View Full Version : Compression ratio?
cupra_matt
28-05-2007, 16:41
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.
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
28-05-2007, 18:20
Thats kinda what i was thinking mate. Thanks for verifying that.
cuprabaz
29-06-2007, 14:07
Matt is this a kit your going for or you going it alone??
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
02-07-2007, 10:56
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
02-07-2007, 15:01
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?
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.