Sydneykid

Yep, a Canter turbo (as made by Mitsubishi) is basically the same as a Trust (as made by Mitsubishi) T88. :jk:

Personally, I don't know that I would be setting the rpm limit at 3,000 rpm. What happens if they drive it around bouncing it off the rev limiter all day? Maybe more damage than leaving it alone. If I was that suspicious of the workshop, I wouldn't take my car there to get the gearbox fixed. I would go somewhere more trustworthy.

Hi geno8r, firstly I have never used an SAFC to add fuel, the standard ECU always overfuels. So you tune the SAFC to remove fuel to increase power. Secondly, the ECU knows how much boost via the map sensor, it knows how much throttle via the throttle angle sensor, it knows how much airflow via the AFM etc etc. So when you run low boost the ECU handles the different fuel; requirements. The SAFC has very little to do with it. Thirdly, the later SAFC11's have 2 steps in their programming for different throttle angles. So you can modify the AFM signals at up to say 70% throttle differently to what you can at 100% throttle. This is great for improving fuel economy up to 70% throttle and then increasing power over that. I have posted a good summary on how SAFC's work, do a search it is worth a read. Hope that helps

We use Jun. :wassup: And don't over tighten the cambelt, I am sure that's where a lot of wear comes from, so beware.

Hi, I have posted this table a few times, but just in case you missed it. Rule of thumb for Air Flow meters RWKW & Engine BHP ------ ---- OD ---- RWKW ---- RWKW ---- BHP ------ BHP No of AFM's ---- ------- 1 -------- 2 -------- 1 -------- 2 RB26 ------ 65 ------ 149 ------ 299 ------ 271 ------ 474 RB20/25 --- 80 ------ 226 ------ 453 ------ 376 ------ 683 Z32 ------- 80 ------ 255 ------ 511 ------ 415 ------ 763 Q45 ------- 90 ------ 302 ------ 605 ------ 479 ------ 890 Please note that this is only an indication, every engine is different and tuning makes a big difference. For example, I have seen a GTR equiped with twin Q45 AFM's make 1100 bhp. RB20/25 and Z32 AFM's are all 80 mm OD, that's outside diameter, not ID that's inside diameter. There is no real difference between an RB20 and an RB25 AFM. On the other hand the Z32 AFM is calibrated differently, so at the airflow the RB20/25 AFM shows max voltage, ~5 volts the Z32 afm is only showing ~4 volts. This means when the airlfow gets higher the Z32 can still show voltage increases to the ECU. Q45 (Infinity) AFM's are 90 mm (OD), so they have the same calibration advantage but they are also larger in diameter for less restriction. Hope that helps

Have you been to GCG and spoken to them face to face? I have never found a new turbo cheaper anywhere else. Fiorget about web page prices, too much politics there, go to the shop or call them on the phone.

As usual BBQ, my first suggestion would be to disconnect the boost controller and let the wastegate spring control the boost. If the boost still climbs then its a hardware problem and playing with the software is a waste of time.

Hi Amaru, this is what we would do on a race car; 1. Check calliper bolts 2. Bleed brakes, make sure to change all the fluid 3. Scuff the rotors and the pads with emery cloth, enough to brake the glaze 4. Run them in again, don't stop with the brakes hot 5. Do another lap of the block slowly before you stop Hope that helps

Hi XR8eater, "Over boost protection" is what it is know as, but it is really "excessive airflow protection". The ecu makes this decision based on what the AFM is telling it. So boost really has nothing to do with it. The fix is an SAFC, voltage clamp, Boost Cut Defeater or better still replace the std ecu with a Power FC. Full fuel cut is the next step in engine protection programming in the ECU, but you get "retard" and "rich" first. Here is a post I prepared earlier that may help .................................................. .................................................. ... Hi guys, a quick, simplistic explanation of how an SAFC works might help... As the airflow into the engine increase, the AFM records this as increased voltage that the ECU sees. What an SAFC does is sit in between the AFM and the ECU and take the voltages from the AFM and either increase or decrease them depending on what you have programmed the SAFC to do. By increasing the voltage, this tricks the ecu into pumping in more fuel, you do this when the engine is running lean. By decreasing the voltage, this tricks the ecu into pumping in less fuel, you do this when the engine is running rich. The next bit is hard to understand unless you remember that the standard ecu does not supply fuel in direct proportion to the afm voltage ie; 4 volts is not twice as much fuel as 2 volts. Engine rpm, boost and throttle position also help the ecu determine how much fuel to add. It has been my experience that RB25's run a little lean down low in the rpm range (Nissan do this for fuel economy and emissions) and a lot rich up high (Nissan do this to protect the engine). So I have to increase the voltage (using the SAFC) up to around 3,000 rpm and decrease the voltage over 5,000 rpm. The real problem is in the 3,000 to 5,000 rpm range as the engine comes on boost. They really need lots of fuel very quickly in this area. This can mean that you need to increase the voltage (that the ecu sees) over 5.1 volts to get the right A/F ratios. The ecu then goes into engine protection mode, rich and retarded (sounds like a girl I knew once). Past that rpm you can start leaning it out as it runs too rich, so the voltage needs to be turned down under 5.1 volts. The ecu sees this as the engine not needing protection mode any more, no more rich and retarded. So you get good performance up to 3,000 rpm, then sluggish from 3,000 rpm to 5,000 rpm and then good performance from 5,000 rpm and over. The SAFC may not help this, in fact as explained above, it can in fact make it worse if the tuner is not switched on to this stuff. With bent afm voltages, the ecu (tricked by the SAFC) also fires the ignition to suite the airflow it THINKS the engine is getting. This is not a good thing as you generally end up with ignition that is too far advanced in some rpm ranges. The poor tuner has to juggle the SAFC settings, so that the A/F ratios are OK, the ecu doesn't get into rich and retard (engine protection) mode and the ignition timing is not too far advanced so as to cause detonation. My experience (I am not a good tuner) has been that this is full of compromises, sometimes you just can't win and have to reduce the boost level a bit to get even a reasonable compromise. Keep in mind that this explanation is very simplified to make it fit in a reasonable space, the rpm's used are rough guides only and every car is different. Hope it helps (and makes some sense).

I could work it out exactly, but fourth gear in an R33 GTST is around 28 kph per thousand engine rpm. So 7,000 X 28 = 196 kph.

Ooops GTR :headspin: I missed that, same deal just jack it up all round.

They are lighter, being aluminium hats. The heat transfer to the wheel bearings is much less, and CV's if it's a GTR. Since they are semi floating, they align better to worn pads than rigidly mounted rotors. It all adds up to better car and braking performance over time, not better braking instantly. Hope that makes sense

Hi, you need 2 guys, one to listen and the other to drive, even better with 3 as you can have one listener on each side of the engine bay. Jack the rear of the car up, chock the front wheels, stick it in gear and load it up against the handbrake and the foot brake. That's usually enough to make boost. You can only do it a couple of times as the brakes get quite hot. Once you get the general location, you can pin point it with a set of mechanics headphones or a stethoscope. Hope that helps

What gear is that in? Third or Fourth?

Hi guys, I have seen 8 X RB's with ceramic turbine failure, 2 X GTR's, 3 X R33 GTST's, 2 X R32 GTST's and 1 X R34 GTT and none of them had any ceramic anywhere other than in the cat. There wasn't any in the turbine cover or in the dump or in the engine pipe, it was all in the front of the cat. Blown there by ~200 cubic metres per second of ~600 degrees celsius exhaust gas, that's better than my Stihl leaf blower. :wassup: Maybe if you were spinning at the time and the engine turned backwards, you might get some sucked up into the manifold. Of if you where starting the engine at exactly the time the ceramic failed and it coughed and ran backwards. :headspin: I don't think so, Tim

Mine didn't have the screen either, I'm up for one at t he right price.

No lag, only if the power increase = the increasein capacity of the intercooler and its pipework. eg. If you put a 100% larger intercooler and make a 30% increase in power, there must be more lag. Boost is irrelevant. Airflow makes power I wouldn't go over 10psi - if you wanna know why, do a search, there are plenty of threads on this subject.

I can't see the retainer that goes on top of the valve, bolts are missing as well of course. The fittings on top of the vacuum/boost chamber are also missing. I can't see the marking on the spring but it looks like a light one, what boost are you intending running? You may have to change the spring as well. Check the diaphram for holes while you are at it and have the valve and seat ground for sealing as it will leak if you don't. If you can't get the stuff you need, let me know as I have one on my car and could do with some spares.

Hi Steve,

The most common problem is cam timimg. It is sooooo easy to get wrong. When you are bolting down the camshafts, a number of the valves have to be opened by their respective camshaft lobes. This has the effect of turning the camshafts to the point of least resistance (by the valve springs). If you are not watching, it happens unnoticed while you are tensioning the cam bearing retaining bolts. Or when you are bolting on the pulleys. Or when you are tensioning the cambelt etc I have seen this a number of times, the easy pick for exhaust cam timing is the CAS. It ends up all the way in the adj slots to get the ignition timing right. Or you get the reverse, guys mark the CAS and put it back in the same place. But the cam timing is say one tooth (7.5 degrees) out. They don't check it with a timing light, so they never know that both the camshaft and ignition timing are both wrong. If you mark the CAS and put it back in the same place and check the ignition timing with a timing light and make sure it is in the same place, then you know the exhaust camshaft is in the right place. The inlet camshaft is little easier to check as you only have to worry about the camshaft timing itself. What I do is mark TDC on the inlet camshaft with a white paint pen and mark the cam bearing correspondingly. I just make sure the white marks line up at all times when I am assembling. You can of course do the same with the exhaust camshaft, it adds another dimension of checking. When I talk to guys who have had trouble, I ask 3 questions; 1. Did you mark TDC on the camshafts before assembly and check it after assembly? 2. Did you mark the CAS before you removed it and did you put it back in exactly the same place? 3. Did you check the igntion timing with a timing light before you started and did you make sure it was back in exactly the same place when you finished? If I don't get all three positive responese (and I can see the marks), then that's where I start looking. Next is other problems with the engine, quite often you find people try to do three or four things at once. Fix a problem, add a new part and swap the cams all at the same time. My suggestion is always, get the engine running perfectly before you start. Do any other maintenance and servicing and make sure the engine is running perfectly before you start playing with camshafts. I have run out of time, so I will make another post later. Hope this was of some help.

Hi Matt, it's not quite as simple as just changing the followers to solid, you also have to change valve springs, valve guides, followers and the valves themselves. There is also machining to the cylinder head to get the valve spring tension correct. It's a fairly expensive proposition.

That's a good point Steve, I can't remember actually measuring an RB20 valve spring. It is written in the data book at the machine shop, but they may not have been standard valve springs. Have you measured a standard set? I don't think it matters though , if there is enough valve spring tension with the standard RB20 cam to control the clearances then there will be enough with RB26 cams. You have worked on more RB's than I have, what do you think the problem is?

That would be a great model to start off with, but they don't comply here. They are not really a high performance import, so DOTARS wouldn't let it off the ship. We only get RB25DET 4WD, mostly auto's, RSFOUR is my model. I haven't seen a fully complied 260RS yet, but there are RAWS working on the paperwork to get them complied. Some pictures would be good

It's a 260RS :aroused: (or equivalent), I was worried :Paranoid: I was thinking that I was going to be happy with a 13 and this guy has an 11!!! :headspin: But I don't feel so bad now

So, let's assume Luke is correct about the camshafts, the extra (anti rattle) ramp on solid cams makes the cams longer in duration when used with zero clearance. The longer duration creates excessive overlap, lowers the vacuum and the engine won't idle. All quite logical. But (there is always a but) whilst it might be true to say RB20's have hydraulic followers and therefore have zero clearance, that does not mean that the valve opens as soon as the follower hits the (anti rattlle) ramp. The follower is in contact with the camshaft lobe all the time and held there at the engine's oil pressure, at idle say around 30 psi. The oil to feed the follower is supplied through the gallery in the cylinder head with the port designed to line up with the matching hole in the lifter at zero lift. The ports are around 2 mm in ID. This means for ~0.7 mm of camshaft lift the ports have enough overlap for the oil to freely flow between the follower and the head. The engine oil pressure is at 30 psi, so as long as the pressure from the valve springs is lower than 30 psi, oil will flow from the cylinder head to the follower. But as soon as the valve spring pushes back at more than 30 psi the oil will flow from the lifter back into the cylinder head. That's how hydraulic followers work, they cycle to keep the clearance at zero, so no rattle and maximum valve opening. RB20 valve springs have about 80 lbs per inch at the seat, so as soon as the (anti ratttle) ramp tries to lift the valve off the seat, the valve spring pushes back at greater than oil pressure. As long as the ports and the holes line up, the oil will flow from the follower back into the cylinder head. This means the valves won't open for around the first ~0.7 mm of lift. That's more than enough to get past the (anti rattle) ramp. Luke posted This means that the hole in the follower and the port in the cylinder head line up at zero lift and things happen (oil flows) as per the standard RB20 cams and therefore as per the description above. Bottom line, I have no idea why some people have success and others don't. But I am going to stick those R34 GTR cams into the RB20 as soon as they arrive.