D356BUD's RB25 engine build

[d356bud]

Well I had the block and crank sent to the machine shop. The block got bored out .02 over and decked and I had crank collar put on the crank.
Parts on the new engine:
86.5mm Wiseco Pistons
Eagle H beam rods
ARP studs for main, exhaust, and head
Tomei valve springs
N1 oil pump
Cometic HG
RAW Crank Collar
Lower Temp thermostat

The rest of the parts are from before.

Here are a few pics of the block before I started working on it.



The underside after I installed the rods and pistons







Some of the work I did tonight




Well I'm going to be putting my HX35w back on it. I'm going to be using the stock manifold. I've bored the internal wastegate hole out to its max. I've got everything fabricated for the setup.

I have a bit of a dilemma on my hands. I have a chipped rb20 ecu right now that worked on the stock internals before I rebuilt it, I don't know if it would be safe to even run that seeings that it was bored and I decreased the compression to 8.5. I've left everything else the same such as my z32 maf, 740cc injectors, etc... The other choice would be to run the power fc that I have. I bought one back a few months ago(the price was to good to pass up). I'd have to tune it.(thats something I really don't want to do) Either way I go I have to have everything ready and broken in by the beginning of Sept. for the meet at the Dragon.

[Sil240]

I'm definitely not an expert.
I would think just a .020" over bore and decreased compression you wouldn't have any problems.
You won't be able to take advantage of the mechanical advantages you now have, but you should be safe.
If you raised compression, then I would definitely tell you to re-tune.

Throw a wideband on it and just keep an eye on your log info.
Maybe throw in a SAFC for some small adjustments to your tune.

[d356bud]

Well I have both a wideband and an SAFC, I just have to hook them up

[l0nestar]

Go with a Z32 ECU and NisTune, or use the PFC you already posses. (Do you have the Hand Commander or DataLogIt? The Z32 ECU will allow you to chip or tune, and still retain VTC vs the 20 that does not.

What wideband do you have?

Don't even mess with the SAFC.

Where is your nearest dyno & reputable tuner? Check with them to see what they think / what they prefer to tune on.

[d356bud]

Well I already have a controller for the vct so there would be no point for buying extra stuff. I have the innovate lc-1 wideband and the hand controller for the power fc. Also there aren't any tuners around where I live. Closest one is 4hrs away.

[Sil240]

I see your from Binghamton, how far away is Albany or The Bronx??
I know there are tuners there

[d356bud]

I live in Binghamton but the car is in PA. Its several hours away. I think more like 3 from my garage in PA to Albany. Well I did some math the difference between my current displacement and stock is 29cc's. Thats the part I'm worried about. I'm not worried about the compression I've run a couple of engines on lower compression pistons before and just got lower hp numbers

[Sil240]

I dunno.
But your engine is only a air pump.
So now it is a bigger air pump.
But it is a MAF setup and it will measure the air of the coming into the system.

[d356bud]

That's exactly what I was thinking.

[RustspecS13]

From what I've been reading from reputable tuners, timing is mostly related to your cylinder diameter. Bigger cylinder = more timing. So your motor with lower compression, and bigger pistons, is likely very safe.

Sounds like your running the exact same setup as you did before with just a ported waste gate and forged internals. Ideally yeah you would get a retune, but I'd bet with marginally bigger pistons and lower compression you'd be 100% fine.

~Alex

[Carl H]

you should be just fine rocking out the rb20 ecu...i'd honestly add the wiring in for the idle switch and sell the pfc for a nice set of cams which kill off the vtc.
vtc gets kinda lame anyways when you start making more power...it will actually hinder you once you get to a certian point.
the lower cr but slightly increased displacement shouldnt be too big of a problem, chance are the map you've got on your 20 ecu (assuming it ran well and made power) will be just fine to run the engine in on and boost on, almost willing to bet you'll end up adding a few degrees of timing under full boost due to the cr change.

[d356bud]

The chip thats in it now came from you

[d356bud]

Did a few hours of work tonight. Got rid of the old HX35w and put the new rebuilt one on. Installed the manifold and created an oil restrictor and all done standing on one leg, lol.

[Carl H]

is that a nitrous jet, lol.
IIRC that chip should be just fine for your setup, make sure the idle switch is wired in else it will run...odd.

[d356bud]

ya I found a link on the DSM forum for making an oil restrictor for the Holset turbos.

http://www.dsmtuners.com/forums/article ... urbos.html

[Sil240]

+1 to that idle switch.
Caused me problems for a long time

[julio]

ya I found a link on the DSM forum for making an oil restrictor for the Holset turbos.

http://www.dsmtuners.com/forums/article ... urbos.html

What size did you go with? I used a .078" restrictor and turned out to give me perfect oil pressure with an N1 pump. 15psi at idle and no more than 60psi at speed.

[d356bud]

same size, I had a .068 but I used a 5/64" drill bit to bore it out

[d356bud]

I put my old ACT clutch back on.

Well I got my engine finally in the car. I'm really hoping I can finish putting all the s*** on it in time for the dragon. The only real obstacle I have left is making the exhaust so it fits. The rest of the stuff that I need to finiah like vac lines, drive shaft, radiator, and fluids are all trivial.

[d356bud]

Well I can start the engine but it throws a code for knock sensor. I have correct fuel pressure, no ticking from the engine, etc... Could there be a small chance of it being that idle switch?

[Carl H]

if its throwing a knock sensor code then chances are the knock sensors are not connected.

[d356bud]

I even put the stock ecu on it(it ran really rich, but still ran) and It game me a knock sensor code. I'll check it thurday and make sure that the sensors are connected.

[Carl H]

it may be that the sensors arnt fully seated...its very hard to get the plugs onto the sensors but a little bit of oil on the orings normally allows them to snap into place.

[R32ONP]

yea check that the plugs are actually pluged into both knock sensors....if theyare then check knock loom (its seperate) for continuity and check the sheilded wire

[d356bud]

ya I'll check them Thursday

[d356bud]

Well I checked it and its on there. I'm getting an high voltage from the front one. Its giving me .6v and its not the wire going to it, I checked the continuity. Its also higher than the other one when the ignition is on .34v compared to .1v

[Carl H]

sounds like a bad knock sensor, will force the ecu to run in knock maps all the time.

[R32ONP]

replace the knock sensor and see what its saying after that.. my understanding is that its a piezo crystal inside..maybe it is cracked and or stuck in one position ( telling the ecu its knocking)

[d356bud]

Well I finally got around to try fixing my knock problem. I haven't really touched it since I knew it was going to be ready for last years met at the Dragon. I noticed last week that one of my plugs for the knock sensors was broken. After looking for a new replacement pigtail and coming up short I was able to fix the old one. Now I'm no longer a member of NRRBA . The car idles perfectly.

[l0nestar]

woot!