Sydneykid

Tuning with a PFC pretty easy, the base maps are not too far from the right shape. All up the R32GTST took about 40 minutes to tune. My method for A/F ratio tuning; 1. Do a power run with zero correction, took about 8 seconds. 2. Closely look at the A/F ratios from that power run. Took about 3 minutes 3. Pick a range where the A/F ratios were fairly constant but very crappy, which in my case was 4,000 to 4,500 rpm where they were just under 10 to 1. 4. Do another run and used the dyno load to hold it in that rpm range and apply correction until the A/F ratios were between 11.8 and 12.0 to 1. Make sure there is no pre-ignition with those corrections. Took about 15 seconds. 5. Make careful note of that correction, about 5 points made 1.5 A/F ratio diff. Then make guesses for the other load points following the A/F ratios from the first power run. Took about 10 minutes. 6. Do a power run, and tidy up the A/F ratios as required. Took about 40 seconds. 7. Finished. The real trick is #5, noting how much correction does what to the A/F ratios and where the various load points are on the map. That reduces the time under load on the dyno and it is very fast loading up corrections off line. Doing it in during a power run is tricky and much slower, plus it heats up the engine rather quickly and is not good for the transmission (no 160 kph airflow to cool it down). Ignition timing is even easier, stick the ears on and advance it up until you hear it ping then back it off. Do that at around 5 or 6 load points, then (off line) extrapolate that over the map. It's always a bit tricky at boost building time, so we have to spend a few minutes in that area getting the timing just right. One power run to log everything and then maybe a little tidy up here or there. That's the real advantage of a PFC, the base stuff is already there, so you don't have to approach it like EVERYTHING needs changing. Most of the tuning on the race team cars is done by our dyno guy, he has a "feel" for it. What takes me 10 minutes to get 99% right, he does in 2 and gets it 100% right. :fart: Hope that helps

What the fuel pressure like when it goes lean?

Tuning the DFA is piss easy, it's only a voltage changer after all. All up mine took 20 minutes to tune. The method; 1. Do a power run with zero correction, took about 8 seconds 2. Closely look at the A/F ratios from that power run. Took about 3 minutes 3. Pick a range where the A/F ratios were fairly constant but very crappy, which in my case was 4,000 to 4,500 rpm where they were just under 10 to 1. 4. Do another run and use the dyno load to hold it in that rpm range and apply correction (lower the voltage signal to the ECU) in "Run" mode until the A/F ratios were between 11 and 12 to 1. Make sure there is no pre-ignition with those corrections. Took about 5 seconds. 5. Make careful note of that correction, about 5% made 1.5 A/F ratio diff. Then in "View" mode makes guesses for the other load points. Took about 5 minutes. 6. Do a power run, and tidy up the A/F ratios as required. Took about 20 seconds. 7. Finished. The real trick is #5, noting how much correction does what to the A/F ratios. That reduces the time under load on the dyno and it is very fast loading up corrections in "View" mode. Doing it in "Run" is tricky and much slower. I had no wild changes in the standard A/F ratios, just very predictable Nissan rich and retard mapping at higher than standard airflow levels. That's why the DFA (and SAFC) works so well on Nissans.

Hi Ian, what cams did I tell you to buy? :innocent:

Last time I looked there were 8 different brake callipers used on R33's, which one do you want measured?

Hi Rob, on the race cars the ATTESSA pump runs most of the time. After all it's just a hydraulic pump, and the hydraulic pressure it produces is used to load the clutch plates via solenoids. When there is no need for hydraulic pressure, the solenoids bypass the flow and if that time is long enough, the pump eventually turns off. On the later systems (R33/34) the solenoids hold a residual amount of pressure (even without the pump running). This means quicker response when 4wd is needed (ie; no delay while the pump builds up pressure). This is one of the reasons why R34 GTR's don't have the initial power oversteer that an R32GTR has. I am not sure what they meant by "leave the pump on" :confused: The reality is the bypass solenoid (controlled by the ECU) will prevent any load on the clutches if the pump is running when it is not needed. The pump has almost zero load, hydraulic fluid simply goes around and around, just like the fuel and the fuel pump does when the engine is idling. If that went on for a few hours then the hydraulic fluid would get pretty hot, but that's about it. All good info, but tell us what was "the 4wd issue in my stagea" that you "just fixed"? And how did you fix it?

Sometimes we all have to leave God's country, if only for a short while

Hi Lumpy, is that for the R33 or R34 PFC? What is the version number?

You haven't posted up the boost trace:cheers:

Can I respectfully suggest uoi have a look at the Pipercross panel filter available from their Australian agent http://shop.fabre.com.au/store/products/it...em113.inetstore Part Number PX-PP1128 Superior product at around half the cost.

Typical MAP sensor driven ECU problem, when the inlet camshaft timing change occurs there is a change in manifold pressure, which the MAP sensor driven ECU incorrectly interprets as a sudden increase in airflow. So its adds some fuel to match the non existant extra airflow, hence the richness. An AFM driven ECU KNOWS that there is no sudden increase in airflow, because it actually measures the airflow, it doesn't GUESS the airflow. This can be quite tricky to fix, as similar MAP load points occur at the same rpm with different throttle positions. It will need careful tuning for those other "matching" load points.

RB30 conrods are 6" centre to centre (152.5 mm) Before you ask, RB26 conrods are 4.783" (121.5 mm) That's where 31 mm of the extra 38 mm in the height of an RB30 block is used The other 7mm is in the 11.3 mm of extra stroke and the 1.3mm balance is the piston deck height difference. PS, when we are changing the rod stroke ratio of Chevy, we don't bother with a handfull of mm's, as you would get between RB20/25/26 cranks. It simply isn't worth the effort.

The same guy who tuned your R33 :idea:

Help, please help......... I keep getting PM's and emails from people wanting pictures of the redrilled engine mounts for an RB30 to lower it in the engine bay of an R32/33/34. Please if you have them, can you send them to Cubes so he can put them in the RB30DOHC guide. Thanks:cheers:

My 20 cents worth... We have found that at sustained high rpm (5500 rpm plus) far too much oil gets trapped in the cam covers. What we do; 1. Block off one of the oil supplies to the cylinder head. 2. Enlarge the return passages to the sump 3. Fit an external drain from the rear of the cylinder head to the sump 4. Always run a filtered catch can (filter on top and filled with stainless steel wool) 5. Never run the PCV back into the inlet 6. Use large diameter hoses from the cam covers to the catch can to keep the air flow velocity down 7. Don't rev the engine on mineral oil, use a heavy grade synthetic (Castrol Formula R 10W60 in our case) 8. We always run a winged and baffled sump with one way doors on all circuit cars. Drag cars have a simple vertical extension with a surge plate at the rear and the front.

= 2,516 cc's Which is pretty much the same as an RB25, so there is no capacity break that isn't already covered. I don't understand why the hell you would want to use an RB30 block. It's bore is the same (86mm) as RB25/26 but it is 38 mm taller, that is to accomodate the extra stoke and the longer conrods. You aren't going to use the extra stoke with an RB20 crank and none of the RB conrods would be long enough to bring the piston to the top of the block, or even close enough to mill the block. So you would have ot get special conrods made. You could build a 500 bhp RB30 for how much that would cost. Simply put, the RB20 crank has the shortest stroke and the RB30 block is the tallest, they just don't go together.

13,000 rpm out of an RB30 :wassup: :wassup: :wassup: :wassup: In whose dreams :bs!: :bs!: :bs!: What is the capacity break you are aiming for? Using an RB20 block---- RB20 standard = 2 litres RB20 with max (safe) bore = 2.3 litres RB20 with max (safe) bore and RB26 crank = 2.4 litres Using RB25 block--- RB25 = 2.5 litres Using RB26 block--- RB26 = 2.6 litres RB26 with max (safe) bore = 2.7 litres Using RB30 block--- RB30 = 3.0 litres RB30 with max (safe) bore = 3.1 litres None of those options (2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 3.0, 3.1) require using an RB20 crank in an RB30 block, that makes no sense at all.

There seems to be a couple of threads on this subject. This is as good a place as any; 1. Why do you want a "high rpm option"? 2. Surely a "high power option" is better? 3. On a $per HP basis the RB30 is waaaaay cheaper than the RB20 4. Then there is the average power, which is what gives the time down the 1/4 5. Regardless of the engine involved, high rpm is expensive to build and expensive to maintain, buying a higher diff ratio is cheaper. 6. Buying off the shelf high rpm parts for an RB20 is even more expensive, if you can actually find any. You would have to get many things hand made, and that's going to be even more expensive. 7. BHP = torque (in ft lbs) X RPM / 5250 So 10% more torque at 10% lower rpm = same BHP 8. The reality is 10% more torque is 40+% cheaper to get than 10% more RPM Sell off the RB20's and buy an RB30 bottom end and an RB25DE top end, spend the same amount of money and the car will be faster, easier to drive and more reliable. PS; this is not knocking RB20's , great engines, but the economics say there are better alternatives for your purposes.

Which one did you build, the DFA or the IEBC?

The only way changing fuel pumps makes a difference to A/F raios is when the previous pump was not holding pressure. The tuning was done to allow for this drop in pressure, now there is no drop in pressure, so the tuning is rich. If the igntion timing (maps) were right on the old pump, they will be right on the new pump, just the A/F ratios need to be retuned. Clutch slip during boost build (rpm) is very common, time for a new clutch, drive gently until then othwise it WILL let you down.

Coils: 10.5mm?? If that is 10.5 turns Spring rate is 142 lbs/inch - 2.5 kg/mm

Yep, tuning on the flat can see warpspeed. Much better to tune it on the track, although I have a couple of long hills near my place that give enough load in 2nd and 3rd gear. Looking forward to getting the new LM1, so I can do it on my own using the logging channels:cheers:

Race tyres are usually only sold by the tyre manufacturer's designated Motorsport outlets.

Yes:cheers:

281 lbs/inch - 5 kg/mm