turbo restrictor? (plug size info needed)
#1
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Hey guys, need a little help from those that have installed restrictors in your hybrid turbos, few disclaimers below...
*Car runs great, boosts well, doesnt smoke at idle or mid throttle (from what I can tell - havent driven it much), seems most apparent at full boost (15+) and I just noticed it recently. Its not major, but just a grayish smoke (not a lot, but enough to **** me off) Dont think it was doing it from day one but I can't be 100% certrain.
*IC pipes clean, minimal oil residue...turbo looks clean - a little oil in front of the compressor wheel once I pulled the jpipe...no shaft play.
*turbo has ~400 miles on it, was brand new. turbo builder is ready to rebuild it (on them) but Id like to try this first before pulling it...Ive read others have had success in running a restrictor on similar turbos even after smoking was present.
T04E - 57 trim, #8 hotside, oil only.
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Before I installed the turbo I bought some allen head plugs to use as a restrictor but none fit, was confused - installed without. I bought a 1/8 NPT which seems like what most use from searching and it doesnt fit...it can be pushed in, too small. After that I bought the next size up from Pegasus racing (1/4) and it was too big. The threads look about right on both but one is small and the other too big.
Went to a few local home stores and bought some 3/8's and some 1/2's and the 1/2's seem to fit the best but the thread pitch is way wrong. I read somewhere that NZ951 had a "gas fitting" thread rather than the standard NPT thread that most turbos use...anyone else?? Why is everything that measures the same "size" different? haha, im confused and its late...
Anyone that can help tell me what to buy from the pics - it would be very appreciated. Seems so dumb but I havent found anything that screws in yet locally (or from Pegasus Auto) and of course my car has to be different and be a pain in the @$$.
Pics:
![](https://members.rennlist.com/sngrant/turborestrictor1.jpg)
![](https://members.rennlist.com/sngrant/turborestrictor2.jpg)
This actually seems to fit the best, it actually starts to thread. 1/2" plug from the local home store - pitch is way wrong though:
![](https://members.rennlist.com/sngrant/turborestrictor3.jpg)
![](https://members.rennlist.com/sngrant/turborestrictor4.jpg)
Blue plugs from Pegasus (L), other plugs (R) are what I sourced from the Lowe's and other home store:
![](https://members.rennlist.com/sngrant/turborestrictor5.jpg)
1/8 NPT plug from above next to oil inlet - this should apparently fit from what I have read, but it just can be shoved in without threading...
![](https://members.rennlist.com/sngrant/turborestrictor6.jpg)
Thanks!
*Car runs great, boosts well, doesnt smoke at idle or mid throttle (from what I can tell - havent driven it much), seems most apparent at full boost (15+) and I just noticed it recently. Its not major, but just a grayish smoke (not a lot, but enough to **** me off) Dont think it was doing it from day one but I can't be 100% certrain.
*IC pipes clean, minimal oil residue...turbo looks clean - a little oil in front of the compressor wheel once I pulled the jpipe...no shaft play.
*turbo has ~400 miles on it, was brand new. turbo builder is ready to rebuild it (on them) but Id like to try this first before pulling it...Ive read others have had success in running a restrictor on similar turbos even after smoking was present.
T04E - 57 trim, #8 hotside, oil only.
--------
Before I installed the turbo I bought some allen head plugs to use as a restrictor but none fit, was confused - installed without. I bought a 1/8 NPT which seems like what most use from searching and it doesnt fit...it can be pushed in, too small. After that I bought the next size up from Pegasus racing (1/4) and it was too big. The threads look about right on both but one is small and the other too big.
Went to a few local home stores and bought some 3/8's and some 1/2's and the 1/2's seem to fit the best but the thread pitch is way wrong. I read somewhere that NZ951 had a "gas fitting" thread rather than the standard NPT thread that most turbos use...anyone else?? Why is everything that measures the same "size" different? haha, im confused and its late...
Anyone that can help tell me what to buy from the pics - it would be very appreciated. Seems so dumb but I havent found anything that screws in yet locally (or from Pegasus Auto) and of course my car has to be different and be a pain in the @$$.
Pics:
![](https://members.rennlist.com/sngrant/turborestrictor1.jpg)
![](https://members.rennlist.com/sngrant/turborestrictor2.jpg)
This actually seems to fit the best, it actually starts to thread. 1/2" plug from the local home store - pitch is way wrong though:
![](https://members.rennlist.com/sngrant/turborestrictor3.jpg)
![](https://members.rennlist.com/sngrant/turborestrictor4.jpg)
Blue plugs from Pegasus (L), other plugs (R) are what I sourced from the Lowe's and other home store:
![](https://members.rennlist.com/sngrant/turborestrictor5.jpg)
1/8 NPT plug from above next to oil inlet - this should apparently fit from what I have read, but it just can be shoved in without threading...
![](https://members.rennlist.com/sngrant/turborestrictor6.jpg)
Thanks!
#2
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http://cgi.ebay.com/ebaymotors/Nut-B...spagenameZWD1V
No affiliation but the above has saved my a$$ with non-standard threads more times than I can count. I have both the metric and sae sets. Well worth the money when you add up all the time you waste trying to identify a thread .
No affiliation but the above has saved my a$$ with non-standard threads more times than I can count. I have both the metric and sae sets. Well worth the money when you add up all the time you waste trying to identify a thread .
#3
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No joke, thanks Travis. Thats a great idea. Not sure if thats covers crazy NPT or other fittings but it would be nice to have...
For anyone else, found these:
Are these the same as the Pegasus NPT plugs?
http://www.jegs.com/p/Edelbrock/761428/10002/-1/10019
Link to Pegasus plugs: http://www.pegasusautoracing.com/pro...p?Product=3258
For anyone else, found these:
Are these the same as the Pegasus NPT plugs?
http://www.jegs.com/p/Edelbrock/761428/10002/-1/10019
Link to Pegasus plugs: http://www.pegasusautoracing.com/pro...p?Product=3258
#5
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I've had the same problem in the past and this is what I've done with good success. I took a 1/8 npt and ran it completly through a 1/8" npt die a couple times to remove the taper of the plug.
#6
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some hybrid turbos do not like the high oil pressure of our cars and will let oil pass through the seals on full to high boost- so you have to slightly restrict the oil pressure to the turbo.
#7
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It wont even screw in, if I take the blue 1/8 NPT plug and set it "to screw in" it falls to the bottom..ie no threads engage.
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#8
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That is odd. all the turbos I have use an 1/8 pipe thread.
If it is only doing it at idle make sure your AOS is properly setup as well but I do agree with using a restrictor.
If it is only doing it at idle make sure your AOS is properly setup as well but I do agree with using a restrictor.
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Sorry, I missed that. The journal bearing turbos I have dealt with have all had 1/8" npt oil inlets. if you can find a bolt that threads into the inlet, you could make a restrictor from it by cutting it down, cutting a screwdriver slot and drilling the center hole you want.
#10
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No problem Rob, that sounds like a great idea using a bolt. My search continues...
Funny enough of my many trips to Lowes and the like the best fitting I have found so far that threads in are flare fittings. Im going to move on to bolts now I guess.
Funny enough of my many trips to Lowes and the like the best fitting I have found so far that threads in are flare fittings. Im going to move on to bolts now I guess.
#13
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Just to make sure there isn't any confusion maybe you could run down to the local hardware store and pick up a couple of 1/8 brass fittings and some plugs.
I only say this b/c I haven't seen anything other than that being used (other than no thread) and I have at least 8 turbos sitting here.
I only say this b/c I haven't seen anything other than that being used (other than no thread) and I have at least 8 turbos sitting here.