Gt3071r On Na Rb25

[grim32]

Well i have to start off by thanking Adam very much, he takes the time to do things right and im very happy with the work he done on the tune for me aswell as doing it as he isnt too keen on the wolf.

The motor that i put in the car is a R32 non vvt RB25de but i put the RB20det cams in it.

Another change to the system was putting the standard fuel reg back on and taking off the 2:1 malpassi, i also run a relay on the fuel pump so it gets full voltage.

First up Adam wanted to re route some vacume line and check timing with the light, after that was out of the way tuning began with idle and light load points, hot start then took a lot of timing out of the map so it could be increased bit at a time. Then he started to iron out the fuel map and everything was going well.

As you can see by the graph we didnt rev it very hard as it started pinging. From ignition timing at 9 degrees we were seeing a 10-12rwkw gain with every degree added. We pulled the plugs to find them all different colours, 4 looked good but 1 was a grey and black weird colour and one was pure white so thats where we stopped the tune. The plan now is to flow test the injectors and see how they go as i had them cleaned before they went in but never flow tested them, Adams theory is that it is still making good power with more timing so one cylinder may be leaning out and causing the pinging.

Anyway pulled it off the dyno to find a big oil patch under the front of the motor, seems to be comming out the front cover, guessing the cam seals and it looks like it may be chewing up the timing belt or cam seals by the black fibre gunk it spat out the back of the timing cover, my fault i guess as i did the work there.

End result im very happy and need a bit more playing with it to get it all sorted out.

[Cubes]

Should be good once its all sorted, looks good now.

What ign timing did you end up with at peak torque and peak power?

Any chance of throwing a set of adj. cam gears on it? You can then shift the power curve around so that it makes peak power slightly higher.

[grim32]

Should be good once its all sorted, looks good now.

What ign timing did you end up with at peak torque and peak power?

Any chance of throwing a set of adj. cam gears on it? You can then shift the power curve around so that it makes peak power slightly higher.

I think that run was at 13 degrees but started pinging. When the bugs are ironed out we will rev it a bit harder, probally to 7500rpm if its happy. Could throw some cam gears at it if i find them cheap as im happy with power level now, dont want to ring its neck too hard

[Roy]

What housings are on the turbo?

[grim32]

What housings are on the turbo?

.5ar front, 71mm wheel 56 trim

.63ar rear, external gate, 60mm wheel 84 trim

[StockyMcStock]

the rear is far too small. your massive exhaust back pressure, coupled with a high compression motor is forcing you to run low timing otherwise it will ping. realistically, you could step that up two sizes (rear housing) and end up with maybe 500rpm more of spool time, but a much better motor. otherwise good luck.

[R31Nismoid]

Yeah, i agree. Im a big fan of the .82 for the RB25.

With my GT30, i had similar results as you did Russell, but i had the .82 not the .63

I could run lots of timing to get the thing to get up on it earlier and i was making 270rwkw on 17psi with 17psi in around 4000/4200rpm under load on the dyno.

It also looks like your gate spring needs to be higher.

To me it looks as if your getting some ext gate creep going by the way the boost ramps up and then slows down for the last 2-3psi after 3500rpm.

If you fix that it should hit 16psi a good 400rpm sooner going by what i can see on the graph.

What spring is in the gate now? 7psi is my guess

Keep the R&D going and it should be a nice package.

[Cubes]

Its the 71mm comp wheel so the .82 really isn't needed as its never going to make much over an honest 260rwkw (450fwhp).

Thats around the GCG ball park. The .63 will be fine.

Sort out fueling issue, throw a set of adj cam gears on it and move power around to where you want it.

[grim32]

Yeah, i agree. Im a big fan of the .82 for the RB25.

With my GT30, i had similar results as you did Russell, but i had the .82 not the .63

I could run lots of timing to get the thing to get up on it earlier and i was making 270rwkw on 17psi with 17psi in around 4000/4200rpm under load on the dyno.

It also looks like your gate spring needs to be higher.

To me it looks as if your getting some ext gate creep going by the way the boost ramps up and then slows down for the last 2-3psi after 3500rpm.

If you fix that it should hit 16psi a good 400rpm sooner going by what i can see on the graph.

What spring is in the gate now? 7psi is my guess

Keep the R&D going and it should be a nice package.

The gate has a 1 bar spring but its only a cheap gate silly me should of got a good one first time around

[dead32]

so the car was pinging and you now have an oil patch under the car with the crank seal poped out, blow by?

[grim32]

so the car was pinging and you now have an oil patch under the car with the crank seal poped out, blow by?

I suspect cam seals are chewed out, the catch can was dry so i dout it was blow by and i couldnt even hear the pinging, the listening guy who had his head under the bonnet picked up on it lol

[R31Nismoid]

The gate has a 1 bar spring but its only a cheap gate silly me should of got a good one first time around

Change it then, 400-500rpm for $700 is pretty cheap return on power for a decent ext gate, if you are indeed getting some creep as i suspect

Are you using a boost controller?

[dead32]

grim i had the same thing when i got my car dynoed, couldnt hear any pinging, but the dyno driver (with earmuffs on) stopped the run, llol oh well i guess thats what i paid for.

[Bass Junky]

http://sau.garagespank.com/login.php

Post results here!

[Cubes]

Its interesting Grim32's RB25 runs a 10.5:1 static comp yet it still makes less off boost power than both Abobobs and BassJunky's that also run a higher 4.11:1 diff ratio.

Most likely just dyno differences.

I wonder if the php script alters makes adjustments for the cars final diff ratio.

I should plug in freebaggins old GT3040 .63 int gate vlt housing setup with cams etc..

[BHDave]

But you haven't considered the cams or r34 type vct which make a fairly massive difference.

Thats some pretty good response on the turbo though. With decent boost control it'll be all in by 3500rpm and on a turbo capable of high 200rwkw thats pretty damn good. I'd expect it's all in by low 3's on the street though? As you can't run silly boost levels due to the high comp i think a step up in exhaust housing could be beneficial, but i'd look at some 264 cams to improve the breathing of the engine before that.

[QRI05E]

One thing i can assure, is that Adam knows his ECU's... he is an expert with Haltec and Power FC! He dynoed my car and was very happy with his service... Did you check out his wall of fame? lol 100 or more dyno sheets

Great result btw!

Regards,

Sarkis

[grim32]

Change it then, 400-500rpm for $700 is pretty cheap return on power for a decent ext gate, if you are indeed getting some creep as i suspect

Are you using a boost controller?

The boost controller i have is run through the computer but is turned off as i dont think i need any more boost at the moment

[grim32]

At the moment im just going to fix what is wrong with it and then see what results i get. Maybe cams and exhaust housing changes may come in the future but i guess ill just have to wait and see as i dont want to push this motor too hard and im quite happy with the power its making.

My car usually spends most of its time in the garage getting worked on , now my aim is to drive it more than i work on it so i really dont want to break it again just yet

[grim32]

Ok just went to have a play with the car and found a few litres of oil under it, pulled off the timing cover and found this......

Lucky this engine is still alive.

Ok the motor is a stock r32 rb25de, timing belt and cams out of my rb20det are the only mods to the inside.

My mate done the timing belt for me then i was told i should change the cams, no worries pulled it down and put it back together exactly the way it was. I turned the motor over a number of times by hand and noticed the belt moving forward and if i turned the motor the other way the belt would go back. I called my mate and he said that the big washer that goes on before the crank pulley would stop the belt from moving.

Motor started fine and drove well. Higher up in the rpm, maybe above 4000rpm it started to make a whine noise like a boost leak. I wasnt driving the car hard so i didnt worry about it, checked all the hoses and all looked fine so i thought i would wait and find it on the dyno as it didnt seem to have a vacume leak.

Some hoses were changed at the dyno then i didnt hear the noise again so i thought that was the end of that, turns out it wasnt, in the second pic you can actually see it worn a hole on the backing plate.

Now my question is, what have i done wrong.

Would it be possible to bend a crank as when i undid the crank pulley bolt it had been lock tighted in and i had to use a big hammer and that hitting bar thing that breaks bolts.

Would i not have lined up the cams properly, i just bolted them in and they spun easily.

Well i guess you learn by your mistakes.

Any thoughts are appreciated.