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Old 20th October 2006, 02:09 PM   #226 (permalink)
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Quote:
Originally Posted by R32 Combat View Post
I don't need a missing tooth, I'll use the CAS #1 for sync.

I think missing tooth is pointless on a 4 stroke, what does it tell you? Where #1 TDC is, but which stroke? Hence using the CAS.
The reason for using 60-2 trigger wheels (or any trigger wheel with missing tooth) is to tell the ecu TDC on cyl nr1.
This is used og ECU`s that use batch fire of the injectors, and wastespark on the coils.

If you want to use sequential drive of the injectors or coils, you will need a "home" signal, that in conjunction with the missing teeth also tells the ECU when cylindr nr1 is at TDC.

Asim...
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Old 20th October 2006, 02:57 PM   #227 (permalink)
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Nisfan,
Have you made an trigger wheel on an ATI damper? I've been told that I can run the DTA without trigger wheel on RB engines as DTA can use the standard Cam sensor,infact on the S-series manual there is the instructions how to wire.

Roger
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Old 20th October 2006, 03:13 PM   #228 (permalink)
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Roger,
Yes mounted same as in pic above, P8pro can't use Nissan CAS (I know S60 can), but due to the issues with potential timing changes due to clocking the CAS, adjusting exhaust cam duration with vernier pulley, etc, I decided a crank fitted wheel would be better/more accurate, that's without knowing that there seems to be a problem with the signal as discussed earlier in this thread.
All the more reason to go crank fitted wheel as Andy has done. I use 36-1 on crank, and seperate cam sensor mounted temporarily on inlet cam wheel, but am planning to move it to inside cam cover directly off cam.

Sorry, Andy for HiJack.
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Old 20th October 2006, 04:09 PM   #229 (permalink)
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What the most worry me to fit a wheel on the ATI damper is the balance as ATI dampers are factory balanced and on the instructions they strictly not to balance the crank with the damper.
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Old 25th October 2006, 03:09 PM   #230 (permalink)
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As it is not a missing tooth disk, the balance was very close, although it was tweeked slightly as you can see.


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Old 25th October 2006, 11:44 PM   #231 (permalink)
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yummy
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Old 11th November 2006, 05:40 PM   #232 (permalink)
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At last it's on. Just gotta mount the sensor now.

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Old 11th November 2006, 06:35 PM   #233 (permalink)
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THATS more like it.

the CAS is a lame idea IMO, im used to proper setups like this.

MAP sensor, crank trigger, and cam trigger, thats much more me

I was talking about this exact same thing with MattJ the other day regarding the AEM, i hope he sees these posts, it explains what i meant.
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Old 11th November 2006, 06:48 PM   #234 (permalink)
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It fitted easily. I had to mod the metal cambelt cover plate, but it cleared the lip on the oil pump, which was my main concern.
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Old 20th November 2006, 02:01 PM   #235 (permalink)
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What would be the big difference than using the CAS? and what is the reason that you want to lose the CAS? Since the CAS has 360 points of recognition, and turns half as fast as the crankshaft, I suggest it has an acuracy of 2 degrees. That would be compairable to a 180 teeth crank mounted wheel.
You're using an 36 teeth wheel directly on the crank, so I would think it has an acuracy of 10 degrees, Would a timing belt strech so much? Wouldn't an uprated timing belt be acurate enough?
And what the torsion of the camshaft does to the timing.. I don't know exactly but it seems to me that the position sensor reads a certain position, and cause of the resistance valvetrain the camshafts are torsioned, and so the actual lift is altered in compairison to the crankshaft position.
But does relocating the position sensor to the crank solve this problem?
the camshaft is still torsioned. And when you read a certain position off the crankshaft the valvetrain is still altered due to torsion.
Or am I missing a part?

I know that sometimes the splines of the cas sensor ware out, and cause timing problems, but I like the idea of 360 slits and an optical sensor.

I'm not trying to prove you wrong! but I'm interested in the pro's and con's of the CAS

Keep up the good work tho
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Old 21st November 2006, 11:54 AM   #236 (permalink)
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The CAS is a superb bit of kit. Giving the cam poition at every 1deg.

The problem is you can't reliably use the camshaft to know where the crankshaft is unless the cams are driven by anti-backlash gears. The cambelt flaps around all over the place giving inconsistant readings. Thus the spark occures at different times of the stroke. Not good.

You don't really need such a fine resolution for position.

All you need is for the cam position to say when #1 is approaching TDC, then for the crankposition to say when to fire. This is usually a time(calculated from engine speed which will also be inaccurate if taken from the CAS) after the last tooth count.
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Old 21st November 2006, 12:22 PM   #237 (permalink)
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Quote:
Originally Posted by SteveN View Post
I was talking about this exact same thing with MattJ the other day regarding the AEM, i hope he sees these posts, it explains what i meant.
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Apparently Japanese Performance Magazine voted my car the second best Nissan of 2008 - Not bad for a car that hasn't had an engine and gearbox in it since September 2007!
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Old 7th January 2007, 01:12 PM   #238 (permalink)
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With you on the valve guide issue here R32 Combat! There's no lateral forces involved with bucket valve setup... Most of my experience is on bikes, stuff like GSXR 1186cc - 162bhp @ wheel / BUSA 1420cc T4 garret - 350bhp @ wheel. And bucket valves have been used (even rocker and bucket) in bike engines for over 25years. I know the stress's arent the same as bike valve/components weigh 3 times less but then Skyline motor does not rev out to 14,500RPM but I ran silicon bronze guides relieved to port and never had any probs. Valve giudes are designed by manufacture's to survive 100k miles so there made longer for relibility. Very nice thread you've created!!! And good luck with your build matey.


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After examining the valves and seats before and after lapping, the exhausts were in better condition than the inlets and the contact area was larger.

The anti-lag had caused no damage which means we must have set it up well.

As for the guide issue, its not such a problem with a rocker less cam setup like the RB's. Although the cam does slide over the bucket, that can only move up and down. So the only force on the valve is along its stroke.

On the ehaust side, the valves are IIRC sodium filled. If you run a pointed valve guide, the narrowest part must get very hot, which I don't want.
I want the gas to heat as little as possable on the was out, hence flush grinding the guides.
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Old 19th January 2007, 02:16 PM   #239 (permalink)
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As you might be aware, all is not well in the RB30 camp.






There are some under lying issues with a number of areas.

1) The honeing was not plateaued,
2) #5/6 were 0.001" bigger than the rest to avoid expansion seizure which brought the piston/bore gap upto 0.006", this is way in excess of the norm.
3) Possably ignition scatter with the AEM, although not confirmed.
4) I really should have used 98ron fuel(that'll teach me to be tight)

All these are contributing factors to DET.

Next step,
1) Check bore to crank alignment and bore,hone and plateau block to 87mm.
2) Order bespoke pistons. There is nothing off the shelf to use.
3) Fit crank position sensor. I can use the AEM to measure the difference between CAS and crank. Should be interesting..
4) Re-build and try again.


The results are very good(525hp and 560ft/lbs @1.5 bar @ wheels), if only the engineering was good then I would be doing all this..


Last edited by R32 Combat; 19th January 2007 at 02:18 PM.
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Old 19th January 2007, 03:45 PM   #240 (permalink)
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Just read through this whole thread (not planning on an rb30, but there is a ton of great info in this thread). I do not have my ecu yet, but was planning on picking up a PowerFC pretty soon and this CAS issue is starting to eat at me a bit. I think your trigger wheel off the crank pulley is a great idea, but what kind of software will allow this to work in place of the CAS on the cam pulley? Also, does anyone know if there are any plans for someone to market this fix?
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