I know tha the A/R on the compressor wheel makes no difference to how the turbo reacts, but it just increases the actual housing. But is a GT2556R which a compressor wheel of .80 A/R and a turbine wheel with .64 A/R workable for out cars. Or should i go with a smaller A/R like .64.

Should i increase the turbo size from a GT25 to a GT2856R which give the same A/R numbers, but its a bigger turbo. Help me out any experience on the subject will really help.

 

Any turbo will work on our cars(within reason)

The big question is where do you want the power? Are you boosting on a stock motor?

The smaller the AR(on the turbine side) the smaller the area the turbine wheel is "working in" thus creating and increase in velocity which equals quicker spool.

If its a street car and you are going for driveabilty go with a turbo that is going to offer the broadest powerband. in this case of the 2 you mentioned it would be the 25.

Regards-

Todd

 

I would like to achieve at first 140WHP, with stock internals and well programmed ECU @ 8psi of boost. Later on i want to shoot for the 180WHP, with pistons, rods and maybe sleeves @ 14psi of boost. If anybody thinks that i can get these kinds of numbers with this setup, please let me know and help me out.

I like to race my car, so i want to keep the power within a reasonable limit because i dont want to loose reliability, which is a BIG issue in my mind.

The real question is: on the compressor wheel .80 A/R or .50 A/R??
As for the turbine wheel im sticking with .64 A/R because it seems like a good even number that will create lag and i have ability to crank up the boost without compromising efficiency.

 

Almost all of the GT2560R's that come from Garrett have a .60a/r compressor housing.(they offer one that is smaller and its a .42) They offer 2 different sizes of turbine housings, a .64 and .86.

Unless one of the Performance dealers offer there own compressor housing, then there might be the .80 you mention.

Honestly for what your goals are you would be better running the GT2554R with the 7psi internal wastegate option. It will give you better low end punch and still provide the top end power you are after. (a broader powerband) It has the .80ar compressor housing with a .64ar turbine housing.

Regards-

Todd

 

Thanks for answering, i was pretty sure that was the turbo of choice. If anybodt else has opinions please let me know.