XKLABA

It depends on how much negative pressure the Venturi system is creating and how much positive pressure is in the intake, as soon as there is boost in the intake the PCV closes and the gases are meant to go to the I take of the turbo [\quote] I'm driving hard on boost - Positive pressure in crank case causing the PCV, negative pressure from the venturi in the pipe leading to the valve. In this scenario, I would expect the valve to be shut but shouldn't it be open to vent the crank case so that the blow by isn't just venting out of the catch tank - it obviously has no where else to go does it? That's right, the positive crankcase pressure should be getting sucked out by the Venturi since the is boost pressure in the I take manifold it can not go in there as the boost pressure will cause the PVC to close [\quote]So, I then take my foot off the gas and theoretically I should be in a vacuum/negative but the crankcase won't have vented because it has no where to go so. I then have very little suction (well a little bit), from the venturi port and still positive pressure which means the port is still closed... This is when the PVC will open and draws gases away from the cam covers pulling gas out of the crank case, the PVC is controlled by the intake manifold unless the Venturi system is creating a higher vacuum level [\quote] This is what I don't understand This is the PCV valve that the venturi port connects to: Now, I see that in some race car setups, they actually have a vacuum pump; even in this scenario, isn't the PCV still always just closed? The Venturi connects to the exhaust side cam cover, the PCV connects to the intake side cam cover and the two covers are connected to each other but both have the volume of cam covers and head and well crank case to draw from effectively separating them from each other The crank case should never be in negative pressure with out external help as even at idle there is blowby just not much The vacuum pumps that race cars have is because they are using stupidly long duration cams and have lost the intake vacuum in doing so so they have to create it somehow, which should not be connected through the PCV as it would just cause it to close

The PVC is a differential valve, when ever the pressure on the out side is higher then on the inside it will open, this usually when the engine is in vacuum and it will draw the oily gases into the intake, the Venturi system is to try and keep the pressure on the outside lower then the inside so the PCV never opens and given you have a full 4" with no restrictions I'd say that is what happens, for piece of mind if it was my car I would like to see how it was working at full noise, but that is answered by the catch can, if the Venturi system was working properly at full noise the catch can should never see oil go into it there should also be no need for that catch can A properly setup catch can arrangement will stop the oily mist getting to the intake Just out of curiosity where are you located ?

It is what was recommended by MSCN, they said I can use either but cause I am using E85 they said the aeroquip would be better suited I don't think Heman or any of the masters of the universe could push these farkers together

I'm guessing he is in Holland so our laws mean nothing really I would be interested to see how that Venturi setup works when at full noise as the exhaust starts to build back pressure The problem with the RBs oiling is the blowby gases trying to escape the crank case via the head trapping the oil in the head, by creating to much negative pressure you will be increasing the air flow through the head making matters worse The crank case breaths though the oil returns from the head and out through the cam covers ( there are no rockers in an RB )

K thanks, I think I will take the aeroquip hose back and get em to swap it cause there's no way on this side of gods good green earth I'm getting them together

Hey Fatz, did you use the Speedflow 400 series push loc fittings ? What hose did you use ? How did you go getting em together ? I got a heap of em and got the aeroquip hose and can not for the life of me get them together

Wow, so it is the same as the factory RB30 fitting that holds the oil filter, interesting

While in theory the exhaust Venturi should work in practise on a turbo engine ( depending on where it is located ) it will not You will be better off putting it back to factory or do a proper breathing setup The thread Bob linked is a good read The crank case breaths through the head and out the cam covers

So that is the filter relocator part of the setup yeah ? Not the part that bolts to the block ? Why would that bit get removed ? Can you remove the one from the block and see if it will screw in, at least that will tell you if its 3/4 unf or not

Have you got an actual picture of the Venturi setup ? The factory setup goes - PCV then hose to cam cover - hose from cam cover to cam cover - hose from cam cover to inlet pipe of rear turbo The PCV is set right, it is suppose to work when the engine is under vacuum and close when engine sees boost at which point the other end draws the gases out of the crank case breathers, so going off what you have discribed the venturi will be doing what the rear turbo is supose to, this will mean you will get blue smoke under full boost situations and be losing oil So other then the Venturi setup the rest is as per factory Also pic of catch can if you can but no line from block should go directly to catch can as it will just pump oil out so disconnect that and put dip stick back in

Unless all the ratios are set properly and tyre size is inputted for every individual car which is a bit of work just for a tune the RPM scale will be wrong anyway, if you need to know rpm ask for the gear ratios and tyre size for the one you want and work it out

Yeah I'm getting bad gate way every other thread I try or if I want to go back to one

I missed these events altogether, I to would like to come down for a watch but with the club day on that Monday I'll need to be under the car that weekend Good luck to all that are competing and show what the nissans can do How does 1 get an invite to compete in these events, would like a crack at it next year if possible

There are so many capable ECUs these days most are much a much, best bet go talk to you chosen tuner what he prefers as any ECU you get is only as good as the dude pushing the buttons I have a Syvecs S8 in my 34 and it is about as good as an ECU gets and has built in E85 strategies for flex fuel setups, but very few people know enough about them to tune then properly, luckily for me my tuner has had experience with Pectal ECUs and said if I got it he will be able to tune My tuner builds his own ECU called a EmTron which is a really good bit of gear but ATM pretty much only he knows enough about it to get the best from it A budget will also help get ideas for the level of ECU your after

I have made 458kw @28psi at all 4, IMO on a 3.0 with gates plumbed in once you pass 300kw at all 4, so a bit more for RWD, then the 3" starts been a restriction, now its not a case of 300 its fine then 301 its a massive restriction, at 314 I don't think it would make much difference, certainly not enough to warrant changing it, over 350 it would really start getting worth it though If you get to 400 with a 3" on a 3.0 then your pushing it really hard and would gain a fair bit I know people can make by power with a 3" but then you can blow a golf ball through a length of garden hose if you blow hard enough, the bigger exhaust just allows the motor to do it easier

I am running twin GT-RSs with internal gates, CES comp series split dumps so wastegates are plumbed in, and this is the exception, if the waste gates vent atmo then you can get away with a smaller exhaust What power are you running ATM ?

I tapped in to the boost gauge signal hose and run to a map sensor on fire wall, no tuning issues Maybe the Syvecs is less susceptible to pressure fluctuations

Some thing else to think about, obviously to late for josh now, but by blocking a oil feed to the head you doing two things 1) creating uneven flow in the head ( not really an issue ), 2 ) creating an air pocket in the block under the plug ( can be an issue ) I am running two 1mm restrictors and a idle while looking through oil cap there is a good solid flow of oil coming out of the cam bearings And while I'm here IMO a 3" exhaust on a 3.0 is to small, on my 2630 I went from a 80mm jap exhaust which had no restrictions in it ( I checked ) to a twin 3" in to single 4" and the difference is night and day, it is better every where

The early E85 walbros had an issues if not submerged fully, the later not so much, I have the newer E85 walbro in my 34 as a lift pump and have run it way down past the pump hieght with no issues

Something I have wanted to know is what's the difference between using the twin 6 blade and the 10 blade compressors pictured ? Other then the fact ones cast and one billet, so say both cast or billet

Really depends on how their made and to what quality with what meterials Still gotta be better then those plastic clip on brake covers Story time , I guy I work with bought a Hitachi Electric hammer Chinese knock off cause his genuine Hitachi farked up, the knock off hit harder and has lasted more then twice as long so far as the hitachi, moral to this story is not all knock off are poor quality rubbish

Double clutching a syncro box is something they do in movies, do it in real life and you will destroy your syncros, double clutching is for dog boxes only and also the slowest way of shifting

I believe they are GT2871R, compressor is 52 trim 51.2 in 71.1 ex, turbine is 76 trim 53.8 ex 47 outlet with .60 comp and .64 exhaust

Agreed, though it is interesting how some races have a higher percentage of arrogant ignorant inconsiderant self centered egotistical elitist arseholes who think they are better then every one else that isnt the same race as them for no apperant reason then other races do

Ok so that turbo would be more comparable to the TD06SL2-20G just with a bigger compressor wheel ( 74mm v 68mm ), in twin form I think they would be to big even for the 3.0