Went to Chassis Dyno, have question.

[TrboVan]

Originally posted by ijames
Hmm. Sounds reasonable as to hp and air. Any chance you had a wbo2 sensor to get the actual air-fuel ratio? Assuming this was with race gas and higher timing (25+ degrees) you could probably use 0.5 as the bsfc and calculate the actual airflow just to compare. Otherwise I'm out of ideas just now, sorry.

Wide band was present.
Car #1 13.7
Car #2 12.7

Timing was at 16 degrees (factory is 12)
110 Octane

I should mention this is a 135 CI 4 Cylinder?
But that should not really change anything, afterall it is just an engine, right?!

 

[Taffy]

Engine size means next to nothing when the turbos are present. That being said.

The Air Flow Ratio on car #1 was WAY TOO lean. You need the AFR on car #1 to look more like car #2. A 12.5:1 ratio is pretty good for horsepower.

 

[ijames]

I agree that #1 was way lean, and #2 may be ok or may be a little lean. Some of the FAST tuners like 11.5-12.0 just to be safe, and I don't think very many at all run leaner than 12.5 on a regular basis. I don't know how efficient your head and chamber are so it's hard to comment on the timing. On the Buicks, they seem to like 20-30 degrees of timing depending on octane. 20 to 24 for 95-100 octane, 26 to maybe up to 28 with C16, and 30 degrees if you are really agressive or have a too-small turbo.

 

[TrboVan]

When doing calculations, what VE do you use for a Turbo car?