R33 Rb25de+t Oil Drain

[SKiT_R31]

Hey All, The time has come to turbo the daily R33 N/A. Blew my clutch, so I put a GTR exedy HD clutch, billet lightweight flywheel and GTR gearbox under it.

In the process of changing the gearbox, I stripped the engine back to a bare long motor (which was good as there were a fair few bolts that weren’t done up, seals/gaskets needing replacing etc). Anyway, I have put it back together with turbo injectors; I’ve fitted a turbo ECU & fuel pump, turbo manifold, High flow R33 turbo, 3" dump with merging waste gate pipe, high flow cat and larger exhaust.

I've got all the stock GTST intercooler piping, crossover pipe, an aftermarket bov, R34 GTT intercooler, with 7" elec thermo fan and twin nozzle water spray (by using an elec bypass on windscreen washers, using an emissions vacuum solenoid, at full throttle, or when a button is pressed, the windscreen washer pump activates, and the solenoid swaps the water to go to the intercooler nozzles instead of the bonnet nozzles).

So yeah, its all ready to go, my intention is to just have tame responsive power, ill get it on a 4wd dyno and adjust the boost and ign timing until I have a comfortable medium of reliable power and response.

Anyway, that’s the back story - but my problem is, I have an oil feed from he block, but I don’t have an oil return, at the bottom of the block where it normally is... I'm guessing this is a GTS4 thing...?

Don’t really want to unbolt everything and pull the engine out to 'do it properly', so I’m wondering how it would go, draining into the stock VCT return? I will replace the fitting with one with a larger inlet, and Y piece the turbo and VCT drains, I’m just curious if anyone knows the volume of oil that flows through this drain? Last thing i want is excessive drain backpressure, and blow the seals out of my turbo OR flood the head (I’ll fit an ATMO catch can, just in case anyway).

Anyone got any info on this, or better yet, done it before?

Cheers,

-Dan

[dori34]

pm WYTSKY (Adam), he did a DE+T to his GTS4.

[N-DAWG]

Sorry to hear about your clutch... but I reallly can't wait to see how this is gonna turn out!!

[dori34]

FYI, my RB25DE in my 34 had a bolt that i could take out that i used for a oil return. if that wasn't there, iw as gonna tap into the sump.

not sure if that was the same for nate's car tho (he has a 34 as well)

[SKiT_R31]

I PM'd WYTSKY, he said he drilled and tapped into the factory position.

I cant drill the sump as its the Alloy 4WD one, and really dont want to pull it all out, as i said before its my daily...

Haha, cheers N-DAWG, it was a pain in the arse at the time, but its for the best .

I've got a dummy turbo i will put on it tonight, a stock R33 one which spat the rear wheel, cracked the front housing and stuffed the centre bearing, so i've gutted it, and welded it, so when i bolt that on the car will be a bit choked but will be fully drivable with the turbo manifold/dump etc fitted, and it gives me somthing to work from, finishing the cooler piping, while still having a car that goes.

I'm thinking ill just T piece into the VCT and hope for the best

I also have an ADJ exhaust cam gear and an AFC-4 Neo, which i can fit and get tuned to get the most out of it. I've set the timing to 15 degrees (from 30 ) also fitted NGK 7's, (replacing the 5's) to help cool the combustion chamber, but i've left the gap @ 1mm, since it will be fine on the low boost, and its sort of an overboost safety feature anyway (spark blow out) .

Edited October 16, 2009 by SKiT_R31

[WYTSKY]

FYI, my RB25DE in my 34 had a bolt that i could take out that i used for a oil return. if that wasn't there, iw as gonna tap into the sump.

not sure if that was the same for nate's car tho (he has a 34 as well)

as I said in Pm to skit_r31....

Racingline Motorsport ( who do not exist anymore) were the ones to tap and drill a hole for my oil line and same for the oil return in the factory location for a GTST block.

Still seems to be working fine

[dori34]

must just be an R34 RB25DE thing then as they seem to have the bolt already there.

or is only just GTS4 motors that have to be drilled, what about GTS RWD motors ?

[SKiT_R31]

I've turbo'd an N/A RB25DE (normal GTS) before, they usually have the drain

[N-DAWG]

I thought the R34 DE NEO's didn't have the blanking bolt? Only the R33's and earlier? interesting. Pretty sure they T'd off the pressure switch or something.. I'm really not entirely sure. They didn't tap the block though due to the risk unless they took the engine out first.

[WYTSKY]

mine didn't have the drain..... but had a perfect spot for it... on the other hand... mine had a bolt where the oil feed was..... but in the wrong spot... so they re drilled one closer

[dori34]

oil feed was from the pressure switch, oil return i had a bolt there (like the one on the gbox) removed that and whacked in the return fitting.

nate, have a good look below the turbo if you can and see where they fit the return.

[dori34]

Heres the bolt im talking about;

another clearer pic

stock return is more to the right tho which on mine was blanked.

still really keen to how they done yours nate-dawg.

[SKiT_R31]

That bolt you've circled, is the bolt R33's use for VCT oil return line, that i am going to T-Piece into

[dori34]

Oh okay, so thats what its suppose to be for.

one problem with it being here is to many bends on the return hose, becareful cause if not done proprely, it can cause oil leaks which are a PIA.

happened first time round and had to get it fixed up

[SKiT_R31]

Don’t really want to unbolt everything and pull the engine out to 'do it properly', so I’m wondering how it would go, draining into the stock VCT return? I will replace the fitting with one with a larger inlet, and Y piece the turbo and VCT drains, I’m just curious if anyone knows the volume of oil that flows through this drain? Last thing i want is excessive drain backpressure, and blow the seals out of my turbo OR flood the head (I’ll fit an ATMO catch can, just in case anyway).

If people are interested, my N/A RB25DE is now turbo (on stock boost atm) I just did what I said originally and got a larger block fitting for the head oil drain and T pieced into it. The turbo is ball bearing, so they don't take anywhere near the oil of some of the sleeve bearing turbo's (could end up with a different result?). But the car has been running fine for some time now, just thought I'd let people know this is an option.

Happy to be boosting again, its makes a respectable amount of power for the street.

[dori34]

how much torque you getting skit? with the BB, im assuming would be quite responsive

[SKiT_R31]

haha, its not bad, seems to boost at around 2000rpm, first gear is now balistic (4.4 ratio AWD with lightweight flywheel), i'm loving the grip/tame wheelspin. Its beautiful to drive, low rpm light throttle just powers up hills etc where before i would have had to shift back, has made the car alot nicer to drive. I've actually never had a ball bearing turbo before, its quite mad, you idle the car for a min or so, turn it off, and you can hear the turbo spin down for at least another minute...

Although without waterspray assistance (which i dont want to rely on) on some of these hotter days (~35degs) i have heard the odd knock after driving the car relatively hard, when everything warms up. So once it arrives, i'm fitting a 600x300x76 SINGLE SIDED bar and plate front mount intercooler with twin 10" thermo's mounted behind it. Then i'll be happy to wind the boost up and give it a bit more ignition timing.

I'm a big fan of single sided coolers, i have a 600 x 200 bar and plate on an R31 RB30e+t wagon with twin 8" thermo's mounted to the rear, and boost is always nice and cool, even after a thrash. I think this is because with a normal cooler, the boost tends to take the easy way through the cooler, not completely filling and empying, so your only effectively using a section of the rows. Wheras with a single sided cooler of the same size, the boost is going all the way through (using probably the same amount of rows as a normal FMIC) but then has to go down and back through again. You can feel the heat in the cooler, its hot at the top on the entry, warm at the top at the end, and cool at the exit at the bottom (wheres a normal FMIC tends to be hot entry warm exit).

You obviously dont get the same flow as you would a straight through Front Mount, but when your dealing with high compression, you want the boost as coool as you can get it .

Edited November 10, 2009 by SKiT_R31