rob82

Was there any method to your madness or is it just something that has been taken from the high horsepower Jap cars? Was there any other coolant system mods like pump impellar redesign or slowing of the pump? I'm guessing that it cant hurt but most GTR's are running that much full load timing that the exhaust coolant ports aren't copping that hard a time. However some of the RB30 with decent street setups are running low timing numbers that will most likely put more stress on the coolant system. I guess what I'm saying is that the higher the average cylinder pressures the less the ignition timing numbers and the more stress imposed on the coolant system.

Just wondering if anybody has tried additional coolant bleeds in any of the RB range? More specifically the RB26 - there is three coolant plugs just under the coils just awaiting - not sure if its a high point but there will be a shitload of localized heating in those locations.

The difference in boost potential between bubba's setup and your is about 750rpm. As in it take your car 750rpm longer to get to the same boost point using the same ramp rate and very very similar setups at WOT. Usually boost on single turbo charged vehicles comes on allmost exponentially with rpm but yours just seems to slowly come up to pressure. Hence why I would be looking for a leak. All you have to do is plug the intake pipe -ie pull off you pod filter and jam something in the end and then pressurise the intake and listen for leaks. Failing that I would then look at dropping the exhuast to see if there is a restriction.

The boost takes a bit to come on, you havn't got a boost leak have you?

What about a Bushcur 20G - twin scroll titanium wheels - blah blah - have seen around 260-270awkw on an evo9 with all the mods. I would also be keeping the compression (10.5:1) in it as well so your average power would be better - might make it a bit nicer mid coner. I would also look at reducing the overlap as well.

If your getting an ignition missfire then your average 02 sensor reading will look as though it going lean as there is excess oxygen in the exhaust system. Your tuner/dyno operator should know whether or not it is running on less than 6 cylinders above 5000 during a dyno ramp and if it is then I would be willing to bet you have a missfire thats showing a lean condition. In which case you looking for a bad coil or plug or connector blah blah blah. The heat range of the plug at 10psi will not be of concern. My thoughts are that if you cannot support at least 0.9mm gap at 10psi on a std rb25DET then its time for new coils!

Anybody seen what they can get out of GTR 440cc injs on 4bar base pressure? By my calcs you would be able to see almost 350rwkw.

You will need the drains as the bolt seperation is different beween the standard turbo's and the GCG turbos - everything else unbolts from the std turbos and bolts into the GCG turbos.

The cam sensor isn't used in ignition firing events or injection timing events - in most high end ecu's so if the sync drifts a bit its no big deal. Its usually only used for the initial sync.

So you needed two degrees less timing with larger duration camshafts??? Did you advance the crap out of it or something?

Good in theory but the more modified an engine becomes the more likely it is that this system wont work. Most highly modified engines are too dynamic for the system to learn once and try to reuse that value again at that same point for the amount of accuracy your talking about. And it kind of allready exist - have we not heard of LTFT and STFT's?

Trent how much tractive effort did it pull on the AUtoSalon dyno? Was it being run in 4th or 3rd? We have a few XR6T's putting out around 500rwkw DD in 5th gear that are pulling over 11000N of tractive effort and I can absolutely agree with you that soft compound tyres will rob the horsepower figure masively.

I've heard thats what some people do but I just thought there is a genuine fix - what is the film that they use from factory? Besides I wouldn't know which color to use !

I have checked that it works electrically but I didn't check if it was gummed up - 1000rpm from closed to full duty seems about right to me. You can physically see large clearances around the throttle plates.

Has anybody had issues with RB26 throttles not sealing. I'm having problems reducing idle speed below around 1500rpm with the bypass screw wound right in and then timing being set to 10btdc cam timing factory setting - I know its not a tune issue. I have used all new std gaskets and know there is no vacuum leaks. I have pulled the throttle bodies off to find that they have been cleaned up. Now apparently there is a sealing film that they use from factory and it may have been rubbed off. Does anybody know how to seal them or are they now a throw-away item?

The ATEN USB to Serial is what we use at work and I can tell you that it works for absolutely everything.

Have never seen that hapen before. Why are you reving your RB30 bottom end to 7300rpm??? What cams and are they dialled in?

The standard boost controller will work much better than an AVCR anyways. Besides the fact that the boost cut is set about 2psi above 4-5psi of desired boost that they run standard so your better off just getting a reflash!!!

Do you drop a cylinder when the lifters float?

The beauy of speed density systems on factory ecu's is that their model for charge temp (the actual air temp of the air in the engine) is mapped over g/s of airflow (which without a map sensor is based on rpm and MAP itself). If I was you I would rescale the maf down to a suitable size to get good airflow figures from it. I would also place a intake air temp sensor into the manifold. I would then get a micro with at least four ADC. Three input chanels for MAF, MAP and IAT and one ouput for a psuedo MAF votlage for the PFC. YOu then will need to be able to map/tune the intake air temp sensor over MAF voltage as a multiplier of AIRtemp to give you a final Charge temp. ie MAF Voltage Air Temp Multiplier 0 2 0.5 2 1 1.9 1.5 1.7 2 1.5 2.5 1.3 3 1.1 3.5 1 4 1 4.5 1 5 1 The actual charge temp of the air in the engine is the "Air temp multiplier" times the current IAT sensor reading. The above mulitplier curve will need to be tuned based on the position of the IAT sensor. You will also need a multiplier of RPM as well to take into consideration the difference in voltage of a linear MAP sensor vs an expotential MAF sensor. I would then apply the ideal gas law and see what happens. My advice is that unless you have a good understanding of microprocessor design and implimentation and a good tuning back groudround then DO NOT DO IT!!

Mate I would be steering clear of the ITB Harrop manifold unless you plan on reving it (which it doesn't sound like your are). THis thing is just screaming for a harrop blower tho. The new HH112 blowers are good for around 400rwk on 12Psi of boost on a stock 5.7L with a flat torque curve. We fitted smallish cam (220@50thou) to a 5.7L Elfin Streamliner - we then proceeded to supercharge it with the old harrop charger(HA122??) with about 10psi of boost it made a touch over 500rwhp in a chassis that wieghed a touch over 1000kg's. Let me say this thing is a missile and its so tractable because the torque curve is flat.

As has been already said - different dynos - different days and neither run with corrections applied or in a industry standard "Shootout mode". So liitle can be made from these graphs and its pointless to try to draw conclusions. Why dont you try logging AFM voltages on the same day in the same conditions with pods and then with the standard Airbox.

Sounds like your going about it the hard way. Quad input NAND/AND logic gate hooked up to any of the four shift solenoids. When it shifts the logic goes high or low or whatever way you design it and triggers an ignition retard event within an aftermarket ECU. The only problem with this is that the troque reduction needs to be more with higher requested torque levels and I dont know of any commercailly available ECU's apart from a bosch motorsport ecu that have this amount of detail and by the sounds of it you dont have a spare $20k.

Anybody know if it uses the factory CAS triggers?

Your an idiot - making a boost leak will only compound the problem. You must have been the load your mother was meant to swallow!