break in procedure for BB turbo.........?

[cjthor]

I'm wondering what trim compressor they were using on that T3/TO4E...if it was a 60trim then that would explain the lag and low power out put at 10psi....a 60trim is just starting to blow a lil bit at 10psi and will support 500WHP. Thats the only way you'ld be able to add fuel and gain that much power. That big compressor at 10psi is actually choking the engine as the turbo hasn't spun up to its proper pressure ratio range.

The bottom line:
http://www.turbodynamics.co.uk/ball_bearing.htm
http://www.suprastore.com/balbearturdo.html

I think those last two links say it all.

if the t3/t4 was larger than adding more fuel to a smaller gt2871 would result in less power from running too rich. we all know running a leaner a/f ratio will result in more power than a rich a/f ratio. so by this we can safely say they were making a very bad comparison with the tinyest most inefficient t3/t4 they could find.

also by looking at the t3/t4 tq on the link u listed, you can see that it seriously falls flat on its face after 6000rpms. like i said earlier you would have to be using the smallest t3/t4 you could find. i know for a fact we can safely say the are using a turbo much smaller than a t3/t4 .63 ar 46 trim which IS THE comparable turbo to the gt2871.

...if it was a 60trim then that would explain the lag and low power out put at 10psi....a 60trim is just starting to blow a lil bit at 10psi and will support 500WHP. Thats the only way you'ld be able to add fuel and gain that much power. That big compressor at 10psi is actually choking the engine as the turbo hasn't spun up to its proper pressure ratio range.

if the turbo was infact a larger turbo than it also proves to be a bad comparison because any turbo including a smaller gt28rs will spool faster than a larger 60trim.

this is why i dont trust comparisons made by companies who do not list complete details when making comparisons. while many companies make good quality products, they are still out to make your money.
to the untrained eye most people will not understand how to tell if a turbo is improperly sized. in this case the t3/t4 in comparison is too small and choking on a tiny 1.8 as we can see by reading the severly falling tq curve.

when it comes down to it comparisons are very one sided and done by companies who want your money.people who are not as well informed do not know how many different t3/t4 combinations there are and assume they are all the same. this is why i listed the dyno comparison for the 46 and the 50 trim t3/t4's. those two are fine examples of how a decently efficient t3/t4 compares to the new gt series. bottom line, do your homework and your t series will perform the way you want.

Just got a gt2871R. we will see how it does.

[Steeb]

even tho the gt2871 is not capable of the 400hp claimed on garretts site, it will make you smile from ear to ear. the dyno's i posted above are 2.0 4cyl so your results will be awesome and very similar but probably a bit more peaky.

cant wait to see how it goes. i wish i was up there so i could get a ride in your car.