R34 Gtr Build

[BOBBYr34]

I'll re-iterate, I am blown away with the whole build - I didn't mean to offend, and certainly don't mean to say I could do it better... at least when it comes to the engine build, fabrication etc. I've never built an RB to make that power (on that note are you going to be running E85?) so far bit it from me to question anything there. The only thing which did make me raise an eyebrow was the T70 based turbo, and hence me asking as I figured you'd either say "wink wink nudge nudge" implying that its hardly an off the shelf T70 if not say what has been done there... because otherwise it is just using an old Turbonetics turbo on what is otherwise an amazing build, and when the turbo has in ways the biggest influence on how the engine is going to be able to perform given most of the good stuff will be relying on the turbocharger to provide extra air mass in a timely fashion.

The reason I say that is I've experienced first hand an RB30 Skyline running a Turbonetics T70 and the thing was horrible in spool and response considering it had a 3litre engine, by comparison I've also experienced a GTR with a T04Z on an RB30DET making similar power to the T70 car and due to expectations of what a 3litre 450+awkw GTR being set by the Turbonetics one I nearly shat myself when the T04Z tried to rip tarmac up at rpm where the T70 one felt like it had just realised it had a turbo and was sheepishly asking it whether it could give it some decent boost at some point, please. The ride in the T70 Skyline was my first experience of an RB30 and I actually didn't think too much of their advantage over a 2.6 for some time because of the experience, so discovering that it was actually nothing to do with the engine so much as the air pump hobbling it... and that is one of the reasons I decided I *really* get my teeth into trying to understand dynamics between engines and the things attached to them as while that was an extreme case, it does show that the turbo can make an otherwise crap setup awesome and an awesome setup crap.

So if you're going to take that line, a formula for a quicker 500kw car is do exactly what you are doing - but put a better turbo on it, because unless there is some very sneaky stuff you have done to the Turbonetics turbo which essentially would mean calling it a Turbonetics T70 would be very misleading and I'd really have no idea of it's potential... then I would be completely surprised to see a result which no other turbo could match on your setup. I like surprises, as it means there is more for me to learn and more ways to go fast - and I love seeing good results, which is the only reason I questioned it.

Looking forward to seeing how it goes, anyway

Well I am sticking with the turbonetics as they have compressor maps . And the whole design is based on the compressor map. This t70 has a 102exducer meaning it can be used for high boost with a trim of 43. If you a lot about turbos you will understand what this turbo can do. And if you don't understand I am happy to explain it .

No offense I know a lot new turbo are out on the market however there is no comp maps 8(

We will see the results

[Lithium]

Well I am sticking with the turbonetics as they have compressor maps . And the whole design is based on the compressor map. This t70 has a 102exducer meaning it can be used for high boost with a trim of 43. If you a lot about turbos you will understand what this turbo can do. And if you don't understand I am happy to explain it .

No offense I know a lot new turbo are out on the market however there is no comp maps 8(

We will see the results

No offense taken, and trying not to offend you either - reason I am here is I am excited about the build, and I naturally like discussing things which are both awesome but also intrigue me.

Yep I know what the T70 can do, and have been able to read maps for quite some time. The trick is the map shows what the turbo is capable of, but not how it goes about it's business. The pumping the compressor does can be produced in different ways - the trim is just one of many different variables, the design of the wheel can be totally different while having the same trim and produce very different results to another wheel with the same measurements. It also can come down to the rest of the turbocharger, ie what turbine is attached to it, how that is designed and how they efectively interact. You can have BB or JB cores, different materials etc etc. The reason I don't really like the T70 isn't that it can't provide the air flow, or do so with reasonable compressor efficiency - its more the energy required to get the thing up and moving, and nature of how it gets up and moving and staying there.

How inefficient it is overall means that I am more comfortable with what I can extrapolate of compressor efficiency of more modern turbochargers which don't have published maps than using something like that - most of them have (or would have if they were supplied) such wide maps they are less of an issue to fit into than the 30+year old T-series wheels that Turbonetics use, there are so many dyno and real world results out that it's pretty easy to tell what is going to work. I recommended the GT3076R-HTA to Mat (who got his car tuned at JEM) without a compressor map, but a reasonable mental picture of what could be expected from both the design and what people I have spoken to have achieved with them - his results ended up within a few kw of where I said it'd be most likely to deliver.

In saying all that - as it turns out the turbo which I think would perform the best for what you are doing DOES have a compressor map, and would IMHO be a complete different beast to the T70:

The turbo has a much smaller compressor exducer (91mm) and only 67.7mm inducer, and has some VERY nice aeros which obviously results in it actually flowing more than the T70 and operating efficiently at very high boost levels, as well as flowing well at low pressure ratios. It has much less inertia so will naturally spool and respond better just off the weight of that, then there is the fancy ball bearing core, the fact that the turbine is made of Titanium Alloy (light as hell and again way better design).

Its essentially like a turbo which is smaller than a T70 which provides everything a T70 would and a bit more - everywhere

[BOBBYr34]

What size rear housing is the above turbo?

Not a big fan of titanium as the life span is short.

[Lithium]

I was envisaging 1.05 twin scroll. It's not straight Titanium, it's a composite they call Gamma-Ti which is meant to be durable in the operating conditions it would experience.

This is the turbo :

http://www.full-race.com/store/turbos/borgwarner-efr/borgwarner-efr-9180-turbo.html

[BOBBYr34]

I was envisaging 1.05 twin scroll. It's not straight Titanium, it's a composite they call Gamma-Ti which is meant to be durable in the operating conditions it would experience.

This is the turbo :

http://www.full-race.com/store/turbos/borgwarner-efr/borgwarner-efr-9180-turbo.html

I have heard they had problems with these turbo's

If we are talking about minimizing turbo lag id want to use a 0.7 twin scroll rear housing.

Let me know when you used the T70 which rear housing did you use?

[Lithium]

Was a mate's one, and it was a long time ago so hazy on details but pretty sure it was quite a small one.

In terms of a/r - not all things are equal, you wouldn't use a 0.7 on the EFR... As evidenced by the lack of option for one haha. The 1.05 EFR would flow quite a lot better and be even more responsive again than the T70- all tighter a/r does is speeds up the exhaust flow for a given amount of energy, it still has the bigger heavier wheels to move and will need to overcome the same inertia.

The early EFRs definitely had issues, and I was not so much of a fan (ie, wouldn't have mentioned them ;-)) until it seemed clear they had sorted it out. Took years for them to finally start being supplied reliably, in various ways haha.

Anyway part of the point wasn't just this specific one, there are various very impressive units out there which will do what you are looking for though alas compressor maps are thin on the ground for them. I do know JEM had a GTR there recently with a Precision PT6466 which would be interesting to compare spool with when you get yours done.

[BOBBYr34]

Was a mate's one, and it was a long time ago so hazy on details but pretty sure it was quite a small one.

In terms of a/r - not all things are equal, you wouldn't use a 0.7 on the EFR... As evidenced by the lack of option for one haha. The 1.05 EFR would flow quite a lot better and be even more responsive again than the T70- all tighter a/r does is speeds up the exhaust flow for a given amount of energy, it still has the bigger heavier wheels to move and will need to overcome the same inertia.

The early EFRs definitely had issues, and I was not so much of a fan (ie, wouldn't have mentioned them ;-)) until it seemed clear they had sorted it out. Took years for them to finally start being supplied reliably, in various ways haha.

Anyway part of the point wasn't just this specific one, there are various very impressive units out there which will do what you are looking for though alas compressor maps are thin on the ground for them. I do know JEM had a GTR there recently with a Precision PT6466 which would be interesting to compare spool with when you get yours done.

Well i have been taught differently and i can see where you are coming from however if the turbonetics is a nugget turbo so be it. This turbo has been chosen by John skola himself and i have no doubt what this turbo will do as he has never been wrong. We will have to wait and see as its not just the turbo that does the work and the wastegate into venturi will bring out the goodness of the turbo.

JEM did tune a 6466 and yes it was impressive outside the normal norm!!

[Lithium]

 This turbo has been chosen by John skola himself and i have no doubt what this turbo will do as he has never been wrong. We will have to wait and see as its not just the turbo that does the work and the wastegate into venturi will bring out the goodness of the turbo. 

 

JEM did tune a 6466 and yes it was impressive outside the normal norm!!

Indeed there is a lot of work there to give it every chance of doing as well as it can, and it will deliver the numbers you are looking for - just not necessarily as nicely as other things... Naturally anything which has been done which would help this turbo will obviously help other ones in the same kind of way and hopefully give you overall setup the best chance of performing to your expectations. Safe bet it is going to be an animal, no matter what - and with that tight exhaust scroll it's probably going to come on quite savagely once it starts getting some moment haha.

The 6466 type result is not outside the norm anymore, it's the new norm for those dabbling in Precision, Forced Performance HTA, Garrett GTX and Borg Warner EFR turbos when sized appropriately

Anyway, will be keeping a good eye on it - will be very interesting too see an old school turbo used with some of the best of the latest technology, it's going to be a heck of a ride regardless of whether it is laggy as or a response monster :-)

[BOBBYr34]

Indeed there is a lot of work there to give it every chance of doing as well as it can, and it will deliver the numbers you are looking for - just not necessarily as nicely as other things... Naturally anything which has been done which would help this turbo will obviously help other ones in the same kind of way and hopefully give you overall setup the best chance of performing to your expectations. Safe bet it is going to be an animal, no matter what - and with that tight exhaust scroll it's probably going to come on quite savagely once it starts getting some moment haha.

The 6466 type result is not outside the norm anymore, it's the new norm for those dabbling in Precision, Forced Performance HTA, Garrett GTX and Borg Warner EFR turbos when sized appropriately

Anyway, will be keeping a good eye on it - will be very interesting too see an old school turbo used with some of the best of the latest technology, it's going to be a heck of a ride regardless of whether it is laggy as or a response monster :-)

I just want to add gtx turbo's are a very old desihn used in F1 back in 80's alot of the new turbo's are from F1 nothing new that i see. As i am still in the search for a F1 turbo i have not found one as yet.

6466 is one amazing turbo.

I havent said much about the turbo on my sti its a hta 76 with a extremly small rear housing 7cm now this turbo has no lag

[Lithium]

I just want to add gtx turbo's are a very old desihn used in F1 back in 80's alot of the new turbo's are from F1 nothing new that i see. As i am still in the search for a F1 turbo i have not found one as yet.

Yep! Its quite funny that, there is not sudden new understanding of fluid dynamics etc which means we are able to produce magic we couldn't before - a lot of the designs around are based on previously documented ideas, if not straight off (ie GTX - which I am mostly not a huge fan of, but threw that in there to not step on toes) already utilised designs etc... however a lot of it comes down to what is available to the public, and for an affordable price. We also of course need things which suit our applications specifically - a F1 turbo may or may not be well suited to an RB. Borg Warner EFR turbos are used in IndyCar racing, Honda IndyCars currently use the EFR9180.

6466 is one amazing turbo.

I havent said much about the turbo on my sti its a hta 76 with a extremly small rear housing 7cm now this turbo has no lag

Yep What I tend to do is keep an eye out on the units which consistently provide good results, the 6466 is one which seems to have delivered WELL for everyone who have used them.... they are one of the good one, but by all means not the only one.

Ahh nice, yeah the HTAs are awesome things - they tend to both spool well for their size, and make good power for their size

[HIRISK]

Hi Bobby,

Sorry to change topic, but I was wondering how you went about obtaining the Z-Tune carbon diffuser?

I have never seen then advertised anywhere?

Such a great investment though, truly gives it the finished Z-Tune look that you just do not get with a normal V-Spec diffuser.

[BOBBYr34]

Hi Bobby,

Sorry to change topic, but I was wondering how you went about obtaining the Z-Tune carbon diffuser?

I have never seen then advertised anywhere?

Such a great investment though, truly gives it the finished Z-Tune look that you just do not get with a normal V-Spec diffuser.

Hi,

I get them directly from nismo Japan if interested let me know

[HIRISK]

Cheers,

Would love to, but have other priorities with the car at the moment.

Need to replace the clutch which will cost me $3k.

Out of interest, what Are the dollars on the diffuser?

Absolutely love the build by the way, has been great to follow, read and learn.

Cheers.

[BOBBYr34]

Cheers,

Would love to, but have other priorities with the car at the moment.

The z tune diffuser are over 6k to buy.

Need to replace the clutch which will cost me $3k.

Out of interest, what Are the dollars on the diffuser?

Absolutely love the build by the way, has been great to follow, read and learn.

Cheers.

[HIRISK]

Wow, $6k....more than even the genuine Z-tune bonnet....there goes that idea

Thanks for the info Bobby, much appreciated.

[BOBBYr34]

Yep! Its quite funny that, there is not sudden new understanding of fluid dynamics etc which means we are able to produce magic we couldn't before - a lot of the designs around are based on previously documented ideas, if not straight off (ie GTX - which I am mostly not a huge fan of, but threw that in there to not step on toes) already utilised designs etc... however a lot of it comes down to what is available to the public, and for an affordable price. We also of course need things which suit our applications specifically - a F1 turbo may or may not be well suited to an RB. Borg Warner EFR turbos are used in IndyCar racing, Honda IndyCars currently use the EFR9180.

Yep What I tend to do is keep an eye out on the units which consistently provide good results, the 6466 is one which seems to have delivered WELL for everyone who have used them.... they are one of the good one, but by all means not the only one.

Ahh nice, yeah the HTAs are awesome things - they tend to both spool well for their size, and make good power for their size

Speaking to john on what you have said about inertia and spool he has said it's got nothing to do with it!! It's more related to the engine build.

It would be a perfect opportunity if you were ever in sydney to speak to Jim about your outlook on turbo's.

[Lithium]

Speaking to john on what you have said about inertia and spool he has said it's got nothing to do with it!! It's more related to the engine build.

It would be a perfect opportunity if you were ever in sydney to speak to Jim about your outlook on turbo's.

The more interesting people and things I can meet and learn about the better, I am going to be in Sydney for a week leading up to WTAC next month - might have to try and swing past JEM sometime. None of us have all the answers, so always interesting to share experience where willing - I'm certainly always open minded to new ideas... as at this stage I can't see how you can't associate spool with inertia (and other things relating to turbo design), considering turbo shaft rpm comes from a mass being accelerated and that mass is drawing and pumping air - the better it is at moving air versus the amount of energy it has available to move it, the better it is going to perform overall... I would have thought. But yes, if there is an opportunity to discuss it when I am over, I'd love to... one of my favourite topics

[BOBBYr34]

The more interesting people and things I can meet and learn about the better, I am going to be in Sydney for a week leading up to WTAC next month - might have to try and swing past JEM sometime. None of us have all the answers, so always interesting to share experience where willing - I'm certainly always open minded to new ideas... as at this stage I can't see how you can't associate spool with inertia (and other things relating to turbo design), considering turbo shaft rpm comes from a mass being accelerated and that mass is drawing and pumping air - the better it is at moving air versus the amount of energy it has available to move it, the better it is going to perform overall... I would have thought. But yes, if there is an opportunity to discuss it when I am over, I'd love to... one of my favourite topics

I best let you speak directly to John then me being in the middle.

Let me know you schedule and i will have to book you in with him and it has to be after 5pm.

[MR 33]

Nearly there bobby! Cannot wait until it is started and I am honoured that you have chosen me to be the first to drive it!!

[BOBBYr34]

Nearly there bobby! Cannot wait until it is started and I am honoured that you have chosen me to be the first to drive it!!

First to drive it yes and wait when we turn it up HANG ON!!!!!