T78 >>>>>> To4z what is needed? - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

Totalburnout · 1st September 2006, 11:19 AM

Im running approx 650bhp with a T78 just now but i feel its too laggy and have to really give it some off the start line (best 1/4 has been a high 12!

)

So i was just wondering what would i need to do to fit a To4z in its place?

thanks,

Andy.

Hedgehog Dodger · 1st September 2006, 12:18 PM

Quote:

Originally Posted by Totalburnout

Im running approx 650bhp with a T78 just now but i feel its too laggy and have to really give it some off the start line (best 1/4 has been a high 12!

)

So i was just wondering what would i need to do to fit a To4z in its place?

thanks,

Andy.

Andy read your sig - Power is nothing without control! - Just practice your runs and you should see low 11's poss high 10's

What I started in my GTR the best time I got was 13.4 @ 107 MPH. My launches and gear changes were poor. Now I have run a 12.3 @ 112MPH after about 30 runs up the strip. Just needs practice mate - and I am only running 1bar @ 400(ish) BHP

Totalburnout · 1st September 2006, 01:12 PM

Cheers Dan for slagging my driving!

seriously mate i do need to get some more runs in, dont nearly get enough practice!
I might still be thinking of a change of turbo next summer though.....

Hedgehog Dodger · 1st September 2006, 01:51 PM

IIRC the T78 and T04Z use the same manifold 4 stud flange. I think that the T04Z turbine outlet is smaller in diameter then the T78 so a modified downpipe would be needed, maybe one of the gurus can confirm this.

As for slagging your driving, we have all been there and I am still a newbie at it. Just wanna get my car in the 11's now

The Admiral · 1st September 2006, 01:55 PM

You'll need the manifold & downpipe welded with new flanges to fit, plus coolant pipes made up and then a remap - I've just changed my T78 to a GT3540 for circuit use

Cheers

Rog

neilo · 1st September 2006, 07:44 PM

Hi Rog

I have a T78 at the mo how does the GT3540 compare?

When is it on full boost.

Cheers

Neil

Barrie · 1st September 2006, 08:35 PM

we run 10.08 on a to4z with no noz - FULL boost is still 5000 rpm though , but spools from a lot lower than that

The Admiral · 1st September 2006, 09:42 PM

Quote:

Originally Posted by neilo

Hi Rog

I have a T78 at the mo how does the GT3540 compare?

When is it on full boost.

Cheers

Neil

I'll let you know once it's all completed - hopefully in a week or two...

Rog

GeorgeGTR · 1st September 2006, 11:52 PM

Quote:

Originally Posted by The Admiral

I'll let you know once it's all completed - hopefully in a week or two...

Rog

Yes I am very interested how you get on, I have 2540's at the mo and am finding them to laggy.

Totalburnout, It's not all about the driving mate, the car setup plays a very important part (the most important) I ran a 12.01 with 385bhp in my old GTR at 0.9 bar. I only managed a 13.03 with my current car running the laggy 2540's and 600+bhp! The car wouldn't launch

Hedgehog Dodger · 2nd September 2006, 08:28 AM

Quote:

Originally Posted by Barrie

we run 10.08 on a to4z with no noz - FULL boost is still 5000 rpm though , but spools from a lot lower than that

What cams are you using Barrie, as I thought the TO4Z would spool up quicker than that.

tpw · 2nd September 2006, 08:35 AM

I am doing exactly the same conversion.

My T78 setup works pretty well from 4K but is a real pig for town driving so I'm making the switch. I have a leaky manifold as well so my choices are a little different from making what I have fit.
I have ordered the HKS kit 1103-RN027 but with the T04Z so it should have everything I need.
Kit lands next week so fingers crossed.

The Admiral · 2nd September 2006, 09:26 AM

Here's my old T78 setup (unknown cams) on 1.2bar:

It pulled 624bhp on 1.4bar, but I don't have the graphs...

Am now running GT3540, PowerFC, bigger injectors, different AFMs and intake, so will be interesting to compare...

Cheers

Rog

AJFleming · 2nd September 2006, 09:48 AM

Quote:

Originally Posted by Barrie

we run 10.08 on a to4z with no noz - FULL boost is still 5000 rpm though , but spools from a lot lower than that

pmsl thats horrendous! I have full boost about 3500-4000rpm on my bridge ported 13b running a TO4Z! my god that RB is a lag machine, the main reason I no longer own one

AJFleming · 2nd September 2006, 10:03 AM

Admiral,

No wonder you dont have a T78 anymore, is that about 30ft/lbs of torque at 3500 rpm

The Admiral · 2nd September 2006, 10:07 AM

Not far off - the baseline is 120lbft, though

I must confess I am a HUGE fan of the old school turbo "launch" effect - makes my m8s 500bhp M5 seem VERY sedate, but given that I need to change my turbo anyway, I thought I'd fit something a bit smaller and more modern for better road and track drivability

Can't fault the T78/T88s ability to produce top end power though...

Cheers

Rog

1st September 2006, 11:19 AM	#1 (permalink)
Totalburnout GTR Register Member Join Date: May 2005 Location: Glasgow Posts: 1,634	T78 >>>>>> To4z what is needed? Im running approx 650bhp with a T78 just now but i feel its too laggy and have to really give it some off the start line (best 1/4 has been a high 12! ) So i was just wondering what would i need to do to fit a To4z in its place? thanks, Andy.

2nd September 2006, 08:35 AM	#11 (permalink)
tpw GTROC Member Join Date: Mar 2006 Location: Cheshire Posts: 403	I am doing exactly the same conversion. My T78 setup works pretty well from 4K but is a real pig for town driving so I'm making the switch. I have a leaky manifold as well so my choices are a little different from making what I have fit. I have ordered the HKS kit 1103-RN027 but with the T04Z so it should have everything I need. Kit lands next week so fingers crossed. __________________ Loving the Skyline Experience! Petrol goes in, noise, flames and big grins come out!

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1st September 2006, 01:12 PM	#3 (permalink)
Totalburnout GTR Register Member Join Date: May 2005 Location: Glasgow Posts: 1,634	Cheers Dan for slagging my driving! seriously mate i do need to get some more runs in, dont nearly get enough practice! I might still be thinking of a change of turbo next summer though.....

1st September 2006, 01:51 PM	#4 (permalink)
Hedgehog Dodger GTR Register Member Join Date: Jul 2004 Location: Warrington Posts: 951	IIRC the T78 and T04Z use the same manifold 4 stud flange. I think that the T04Z turbine outlet is smaller in diameter then the T78 so a modified downpipe would be needed, maybe one of the gurus can confirm this. As for slagging your driving, we have all been there and I am still a newbie at it. Just wanna get my car in the 11's now

1st September 2006, 01:55 PM	#5 (permalink)
The Admiral GTR Register Member Join Date: Jul 2004 Location: Scotland Posts: 614	You'll need the manifold & downpipe welded with new flanges to fit, plus coolant pipes made up and then a remap - I've just changed my T78 to a GT3540 for circuit use Cheers Rog

1st September 2006, 07:44 PM	#6 (permalink)
neilo New Users Join Date: Nov 2004 Location: Essex Posts: 984	Hi Rog I have a T78 at the mo how does the GT3540 compare? When is it on full boost. Cheers Neil

1st September 2006, 08:35 PM	#7 (permalink)
Barrie GTR Register Member Join Date: Jan 2006 Location: DISTINCTIVE CARS YORK Posts: 489	we run 10.08 on a to4z with no noz - FULL boost is still 5000 rpm though , but spools from a lot lower than that

2nd September 2006, 09:26 AM	#12 (permalink)
The Admiral GTR Register Member Join Date: Jul 2004 Location: Scotland Posts: 614	Here's my old T78 setup (unknown cams) on 1.2bar: It pulled 624bhp on 1.4bar, but I don't have the graphs... Am now running GT3540, PowerFC, bigger injectors, different AFMs and intake, so will be interesting to compare... Cheers Rog

2nd September 2006, 10:03 AM	#14 (permalink)
AJFleming GTR Register Member Join Date: Feb 2003 Location: Poole, Dorset, UK Posts: 3,789	Admiral, No wonder you dont have a T78 anymore, is that about 30ft/lbs of torque at 3500 rpm

2nd September 2006, 10:07 AM	#15 (permalink)
The Admiral GTR Register Member Join Date: Jul 2004 Location: Scotland Posts: 614	Not far off - the baseline is 120lbft, though I must confess I am a HUGE fan of the old school turbo "launch" effect - makes my m8s 500bhp M5 seem VERY sedate, but given that I need to change my turbo anyway, I thought I'd fit something a bit smaller and more modern for better road and track drivability Can't fault the T78/T88s ability to produce top end power though... Cheers Rog