Internal gated TO4E

[FATGTS-R]

I have a GTS-R with an internal wastegated TO4E.

According to most peoples thoughts and what I have searched for on the net on my RB20DET-R it should not make full boost untill approx. 5,000rpm.

Now it is at full boost at 3550rpm. The only mods are 3inch cat back, pod and GREDDY under bonnet boost controller ( non electronic ).

It made 135kw at wheels on 0.56BAR on NIZPROS dyno.

Would it sound feasible that the previous owner modified the turbo to promote earlier boost responce?

And if so would this sacrifice the HP potential of the turbo had it not been touched?

[B-Man]

Hi, I'm not claimimg to be in expert here - but something sounds wrong here to me.

Maybe you are not realising 'full' boost on your setup @ 3550 RPM? 0.56 bar what's that 8 PSI ? You should be able to get more than that out of the T04e - which would come on later then 3550

I've just gone thru a bit of a time consuming 'experiment' on my RB25DET. I was running a T04e compressor (.60AR) with a VG30 exhuast housing (internally gated)

At 9PSI I was getting 200rwkw - boost reached 9PSI by 3800 RPM

At 14 PSI I was getting 250 rwkw - full boost by about 4300 RPM

Max power we could get out of the turbo was 255 rwkw with boost wound up to 19 PSI - turbo started 'cavitating' (what ever the hell that means - to me it means that the turbo ran out of effeciency)

I know that out engines are different, so this only a guide.

Have you tried turning up you boost to .7 or .8 bar ?

Cheers,

[FATGTS-R]

I have contemplated turning up the wick but I am paranoid about detonation.

When I get my dump it will be getting the ecu remapped at which time I will turn up the boost when its on a dyno.

[FATGTS-R]

I guess anyone running a TO4 on an rb20 would also be able to give me something to compare to.

Mine is a red top but pretty much the same as R32 except for I have factory nizmo stainless extractors.

[Steve]

The R31 RB20 has more aggressive cams according to the Tomei site, also, the problem with a term like 'full boost' is it's very arbitary.

My full boost is 1.7bar, but my turbo makes 1.2bar ar around 4150rpm.

B-man, cavitating I believe is compressor surge (reaching the surge line on the compressor map). The turbine is out of its efficiency range, I think you may find that the turbine housing/wheel is a bit small for the compressor. If you have a read of BOOSTDs thread about his $350 turbo, it may explain things a bit better. He was experiencing similar problems with his hybrid, and managed to find a few fixes.

[B-Man]

Thanks Steve - yeah the turbo people have offered to change over the wheels, which would increase lag in the quest for more power right ? -

I'm thinking of a HKS3040 with HKS manifold too. Steve did you get my e-mails ?

Sorry FATGTS-R - i'm off topic....

[Steve]

Yep, got your e-mail, I will send you a detailed reply:)

[FATGTS-R]

Gotta be somebody running a TO4 on a RB20.

[geraldjohn]

Hi, I'm not claimimg to be in expert here - but something sounds wrong here to me.  

Maybe you are not realising 'full' boost on your setup @ 3550 RPM? 0.56 bar what's that 8 PSI ? You should be able to get more than that out of the T04e - which would come on later then 3550  

 

I've just gone thru a bit of a time consuming 'experiment' on my RB25DET. I was running a T04e compressor (.60AR) with a VG30 exhuast housing (internally gated)

 

At 9PSI I was getting 200rwkw  - boost reached 9PSI by 3800 RPM

 

At 14 PSI I was getting 250 rwkw - full boost by about 4300 RPM

 

Max power we could get out of the turbo was 255 rwkw with boost wound up to 19 PSI - turbo started 'cavitating' (what ever the hell that means - to me it means that the turbo ran out of effeciency)

 

I know that out engines are different, so this only a guide.

 

Have you tried turning up you boost to .7 or .8 bar ?

Cheers,

hi there b-man,, is your engine an rb20 or an rb25?,, the reason i'm asking this is cause i am thinking of usung the same turbo you got there on my rb25,, and wondering what response i should get with it,, any ideas?

[geraldjohn]

hi there b-man,, is your engine an rb20 or an rb25?,, the reason i'm asking this is cause i am thinking of usung the same turbo you got there on my rb25,, and wondering what response i should get with it,, any ideas?

oops sorry there b-man i must have skipped over the part where you said you are running an rb25,,, ok next question,, what other mods you got? in order to achieve those figures?

[B-Man]

Dude - I'll tell you if you put my up for a room , the next time Australia plays the West Indes at your place.....

FMIC

550cc inj

Forged Internals

Ported head

8.6:1 HKS 1.6mm head gasket

3" Dump, front & Cat back

PFC

Q45 AFM

256 Cams

Isky Valve springs

Exh Cam gear

N1 Oil & Water pump

9 litre baffled sump

[geraldjohn]

Dude - I'll tell you if you put my up for a room , the next time Australia plays the West Indes at your place.....

 

FMIC

550cc inj

Forged Internals

Ported head

8.6:1 HKS 1.6mm head gasket

3" Dump, front & Cat back

PFC

Q45 AFM

256 Cams

Isky Valve springs

Exh Cam gear

N1 Oil & Water pump

9 litre baffled sump

sure no problem dude,, you just get here and i'll put you up

thanx