Turbo Garrett GT28.. which one? Options

[miguelst205]

Hi everybody from 6gc.net, the best celica forum in the net..

I'm from Paraguay, South America and I have a Toyota Celica ST205 JDM, these days I will put pictures and specifications... my English is very bad, but I will do what I can...

Here are the problems... the engine is forged, pistons and rods.. without work in the cylinder head.. the ct20b turbo shaft broke, now I'm using a ct26 to use the car.. but I want to buy a garrett ball bearing, specifically a GT28, because I want quick spool at low rpms, not a loooot of hp, good torque and a decent top end power, and is possible low or medium boost... but which one I choose??..

I'm in doubt between the GT2860RS and the GT2871R.. so, in how rpm each of these give me a good boost (like 1.2 bar), and torque??.. How much power will give me with that boost in any of these turbos??... anybody have dyno results or boost-rpm graphics to see??.. my power goal is 320 whp, because I use my car for everyday, for travel and sometimes drag race of 1/8 mile... it's a street car in conclussion...

The main thing concerning me is that will the 2871 spool a lot slower??..

Also getting new manifold or flange adaptor obviously, new downpipe (either 2.5" or 3") and injectors+electronic, etc..

I hope you can help me.. greetings, thanks in advance..

Miguel.. from Paraguay..

[jgreening]

Generally, those modifications are designed to increase flow. In most cases, such modifications have the effect of delaying spool because air velocity decreases in lower rpms. However, a good tuner can do wonders with cams and tuning. It is possible to make a medium sized turbo spool like a small turbo with good tuning. Here is a plot of a tdo6 on 3sgte that spools as fast as tiny turbo but with 400whp:

This type of tuning takes expertise and some significant dyno time (read: $)