RB30 engine conversion (lots of pics)

[R32 Combat]

Interestingly, the RB20E engine used a crank position sensor on the flywheel ring gear.

No silly CAS on that one.

[R.I.P.S NZ]

All the RB20/30e's we have here use a conventional style electronic distributor with 1 coil and 6 ignition leads, never seen one with a sensor on the ring gear??????

[R32 Combat]

When looking through the R34 workshop manual sensor output signals, I noticed that pin 47 of the ECU is stated as a crank position sensor ring gear signal.

Strange...

I've never heard of one either, it's just what the info stated.

[Scooby]

Hi Andy;

Rumour has it the RB30 suffers from harmonics over 7250. Not sure if you've had the chance to rev it that high yet, have you noticed anything?

It appears you used the RB26 damper, is that correct?

Cheers

[R32 Combat]

I never took my RB26 over 7k. My RB30 has a 7k rev limit because I've also been told not to rev over 7200.

To be honest, I don't think i'd gain anything from revving past 7k.

Yes, I'm using a RB26 crank pulley. I don't know is thats the best option. I've not heard either way...

[shanef]

You have to use the RB26 blancer as it is different to the RB30 one. I've attached 2 pics showing the differences of each (each are labeled)



Not sure why u guys dont rev them to 7500rpm, unless u have found some dramas revving them to that. I've been told by a few engine builders that it will be fine to rev it to 7500rpm.

[tyndago]

Originally Posted by R32 Combat

When looking through the R34 workshop manual sensor output signals, I noticed that pin 47 of the ECU is stated as a crank position sensor ring gear signal. .

In the R34 GTS service manual I guess it says that. In the R34 GT-R manual pin 47 is the diagnostic signal line.

As far as revs go, probably all about the piston speed at 7200 or 7500 rpms. When I did some calculations the RB30 at 8k was like a RB26 in piston speed at 10k.

[R32 Combat]

It is generally accepted thats it's ok to use the RB26 pulley on a RB30?

[Scooby]

Just to clarify on the balancer issue, RB30s seem to have a reputation for harmonics at anything over about 7250. It may well be undeserved, and admittedly I'm yet to find an explanation for it, but nevertheless it seems reasonably common.

I'm tossing up the use of an ATI/'Fluidampr' or Ross damper but again I'm yet to find any concrete evidence that they make a difference. They're also underdriven which doesn't appeal to me.

I was just wondering if you'd spun it that hard - although as you say there's probably not much point - and if you noticed anything.

Cheers

[sleepyfox]

Originally Posted by Hugh Keir

Here is a logged example of the problem that is caused when a high power GTR runs the CAS for ignition timing. The graph shows a the CAS error as you go up the gears in my car, although I do not use the CAS to provide ignition timing.

The 0 to 100 scale on the left = 20° of ignition timing which if you look at the trace = 10° of ignition timing wobble

Great post Hugh - though this confuses me more: If this is a harmonic problem or due to 'belt flex' then why does it manifest itself more in a higher gear? Surely it should be the same at the same engine revs no matter what gear you are in?

[R32 Combat]

As a rough performance comparison between my RB26 and RB30

RB26 @ 1.4bar 1/4 12.02s @ 120
RB30 @ 1bar 1/4 12.1s @ 116 (some difficulty getting it off the line without huge amounts of wheelspin in 1st and 2nd)

[ahapartridge]

Sorry to repeat a point if it is covered earlier in the thread Andy but what is the long term maximum boost for the current set up?

[R32 Combat]

I don't know. Somewhere around the 1.2-1.4bar mark. 600hp is my goal so however much boost is needed.

[Hugh Keir]

Originally Posted by sleepyfox

Great post Hugh - though this confuses me more: If this is a harmonic problem or due to 'belt flex' then why does it manifest itself more in a higher gear? Surely it should be the same at the same engine revs no matter what gear you are in?

sleepyfox,

As far as I understand it, the cam belt flex is induced by the resistance of rotating the cams + crankshaft flex.

As the engine becomes more loaded under high boost at high RPM the crank will flex more with each combustion which causes more inaccuracies in cam and ignition timing.

Removing the ignition timing aspect of the above by triggering the ECU from a non cam belt driven source is a large part of the solution.

[R32 Combat]

Hopefully, if everything works out OK, I can use the AEM to plot crank position against cam position. This will confirm any speculation and will show realtime errors.