changing a gasket on my skylines RB25DET inlet manifold, specifically the one in this picture with the dotted yellow line, inlet manifold is in 2 halves and the gasket goes between them, should i use some kind of sealant or not? i've heard people say i should and some say not to.
I refreshed my rb20 and didn't use any sealant between the upper and lower plenum, just the OEM gasket. No leaks a year later. I don't recall if the service manual said any was needed or not
A Stock one is good for as much boost as you can safely run through a standard intake manifold.
If you are blowing them trying to run 30 PSI on a stock manifold that gasket is going to be the least of your problems.
Even a 3071R is too big for the stock manifold, you are limiting the turbo so much, even more at 10PSI. I would be going a proper forward facing plenum, proper intercooler piping as yours will be slightly all over the shop with how the intake on the manifold faces. And if your fuel system can support it slap 18PSI into that bitch and make very high 300 HP easy.
I can't remember what the stock ones are because I never had my manifold apart but I'd put money on it being jelly.
>run 20psi through td05
>ffp cut n shut from stock
>320hp or 240kw
>standard rb25 with highflow to 3076r
>makes 320kw on 18psi with e85 or 270kw on 98
Most dudes run the standard plenums up to 350kw.
>doesn't even know rb's
Very high 300 hp, like 370/390hp at the wheels, and while yeah you can run big enough HP on a stock plenum it is stupid. The stock intake on RB's are renowned to run 5 and 6 cylinders lean. They have a very bad flow pattern.
Cheap cunts do a cut and shut moving the intake/throttle body position to the front of the stock manifold BUT its still shit. Even a cleaned up ebay special forward facing plenum does a better job.
>Stock intake manifold and 350KW...fucking where and for how long?
Skyrine knows his RB's, come at me bro.
It's actually the cheap ffp's that lean out your rear cylinders and fuck your rings on 5 and 6. Standard side feed plenums are well designed and allow for an even spread over all cylinders.
Pretty much anyone who makes power out of 25's in straya keeps the standard manifold because they are good. Shorter runners might be better for higher hp figures but they also create lag due to short runners and lower torque. Workshop I had my car tuned in had 6-7 rb25's in for work and even the ones with big fuckhuge turbos were running standard plenums. For high power applications on the track obviously your gonna need to scrap it, but for street guys running decent power everybody swears by the standard plenums.