R33 Rb30 Conversion

[OFENSV]

thanx, see how i go on sunday at the drag day

[Sydneykid]

I keep comapring all results to Sydney kids original rb30 engine.

475hp on engine dyno, using old t04e and standard everything on 1 bar boost..

anyway.. great results.

Some numbers to think about;

475 bhp = 355 kw

less 60 kw for losses = 295 rwkw

The engine dyno room is airconditioned at 21C , no radiator, oil cooler etc so you don't get as much heat soak as you do in the engine bay of a car on a roller dyno. The intercooler sits in a tub of water (no ice), so the temp is pretty constant. Plus we tuned the ever living crap out of it, spent 3 days on getting the maps absolutely perfect. There might be 15-20 kw advantage in all of that.

So I reckon 297 rwkw at 17 psi is damn fine effort OFENSV, well done.

[Cubes]

I know of a RB25 with 26 internals, big cams, head work the works make 580hp (432kw) on an engine dyno with a GT30 600hp .82 Garrett turbo.

On the rolling road it made 335rwkw or there abouts.

Thats 97rwkw drive train loss??

[StockyMcStock]

through a powerglide?

97 is a fair bit nonetheless - i'd put it down to dyno differences mostly. who cares what the number is so long as it goes very very fast, very very quickly.

[Cubes]

Through a RB25DET 5 speed.

I found it quite interestering the before and after...

No doubt air temps and dyno differences make a difference. But non the less it was interestering to note.

I can't remember exactly how much boost, it was running but it was somewhere around the mid 20's.

[Cubes]

For those interestered I went for a little drive and did a complete map trace.

Lots of light load cruise and a bit of spirited driving through the hills.

A few WOT's to 6000rpm also.

RB20DET PFC, RB30DET, Stock RB20DET Turbo that initially hits 12psi then tails off to 8-9psi rather quickly.

[StockyMcStock]

interesting piece of trivia:

the 152-tooth Dayco 94407 timing belt is the same as that used on the Audi (Passat?) 1.8 litre twin turbo engines in their newer model cars. it is, however, much more expensive to buy it from an Audi dealer, trust me!

Cubes i have NFI what that 5hit means.

also: the 94407 is 25mm wide, but in the DIYrb30DET guide it says that it is 30mm wide. can anyone confirm that theirs is 30mm?

[Cubes]

RPM points are the X axis every 400rpm, starting from 400rpm.

Load points are the Y Axis.

I didn't actually measure my belt. It did however fill up the complete cam gear with only a mm or two to spare, so what ever the cam gear width is is pretty much what the 94407 belt is.

[StockyMcStock]

interesting - the RB30 crankshaft drive cog for the cam belt is 25.4mm wide, the same as the RB30 timing belt and the belt i just bought from the audi.

the RB25 cam gears are 30mm wide, as are the RB30. i assume this is to allow for a bit of belt movement as there is no lip to guide it on to these.

are you guys using RB25 harmonic balancers and timing belt drive cogs, or are you using RB30 drive cogs? the 25 ones could be wider?

with my RB30 drive cog there is no way i could get a 30mm timing belt on there, that's all.

[Cubes]

RB25 harmonic balancer & RB30 drive cog.

I just had a quick measure and it is indeed ~25mm.

I don't know if a 30mm belt could fit in there to be honest.

Are u using the R32 RB25 head or??

[StockyMcStock]

yep i'd say the DIY guide is a bit misleading in that regard, all the RB series timing belts are 25.4mm i would suggest.

a 30mm belt would NOT fit on any of the drive cogs, which are just barely the width of the belt. if the belt is enough for a 1.8L quad cam twin turbo it should be good enough for me, using standard cams and springs in addition keeps the loads down on the belt.

i have an R33 DE head - i believe the cams and springs are the same as the DET, only difference is injectors.

[Cubes]

I'll update the pdf.

I've got an old RB20DET Nissan belt around here. I will measure it.

I suspect they are infact all 25mm's.

[Cubes]

I've just had a look at the guide and it doesn't state anywhere the width of the 94407 belt.

It does state that the gates belt has been cut down from 30mm to 25mm in the factory.

I don't really know I used that information from some one else so it's only hearsay.

I'll find that rb20det belt and measure the sucker.

[StockyMcStock]

on page 8 of the guide above the pictures it sort of implies that the "thinner" belt of 25mm is not quite as good as the 30mm belt. i dunno just reads to me like it was suggesting that the 94407 is 30mm

[Looney_Head]

hi guys just a quick question about head gaskets. i don't under stand squish zones. i have a rb30 with a r32 25de head, i am going to use stock pistons. which head gasket would be best, what thickness as well?

sorry if this has been covered before.

thanks

[Sydneykid]

I suspect they are infact all 25mm's.

Yes, RB20/25/26 are all 25 mm.

[retrotec]

interesting piece of trivia:  

the 152-tooth Dayco 94407 timing belt is the same as that used on the Audi (Passat?) 1.8 litre twin turbo engines in their newer model cars. it is, however, much more expensive to buy it from an Audi dealer, trust me!

Yes that's right, it suits the 1.8L motor used in VW passats and Audi A4's. Going by engine codes they would be the same motor.

The belts costs approx $40 from most auto parts shops.

I'd check my 94407 belt but its stored among the other parts.

[StockyMcStock]

well that's sorted - also the front-on picture given in the guide which shows the measurements where the tensioner hole needs to be drilled are spot on cubes, i put mine there and it will tension perfectly once i've tapped the hole.

did anyone use return springs on their two tensioners?

[Cubes]

I didn't bother with springs on mine as the tensioners are locking types.

That pic was thanks to another bloke.. I forget his name.

[StockyMcStock]

yeah they are locking, i wonder why there's a return spring on the RB30 tensioners, they're the same as the 25 ones i'm 99% sure? anyway i'm using two RB30 tensioners on mine and a friend's 25/30 doesn't use return springs either.

p.s. where do you get new studs for them from? they have two different threads on each end :confused: which is weird, i imagine they'd have to come from nissan..... i shudder to think of the price