roba

Pic's on the link in my first post, double checked the numbers on the turbo def correct. Do you kno what they mean ie is the 706451 related to the compressor and the 5015 related to the turbine??? The compressor inducer on my turb is def 61.4mm, not sure on the turbine wheel diameter tho...

Hi, as some of u maybe aware ive had trouble getting my RB30DET / GT35r to make deecent power. http://www.skylinesaustralia.com/forums/Rb...l=missing+100kw I still have high exh manifold backpressure, and im making approx 450hp at the fly at 1.5 bar. Anyway Ive noticed something strange with the turbo CHRA#... my turbo CHRA number is 706451-5015 looking on the garrett parts list this doesnt match the GT35r turbo. the 706451 matches but the 5015 matches a GT3076r http://www.turbobygarrett.com/turbobygarre...am_May_2007.pdf any ideas why this is? what is the number on yr GT35r Cheers rob

Ahh, version 1.07 from memory, yes it required a change of the trigger disk. (recent versions do not) Ive finally got a bit more power but its still not all there. Ill run through when has happened since last post. 1. Dealer changed some settings and ignition modifiers to stabilise spark timing (on different car as we are not in the same city) 2. Spark timing on my car STILL changing with revs, so took car to dealer and after 3/4 of day found the problem to be the spline in the cam that drives the CAS was missaligned causing a nasty vibration. Aligned as best we could but still a 2 deg shift at 3000-3500rpm. 3. Fixed a few issues - seated injectors 4mm deeper, sealed a hairline crack in the inlet manifold that was causing crap idle, replaced dead alternator. 4. The big one, checked the cam timing again with degree wheel and found in and ex to be 7 deg out. Retuned (road) with correct cam timing and got another 15% duty cycle, now up to 65% on denso 720cc injectors at 21psi. Therefore approx power 280 - 300kw. The exhaust manifold backpressure is still 2 to 1. ie over 40psi which i really need to sort out. Next plan is to try another turbo wastegate setup - as soon as i can find a donor... Unfortunately speedo drive has sheared off and gone through the gear box so ill have to sort that first. Choice. Ill let u kno how i get on, any ideas on the backpressure would be great. cheers rob

Hey Has anyone had their speedo drive shaft shear off??? I have a rb25det box in my r32, ive used a r32 gtr case and shaft and fitted the rb25det gear on top (red). It has worked sweet for the last 2000 odd km's but has recently sheared off and lodged its self in my box. Gotta pull the box apart and fix the drive, I dont want this to happen again... Did i do something wrong??? The shaft has some wear, may have been expanding when warm causing the other end to shear? I had also been doing some tuning and seen several off the clock speeds... but speedo didnt go right back to zero so shouldnt be a problem aye? cheers

What is the correct tightening torque???

http://www.skylinesaustralia.com/forums/in...t&id=144591 i dont think that the injectors being set back into the open in each runner would cost you 100kw from low atomisation. Chasing up any and all possiblites at this stage... If injectors spraying onto the walls and dribbling into the cyclinders then I would assume that would make a huge differance to combustion??? why dont you sell the top feed, then buy some side feed injectors that are suited to your rail. Problem solved? Looking into it... but will have to find injectors and plugs, and new fuel rail then modify to suit my fuel system etc will be easier and cheaper to mount mine a little better. just after a few ideas on how other people have done it... cheers rob

Im using top feed injectors in a rb25det (side rail) inlet plenum. Ive had a few problems making power and im chasing up any potential issues. http://www.skylinesaustralia.com/forums/Rb...l=missing+100kw One that has come up is the injectors dont sit deep enough into the flow causing inefective atomisation. Has anyone else come accross this? Please post pic of yr setup. cheers rob.

cheers, I blew a wad too. - of money. Wont point the finger at the autronic just yet as my tuner may have used some incorrect settings, but hes pretty experienced so i doubt it.

Just a quick update, finally got the ecu back with the starting problem patched up (some interference/noise from the idle controller so the dealer just turned it off) Anyway run it up on the dyno again checking the timing manually found it to be drifting around 10 deg or more under load. Called the dealer to check all settings ie sync falling edges etc. Could not get it stable. Quickly tried a untuned motec - dead stable. So ecu is back with dealer. Has anyone had problems with these TF electronics plug in autronic ecus before ??? Cheers rob

I love this colour, I dont think its factory. Anyone know what it is???

cheers for the advice just looking at the dyno plot, the torque curve drops off at 4100 rpm where as the manifold pressure doesnt riset above boost pressure till 5000rpm how do you explain the torque dropping off before the pressure (restriction) rises in the manifold. Im not trying to discount anyones theories - i welcome them. But i would like to be certain before spending anymore time and money on this bloody car. cheers rob

Could you explain this a bit further dangerman, i dont really understand what you are getting at. But i tend to think the restriction is in the turbo/gate setup. But i cant see how. ps. the pressure drop is only 1-1.5 psi

1 Knock sensors not connected 2 O2 sensor not connected Correct me if im wrong... these are not accepted/required on this ecu ie. no knock function, and o2 only required for closed loop running for fuel economy. Dont think its the exhaust as it 4 inch right through with no cat (not rqd in clean green nz) but i will be checking the back pressure when i get the ecu back. cheers

Dyno Plot uploaded, first plot is manifold pressure vs boost pressure. It is not the cam gears, they were checked and adjusted during the tune. Yeh its a TF electronics unit, I dont know what the fault is but hopefully the dealer who is fixing it does. 230208_dyno.pdf

PS. Is there any way the computer could be causing this? I dont see how, but my engine builder (not tuner) likes to swear and curse about 'that bloody computer' (autronic SM4 plug and play) cheers rob

Thanks for your offer 6boost. unfortunately i havnt checked posts for a while Based on the backpressure we were pretty sure it was the manifold but not 100% as the power droped off just before the backpressure rose... Built a new one anyway, based on a well proven design Bolted it up, drove, and hello, NO CHANGE. (I now own 2 manifolds:( Decided at this stage to rule out and cam timing valve float issues so fitted Kelford RB20DET 272 - 9.35mm cams and uprated valve springs... some change but minor. Computer is away getting fixed as had a ramdon issue causing the injectors to wildley pulse when the key was turned on - flooding the engine and making it impossible to start. When i get it back I will pressure test manifold and exhaust. So I still have something causing high back pressure issues killing flow... *exhaust is 4" straight through *turbo is GT35 0.82 rear what am i missing??? this is driving me nuts!!! will post dyno sheet cheers rob

Spent a bit of time on the dyno this morning, checked / adjusted a few things incl cam timing and gained 10-15 rwkw at low boost. Still couldnt find any significant power, so checked manifold back pressure, ended up being 27psi compared to boost pressure of 11psi. Everything starts to happen about 3700rpm - torque falls through the floor as manifold back pressure goes through the roof. My manifold fabricator is going to replace at no cost, ill let you kno how we get on in a few weeks... ps Thinking of a tomei solid lifter kit so i can run some 272deg cams, do I use RB26 cams with this kit in my 25 head ? Whats the max lift i cn run without machining...? cheers rob

without a dyno plot its just guess work - dyno booked for sat, but i dont see how that will help me diagnose the problem it will just prove the power is down, -Im hoping to get from this forum a range of ideas and comments, esp on the ex manifold design as im sus on its design, but in saying that - its got to flow better than a standard one, and plenty of mid/high hp cars use them dude, i recon its your cams.... if you were to upgrade the cams youd be looking at the power level you are expecting. - Plenty of people have made good power on these cams. but will be rechecking the cam timing sat. What didnt you use the RB25 complete head? What happens when you use more boost? No more power? -The head came with some locally reground cams that had a terrible profile, so i threw in some rb20 ones i had. -Didnt add more than 1.3 bar as didnt see much point, from 1 to 1.3 bar was not much improvement. just wondering on what the manifold cost you? paid for all fabrication work in one go so dont kno exact cost - prob around 800-1k. cheers for the comments, hopefully i can get more of a clue to whats going on after the dyno run on sat.

A couple of pics...

I have finally got my RB30 going despite a few stupid faults with the plug in autronic. Problem is at 18psi its not making the expected power - (around 330-360 rwkw). By my seat of the pants estimation (feels similar to last engine) it feels no more than 250rwkw - this is backed up by the injectors which are 720cc and running at 55% duty cycle. The specs are: CP pistons / eagle rods rb25 head with rb20 cams GT35r turbo .82r 115mm gtr style intercooler Jun style inlet plenum custom exhaust manifold 4" exhaust 44mm wastegate - plumbed back autronic SM-4 ecu I guess the restriction is between the inlet plenum and the turbo. namely the cams or the exhaust manifold. I have used non vct RB20det cams which i believe are similar specs to RB25det ones . 240in 240exh 7.8mm lift. The cam timing was set using the RB30 pdf which states, lobe centre angle (in) = 115, and lobe centre angle (ex) = 120 The exhaust manifold is a custom 3into2into1 design. The fabricator has had great results for 4 cyclinder engines using this design but im not sure he has used this design on other skylines. I have installed a pressure sender in the collector and it gets up around 30psi at full boost. (18psi) Any ideas would be greatly appreciated.

FYI Solved the problem. It was the timing loop in the factory wiring loom giving the faulty readings. We hooked the timing light onto coil No. 1 and bingo - sweet as. cheers rob

tried ray, he's stumped as well...

All maps set to zero. Put scope on CAS, apparently ecu is not changing anything. This is real fustrating, its been a few years in the making and I just want it to go... [

It keeps on advancing well past 30deg with revs, have not reved to 6000rpm tho - didnt think this would be a good idea. changed the CAS, no differance.

I am trying to get my RB30/25DET running using a plug in Autronic ECU. We have it running ok, BUT went the engine rpm is increased the ignition timing increases correspondingly. ie idle 0deg, 3000rpm 20deg idle 10 deg 3000rpm 30 deg the timing keeps advancing further the more we rev it. It is not mechanical as all new belts, idlers, etc, and has run on std ecu ok. A friend is helping with the tuning and he thinks its not the ecu as he has the idle map, and timing map, and ignition mean angle all the same - 10deg i think. He has tried different cyc trigger edge, digital angle filter, sync, and a lot of other shiit i dont understand. nothing changes - still advances with rpm. the CAS has had a 6 pulse gear tooth sensor installed by our local NZ distrubutor - who also has no idea why it it doing this... any ideas would be greatly appreciated cheers rob