R33 Rb30 Conversion

[Guilt-Toy]

Guilt Toy

Bonnet definately wont close on an r33. I know a mechanic in Newcastle who has done 3 of these conversions to r33's and he buys a custom made plenum everytime to solve the prob. If you want his number pm me.

Does anybody know why my r32 rb2530 will cut out sometime at the top of the rev range in third gear. Im assuming I have maxed out the afm, but does anyone know what the built in cut outs/defenders are and how they feel. Mine will cut all ignition to the motor until i remove my foot from the accelerator, it will just coast, then it goes again as if nothing happened.

Any ideas and how it can be overcome are appreciated.

Grey

This is the same mechanic doing my conversion I believe.

[the phantom]

Hi Joel,

After about 70000 very hard km now, I have not noticed any ill effects with the engine lowering. I too initially thought this may cause universal joint issues, but there have been none...no vibrations...ever. The effect on the drive shaft angle is very minimal, and the lowering of the centre of gravity can only do good things.

[Cubes]

So when you say the holes are around 25mm lower do you mean the holes are 25mm higher than the standard postion in turn allowing the engine to sit 25mm lower?!?

[the phantom]

Joel,

oops sorry...Yes your right, the new holes in the plate are ABOUT 25 mm HIGHER thus lowering the engine assembly by that amount. You cant go much lower than that because the sump will hit the sway bar. When I was working it out I had the engine bolted to the gearbox but supported on a jack from below on the sump rather than the mounts. I lowered it enough to clear everything ensuring normal movement room, then marked out the hole positions on the plates through the original engine-side holes in the mounts, which were placed in the elongated crossmember-side slots so they could move outwards as required.

[GreySky]

I got one of those ecu lcd displays and have mounted it in my car, i get my afm up to around 4.8v before it cuts out. And yeah your right it scares the s@#$ out of you the first time it happens.

The rb2530 maxes it out in that case around 5500rpm at 9 psi, less in 4th. Think its time for the next stage of the project....

[Cubes]

I would be curious to see what power it is making on 9psi.

Would have to be up around 170-180rwkw?!?!

How does the 2530 spool on the rb30? With 9psi it would feel like an NA..

[GTR-Ben]

I think he means a RB25/30 engine, not a GT2530 Turbo. That would feel like a NA

This engine lowering looks promising, only trouble for me is I have to space out my Swaybar as it is, lowering the engine another 25mm would mean the swaybar would have to be spaced out a lot more..

Worth a try though if it means not having a huge bonnet scoop..

My old RB20 Powered cars would max the AFM out at the top of 4th, which was always about 198km or so. Was really annoying on flying 1/4 runs.. had so much more to give but it would only let you coast. It is damn scary when it cuts out like that at those speeds.

I'm not running AFM's on this car so no probs hopefully.. just other ones.

[Cubes]

der....

[GTR-Ben]

Oh I have an actual OS RB30 in the garage at the moment. They actually don't mount an idler or anything higher like some of us have for our cambelt due to them supplying a cambelt that is custom made for the RB30.

It also comes with really nice Cam Sprockets.

Quite a bit more coin than making your own 3L though..

Quite funny comparing it with the old VL RB30.

[Bl4cK32]

How about taking some pics, so we can see the differences between the two engines. I may never be able to see it any other time....

[Guilt-Toy]

Can we get photos of these engine mounts modifications?

[Sydneykid]

Oh I have an actual OS RB30 in the garage at the moment. They actually don't mount an idler or anything higher like some of us have for our cambelt due to them supplying a cambelt that is custom made for the RB30.

It also comes with  really nice Cam Sprockets.

Quite a bit more coin than making your own 3L though..  

Quite funny comparing it with the old VL RB30.

Hi guys OS RB30 is simply an RB26 block, with cylinder liners that stick out of the top of the block. There is a spacer that goes around the liners to fill the space to the head. So you basically end up with 2 head gaskets, one between the spacer plate and the block and one between the head and the spacer plate. There are longer (than standard) head studs that thread into the block, go through the spacer plate and the head with nuts on top. They look like the standard ARP RB26 head studs only longer.

For cam belt tension they have an adaptor plate that bolts to the RB26 block in the standard position. It has 2 adjustable tensioners that bolt to it and squeeze the belt close together. It is similar to the (optional) low mount tensioner that some guys use on the RB30 DET conversion. The belt itself is the same dimensions as the Dana one most people use.

I have detailed pictures of one being assembled, but they are quite large. So I will put them up with the host later.

[GTR-Ben]

I have some pics, just havn't uploaded them yet.

Did you have to assemble it yourself SK? This one came with the liners etc all done and crank installed. Looks like a pretty big job involved putting it all togethor if you had to.

[Sydneykid]

I have some pics, just havn't uploaded them yet.

Did you have to assemble it yourself SK? This one came with the liners etc all done and crank installed. Looks like a pretty big job involved putting it all togethor if you had to.

It's actually pretty simple, just bore the block to suite the liners, same as any RB26 liner, but longer. The trick is getting the deck height perfect, you have to fit the lower head gasket and then machine the liners down to match. You can't machine the spacer plate, so if the liners are too short you're screwed. The crank is just like fitting up any RB crank, standard bearing sizes. The one I helped with didn't have main bearing studs, but I think the current version might.

The rods are not as long as RB30 rods (152.5 mm), I didn't measure them so I don't know exactly how much shorter they are. RB26 rods are 121.5 mm, so I suspect the OS ones are around 140 mm. This gives a less than ideal rod stroke ratio of 1.65, which is the same as an RB26, so it is logical. Personally I think the RB30 rod stroke ratio of 1.79 is superior.

If I was doing my own conversion, I would go for the standard RB30 rod length and make the spacer thicker to allow for it. You could then use an RB30 crank and standard height RB30 liners. It would be about 1/5 the cost of an OS 3 litre. :aroused: The only draw back is the liners would be further out of the block, but that's what the spacer plate is for.

That said the OS Giken 3 litres do the numbers and seem to last very well, if properly assembled of course.

[Cubes]

Nice little read regarding R/S Ratios.

http://www.hotrod.com/techarticles/pit/index14.html

[Fitzpatrick Speed Works]

out of interest and after opinions, im thinking of perhaps 272 degree cams with 10.2mm lift for my rb30/ 26 combo.... Normally i wouldnt consider this as on a rb26 i wouldnt go bigger than a 264 unless the thing is going to be reved beyond 9k.. Why? becuase shorter duration high lift cams give a greater torque spread and better average power resulting in a faster car....

However due to it being a 3 litre i thought i might get away with 272 due to overlap not being as big an issue on a larger capacity engine???? But is 272 too big due the fact the r30 will only be reving to 7.5k???? I want a good flat power curve and i know there are other considerations in the equation for that but what are some thoughts!!!!

[Sydneykid]

out of interest and after opinions, im thinking of perhaps 272 degree cams with 10.2mm lift for my rb30/ 26 combo.... Normally i wouldnt consider this as on a rb26 i wouldnt go bigger than a 264 unless the thing is going to be reved beyond 9k.. Why? becuase shorter duration high lift cams give a greater torque spread and better average power resulting in a faster car....  

However due to it being a 3 litre i thought i might get away with 272 due to overlap not being as big an issue on a larger capacity engine???? But is 272 too big due the fact the r30 will only be reving to 7.5k???? I want a good flat power curve and i know there are other considerations in the equation for that but what are some thoughts!!!!

My own RB31DET has 268 inlet and 272 exhaust both with 10.5mm lift.

[awurth]

This is the Vl RB25/30 conversion i was talking about a while ago, pics are from a camera phone so sorry about the clarity. car is fully finished now and is waiting for the tune, will do around 500k's with the wastegate fully opened and then it will come back in for the boost side of things to be sorted. the turbo was off a 12a rotary that featured in zoom a while ago.

[Cubes]

The bonnet definately won't close with the RB30 in a R32.

I'm redrilling the holes on the engine mounts that bolt to the block, then welding up & grinding flat the old holes. All it needs is around 8-10mm.

The problem appears to be with the front of the plenum fouling the bonnet.

Luckly its not on the torque side.

[predator]

joel.. What loom and ECU combo are you running with your engine (if you have got to that part yet ? Are you running the rb25 loom or RB20 engine loom ?

Can you use the RB20det loom & ECU in conjunction with an rb25de/t head ?

Edit: now i think about it, rb20det ECU would be useless without remapping as the injectors would be wrong size, and there is probably other problems with that. Next question: can it be remapped at all to properly run an RB30DET ?