850 t5 Bigger turbo? or Rods?

[merc85]

Next up grade of my 850 has to be A bigger turbo, and Rods.

But what to do 1st? i am on a budget and need to keep car uning as it's used everyday, saying that i do have a Really good spare engine waiting.

Do i buy and fit a 19t or any other surggestion's (turbo wise) upgrading my 15g, or buy and fit new Stronger rods?

Will a 19t or similer destroy a non forged engine quickly?

Any surgestions appreciated.

[The Flying Moose]

Many have said that the 19T is a rod bender, however like anything its your driving style that counts. If you have a decent map or electronic boost controller you should be fine. I have always applied the never boot it under 3k rpm rule.

I will be fitting a 19T to mine soon and I know many who have without forging engines. I think the biggest issue is boost spikes which the pre ME7 engines cannot handle effictively.

If you have a spare engine then I would buy the 19T and fit it. Worse case scenario if you do happen to be unfortunate enough to bend a rod you have another engine sat there waiting which you could get forged and dropped in at a later time.

[The Flying Moose]

Here are a couple of good references from a guide off Turbo-Bricks

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.

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.

[WOODY T5]

yea been running a 19t for over a year and a bit @1.3 to 1.4 bar with standard rods with probs touch wood but like the moose says good boost controller will help.