oh no no no i wouldnt boost over fuel cut point without an aftermarket tune. that would be insane man. i have done alot of reasearch on the 850's and i understand them alot more now but some questions that i cant find or if i need opinions that what i come to you guys for. i thank you for helping.

 

Ok, but the Garrett will probably require different fuel/coolant lines and DP. And if your running a turbo as large as a GT30 or GT35, I don't know how much fun it's going to be with stock injectors and tune.

 

the 15g also known as a TD04 is a garrett turbo they also came on the wrx and the SRT4 neon stole the compressor for there ride. so basically the flanges will bolt up and as long as the boost levels are the same and im not trying to boost over fuel cut or boost over what the boost level is set at i will be all set. im not completely sure about coolant/oil lines but those can be customized easy enough.

 

15G is a Mitsubishi.

 

B. If you choose to upgrade the turbo (upgraded compressor wheel for the 15G, or using 16T, 18T, or 19T turbos are easiest), then you will potentially be able to yield significant gains in power beyond 17-18 psi. The 15G isn't too efficient even at 16 psi, so even at the same boost levels, you will feel a gain because the air won't be so superheated. However, you won't be able to increase the boost as high on this turbo as with the 15G, because it's actually flowing enough air at those higher boost levels that you'll be needing more fuel in order to make more power (*Bill at Adrenaline Racing recommends upgrading ECU map at any level above 16 psi when using a 19T).
This is the seperating factor for this level, because fuel mods apart from the pre-made performance chips are a consideration. Larger injectors and a rising-rate fuel pressure regulator are options, as well as the possibility of a custom ECU program. Best case scenario would be a custom ECU program used in conjuction with larger injectors.
*Since the time of writing this, it is easier to obtain ECU tuning for higher levels of modification from companies like RICA and IPD/TME, among others. That would be the route I would recommend. Civinco has also proven to be a viable option, depending on the user.

The difference in turbine housings:
There are 3 turbine housing designs (with two variations having been seen internally in the angle-outlet housing, but we will ignore that for now!). Conical outlet flange (94-95 850 turbo, 95 850 T5-R), straight outlet flange (96-97 850 R, T5 and GLT, 98 model S70 R, T5, And GLT), and angled outlet flange (All cars 99+ excluding the newer cars with KKK turbos). User jonsayre has contributed a photograph of all three side-by-side.

As you can see, the difference is in outlet size. This has an effect on performance, and all three housings are interchangeable and can be placed on any TD04HL turbo (13G, 13T, 15G, 16T, 18T, 19T, sorry if I forgot anyone!) by removing the center band clamp. Outlet sizes are <2.5" for the conical, >2.5" for the straight, and ~3" for the angled outlet. They also come with varying wastegate actuators, with the angle-outlet turbos receiving the 300/70 actuator with the strongest spring (straight outlet 16T was 215/60, conical 15G was 150/30, others may vary).

Beyond the TD04HL Volvo turbos, there are a few more options. The first is the Hahn Racecraft TD05H series of turbos, which are Mitsubishi TD05H turbochargers with a Hahn Racecraft turbine housing which gives it the standard T3 inlet flange. This is the same flange Volvo uses, but they use a raised lip on the exhaust manifold and recess in the turbine housing to make a mechanical gasket-less seal. This lip on the manifold must be machined down by a mill in order to use one of these turbos. There are 16G, Big 16G, and 20G compressors available in this series of turbo, and there are a handful of members using these turbos with great success.

In addition to the Hahn 16G/20G turbos, it is possible to use most Garrett T3-flanged turbos. This opens you up to a whole new world of sizing possibilities. It seems that the older T04B and T04E compressors (which are used in T3/T04B and T3/T04E hybrids) are being replaced by more modern GT-series ball-bearing turbos, although the 50 trim T04E is still an outstanding compressor and very versatile for power levels from 300 whp to 400 whp. The GT-series of turbos from Garrett provide a number of options, I would start with the GT2871R as a great turbo to use with the stock transmission and bottom end. This turbo will comfortably make 270-320 whp on our engines I would say. The next step is a GT3071R, and the GT3076R... These are great options for mildly built bottom ends using manual transmissions or upgraded automatic transmissions. The GT35R is an excellent turbo, but unless you are aiming for over 450 whp I would not say it is necessary. It is also possible to use some Holset turbos. When using big turbos like these, you may run into firewall clearance or rear transmission mount clearance issues. Don't be surprised...

Internals
The engine's internals are reportedly good to around 400 horsepower with proper air/fuel tuning. However, many premature failures of connecting rods have happened due to high boost levels at low RPMs, or poor tuning in general. With boost coming on gradually however, 320-340 wheel horsepower or possibly slightly more should be attainable if done carefully. The problem is how well the ECU can respond to and correct detonation events. At higher, less stable boost levels with stock boost control and oddly proportioned turbos (like the 19T), it is difficult for Motronic's algorithms to effectively combat these problems before permanent engine damage has occurred. There is also a much much thinner margin for error and bad gas and such at the highest power levels.

There are now affordable H-beam rods available from either Sten Parner (bad because of exchange rate now), or R-Sport International, among a few other companies. These rods will allow you to do a mild rebuild of the engine and take out the weakest link in the bottom end. This will allow you to make 350-400+ whp safely and reliably with proper tuning.

 

ok. i just searched the td04 on yahoo and it showed me some pictures and i would need a custom manifold or switch out the exhaust housing.

 

Right, the 15Gs are TD04 with a T3 flange, which is why people use the GT28/30/35 when upgrading turbos because they share the same flange, however, that's pretty much all they share in common, the rest needs to be customized. And I'm pretty sure I remember seeing pictures of the exhaust manifold for at GT28/30/35 turbo and it was different compared to a TD04 bolt on upgrade turbo such as the 16T, 18T, or 19T.

I'm just saying that I don't know if a Garrett turbo will run on a stock map and injectors. They're much larger turbos and you will need more to get them spooled. I have a feeling if you put on a Garrett turbo when you left everything else stock, you wouldn't have enough RPMs to reach 15 PSI, I think the turbo would be extremely laggy.

 

wow man thank you for the info that is some great stuff!

 

true now that i think about it. like i said thanks for the help man.

 

No problem. I think for a future project you have one of the most expensive pieces, which is the turbo. So who knows, if you like your car enough and want to build it, you have a nice platform to start with.

 

thats for sure but i can get my hands on a evo killer 16g turbo and i was just wondering if i can put that one on.

 

the guy offered me both the 850's for $850. what do you guys think of that for a deal?