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hey guys just after a bit of advice have been looking at a 1.2mm trust gasket for my rb25det but they offer them in either 87mm or 88mm can anyone tell me which one i would need or how to tell which one i need.

bit up in arms and want to get it right

cheers

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and whats meant to be the ideal comp ratio? 1.6 wouldnt that give you close to 8.4:1 compression ratio?

Are you being a smart ass?

I have been told the ideal compresion is 8.6:1 achived by a 1.6mm head gasket.

I have no dramas with it.

your ideal comp ratio all depends on your setup and what boost your going to run its an individual thing. ie if your gonna run 28psi through a 3540 then a 8.6:1 you might want 8.0:1 as an example but if your running 14psi through a small turbo then theres nothing wrong with 9.0:1

there is no ideal comp ratio..... machine the head and deck the block and a 1.6mm head gasket is not going to have the same effect as 1.6mm on a stocky..... h/g size is relative to application and there are plenty of differrent comp ratios that achieve the same goal... i know of a certain supra making over 600rwkw on an engine with higher comp than std.... horses for courses.

just a quickie how do you know what compression ratio you are running is it just what someone has told you or did you have it tested

ill be running 555cc injectors remap ecu and a trust tdo5h-15g turbo what compression ratio (gasket) is required for around a 250rwkw application

just a quickie how do you know what compression ratio you are running is it just what someone has told you or did you have it tested

ill be running 555cc injectors remap ecu and a trust tdo5h-15g turbo what compression ratio (gasket) is required for around a 250rwkw application

dont even bother std is fine for that setup, done a few now. Just make sure you get a good remap.

Im going h/g even though I only want to push 250rwkw daily and 280-300rwkw max seeing as I will be drifting the car a bit

I'd rather have a bit of a safety net there seeing as I dont wanna have to rebuild the motor or replace it anytime soon

I know a 20 can take a hell of a bashing probably due in part to its comp ratio

Edited by 1400r

hi all

from what im led to belive

is that running a highr comp ratio than standard is a good thing you will make the same if not more power with less boost and have more bottom end torque=off boost response, but on the down side of things your tuner has less "room"or much narrower window so to speak to tune in regarding getting timing, a/f maps etc rite.

Im going h/g even though I only want to push 250rwkw daily and 280-300rwkw max seeing as I will be drifting the car a bit

I'd rather have a bit of a safety net there seeing as I dont wanna have to rebuild the motor or replace it anytime soon

I know a 20 can take a hell of a bashing probably due in part to its comp ratio

Does zero for longevity, but it will allow you to run more boost if your turbo is inefficient at lower boost levels. This is where turbo choice is most important.

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