Just did a swap from a internally gated 2876 to an externally gated gt3071r.....test tomorrow in some fresh, steep stuff!
![IMG_0912[1].jpg](https://www.snowest.com/forum/data/attachments/125/125643-3025fa4b8a6007db56ce39a58ad53c24.jpg?hash=MCX6S4pgB9 "IMG_0912[1].jpg")
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Twisted 3071
- Thread starter Eli
- Start date
... that should pull ok then i guess..... j/k aside, looks killer!
Noob question...what's the advantage of externally waste gated vs internially?
C
cpatts2000
Well-known member
what are you hoping to gain? You my friend are never satisfied and I like it!!
T
TurboMatt
Well-known member
more precise control of boost
The external gate is supposed to have a more efficient, less disrupted airflow around the turbine housing and make more power for the same amount of boost. OVS claims the Garrett with internal gate would need 3 more lbs of boost to make the same power as an externally gated Tial.
http://ogdenvalleysports.com/m8_tial_65.html
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I am hoping to gain a little quicker spool and possibly a little more power. The 30 series Garretts have a 60mm turbine wheel and the 28 series Garretts have a 54mm turbine wheel. I went to the smaller .63 housing so backpressure should be near identical to the 28 series .86 housing.
There is an smaller 30 series that is designated by the -WG after the number. This -WG series can have the identical internally wastegated turbine housing as the 28 series, but they only have a 56.5 turbine wheel. So not all 3071's or 3076's are the same!
I really wanted to try the gtx3071r but couldn't justify the extra $500 right after Christmas. The cost of this was starting to add up. They don't give away Tial wategates! If the 3071 leaves me wanting more, the gtx can be purchased without an exhaust housing and it will bolt right up to this setup.
Who wants to purchase a gtx3071r and have me do a back to back test?
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One thing I didn't make clear....with backpressure the same, I believe the spool of the larger diameter hotside wheel will be better. We shall see......
What boost are you running?
In the past, 13lbs at 5k feet on 100LL. Last outing 15lbs at 6k 110..
Also, this is the .70 a/r bigger compressor housing. 4" in, 2.5" out.
Also, this is the .70 a/r bigger compressor housing. 4" in, 2.5" out.
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What's the map look like for that turbo, I'm assuming 13-15 is towards the bottom?
2.25 pressure ratio is in the heart of it pressure-wise. I am not totally sure on airflow, but think it is in the 25-30lb/min. So, to try to answer your question, not not at the bottom if one "figures". Some two-stroke turbo gurus will tell you not to "figure" and analyze the maps. Run what works for real, not in theory.
YUP! your gonna like this setup a LOT... excited to know how it works on your particular setup before/after.
Had a couple gremlins in my sled yesterday. My last ride on the 2876 was with straight 110, and I was having to add quite a bit of wot fuel, which seemed odd. So, I still had straight 110, and had to work out the wot fuel. Also, my digital speedo/tack decided to sporadically work, so I am not sure what rpms I was turning!
The turbo worked great. Response when stabbing wot from engagement was about the same, but it pulled much crisper/harder and spooling was more instant. The engine has a little different tone. In and out of the throttle while climbing was instant, with the needle almost instantly stabbing 13lbs. So far I am very happy with it. I did get some long pulls, no det, pistons are still working! 5k feet yesterday.
The turbo worked great. Response when stabbing wot from engagement was about the same, but it pulled much crisper/harder and spooling was more instant. The engine has a little different tone. In and out of the throttle while climbing was instant, with the needle almost instantly stabbing 13lbs. So far I am very happy with it. I did get some long pulls, no det, pistons are still working! 5k feet yesterday.
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cpatts2000
Well-known member
good to hear, should be getting my sled this week, lets ride next weekend
Eli
Im going to try the 3071X with the billit wheel on my 925.
Did you see any more exhaust heat with the smaller ar on the hot side?(long pull) Are you running any kind of timing retard?
I was thinking the same as you, and hoping to spool as good as the 2876 but a much better big end.
Keep us posted and Thanks, Kevin
Im going to try the 3071X with the billit wheel on my 925.
Did you see any more exhaust heat with the smaller ar on the hot side?(long pull) Are you running any kind of timing retard?
I was thinking the same as you, and hoping to spool as good as the 2876 but a much better big end.
Keep us posted and Thanks, Kevin
J
jskattum606
Well-known member
Any new news on this? I like the back to back comparisons and i like the fact that you keep going bigger. Im running a 3071 with the .63 tial as well and it works great. The Wg turbo is something ill have to look into. Not sure which mine is.
I don't have egts, just a/f gauge, so I am not sure. I have had it on a few pretty long pulls, though. According to the charts, backpressure should be the same with the smaller 30 series housing compared to the .86 a/r 28 series. I feel that is spools a bit better with great topend for sure.
Kevin, also no timing mod.
I figured out my fuel gremlin. Bad o2 sensor showing lean! I will be back to 15lbs the next ride and report back compared to the 2876 at 15 lbs.
I figured out my fuel gremlin. Bad o2 sensor showing lean! I will be back to 15lbs the next ride and report back compared to the 2876 at 15 lbs.
