R33 Rb30 Conversion

[r33_racer]

Shane if that bloke told you not to do the oil return from the back of the head....hes an idiot. We didnt do all the modifications as SK had stated in the guide, because my old man is so farking worried about oil starvation for the top end, well bingo we have oil problems houston! We did the oil return from the back of the head, not full size though, blocked off the rear feed and put a 1.5mm in the front when it should have been a 1mm and we didnt oversize or shape the return holes to the sump. So now we have to run a pump from our 4.5l catch can to the sump to help get the oil back into the motor, so we dont lose it everywhere.

Not saying yours might be like that, but ours is and i believed SK and my old man didnt and now until we pull it down for rebuild and more mods, we have to put up with that problem with our bandaid fix. I hope your setup doesnt yield the same problems as ours.

[R32 TT]

Anybody has experience with HKS 2530's (or Garrett 2860r -5's) on an RB26/30?

Aiming for sooper-dooper response (e.g. Mines car) and say 550-600hp at the flywheel.

I want to keep twin low-mounts. I know they are perhaps 'small' for the 3 Litre. Intended use is for a weekend street car - bit of street - lots of short track/hillclimbs/motokhanas etc.

Achievable? Anyone actually running this combo?

[benm]

That's the combo I want, just need the bottom end done.

[R32 TT]

That's the combo I want, just need the bottom end done.

Well mine is nearly done.. so time to actually buy the Turbo's!

The question of going between 2530's and GT-RS has been a question I just can't answer for the last few months... and I'm getting very close to D day...

I'm still leaning to 2530's... also keeps the power down away from the 700 odd that the GT-RS will most likely make (= break things)

[shanef]

Shane if that bloke told you not to do the oil return from the back of the head....hes an idiot. We didnt do all the modifications as SK had stated in the guide, because my old man is so farking worried about oil starvation for the top end, well bingo we have oil problems houston! We did the oil return from the back of the head, not full size though, blocked off the rear feed and put a 1.5mm in the front when it should have been a 1mm and we didnt oversize or shape the return holes to the sump. So now we have to run a pump from our 4.5l catch can to the sump to help get the oil back into the motor, so we dont lose it everywhere.

Not saying yours might be like that, but ours is and i believed SK and my old man didnt and now until we pull it down for rebuild and more mods, we have to put up with that problem with our bandaid fix. I hope your setup doesnt yield the same problems as ours.

Michael, ive got full confidence in what john recommends, and i think it could be different if i was only running an RB25 head, not sure though. Time will tell though.

Anybody has experience with HKS 2530's (or Garrett 2860r -5's) on an RB26/30?

Aiming for sooper-dooper response (e.g. Mines car) and say 550-600hp at the flywheel.

I want to keep twin low-mounts. I know they are perhaps 'small' for the 3 Litre. Intended use is for a weekend street car - bit of street - lots of short track/hillclimbs/motokhanas etc.

Achievable? Anyone actually running this combo?

Matt dont be soft, get them GT-RS's and you wont regret it!

From the figures SK has been stating, the RB30 will generate 20% more power at the same RPM as an RB25, so i wouldnt want to run the 2530's as they'd be, "too responsive"

[Cubes]

From the figures SK has been stating, the RB30 will generate 20% more power at the same RPM as an RB25, so i wouldnt want to run the 2530's as they'd be, "too responsive"

Don't be concerned. Select turbo's for your power goal and go with that. 300+rwkw isn't going to get going before 3500rpm minimum anyway.

[R32 TT]

Don't be concerned. Select turbo's for your power goal and go with that. 300+rwkw isn't going to get going before 3500rpm minimum anyway.

Hey Cubes, I'm not sure what you're saying:

Do you mean Don't be concerned about the response? ie Go for the GT-RS since I won't see anything below 3500rpm with either combo?

Or do you mean Don't be concerned, if 2530's make the power goal I am after then just get those.

And how come you say I won't get them going under 3500rpm anyway? To exaggerate for a second - if I put GT-SS on a 3Litre (not that I would), wouldn't you think I'd see full boost under 3500rpm?

If I manage to get 2530's on near to full boost by 3500rpm and go to 7000rpm and make 550-600hp I think I'll be a very happy camper - but maybe that's a little wishful...

Matt dont be soft, get them GT-RS's and you wont regret it!

tempting...

so i wouldnt want to run the 2530's as they'd be, "too responsive"

Seriously, do you think they would be 'too responsive'? I'm used to a supercharged V8 which is more or less instant response and you just control that with your right foot. I would have thought it would be great?

I'm not going for fuel economy here...

[Cubes]

Hey Cubes, I'm not sure what you're saying:

1. Do you mean Don't be concerned about the response? ie Go for the GT-RS since I won't see anything below 3500rpm with either combo?

Or do you mean Don't be concerned, if 2530's make the power goal I am after then just get those.

2. And how come you say I won't get them going under 3500rpm anyway? To exaggerate for a second - if I put GT-SS on a 3Litre (not that I would), wouldn't you think I'd see full boost under 3500rpm?

1. Thats it... Don't be concerned with too much response as its not going to be insane supercharger style response.

2. To be honest I'm not familiar with twins on a 3ltr but I wouldn't expect you to feel a hard punch below 3500rpm for over 300rwkw. It appears you can pull roughly 600-700rpm or so off the spool of an rb25 or rb26.

[shanef]

Seriously, do you think they would be 'too responsive'? I'm used to a supercharged V8 which is more or less instant response and you just control that with your right foot. I would have thought it would be great?

I'm not going for fuel economy here...

Personally, yeah i do. I think they'd be on boost 24/7.

What we need is, is a test bed so we can compare turbo's. I've been thinking about teeing up one of the garrett suppliers to help me test different turbo's and get some results. Same engine only thing that gets changed is turbo's. Otherwise all we can do is speculate.

[ossie_21]

Does anyone know cost wise, how similar would it be for rebuilding an rb25 as compared to an rb30 conversion?? There is a chance my block won't be able to be used for a rebuild, so a conversion is a possibility for me now.

[Cubes]

Once you drop the rb30 in you will see that you don't need to accelerate it up on boost to leave traffic.

Go for a drive in a rb30det and you will see what I mean. Even with a small turbo its VERY easy to control spool as the torque of the motor lugs the car around very well and simply doesn't require you to crack open the throttle.

Whats wrong with boost 24x7 anyway? Put your foot down and its off.

If it makes the power you are after whats the point of running a turbo's that flow 700-800hp worth of air when you only require 500-600. Its a lot like over clutching a car.

Remember the whole idea of the rb30 is average power. If you don't want boost being made earlier and have the car acelerating off idle at a faster rate stick with the rb26.

[Cubes]

There's a bloke thats done a 2.9ltr stroker. So close enough to 3ltrs.

http://www.skylinesaustralia.com/forums/in...t&p=2396511

He's running GT-RS's, as you can see its no where near too responsive (4500rpm) but sounds quite linear and a reasonable package for the power being made.

I put bigger injectors in and the car ended up making 406rwkw @ 18 pounds on pump fuel. Any more boost and it only picked up small amounts of kw and started to heat the air, not sure if the turbos are maxed out or if something in the induction setup is causing a restriction... not sure if my cooler is big enough. I've got another dyno sheet but its done in shoot 8 insted of shoot 6 so the torque figure is different due to the different ramp rate?? ( i dont know much about dynos). The power curve looks identical, just goes a few kw higher... To drive, the car is nice and broad and controllable in power delivery,pulls well from 3000 rpm and hard from 4500 through to 8500rpm...

Ive two more cranks almost ready to go, and more started for those that are interested. Please PM if you are intersested, so we can discuss options. It can be set up with std rods, or after market, 21mm or 22mm pins. My car will be on display at Adelaide auto salon, as will a 2.9l short engine. As usual any questions, comments or ideas just shoot

[Sydneykid]

Well mine is nearly done.. so time to actually buy the Turbo's!

The question of going between 2530's and GT-RS has been a question I just can't answer for the last few months... and I'm getting very close to D day...

I'm still leaning to 2530's... also keeps the power down away from the 700 odd that the GT-RS will most likely make (= break things)

Based on my experiences, 2530’s on a 3 litre would be like 2510’s on a 2.6 litre, which was a very popular selection for a road/circuit GTR. Highly responsive, without feeling too choked at high rpm (7,000 rpm or so). You could easily get 1 bar at 3,000 rpm at WOT, but if you don’t want/need boost then, don’t open the throttle so much. I very nearly went for a pair of 2530’s on my first RB30, but the old T04 came up at a good price.

I would really like to see an RB30 with 400 rwkw using 2530’s, it would be a real high average power weapon. Keep in mind that 2530’s are used on the re-released R32GTR Z Tune, which uses an RB27 with a 264 inlet cam and a 272 exhaust. The 272 exhaust indicates that maybe they used the longer exhaust duration to smooth out the boost hit. Which is a trick you could use on an RB30.

cheers

Edited September 11, 2006 by Sydneykid

[Bl4cK32]

Personally, yeah i do. I think they'd be on boost 24/7.

What we need is, is a test bed so we can compare turbo's. I've been thinking about teeing up one of the garrett suppliers to help me test different turbo's and get some results. Same engine only thing that gets changed is turbo's. Otherwise all we can do is speculate.

Well your wrong. Boost is controlled by the right foot. Im running a rb20 highflow on mine and its a simple matter of keeping off wot to control how much boost is made.

I can put my foot down and run whatever i want ie, my ebc is set to 16psi, but i cant run that much as my coil packs are shagged, so i can go say 1/2 down on throttle to get to 0.5 bar which will still pull to redline.

I agree with cubes, choose the turbo to suit the power u want, not just get a gt35r (or larger) cos thats whats recommended on a 3lt motor.

[Adriano]

Could not agree more, get the smallest turbo possible that will achieve the power you want, area under the torque curve wins races on the street every time, nothing worse than having 700hp and having to look like a tool to beat a standard v6 commodore with big revs/noise and wheelspin.

[sky30]

So does anyone actually know what RPM a pair of 2530's make full boost on a RB30det??

Sydneykid:- Have you actually used them on a RB30?, or any twins for that matter, when did they make boost>?

[Orphan]

Hey, sorry if this has been covered but there is 213 pages so a bit to much to look through. Just wondering the differences between using an RB25 head on an RB30 and just boaring out a RB25 to 3L. The RB25 block is shorter isn't it? but is there any power differences etc, which would be better basically.

If you don't wanna reply to me a page number would be great so I can at least check out what has been covered before. Thanks.

[Cubes]

Not possible.

[Rolls]

I dont think theres many engines you could bore out a whole 500cc.

[R32 TT]

Cheers for the responses (no pun intended) guys. That settles it then. Twin 2530's it is.

And frankly - I can't wait.

(just hope the gearbox copes!)