R33 Rb30 Conversion

[shanef]

All of my questions are related, use the wrong engine mount holes on the RB30 block and you get fouling problems

Try and fix it with drilling the engine mounts and you get fouling problems

Use the wrong engine mounts and you get fouling problems

Keep in mind that the sump adaptor lowers the front dif (and drive shafts) 6 mm anyway.

Think about it, an RB20DET with cross over pipe (75 mm in diameter) fits under the same bonnet height as an RB26. The RB20 block and head are the same height as the RB26 block and head. The RB30 block is only 38 mm taller than the RB20/26 block, so you should have 37 mm free space.

My guess, someone is using the wrong combination of bolt holes and engine mounts. Hence the questions.

cheers

not sure about the plates you use gary, but the one's i do and others i've seen are 10mm plate, then add a couple mm for gasket glue, so more like 12mm.

i personally tried every combo possible with both the std rb26 mounts and std rb30 mounts with different bolt hole combo's, and i found i could only use the rb26 mounts and there were only 1 set of holes in the block that lined up. i didnt however try redrilling the mount holes.

with the cf bonnet i had, the latch was about 2inches from latching, and that was with the gearbox on and bolted up inplace. i'm yet to try a std bonnet.

i was just going to get custom carbon to do me up a bonnet. maybe if i do that i can get them to take a mould so there's a ready to go bonnet for this

[shanef]

You are concerned with drive shaft angles from lowering the sump a few mm, but I bet you lowered your car 40 mm and didn't even think about it.

cheers

car is std height atm gary, still has std susp in there (for now)

soo i take it if i lowered the subframe the change in angle wouldnt be detremental to anything?

[Sydneykid]

not sure about the plates you use gary, but the one's i know of are 10mm plate, then add a couple mm for gasket glue, so more like 12mm.

i personally tried every combo possible with both the std rb26 mounts and std rb30 mounts with different bolt hole combo's, and i found i could only use the rb26 mounts and there were only 1 set of holes in the block that lined up. i didnt however try redrilling the mount holes.

with the cf bonnet i had, the latch was about 2inches from latching, and that was with the gearbox on and bolted up inplace. i'm yet to try a std bonnet.

i was just going to get custom carbon to do me up a bonnet. maybe if i do that i can get them to take a mould so there's a ready to go bonnet for this

You must be using an alloy 4wd sump adaptor, we use mild steel, hence the 6 mm.

If you are concerned with drive shaft angles, simply raise the suspension up 10 mm and you will be back to where you would be an RB26.

cheers

[Sydneykid]

car is std height atm gary, still has std susp in there (for now)

soo i take it if i lowered the subframe the change in angle wouldnt be detremental to anything?

What's better, lowering the suspension 40 mm or the sump 6 mm plus 6 mm for the diff and drive shafts?

ie; 40 mm versus 12 mm.

The only difference is the front tailshaft angle, simple Pythagoras, what’s the angle change for 6mm over the length of the tailshaft?

Then do the same for the centre tailshaft, it’s even longer. Plus, if you are really paranoid, you can lower the centre bearing carrier. Spread the angle change over the full length of the tailshaft.

High school geometry comes in handy sometimes.

cheers

[Sydneykid]

car is std height atm gary, still has std susp in there (for now)

That's OK, they settle 5 to 8 mm from new anyway.

cheers

[shanef]

You must be using an alloy 4wd sump adaptor, we use mild steel, hence the 6 mm.

If you are concerned with drive shaft angles, simply raise the suspension up 10 mm and you will be back to where you would be an RB26.

cheers

i use mild steel and when i've finished drilling/tapping it i get it plated so theres no chance of rust/corrosion

What's better, lowering the suspension 40 mm or the sump 6 mm plus 6 mm for the diff and drive shafts?

ie; 40 mm versus 12 mm.

The only difference is the front tailshaft angle, simple Pythagoras, what’s the angle change for 6mm over the length of the tailshaft?

Then do the same for the centre tailshaft, it’s even longer. Plus, if you are really paranoid, you can lower the centre bearing carrier. Spread the angle change over the full length of the tailshaft.

High school geometry comes in handy sometimes.

cheers

i read over this better when i get home, but i see ur reasoning

thanks again gary, ur a great help

[Cubes]

Thanks Gary,

Antony has his rb30det out at the moment, soon to be dropped back in within a few days which I'm giving him a hand so I'll check it out, take some pics etc.

[Sydneykid]

i use mild steel and when i've finished drilling/tapping it i get it plated so theres no chance of rust/corrosion

Somewhat of an overkill. There's an engine block on one side, a sump on the other and oil splashing around the inside. Not much chance of rust/corrosion there. We simply paint the outside edge of the adaptor when we paint the engine block. This also coats the adaptor strips and the exposed threads/heads on the bolts.

cheers

[r33_racer]

See all these height issues....thats why GTR's suck

GTST FOR THE WIN!!!!!!!!!!!!!!!

[Sydneykid]

See all these height issues....thats why GTR's suck

GTST FOR THE WIN!!!!!!!!!!!!!!!

12 mm that's nothing. I am going to lower the RB31DET in the R32GTST as much as I can. Just have to keep that High Energy 8 litre sump no lower than 100 mm from the ground.

Plus angle reduction is a good excuse to buy that 1 pierce carbon fibre tailshaft.

cheers

[r33_racer]

its going to get hammered with crap, it was bad enough at std height....just stay on the track gary and it might keep that nice black paint job.....when the old man goes off every once in a while (when we had the high energy sump/and first proto anti-roll bar) it used to take a beating from the gravel traps...haha....good thing i dont spin off.............much:)

Edited April 16, 2007 by r33_racer

[nemini90]

with my mounting i lowered the cross member then modified the lower control arm on the ball joint end to get the arm to work at the right angle that is the only problem i can see with lowering the crossmember

[Scooby]

I had never had any fouling problems.

What engine mount holes did you use on the block?

Did you use the RB26 alloy mounts or the RB30 streel mounts?

Have you redrilled the lower engine to subframe mount?

Have you spaced the subframe down from the rails?

cheers

Hi Gary;

I could only get one set to line up

Alloy RB26 mounts

Engine to subframe mount has not been redrilled

Sub Frame has not been spaced down

Just out of interest I thought I'd add that I'm running twin turbos, but it's an annoying job. The steel lines that run along the rear of the head are attached by a bracket that is now exactly in front of one of the heater outlets in the firewall and there is no hope of getting a hose on (no problem in a race car but mine isn't), the BOV plumbing under the stock airbox doesn't align anymore, a BOV plumb-back tube into the rear turbo fouls the ps reservoir, and the forward turbo inlet is too close to the AFM when mounted in the stock box so now I need an airbox, which I didn't want. If I can raise the stock box 38mm or so it should be fine, just need to get the clearance to do it and then extend the BOV plumbing under the airbox by 38mm and get the ps reservoir reprofiled to accomodate the plumb back pipe.

There were also a couple of people on here stating that a 149 tooth belt and two tensioners in the stock location will work. I reckon bollocks unless you're using a really thin head gasket and have skimmed the block and head quite a bit. If it works for others great, I tried this combo and it was so tight the only way to get the belt on was to set it up, back the tensioners off all the way, tighten them and then lever the intake cam sprocket over the cam snout - not something I'd recommend. I'd seriously consider going to the high/low configuration but the thing is in the car now so not sure if I can get the hole drilled perpendicular. Looking at making up a plate that moves the one tensioner outwards slightly and then finding a belt to fit.

Also tried a 150 tooth belt as per the guide but could not get enough tension unless the teeth were almost touching.

Joy. Better be bloody worth it. Meanwhile I have an RB26 sitting there on a stand, that could have been rebuilt and running months ago with no engineer cert hassle etc and a nice 300 rwkw.

Cheers

Edited April 16, 2007 by Scooby

[Cubes]

Also tried a 150 tooth belt as per the guide but could not get enough tension unless the teeth were almost touching.

I haven't used the 150 tooth + 2 lower tensioner method. So I can't get behind it. :S

I and a few others here in Adelaide run the Dayco 94407 152 tooth belt.

We all run 2 tensioners, one above the water pump and the other in the lower position.

It fits and it works, plenty of adjustment.

Maybe just drill and tap. Will take 30mins to 1hr tops to get it all in the right position.

The RB30 and RB26 difference in spool, drivability, low gear acceleration and average power is simply not comparable.

Dyno sheets don't show how much better the 3ltr spools a turbo at part throttle and lesser load gears.

Providing you have previously driven the setup on the 2.6ltr you plan to run on the 3ltr I'm confident you will be happy with it.

[Scooby]

Hi Cubes yeah I'm just bitching. Leaning towards the higher tensioner, now it's in the car though i'll have to make up a jig to get the hole perpendicular. I only went for the stock type setup as it's got significant reinforcing behind the stud/bolt holes whereas the high mount option only has the 9mm of block.

[Cubes]

lol.

Yes the lack of meat was a small concern especially if one is running big springs.

After 2-3years and we are still leaning crap about these build ups.

Are you going to drill straight in to the water galley and tape up or place sealant on the thread?

Thats how mine was done.

[r33_racer]

just drill and tap it scooby and then use some thread sealant on the stuf. Weve done that to two weve done so far with no issues. However i reckon the hole needs to be a little to the left...maybe a few mm cause the timing belt was a bitch to get on...it was pretty tight...unless the drill wandered abit or it wasnt sharpened evenly and it moved the hole a little to the right. Thats my thought on making the cam belt easier to put on that way, there is enough adjustment in that tensioner to take up any difference in slack.

[GTRgeoff]

I went with the high drilling for the mounting on the 26/30 but with no time to grab a second adjuster I fitted the belt as it was. While tight it wasn't too tight for the Dayco belt so I kept it on. No adjustment needed.

Now I just need to pick up cam gears as it isn't making power. Just 160rwkw for the run in 2000km drive from Melbourne to Brisbane. I may yet change from GTS25t PFC to GTR32/33 PFC and a GTR33 wiring loom so I can run twin AFMs and GTR airbox.

The drive was fun though with a little light rain. I've temporarily located the pod and AFM in front of the LF tyre so it gets spray and the AFM signal maxes, cutting power so I just ha to crawl along until the rain passed.

[Sydneykid]

its going to get hammered with crap, it was bad enough at std height....just stay on the track gary and it might keep that nice black paint job.....when the old man goes off every once in a while (when we had the high energy sump/and first proto anti-roll bar) it used to take a beating from the gravel traps...haha....good thing i dont spin off.............much:)

Are you running an undertray? They save the sump from the sand blasting. My current one is alloy, based on a V8Supercar (pre Project Blueprint) Commondoor. Once I am happy with it I will get it duplicated in carbon fibre.

cheers

[Sydneykid]

Hi Gary;

I could only get one set to line up

Alloy RB26 mounts

Engine to subframe mount has not been redrilled

Sub Frame has not been spaced down

Just out of interest I thought I'd add that I'm running twin turbos, but it's an annoying job. The steel lines that run along the rear of the head are attached by a bracket that is now exactly in front of one of the heater outlets in the firewall and there is no hope of getting a hose on (no problem in a race car but mine isn't), the BOV plumbing under the stock airbox doesn't align anymore, a BOV plumb-back tube into the rear turbo fouls the ps reservoir, and the forward turbo inlet is too close to the AFM when mounted in the stock box so now I need an airbox, which I didn't want. If I can raise the stock box 38mm or so it should be fine, just need to get the clearance to do it and then extend the BOV plumbing under the airbox by 38mm and get the ps reservoir reprofiled to accomodate the plumb back pipe.

There were also a couple of people on here stating that a 149 tooth belt and two tensioners in the stock location will work. I reckon bollocks unless you're using a really thin head gasket and have skimmed the block and head quite a bit. If it works for others great, I tried this combo and it was so tight the only way to get the belt on was to set it up, back the tensioners off all the way, tighten them and then lever the intake cam sprocket over the cam snout - not something I'd recommend. I'd seriously consider going to the high/low configuration but the thing is in the car now so not sure if I can get the hole drilled perpendicular. Looking at making up a plate that moves the one tensioner outwards slightly and then finding a belt to fit.

Also tried a 150 tooth belt as per the guide but could not get enough tension unless the teeth were almost touching.

Joy. Better be bloody worth it. Meanwhile I have an RB26 sitting there on a stand, that could have been rebuilt and running months ago with no engineer cert hassle etc and a nice 300 rwkw.

Cheers

Is this where I get to say "I told you so"?

I did advise you to go for the high mount tensioner for very good reasons. I have no idea why people think the lower mounting is better.

You can use the RB30 engine mounts, but you have to modify them. The RB26 mounts are OK too, but they place the engine too high. Lower the engine, it solves all the problems you are currently having.

cheers