Perhaps I should rephrase my statement. It's true that on the street full boost will be made just before 4000 rpm. However, Smoggys car looks like it is making identical power to the stage 1+ during spoolup (e.g. when the TME hit it's peak torque, the stroked 35r was producing almost the same amount of torque).

Also, boomtown, the 3071 spooled much later than expected. I was getting full boost between 3900 and 4000 rpm. Granted, some of that is due to how my engine is built (it's all geared towards topend), but we compared my dyno charts to a 50 trim dyno chart, and the 50 trim was spooling earlier and is able to make more power up top. Go figure.

We'll see what the 50 trim can do on my car next week.

l8r)

 

Here is the 50 trim mapped next to the GT3071R.

Assumptions made for both are:
- 2.0 liter
- 21 psi
- 100*F intake

and...

Point 1 is 10 psi, 3250RPM @ 75%VE
Point 2 is 21 psi, 4500RPM @ 100%VE
Point 3 is 21 psi, 7000RPM @ 100%VE

-Brian

 

You will excuse me for thinking theres bugger all difference between the two under those assumptions apart from the 50 trim running closer to the surge line.

 

One of the biggest problems with the compressor maps is that they do not accurately represent the actual turbos going onto Evos. You can get a very general idea to see if the turbo will suit the application, but that's about as far as you can take them.

Also, I think the assumption of 10 psi @ 75% VE @ 3250 rpm is not realistic with the bigger turbos. My boost gauge doesn't clear 5 psi until the turbo (3071) really begins to spool up, which is around 3400 rpm. Then it rapidly ramps up until full boost is reached around 3900-4000 rpm.

l8r)

 

yeah just wanted to clarify as it's not exactly correct to compare as such. not saying you're wrong, there's not real right and wrong here but it's just htat even if there is now loss in 'power' to a smaller turbo setup the driving characteristic will not be the same. you'll keep ramping up power until you hit peak boost and if that is later then the driving characteristics will reflect as such.

 

^ no problem, mang.

l8r)