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car already has r33 gtr fuel pump, fmic, after market ecu and full exhaust. everything else is bone stock. i plan on swapping a stock rb25 turbo as i have been told its a small cheap upgrade. and then i would like to turn the boost up to 1bar. what other modifications are needed at 1bar? fuel injectors? maf? FPR? i'm new to these motors so any help/tips/tricks would be helpful.

and before i get flamed too bad, i have used the well known "search feature", and didn't have any luck.

Edited by hale1320
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ok i was under the impression that with the rb25 turbo that i would be safe at 1 bar..... the main thing im worried about is tuning, there is no dyno on this island so i cant just go get a tune. and to be honest i dont know what a "dual vane bb one" is... i am guessing dual vane has something to do with the impeller, and bb means ball baring? im sorry for my ignorance....

no standard turbos have steel turbine wheels or dual vane. they all have ceramic turbine wheels which are their weakest points. having said that they're fine at 12psi on rb25s so 13-14psi on a rb20 should be fine. with 1 bar (25 turbo) and a safc tune my old 20 made 250rwhp, which is about the limit of the standard injectors.

You will defently need a tune, have being running my r32 with the 45v2 turbo (rb25 series 2) @ 14psi had to drop it back down as it was pinning in the upper revrange. also ive noticed the boost comes on about 4500rpm, mind you i only have exhaust, dump, boost controler fitted ATM.

If you wont a cheep ecu, look at www.nistune.com matt (the owner) might be able to put a diffrent map in it that would work for you, just ask him. I know he did this for me when they first started. had put a custom cam in my RB30 along with a few other mods and stock ECU wasn't running properly.

Are you in the carribean?

If your on a small island, your fuel is going to be of poor quality and inconsistant. So you will be pushing the limmits as it is with the stock turbo, running stock boost and mods you have. These cars were designed and tuned from factory to run on 95+ ron fuel. In the heat, even stock cars ping a little on 95 and you should really run it 98ron fuel.

By running a larger turbo, with more boost and no tuning (especially timing maps) you will just kill the thing on poor quality fuel.

There is no 'cheap' way to re-tune these engines...

SPEED COSTS MONEY!!!

If you can't get anyone to tune the thing, why do you have an aftermarket ecu?

My advice would be to send your ecu to an experienced tuner, have the maps changed to suit your modifications and fuel type... Then get a water methanol injection kit and run it all the time.

Good luck

Justin

I'm in Okinawa japan so getting good quality gas is not a problem. Lowest quality around here is 95. I have no idea why this car has an aftermarket ecu as it is still running stock boost.... It was in the car when I bought it. I just want to make a fun daily driver and maby go slide it on the weekends. I just don't know where to start tuning these cars. There is no dyno's on this island that I know of. Can I just get a good wideband and buy some decent software to get the tuning close enough to be safe? Im new to skylines but not to the performance world.

I beg to differ my 33 in nz had one and I currently have 2 of them in my driveway and one on my rb20 I can post pics if you like

do the impossible, post a pic of a 100% stock turbo with a magnet sticking to the turbine wheel

You don't need a dyno but you do need a wideband meter. Are you sure there is no tuner on Okinawa? Who made your ecu - when you say aftermarket is it an apexi pfc or just a chipped stock ecu like a mines?

Leave the mines ecu in it... they usually run a fair whack of timing and a heap of fuel all up and down the map...

I'd get a knock meter and a wide band... (just borrow them if you can)

Grab a nismo adjustable fuel pressure reg/ fuel pressure guage and slap on a r33 or even better a r34 rb25 turbo with the rb20 actuator (10psi). If your in Japan, there 'have' to be better options for turbo's though.

Run the base timing back a couple of degrees, bump the base fuel pressure up 10psi then get out on the track for some testing. Start rich, lean it off at the pressure reg as needed, then push some timing back into it as you can, up to stock- without knocking/pinging/detonating.

As long as your running quality fuel, you have slightly rich mixtures, you have enough timing but not enough to ping/detonate- and you can keep your air intake temps/oil temps under controll.... you'll be most of the way there.

Or find a hks 2510- or similar, get an axpexi AFC or similar and get a bit better result.

Have fun

J.

Don't boost the 25 turbo much past 11psi, they def break their turbine wheel at that boost.

It won't last long at 1 bar...

On a RB25DET yes, on a RB20DET no, I ran my old RB20DET with a RB25DET @ 1bar all day long, all night long, all day on the skid pan. I'm pretty sure the current owner still has it set on 1 bar till this day.

RB25DET produce more exhaust flow hence when boosted the wheel "might" just come off, on a RB20DET it will produce less exhaust flow.

I really need a coffee, my explanation isn't that clear

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