Discussion and questions related to the course Practical Dyno Tuning
Hi, not sure if this has been covered in any of the webinars, I'll be tuning a high power 2.0 turbo vw soon, and I have added a egt to the manifold before turbo, and also a take off for steel pipe for reading the manifold pressure, after run in I'll be winding it up for max safe power, Im expecting the limit will be the turbo and egt in the manifold, what do you usually aim for with EMP compared to boost pressure across the rpm range.
Exhaust manifold Pressure?
That's a good question, as that has a big affect on the engine's breathing and is critical when looking at the exhaust housing's A/R value.
From what I can gather - and it could be quite wrong - the best overall pressure ration is in the 1.5-2.0:1 range, with the exhaust being the first. Lower is better for top end power potential as there is less restriction but it can be rather sluggish at lower power levels, and higher for response and lower rpm boost at the risk of choking the engine at higher levels of power.
Probably best to use what is recommended by the manufacturer of the turbo' for the power level you're looking at.
OK thanks for the response, I'll report my finding when the time comes for tuning
Gale Banks has some good insights into this and, as he's been doing turbo' applications for close to 40 years, this particular video is very well worth watching as it's directly applicable to your question!