, try the ignition again and get out...sounds like something is bouncing through my motor....run to shut it off, then nothing. blip the throttle, sounds great. decide to continue to drive to work.
put two and two together and discover this:
BLAH:
Decided to ignore it and pretend I was very lucky. However it seems that's not the case.
Here's the comparison of what I ran last year with no headwork and a restrictive exhaust and a shitty tune:
So something is fubared :( there's no way my resonator did that....so I have to blame a fubared turbo. I absolutely cant make more than 12.5psi. I fear chewed up turbine blades, I all my logs from last week show me at 13.5-14psi and I was hitting it closer to 3700. Compression check resulted in 185 - 177 - 180 - 187.
Here's how the motor ran on the exact same setup. Only difference physically is an added resonator and larger FMIC:
I fail.
Inevitability: Car runs great for 5 months driving over 100 miles a week to work, averaging something like 25mpg.
A few days before I have a scheduled dyno tuning hour, I stop at a stoplight and notice my idle is smooth at 1500RPM. hmm. try to blip the throttle, turn the a/c on/off...nothing, steady at 1500RPM. Light turns green. Sounds of death and lack of power. shut it off.
pull over, try the ignition again and get out...sounds like something is bouncing through my motor....run to shut it off, then nothing. blip the throttle, sounds great. decide to continue to drive to work.
put two and two together and discover this:
BLAH:
Decided to ignore it and pretend I was very lucky. However it seems that's not the case.
Here's the comparison of what I ran last year with no headwork and a restrictive exhaust and a shitty tune:
So something is fubared :( there's no way my resonator did that....so I have to blame a fubared turbo. I absolutely cant make more than 12.5psi. I fear chewed up turbine blades, I all my logs from last week show me at 13.5-14psi and I was hitting it closer to 3700. Compression check resulted in 185 - 177 - 180 - 187.
Here's how the motor ran on the exact same setup. Only difference physically is an added resonator and larger FMIC:
I fail.
Reply
0
0
07-12-2008, 06:56 PM
#3
Scott, could you post a pic of the TB like it should be so we have an idea of what you think the motor ate?
Is it a screw or bolt or what? How much room is there between the valve and the seat? Could it have gotten through? Do you think you bent a valve a little or what? Take the head off? Pop the turbo off at the least... what?
Is it a screw or bolt or what? How much room is there between the valve and the seat? Could it have gotten through? Do you think you bent a valve a little or what? Take the head off? Pop the turbo off at the least... what?
Reply
0
0
07-12-2008, 07:15 PM
#4
Elite Member
iTrader: (1)
Join Date: Jun 2007
Location: VA, Germany, Afghanistan
Posts: 2,945
Total Cats: 3
https://www.miataturbo.net/forum/showthread.php?t=22438
Post two has the original pictures before he messed with it.
Post two has the original pictures before he messed with it.
Reply
0
0
07-12-2008, 07:50 PM
#6
Elite Member
iTrader: (1)
Join Date: Jun 2007
Location: VA, Germany, Afghanistan
Posts: 2,945
Total Cats: 3
I'm just trying to figure out the purpose of the screw, it's no onger there and the butterfly valve didnt fly in the mootr or anything, so why couldn't you just remove the screw and fill the hole with JB weld or something along those lines?
Reply
0
0
and the privelege of buying a new turbo
07-12-2008, 09:37 PM
#14
Boost Czar
Thread Starter
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,488
Total Cats: 4,077
I actually tried this as a safety measure. I literally couldn't remove them.
Furthermore, I figured I'd take a screw from my stock TB and simply plug the hole...but again, even after an hour in PB, I couldn't remove the screw... stripped.
The motor seems to be fine, compression is good, no issues relating so a bad valve. The turbo is what seems to be Fubared. Chad has a spare turbine that he can send me, what a nice lad. Probably be back at 100% next weekend. Got my Begi heatshields I can mount too
Furthermore, I figured I'd take a screw from my stock TB and simply plug the hole...but again, even after an hour in PB, I couldn't remove the screw... stripped.
The motor seems to be fine, compression is good, no issues relating so a bad valve. The turbo is what seems to be Fubared. Chad has a spare turbine that he can send me, what a nice lad. Probably be back at 100% next weekend. Got my Begi heatshields I can mount too
Reply
0
0
07-12-2008, 09:45 PM
#15
Boost Czar
Thread Starter
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,488
Total Cats: 4,077
Is it a screw or bolt or what? How much room is there between the valve and the seat? Could it have gotten through? Do you think you bent a valve a little or what? Take the head off? Pop the turbo off at the least... what?
but like i said, if i completely close my wastegate (100% DC), i still make 10psi at 4k and builds to 12.5psi at redline. when last week, the ebc was flat at 13.5psi at 22% DC.
sidenote: i was lucky to find a modded TB at the shop we were at that had a Wells TPS120 on a miata TB. so I took it, and now i can have tps on my stock TB.
anyone want a ported auto TB with a missing screw?
Reply
0
0
07-14-2008, 01:06 PM
#19
Boost Czar
Thread Starter
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,488
Total Cats: 4,077
i know right! but it seems to be that way. ill know for sure this weekend. but the compression check says the motor is healthy and the symptoms of slow spool and low peak boost is identical to Rob's issues....where he had a chewed up turbine.
Reply
0
0
07-14-2008, 02:09 PM
#20
Senior Member
iTrader: (7)
Join Date: Aug 2007
Location: Southern Indiana
Posts: 1,369
Total Cats: -1
I remember a couple of months ago, you were talking about how you have so much build time and so little seat time. This seems to be holding true... That really sucks!
Reply
0
0
