Jump to content
SAU Community

Recommended Posts

just finished putting an rb30det into my skyline and have a couple of questions.

1. What is ideal running temp ? Mine seems to want to sit at the 100 degree mark it has a large alloy radiator and twin thermos and Nissan thermostat, 100 just seems a bit hot to me,

2. Does the hose for the aacv have to be run in between throttle body and air flow meter ? Or can it run from atmosphere ( with a filter) ?

3. I found I have a leaky welch plug, just a slow leak a drop every now and again, it is in an awkward spot behind an engine mount, will this get worse and worse over time ? Or can I use a sealant to fix this issue ?

4. I have read a lot about bov, and am a it confused some people say it is a must have item and other say it is not needed. Will it harm my turbo if I am not running a Bov if it is only running low boost pressure ?

Link to comment
https://www.sau.com.au/forums/topic/456702-ideal-temperature/
Share on other sites

1. Standard RB30 thermostat is 82.6deg if I remember correctly. Should sit around that happily. I suggest doing a proper bleed of the coolant system before anything else.

2. AACV hose goes anywhere between before the throttle body and air filter. Most people run it immediately before the TB.

4. There is no requirement to run a BOV. Personally I have never run one in my 5 years of ownership and none of my mates have ever run them.

1. 100 is much too hot. It should sit arounc 85C operating temp.

2. if you run an airflow meter then you must have the AACV taking air after the airflow meter (so the air usage gets measured... otherwise the car won't idle). if you run a MAP based ECU (ie aftermarket) then you could atmosphere + filter it.. but then you need an extra filter etc.. I don't see the point personally.

3. pretty unlikely it'll get better on its own. you may be able to tack it up with some sealant. I once sealed the turbo water line behind the block by dripping some superglue on it. that held until I had time to get in there and replace the hose properly.

4. nobody has ever had a turbo die from not running a BOV. I ran a bovless skyline for several years pushing 14psi no problems.

Thanks, what is best way to bleed cooling system ? I don't have bleed valve as I have a Freddiy plenum, I read that you can just raise the front of the car so that the radiator is highest point of cooling system and just run it with the cap off ?

sugestions as above are good. Also there is often a fitting with a warning label that says "do not open when hot" near the front of the inlet manifold (ie at the top of the inlet manifold, closest to the radiator). This is the highest point in the cooling system and can also be used for bleeding. To bleed it you need the top half of a 2L coke bottle jammed in the radiator neck with a bit of gaffa tape around it to provide a seal of sorts. you need an inch or two of water above the radiator cap level to effectively bleed the system.

sugestions as above are good. Also there is often a fitting with a warning label that says "do not open when hot" near the front of the inlet manifold (ie at the top of the inlet manifold, closest to the radiator). This is the highest point in the cooling system and can also be used for bleeding. To bleed it you need the top half of a 2L coke bottle jammed in the radiator neck with a bit of gaffa tape around it to provide a seal of sorts. you need an inch or two of water above the radiator cap level to effectively bleed the system.

In the 32 GTR i get full coolant out the bleeder by just topping up the radiator.

BOVs are designed to vent off the air that would otherwise slow the turbo down after the throttles shut. So if you have one you should produce boost more quickly after gear changes.

BOVs are designed to vent off the air that would otherwise slow the turbo down after the throttles shut. So if you have one you should produce boost more quickly after gear changes.

Yes, if you have a correctly set up plumb-back on a MAF-based engine then it may help throttle response as opposed to BOVless. (remove plumb-back requirement for MAP-based). And if you are running REALLY high boost pressure then BOVless may accelerate turbo bearing wear.

There is also some thought towards keeping pressure inside the intercooler + piping. The rotating assembly in a turbo is quite light, and rather than worrying about slowing it down you can rely on maintaining a bank of pressurised air so that when the throttle opens you have a volume of pressurised air available that can go straight into the engine, produce power, and produce a lot of exhaust gas to spin the turbo up again. With a BOV that is venting all pressurised air, you may have a faster turbine speed but when the throttle opens you have no pressure and the turbo has to build pressure in the intercooler + piping all over again.

It would probably be fairly straightforward to measure the result by logging TPS and MAP, come to think of it.. I may play with it sometime in the future to see what works better :)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • You are selling this? I have never bought something from marketplace...i dont know if i trust that enough. And the price is little bit "too" good...
    • https://www.facebook.com/share/19kSVAc4tc/?mibextid=wwXIfr
    • It would be well worth deciding where you want to go and what you care about. Reliability of everything in a 34 drops MASSIVELY above the 300kw mark. Keeping everything going great at beyond that value will cost ten times the $. Clutches become shit, gearboxes (and engines/bottom ends) become consumable, traction becomes crap. The good news is looking legalish/actually being legal is slighly under the 300kw mark. I would make the assumption you want to ditch the stock plenum too and want to go a front facing unit of some description due to the cross flow. Do the bends on a return flow hurt? Not really. A couple of bends do make a difference but not nearly as much in a forced induction situation. Add 1psi of boost to overcome it. Nobody has ever gone and done a track session monitoring IAT then done a different session on a different intercooler and monitored IAT to see the difference here. All of the benefits here are likely in the "My engine is a forged consumable that I drive once a year because it needs a rebuild every year which takes 9 months of the year to complete" territory. It would be well worth deciding where you want to go and what you care about with this car.
    • By "reverse flow", do you mean "return flow"? Being the IC having a return pipe back behind the bumper reo, or similar? If so... I am currently making ~250 rwkW on a Neo at ~17-18 psi. With a return flow. There's nothing to indicate that it is costing me a lot of power at this level, and I would be surprised if I could not push it harder. True, I have not measured pressure drop across it or IAT changes, but the car does not seem upset about it in any way. I won't be bothering to look into it unless it starts giving trouble or doesn't respond to boost increases when I next put it on the dyno. FWIW, it was tuned with the boost controller off, so achieving ~15-16 psi on the wastegate spring alone, and it is noticeably quicker with the boost controller on and yielding a couple of extra pounds. Hence why I think it is doing OK. So, no, I would not arbitrarily say that return flows are restrictive. Yes, they are certainly restrictive if you're aiming for higher power levels. But I also think that the happy place for a street car is <300 rwkW anyway, so I'm not going to be aiming for power levels that would require me to change the inlet pipework. My car looks very stock, even though everything is different. The turbo and inlet pipes all look stock and run in the stock locations, The airbox looks stock (apart from the inlet being opened up). The turbo looks stock, because it's in the stock location, is the stock housings and can't really be seen anyway. It makes enough power to be good to drive, but won't raise eyebrows if I ever f**k up enough for the cops to lift the bonnet.
    • There is a guy who said he can weld me piping without having to cut chassis, maybe I do that ? Or do I just go reverse flow but isn’t reverse flow very limited once again? 
×
×
  • Create New...