My Rebuild And What I've Found Out.

[Abo Bob]

This is my thread for the things I find out as my engine gets rebuilt.

I blew the ringland between the 2nd and 3rd rings in no.6. All the other pistons were pitted etc.

The rods are indeed the same as GTR rods (anyone want to buy the set I bought in case they weren't )

It appears that the head uses quite a different design than previous RB25's. More details to come.

It uses a RB26 style oil pump but retains the short drive on the crank like early RB26's and all RB25's so I'm going to try to source a Jun crank collar.

At this stage I'm thinking of 8.8:1 compression ratio to give me a bit of safety with the tune but hopefully not losing too much in the way of response or power. I've had everything from 8.2 to 9+ recommended to me which has been confusing.

Removing the engine wasn't too hard with the help of Duncan and Ed. Thanks guys.

I think that's it for now.

[ed]

9:1 comp ratio!

you know you want to!

[Robo's]

How did you blow it?

[PHATR32]

8.0cr and 90psi boost

YOU know YOU want it!

[Cubes]

Whats the final power goal Abo Bob?

Think of Optimax Extreme.. This would no doubt give you a little buffer running a high static comp with some decent boost.

[Bass Junky]

What was the stock compression of the R34 Neo?

[Oosh]

9:1

[Abo Bob]

Stock compression wasn't measured.

Blew it - http://www.skylinesaustralia.com/forums/in...topic=87738&hl=

Can't rely on the availability of Optimax 100 just yet.

Bass junky with the same setup to what I will have (ie cams and turbo) could only put 0.9 bar into his engine but got great power there so I thought that with a little less compression I might be able to squeeze in the extra boost to make up for lower CR plus a little more for happy days.

Some pics to come.

[Bass Junky]

I spoke to GCG today about my turbo maxing out at 14 psi.

He said that he's never heard of one making that power at that boost.

He said they were most efficient at about 17 - 18 psi.

I'll get to the bottom of this. Maybe RacePace are just the worlds best tuners.......

[Cubes]

Abobob,

Its definitely a concern, go with an 8.5:1 to be safe.

On that note I believe Freebaggin is still running the stock 9:1, he hasnt mentioned the use of a thicker headgasket.

He's running an internal gate .6 something GT3040R. I remember back when it was first fitted, ~270rwkw on 17psi, he has since fitted 256duration cams and cracked 300rwkw. Its not on an optimistic dyno either.

It's not a NEO. Maybe the Neo has some issues with cam timing or something silly? I'm not 100% sure on the NEO VCT, is it constantly variable or??

Edited November 22, 2005 by Cubes

[Abo Bob]

I will be fitting the Tomei Tybe B Poncams which are 260 degrees both sides and 9.15 lift. This will lower my dynamic compression ratio a little and hopefully make it a little more resistant to detonation.

I don't know anything about the VCT. As for cam timing, all I know is that adjustable cam gears have been proven not to work on the NEO.

Bass - maybe GCG are making better turbos than they think because I had 228 at 0.85 bar, no cams and auto. One dyno operator reckoned that was close to 250 in a manual although I think the R34 auto seems to be a less lossy transmission than some. It makes me wonder if Sydneykids GTT had a turbo with different specs (ie GCG are doing them different nowadays) or that it had a thicker head gasket in place before he saw it because with the same cams it takes an extra 0.5 bar to make not that much extra power.

And let's not forget the reputable workshop who told me not to expect more than 220 at the limit of the turbo. Methinks some people have an agenda.

Here are some photos my engine builder sent me last night.

[Bass Junky]

Agenda? Definently.

SK's 265rwkw figure was recorded in Shootout mode which at 250rwkw reportedly gives about 10-15 rwkw higher figure.

Until the next dyno day on a shootout dyno, I'll not know what my car makes in shootout.

I have the same cams Abo Bob.

Here's my power curve.... It's fat.

[Rolls]

Agenda?  Definently.

SK's 265rwkw figure was recorded in Shootout mode which at 250rwkw reportedly gives about 10-15 rwkw higher figure.

Until the next dyno day on a shootout dyno, I'll not know what my car makes in shootout.

I have the same cams Abo Bob.

Here's my power curve....  It's fat.

<{POST_SNAPBACK}>

Thats a nice curve, must be pretty damn quick on the street.

[Bass Junky]

It's nice!

[silva33]

Bass,

Id like to compare your car to mine as i pulled 244 rwkw in my R33 HKS 2535 on 14psi (no cams), on the Racepace dyno.

It would be interesting to see how they compare!

[Bass Junky]

DYNOCHARTSORBAN!

[satanic]

So you guys really rate the GCG hi-flow as the best option for the 34GTT? I have an auto as well and probably chasing 250rwkw for the time being. How much extra kw will this turbo give just by itself I'm currently on about 200 so I don't know. If it's a long way off, I might as well get a different turbo.

[Cubes]

Silva33,

Whats your diff ratio and tyre size. These should be compared in order to compare a dyno chart.

[silva33]

Cubes,

im running 245/40/18, and stock diff artio

and mods are:

PFC

FMIC

HKS 2535

Nismo Fuel Pump

Turbo back Exhaust, (3inch front, Apexi N1 Catback)

14psi

Sorry the dyno graph is really bad, ill ahve to scan it in soon

244.bmp

[Bass Junky]

Those lines are oth almost identical!!!!

I'm keen on seeing your ignition maps!

Mine are very conservative