1.2mm or 2.0mm decomp plate?

[hosedogg]

hey guys. just in the process of buying a decompression plate for when i put my turbo on. and just wondering if anyone know's what the compression will be dropped to with the 1.2mm? and also what it would go to with the 2.0mm? cheers.

[mag]

hey guys. just in the process of buying a decompression plate for when i put my turbo on. and just wondering if anyone know's what the compression will be dropped to with the 1.2mm? and also what it would go to with the 2.0mm? cheers.

Dude more important info is needed but done on some guess work,

the 1.2mm would drop comp to 8.1
the 2.0mm would drop comp to 7.5

Just want to add: no 1 else has answered ur post.
Now I have watch the people answer saying it's wrong-
IF they know the correct anwser why didn't they say??

[lxhatch]

how did you work that out is there a fromula you used?
would be interesting to see how its calculated....

[TURBO_VK]

here do u get decompression plates from

[gungazza]

the vk sounds like a beast

[mag]

how did you work that out is there a fromula you used?
would be interesting to see how its calculated....

If I tell you then I'd have to kill you

I'll look 4 it and get back to ya

[TURBO_VK]

the vk sounds like a beast

nah shes no beast at the mo,i keep blowing diffs

[hosedogg]

got it off ebay. asked the bloke i'm getting it off what each one should drop comp to. i'm leaning for the 1.2mm as i was going to leave it standard n/a comp, but after all the things i've been told i thought it would be a good idea to drop it a bit.
if the 1.2mm does drop it to 8.1:1. would that be alright to run around 10 or so psi though the motor without an intercooler? cheers.

[mag]

how did you work that out is there a fromula you used?
would be interesting to see how its calculated....

Here it is, You ready

16.387 is a number than converts cubic inches to cc's.
Displacement = (Bore ÷ 2)2 x 3.14 x Stroke x 16.387
Head Gasket space = (Bore ÷ 2)2 x 3.14 x Gasket thickness x 16.387064
Deck Height space = (Bore ÷ 2)2 x 3.14 x Deck Height x 16.387064
Compressed Volume = Head Gasket space + Deck Height space +
Piston Top volume + Combustion chamber volume
Uncompressed Volume = Compressed Volume + Displacement
Compression Ratio = Uncompressed volume ÷ Compressed volume



But this is easier http://www.turbofast.com.au/Tfcomp.html

[mag]

got it off ebay. asked the bloke i'm getting it off what each one should drop comp to. i'm leaning for the 1.2mm as i was going to leave it standard n/a comp, but after all the things i've been told i thought it would be a good idea to drop it a bit.
if the 1.2mm does drop it to 8.1:1. would that be alright to run around 10 or so psi though the motor without an intercooler? cheers.

I'd say 10psi with the 8.1 that would make it 11.1 so intercooler needed,

and 10psi with the 7.5 would make it 9.1 and intercooler no sure but would run on "PULP"...

[lxhatch]

thanks for that mag seems you would need a fair bit of info on an engine first,

[hosedogg]

hey thanks for that. yeah i've got an intercooler on the way now. just one question. when putting the decomp plate on, which side of it do you put the head gasket? i.e below it (inbetween block and plate) or above it (inbetween plate and head)? thanks for all the info, muc appreciated. cheers.

[mag]

hey thanks for that. yeah i've got an intercooler on the way now. just one question. when putting the decomp plate on, which side of it do you put the head gasket? i.e below it (inbetween block and plate) or above it (inbetween plate and head)? thanks for all the info, muc appreciated. cheers.

If the plate is metal on both sides you will need 2 head gaskets, 1 below the plate and 1 above the plate...

[hosedogg]

ok thanks for that. anyone know how long roughly it'll take putting a decomp plate on an rb30? doing it all by hand, no air or electric tools. it'd be the same as doing a headgasket on one really. cheers.