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DIY Turbo Discussion greddy on a 1.8? homebrew kit?

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Old 05-15-2013, 03:31 PM   #81
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I was trying to buy a 50 trim, was too stupid to know that a 2.75 inlet would not be a 50 trim, but got lucky and ended up getting one anyway

Alright you've made me want go fix my car now. Have to go mighty vac the clutch slave and replace the lower alternator bolt which randomly decided it didn't want to have threads on it anymore. I haven't touched the alternator since I got the car so for all I know it's been like that the whole time, I noticed it the other day when I saw the bolt sticking out and almost rubbing on the belt...
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Old 05-15-2013, 05:54 PM   #82
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Ok, just got the clutch bled and the alternator bolt in. Backed off the AFPR a little and went for a drive, still seeing pretty much a solid 10.0 on the wideband under boost. Backed it off some more, same thing though it felt faster. Backed it off some more, felt faster, backed off some more etc. etc. until now I have the adjuster set all the way lean, but my wideband still reads 10.0 AFR under boost, it reads like 10.4-10.5 in the lower rpms as boost is coming on but in the midrange through redline it just sits at 10.0. I played with the AFM adjustment too but that just seemed to affect how it performed until boost came on, so I played with the adjustment until it seemed to pull the hardest off-boost (AFR stayed pretty much the same no matter where I had the AFM screw, but the feeling of the car seemed to change). So, it would seem I'm running way too rich, should I put my stock injectors back in?

Also I'm pretty certain that I had/have an exhaust leak from the V-band clamp right off the turbo. When I tried to tighten it the other day the nut was hard to turn like it was stripped, I sprayed some wd40 on it and worked it back and forth until it was tight. Then when I drove it just now, my first 2 "pulls" the car sounded completely different and the exhaust didn't rattle, then by the 3rd it was back to sounding how it did and the exhaust rattled. After the car cools down I'm going to check the tightness of that clamp and I'm willing to bet it's loose again.
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Old 05-15-2013, 10:38 PM   #83
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The high exhaust heat destroys threads. They're fairly tight tolerances and the heat warps and distorts them enough to make threads feel stripped, they're not.

There's a boost onset adjustment you should try, basically the boost point in which the AAFPR actually starts to take affect. Read the directions of BEGI's site, I think you're supposed to tune that first IIRC.
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Old 05-16-2013, 01:22 AM   #84
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Quote:
Originally Posted by curly View Post
The high exhaust heat destroys threads. They're fairly tight tolerances and the heat warps and distorts them enough to make threads feel stripped, they're not.

There's a boost onset adjustment you should try, basically the boost point in which the AAFPR actually starts to take affect. Read the directions of BEGI's site, I think you're supposed to tune that first IIRC.
Yeah, I did set the boost onset adjustment according to BEGI's directions, with the exception of the fact that they wanted base fuel pressure to be adjusted down to 28/30 PSI and mine wouldn't go any lower than 35 with either the stock pump or the walbro. Maybe I'll try to back it off 1/2 turn and see what that does.
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Old 06-14-2013, 10:50 PM   #85
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Well, I figured out why I had so much lag:




Reason I took the turbo off though is out of nowhere it would only boost 3 psi. Checked for, found, and fixed a couple small boost leaks and then drove it again. Still only boosted 3 psi but also gave me a huge cloud of blue smoke out the tailpipe! Yay! The turbo has a good 1/8" of shaft play too... I went back and re-read the ad I bought the turbo from and they make it very clear that there is no warranty at all. So, I ordered another ebay turbo! Except this time they actually posted the exducer/inducer sizes so I could confirm it's a 50 trim, and it comes with a 60 day warranty, which is about 45 days longer than this one lasted. Actually, I e-mailed and asked about the warranty and got this response: "HI! our warranty is 3 months cover the oil leaking and smoking. Thanks!"

As for tuning, after backing out the center screw of the AFPR a LOT (probably ~15 turns) I was able to achieve AFR's of 11.2-ish at WOT. This is with the enrichment screw still all the way lean, and backing out the center screw further has no effect anymore. Not perfect, but I imagine I'll have to re-do all this again with the new turbo anyway. In the meantime the car is getting put back to stock since I have to smog it by mid next month anyway, it really sucked getting that dmv notice in the mail only like a week after I finished putting the kit on, lol.
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Old 06-15-2013, 12:25 PM   #86
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Legend has it you can rebuild ebay turbos with gopopshop rebuild kits. Best way to get the right one is to give them the serial number, which yours probably doesn't even have. If you know which one the chinese copied though, you can put quality bearings and bushings in your ebay turbo.
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Old 06-15-2013, 09:02 PM   #87
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Quote:
Originally Posted by curly View Post
Legend has it you can rebuild ebay turbos with gopopshop rebuild kits. Best way to get the right one is to give them the serial number, which yours probably doesn't even have. If you know which one the chinese copied though, you can put quality bearings and bushings in your ebay turbo.
Interesting. I don't think there's any sense in rebuilding this turbo since it's a 69 trim, not a 50 like I thought, so it's way too big for me and explains why I had so much lag. I've got a 50 trim on the way though, but when that one fails (probably like 20 minutes after the warranty is up...) I'll have to look into that. Thanks
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