Compression ratio?

[cupra_matt]

Iam stuggling to decide which pistons to go for and what compression i will need/suit the engine best?

Iam staying STD bore.

The options i have are: Wiseco Pistons @ 9.25:1
JE pistons @ 8.5:1

Whats best? iam going GT2871R kit with full 3 inch exhaust and inlet on 550cc injectors. Hoping for around 360 - 380 BHP

Any help would be much appreciated.

 

[myk3]

9.25:1 i would go for, the gt2871r isnt really a massive turbo so you will be fine. im running 9.5:1 and its fine.

8.5:1 on the other hand you will loose a bit of off turbo power but can run more boost and advance the timing a bit.

both have there goods and bads but i would recomend 9.25:1

where you getting the DP and manifold from? what kit is it?

 

[cupra_matt]

Thats kinda what i was thinking mate. Thanks for verifying that.

 

[cuprabaz]

Matt is this a kit your going for or you going it alone??

 

[PhilW]

Slightly off topic a bit, but are you sure those injectors ok for that turbo? I know revo use them but i'm sure they seem a bit overkill for other software.

Who's mapping it and what do they say?

 

[Mark@VAGWORX]

I've got Genesis 430s running at 4.5 bar and these were at 90% duty cycle on GT28RS. I'd definately go for 550s.

 

[cuprabaz]

Am i right in saying that:

GT2X = 386cc @ 4Bar or 440cc @ 3Bar
GTRS = 440cc @ 4Bar or 550cc @ 3Bar
GT28RS =
GT2871RS =

Anyone fancy filling in the gaps?

 

[PhilW]

Revo use 550cc at 3 bar for Stage 3, so that can cover GT28RS and GT2871R as the compressor maps are very similar.

GTRS is basically a GT28RS but with a different exhaust housing.