TRD headgasket compression Q

[touge_ae101]

so after starting my blacktop up i am suspecting it has a BHG. want to try to get a good discussion from you guys about increasing the compression ratio by using a 0.8mm TRD gasket which is only $50 more than TGP gasket so IMO well worth.

for now it will just be running std tune etc but hopefully by end of the year i will be running some nasty cams and a link of some description.

just wondering what the limit in terms of CR is for a blacktop?and also i gather i should probably upgrade to ST rods at the same time to prevent a big bang...
have done a search and everyone says you are running towards the limit of what fuel in nz (98oct) can run safely without getting heaps of knock. but both acesniper and BZR4AGE runs CR's well into the 12's.
from what mark could remember TRD .8mm would increase CR to 11.5:1.

[KwS]

Wouldnt a decent tune play a real big part in how long a high CR engine stays in one piece?

If you did nothing but raised CR, and ran the standard tune etc would it knock more, or would ecu compensate by pulling timing etc?

The guys that run 12CR, i doubt they run standard ecus?

[QikStarlie]

will be fine, isnt a big increase in compression with the trd gasket. cams, cam timing etc will make a difference, as to what you will get away with also. with big cams you'l want to be well up into the 12's like those other guys

running 11.5 pistons and a trd gasket on my 16v. got away with 6psi boost on top of that also. using gull force10. now its na again. im very tempted to get the head skimmed for more compression. just too lazy

[frost]

head a piston design play a bigger part,
better to change comp with pistons then thin gasket.

[NILPSI]

Mine has a TRD headgasket in it, runs standard ecu and tune, has been going for 3 years and never had a problem with it

I had the block and head skimmed before putting them back together, but it was purely to get them flat for the metal gasket, I doubt enough was taken off enough to make a big difference in compression

[touge_ae101]

sweet might look into it. need to find the right temp sensor first to see if its getting hot or not.

wouldn't a TRD gasket be a wise choice even if increasing the CR by high comp pistons as it is metal (ie more durable).

thanks guys.

[frost]

even on the oem gasket there are metal rings surrounding the bore so durability is not an issue,

make sure you tell the guy who is doing the skimming your using a metal head gasket, MHG need a much smoother/fine surface to seal proper,

[touge_ae101]

cheers frost.

what fuel has the highest rating in nz?i was under the impression gull force10 is still only rated to 98? or does it have other benefits for running in high performance engines with high CR etc?

[soopachargen]

The reason QikStarlie runs force10 is coz its the best gas that we can get up here in the sticks, we dont get the other 98s, its 91, 95 or force10

[AceSniper]

Iv done a blakctop for someone with silvertop rods, block surfaced, head .3mm skim, TRD heady... stock ecu and cams runs on gull 98 no issues