More Turbo Questions ?

[B-Man]

Hi,

Ok, well I think I'm still missing something....

Q1.

Why is it that a small turbo producing lots of boost, but low flow induces detonation, but a larger turbo with lower boost but more or the same flow will not detonate ?

/Professor Julius Somner Miller "Why is this so ?"

Q2.

I have a GCG500HP Hi Flow Turbo - and I am seriously thinking of a RB30DET conversion - How would this turbo go with the 3.0L Block ?? Anyone done this already ?? On the RB25 Boost came on at like 2200RPM (full boost at 3500) I would expect that on the RB30 I'd be starting to boost at 1500RPM (full at 3000). Would my turbo still be able to pump enough air at 6500-7000 RPM with the RB30 ?

Q3.

I'm going to build the RB30 to be able to cope with 26PSI. With forged rods and pistons etc. If the GCG500HP is too small for the RB30, what would be a good turbo for boost from 2500 thru to rev limit, ie not much lag - Not looking for HUGE power, just good useable, effecient power accross the rev range. Also Turbo should be low mount, stockish looking (ie not stand out high mount)

Q4.

If the GCG500HP is good good for 500HP (372kw) at the flywheel. Factoring in the 52kw driverain loss - and everything else being equal. Theory says that I should be able to attain 320rwkw. Is this realistic ? Or not & why ?

Cheers all

[netrati]

Q1 I think because when you run a smaller turbocharger the more boost you have the hotter the air gets. So get an intercooler.

[B-Man]

Yeah, makes sense. Yes, I have a FMIC.

We tested it with a laser thermometer whilst on the dyno - the piping was 90degC exiting the turbo, 43degC after the FMIC. (if i remember correctly)

[netrati]

Q3 26psi will call for a pretty big turbo. I don't think it'll be boosting very much at 2500rpms.

[B-Man]

Yeah, maybe not with current turbo - Since current turbo is still fairly new, one option would be to sell it and get a bigger turbo. But I like the responsiveness of my current one. So choosing a new one and factoring in costs versus benifit is the hard bit. Hence the questions.

Thanks,

[akeenan]

Not looking for HUGE power, just good useable, effecient power accross the rev range.

Theory says that I should be able to attain 320rwkw. Is this realistic ? Or not & why ?

:confused:

[B-Man]

Why are you confused ? State it and I can clarify ! Otherwise, someone else may be able to clarify. Thanks,

[Steve]

Originally posted by B-Man

Hi,

Ok, well I think I'm still missing something....

Q1.

Why is it that a small turbo producing lots of boost, but low flow induces detonation, but a larger turbo with lower boost but more or the same flow will not detonate ?  

/Professor Julius Somner Miller "Why is this so ?"

The higher the pressure in the cylinder the more heat will be generated on compression stroke the more prone to detonation - this is my understanding its not the amount of air, but the pressure (or boost) that is the problem.

Q2.

I have a GCG500HP Hi Flow Turbo - and I am seriously thinking of a RB30DET conversion - How would this turbo go with the 3.0L Block ?? Anyone done this already ?? On the RB25 Boost came on at like 2200RPM (full boost at 3500) I would expect that on the RB30 I'd be starting to boost at 1500RPM (full at 3000).  Would my turbo still be able to pump enough air at 6500-7000 RPM with the RB30 ?

Sorry I wouldnt have a clue how it would go on an RB30 except it will probably be a bit on the small side for my liking:D

by putting on a 3L bottom end probably wont effect the peak power output overly as this will be the product of the turbo and support systems bolted on (intercooler, exhaust etc) just where the power is made.

Q3.

I'm going to build the RB30 to be able to cope with 26PSI. With forged rods and pistons etc. If the GCG500HP is too small for the RB30, what would be a good turbo for boost from 2500 thru to rev limit, ie not much lag - Not looking for HUGE power, just good useable, effecient power accross the rev range. Also Turbo should be low mount, stockish looking (ie not stand out high mount)

I would personally be looking at a GT35R or similar. Have a chat to Per4manz Turbochargers, they do a version of this that on a 2jz made boost from about 1800rpm and was sitting around 1bar by 2500 - this is from memory, they would be able to confirm for sure. They quoted me $2477 new. They claim 80% compressor efficiency at 1 bar - but wouldnt give me a copy of the map as it was inteletual property. http://www.per4manz.com/

Q4.

If the GCG500HP is good good for 500HP (372kw) at the flywheel. Factoring in the 52kw driverain loss - and everything else being equal. Theory says that I should be able to attain 320rwkw. Is this realistic ? Or not & why ?

Cheers all  

Because it those figures are in a perfect world, no flow loss, no thermal loss etc. When a turbo is rated at xxx hp, that is in a 'perfect' test environment.

Hope I havent led you too far astray with any of the answers, just passing on my understanding and hope that I have come close to the mark.

Hope the new donk lasts a bit longer than the old one:p

[B-Man]

Hope I havent led you too far astray with any of the answers, just passing on my understanding and hope that I have come close to the mark.

Not at all Steve, always appreciate your knowledge/experience. Thanks.

Hope the new donk lasts a bit longer than the old one

He He - so do I !

I thought as much - current turbo may be too small for RB30DET> But I'm still keen for it.

On with the research.

[MRK25T]

Did you think of swapping the rb25 for a rb26? If you had, why are you choosing the more expensive 3L option?

so your selling your turbo huh?.... someone I know may be interested

Could you PM the quotes for any rb25 rebuilds you have had?

good luck. Can I go for a ride when your finished?

Mark

[B-Man]

Originally posted by MRK25T

Did you think of swapping the rb25 for a rb26? If you had, why are you choosing the more expensive 3L option?

so your selling your turbo huh?.... someone I know may be interested  

Could you PM the quotes for any rb25 rebuilds you have had?

good luck. Can I go for a ride when your finished?

Mark

Hi Mark,

Yes I thought about an RB26DETT - here's why I didn't :

2nd Hand motor $6,000

plus ECU

plus Sump & gearbox mods (not sure if required)

plus fitting

plus ECU

plus plus plus

Still not new.

RB30 DET = brand new motor

Not neccessarly selling my Turbo - just and option at this stage. Still researching.

re: RB25DET rebuilds - the range is awsome , depending on what you want of course. - $6000 - $15000

Of course I will take you for a ride, no worries ! I got to get it built first, which means I got to save $$ And work out which way to go - As far as I can see, all the performance shops push what they make the most margin on. Which is OK in isolation, but when you are talking a package deal, you think that the scale of economy would kick in !

Cheers,

[RIPS]

Hi, If you want a package deal that has a fixed price and you know exactly what you get, try this.

RB30det rebuilt, stage 1 with custom intake system (series 1 or 2)

Stock pistons,rods,crank. Stock R32 RB25 head. 8.3:1 compression ratio. Stock exhaust manifold. Stock type throttle body with 15% larger butterfly and flowed intake, twin inlet fuel rail, No turbo, No injectors, No electrics but comes with everything else in picture as well as custom cam cover that fills the gap from having a taller block . This is a base model motor good for 250-280rwkw reliable. NZ$6000+gst (if any) for a 2WD or NZ$7000+gst (if any) for 4WD.

If you want just the long motor, ie no inlet or exhaust manifolds the engines are NZ$3500 +gst for 2WD and $4500 +gst for 4WD.

We have found them ideal for someone who already has a FMIC, computer, exhaust, fuel pump etc and wants strong low-mid range drivability as well as a good top end.........Regards Rob

[RIPS]

Can also do fuel systems to suit from NZ$1000 +gst

[Craved]

if you want info on this setup, even with the rb25, you might want to look at the HPI R34 --- just got 291KW at the wheels, will give you an idea of what is possible!!! think they are similar turbos too!

[B-Man]

Hi RIPS,

That's quite a plemun - How is the inside of it done ?

BTW - I was the one on SDU that asked you about the RB30DET with forged internals (brendanf on SDU)

You got me thinking some more now.

Nice Pics.

Cheers,

[red900ss]

B-Man the NZ prices should be GST exempt for export too.

Combine that with the exchange rate and there's some more food for thought.

nb. This advice is not given free of charge. The afformentioned turbo will suffice as payment.

Just think how much I saved you!!!

[B-Man]

Yes, it's very tempting Dino.

Does anyone know what (if anything) is required to import a motor ??? Is there any probs with Engine Numbers etc ?

OT on my own thread.... Geez !

[Steve]

Originally posted by Craved

if you want info on this setup, even with the rb25, you might want to look at the HPI R34 --- just got 291KW at the wheels, will give you an idea of what is possible!!!  think they are similar turbos too!

The turbo on there is a HKS 3037 - he upgraded from the GCG one he had as he wanted more than the 240?oddrwkw.

RIPS - any info on what sort of freight cost would be involved - also do you know if customs will be hitting duty+gst to bring from NZ to aust?

What sort of prep do you do to the internals, I noticed you said stock internal, but have they been balanced, blueprinted, crank nitrited, rods linished, shop peened crack tested?

Do you sell short motors, just with relocated belt tensioner and larger cam belt as a bolt up arangement for someone who may have an RB25 head already? What prep has been done to the block? Has the head been ported at all? What cams do you use? Does your plenum include a fuel rail?

And, which oil pump do you use for the RB30 block? do you fit piston oil squirters? What bearings do you use? If you are getting 8.3CR does that mean that you just using RB30E pistons with a RB25DET head - no decking of the block or head?

Thanks

Steve

B-Man sorry for the whore, but it looked like you may be interested in the answers as well?

[RIPS]

I will have to look into freight etc. There's no problem getting a motor out of NZ, but you may need to check your end as to what you will need to do.

Go to "I need help with plenim" further down the threads, there are pix and info on what you get with the plenim kit.

All our motors start with a acid dipped block, crack tested crank etc, but for the base motor its all very stock. There are alot of tricks to get them to hold together and just to show you what can be done with a properly prepared and tuned stage 1 RB30det, I'll include a roller dyno run. With the bottom of the range R.I.P.S RB30det with 75hp of NOS, we made 342rwkw by 5500rpm, then the clutch blew. As you can see it was still climbing hard and now that we have a real good clutch we should be able to go to 400rwkw @ 7000rpm for short bursts (ie drags)

I just wanted to prove that you don't need flash this and flash that to make a good drivable 250+rwkw, and for the price, I have not seen better value.........Regards Rob

[RIPS]

In case your wondering about the flywheel/clutch up set we now do these.......NZ$2000 for the lot to suit RB20/25/26/30/31

NOTE: this one is a couple of drag mettings old.....Rob