T04z Specs.

[mazgtr]

Just bought and read the complete T04Z article in the latest HPI mag. Interested to see that the HKS T04Z comes in 3 different exhaust trim houseings, 0.61 - 0.81 -1.00.

In the test they use the 0.81 option, and find it to be a bit laggy on a RB26DETT. It generates 420RWKW odd, at 1.4Bar, but the midrange wasnt great. Martin Donnon also noted that at the engines 8200RPM limit the turbo was still increasing power and so was a bit big for an internally stock GTR.

Funny though, even with what they described as being a laggy option, the 0.81 T04Z was still more responsive than my HKS 2540's when i compared it with my dyno graph!!!

Just wondering if anyone knows of the results achieved with the smaller more responsive 0.61 option. I wouldnt be looking for 450RWKW, high 300s at about 18-20PSI with good midrange is what im chaseing.

Do Garret offer the different trim options?

Is the only thing you can change is the 0.61 - 0.81 - 1.00 exhaust rim?

Any thoughts experience would be appreciated..

Cheers

[paulr33]

there are probably better bolt on twins that should fit in the stock location and give you some good power and midrange. the 2540's are known lag monsters and create extra lag due to a mismatched combination which is what you are experiencing with your current setup. twin 2530's may change that

[R31Nismoid]

Are you referring to the article... that as you know has been debated here

http://www.skylinesaustralia.com/forums/in...howtopic=121442

because if so, i wouldnt really take any write up about it as i think its totally wrong just be the results that have been supplied.

I dont think the .8X is laggy at all.

I think all the GTR's here in Vic using it are using the .8X housings.

I'll ask around just to be sure, and certainly all the owners are more than happy having spoken to them all.

In a .6x i think is is going to be choked quite substancially which would really limit power, and the top end.

It would have a meaty mid-range. IMO the .8x still has a great mid.

RE: 2540's... they are hotly regarded as somewhat of a mismatch on many scales and not really a good performer at all.

I'd say use 2530's... or hold out for the GT-ZZ release later this year.

Being you have all the gear now using 2540's. Should be a direct swap i think?

[mazgtr]

GT-ZZ's???!!!! Are these the low awaited replacement for the 2530's?

Yeah i allready have all the HKS Manifolds and Dump pipes for the 2540's, so in theory a change to a another HKS low mount combo should be a straight bolt on affair, give or take an oil feed or two. Prolly cheaper and easier than starting out with a whole new high mount setup. I do like twins aswell.

I did think of either 2530's or the new GT-SS's, but i think the GT-SS's are a bit small for my power goal. Although laggy my 2540's still give me 330AWKW at 18PSI so i dont want any less power than this. The 2530's are starting to get a bit old IMO, but if theres a newer replacement for them comeing, i might have to wait and see how they go. The new HKS GT-Rs are the reaplcement for my 2540's but from the sounds of things they still dont live up to the hype and would prolly be as laggy as mine are now, with a bit more top end.

Cheers guys...

Edited June 21, 2006 by mazgtr

[R31Nismoid]

GT-RS is not what you want.

the GT-ZZ, i dont think there is a release date as yet.

GT-SS/GT-RS are out... so one would think the GT-ZZ surely couldnt be much further away.

There has been basic discussion here, and some on GTR UK... but not a lot really firm information as yet. But they were marked as the replacements for the 2530.

If your only getting 330 from 2540's i say there is a problem.

2530 will easily make more than that and the 2540 are just laggier

[mazgtr]

If your only getting 330 from 2540's i say there is a problem.

2530 will easily make more than that and the 2540 are just laggier

No from what ive seen thats a good power figure for this particular dyno. Ive seen a healthy stock R33 GTR struggle to make 140AWKW so it does read a little low. Generally a GTR with 2530's needs a few more PSI (3-4) to match mine on that dyno. But their much more responsive.

Ive got an old dyno sheet from the previous owner with 360AWKW, but i dont know at what PSi, prolly about 20-22 pounds.

Im happy with the added reliability i have "only" running 18PSI. I havnet yet found a situation where 330AWKW wasnt enough........ for now

Edited June 21, 2006 by mazgtr

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