Harey

I think turbo_xtrail needs to find out from his tuner if this is the case. I wouldnt have thought a few psi below 3 bar would be this severe. Would be great to hear what fuel pressure is in the rail under load as well.

Yeah I think this thread has stalled till you find out some more info.

The more info you provide us the more helpful we can be. If you barely get out of second gear drifting then I would suggest your target of 300rwkw is too high for what you want out of an RB25. I would drop it down to 260-270 and go for response. I think a GT3071 or GT3076 with a 0.63 housing would enable you to really use the power drifting. Then you can throw a 0.82 housing on if you want the headroom for bigger power later on.

I dont understand this, your saying the GT30 comes on harder than a GT35? Yes it will come on sooner but harder???

yes I think you are fussy

Exactly, this is a perfect example.

The way I read Elite Racing's post was that because the fuel pressure was dropping with boost that it couldnt run properly. Yes it is not ideal to have the fuel pressure dropping but when tuning you just add more fuel in to compensate (as long as the fuel system can handle it). Yes there is a fuel supply issue here which tuning cannot replace.

Who said there is not enough fuel pressure in the rail? We are saying there is less than if it didnt have a turbo on it. 39psi is only a bit less less than 3 bar. Injectors are flow rated at 3 bar of fuel pressure so its hardly a "dodgy" fuel pressure. I agree with hard wiring the fuel pump, but converting it into a return fuel system is a big job and from the sound of it not something the owner is prepared to do. 2 things to do turbo_xtrail: check the fuel pressure and the fuel pump voltage under load. Have you read about the kennebell boost a pump? http://www.kennebell.net/accessories/boost.../boostapump.htm I am not necessarily saying to get one, but it does show you how important the voltage to the fuel pump is.

Why cant you tune it out? Even if he runs it on 10psi, its still the tune making it run properly. The tune doesnt care if theres 39psi, 52psi or 65psi as long as its the same as when its tuned.

Yes that would be the best solution, but its far from simple. 39psi can be enough fuel pressure if the injectors can flow enough fuel (also if the fuel pump can flow enough). Increasing the voltage to the stock fuel pump could also be enough. It doesnt look like it needs a lot more fuel. Whether you do this by running dedicated power cables from the battery or you use a voltage amplifier.

Dont give up yet http://autospeed.co.nz/cms/title_Modifying...36/article.html Are you running the stock fuel pump? Have you ensured your fuel pump is getting max voltage?

That is very strange, I would be quizzing your tuner and saying why dont you put more fuel in?? As said above, your ecu needs to compensate for the lack of effective fuel pressure. I ran a turbocharged car with 43psi of effective fuel pressure, so I dont see why you cant on 39psi. You just need your ecu and injectors to compensate.

Quote from here: http://www.aa1car.com/library/returnless_efi.htm " A returnless fuel injection system, by comparison, manages fuel pressure a little differently. Instead of using a spring-loaded vacuum diaphragm in the regulator to change fuel delivery when throttle opening and intake vacuum change, the regulator in a returnless system operates at a constant pressure. The older return-type systems need to vary fuel pressure to maintain the same pressure differential across the injectors when intake vacuum drops. When vacuum drops, the regulator increases pressure to compensate. But in a returnless system, this isn't necessary because the line pressure is always the same. So how does the system compensate for changes in engine load and vacuum? A returnless system uses the Powertrain Control Module (PCM) to regulate fuel delivery. A fuel pressure sensor mounted on the supply rail allows the PCM to monitor fuel pressure. When pressure in the supply rail drops as engine load or speed increase, the PCM compensates by increasing injector duration (on time) and/or the operating speed of the fuel pump." 1psi of boost basically reduces the fuel pressure by 1psi. Therefore, if the fuel pressure going in is 52psi, under 13psi of boost, the fuel rail pressure will only be 39psi! The only way to combat this is for the ecu to get more out of the injectors, however the injectors can only flow so much fuel at 39psi. I am assuming your tuner cant put in any more fuel, therefore if you dont want to change the fuel system design I believe you need bigger injectors.

They will fit both sedan and coupe. I measured the springs up last night: - Inside diameter: 72mm - Thickness of spring: 12mm - Number of coils: front 7 and a bit, rear 6 and a bit Now I just need to work out how to calculate spring rate from this. I dont think sydney kid is on here anymore. I was thinking about reading through that thread and looking for springs of similar dimensions to get an idea on the spring rate. I showed them to a suspension place and they said one of the rear coilovers had a leak. I will sell them all for $200ono seeing as one of the rears has a leak. The other 3 are fine.

I am not sure what power you are making so its hard to say. Obviously in your case 3" even at the end of the exhaust is too much of a restriction. In this case I would propose that maybe a 3.5 inch dump pipe at the front is only just flowing what you are giving it. Possibly a 4" dump would increase power and response. And yes you could leave the 3.5" cat back system as the exhaust gasses have cooled down by then.

Yup I agree but surely at some speed I will want traction Anything on the edge of traction and it axle tramps harshly. Cold tyres and 4k rpm clutch drop and no axle tramp hahaha

Chris fitted them Yeah I am going to drop it back there and let him do his thing.

Bump $500!!!

Pineapples were fitted yesterday, the rear end feels tighter and better BUT still axle tramps like a WHORE!!!! ARGGHHHH!!! I spoke to Chris and he said to bring it in for another look as it might be something like engine mounts or transmission mounts. Sydney Kids list of axle tramp causes: 10% of the time it’s tyre pressures, the sidewall flexes and releases. Try pumping the tyres up and see if the axle tramp stops and/or gets less. done, made no difference 5% of the time it’s worn subframe bushes. Fitted pineapples and still axle tramps 25% of the time its drive shaft angle, the car is TOO LOW and the angle of the universal joints are winding up the drive shafts. If your car is lower than 345 mm centre of wheel to guard on the rear, then try raising it up. 350mm on the rear, so not that low. 60% of the time it’s incorrectly matched spring and shock damper rates. The rebound (extension) damping is not sufficient to control the oscillations of the springs. Standard springs with worn shocks get this problem. BRAND NEW aftermarket coil overs get this problem where the spring rate is too high for the shocks to control. I have brand new bilstein shocks all round I am starting to run out of ideas!

Dude do you have some meditation music on in the car because you look so calm and relaxed as your front wheels are lifting in the air!!! Hahahaha

which gear? boost reponse in rpm varies greatly between gears

Price drop $600!! Price drop as these are the japanese version.

Good question, I will do the sydney kid calculations on them tonight!

Hi all, I am wondering how much I should sell my Ohlins coilovers for an R34 GTR or GTT? They are both height and dampener adjustable. They are in great nick. Any help appreciated!

Hi, I am selling a set of Genuine Ohlins Coilovers for an R34 skyline. They came off an R34 GT-T but the part number also fits the R34 GTR. See ohlins website below: http://www.ohlins.com/Our-products/Automot...ts/RT/NIS-MI10/ They are height and dampener adjustable. They are in great condition as per the pics. Price: $700 for both front and rear. Located in Melbourne put can post at owners expense. Jeff 0400648813