Garrett G Series

[diesel des]

2 hours ago, Full-Race Geoff said:

what is your max engine RPM?  and what is your max boost target, 2bar?

for a 2.5L engine at 500ft above sea level,  revving to 7000rpm or 8000rpm, you may want to play around with garrett boost advisor or bw matchbot.  this can help dial in your setup.  youtube videos at the bottom of the bw page.  

If you want to post up a link or a map with plotting points, it is much easier to understand what your operating parameters will be.  Unfortunately aftermarket "upgraded" compressor wheels are typically a mystery and do not have any compressor maps to work from

Thanks Geoff. Yea im expecting max power to fall between 6 and 7k rpm with the headwork and cams I have with the engine speed hard cut to be at or just before 8k rpm. The engine should be able to tolerate 2 or even 2.3 bar boost max if it can be generated efficiently with low back pressure in the exhaust manifold. Compression is low to tolerate the pump fuel here, it was 8.2:1 on the build that melted and it's now just under 8:1, again for more safety.

 

I have had a play with matchbot with the results here.  http://www.turbos.borgwarner.com/go/7D9ZYN

 

If I was to start again, eg make a new manifold, downpipe, oil and water pipes etc I would definitely go with the efr 8374 or perhaps the 84mm compressor version, but I just don't have the time or money to redo all those things hence wanting to stay with a bolt on turbo. I did have an efr6758 and then a 7163 on a road car with the same engine as my quattro, just less aggressive cams and cast manifold etc, and really liked how it preformed. It topped out at 450 and 500 hp respectively on those turbos on the same pump fuel. And that was properly topped out, eg running 2.3 bar though the mid range with boost dropping to 1.5 bar at 7k with the wastgate almost fully closed. Just to give some idea of what it takes on theses engines and our dynos to make that power.

 

Can you confirm if the garret v band sizes are the same as the tial units? I measured the tial unit today to be 2 inch id and 3 inch od.  Would you compare the g35900 to be of similar size and response to an efr 8374? 

 

I agree on your point on the aftermarket compressor.  Its frustrating due to having no map so God knows what it's doing. Maybe a proper gtx3582 gen 2 wheel and housing would be worthwhile and not too expensive.  Cheers.

[Phat_Toni]

So today was the day. This is a G25-660 0.92 on a 30+ year old unopened RB26 with unknown kms. Green is my previous tune using factory R34 GTR twins. My tuner seems to think that there would be another 40ish kw in it with e85 on similar boost.

I had the pressure source coming from the comp cover when I probably should have had it coming from the plenum (before throttles) as I did previously. I think this at least contributed to the boost taper. (Hits 18 sofltly and tapers to 16)

This was done with a 6 Boost manifold, 4" dump into a 3.5" system. I don't know how hard he leaned on the gate pressure setting (eBoost Street) but boost response doesn't look overly impressive by these graphs. 130kmph is just under 4500 if the calcs are right (643mm rolling diam tyre, 4.11s, 4th gear 1:1)

I cant stand the waste gate cycling sound that the EBC and the screamer make. It sounds sooooo good on gate pressure with no pulsing so I might be back to sort something out soon.

Peak power was at 8000rpm. Retains factory 8200 rpm limiter

 

 

[blah_blah]

I would have thought a G25-660 single would have been more responsive than factory twins?

[discopotato03]

I don't like guessing but if I had to I reckon this is partially the result of a bigish turbine housing on an around 54mm turbine .

Yes it flows well but probably at the expense of turbine response down low . Also the standard twins basically achieve the same thing on an I6 as a twin scroll twin gated turbine housing .

I don't think we will realise the true potential of these G Series turbos until Garrett or whoever starts making twin scroll turbine housings for them . V band is a bit nowhere for the mass market .  

[Phat_Toni]

This 2.5 STI makes 20 PSI by ~4100 with a 0.72...G25 660 - that kind of puts my result in the ballpark with the bigger housing.

https://www.youtube.com/watch?v=eoem4Gv06ec&feature=youtu.be

That SR with 400kw was surely using a 0.92 and looks to spool better than both of these setups. Was that on a hub dyno?

Need more examples to gauge what to really expect spool wise on an RB I think

[Full-Race Geoff]

On 2/6/2020 at 7:19 AM, Phat_Toni said:

So today was the day. This is a G25-660 0.92 on a 30+ year old unopened RB26 with unknown kms. Green is my previous tune using factory R34 GTR twins. My tuner seems to think that there would be another 40ish kw in it with e85 on similar boost.

I had the pressure source coming from the comp cover when I probably should have had it coming from the plenum (before throttles) as I did previously. I think this at least contributed to the boost taper. (Hits 18 sofltly and tapers to 16)

This was done with a 6 Boost manifold, 4" dump into a 3.5" system. I don't know how hard he leaned on the gate pressure setting (eBoost Street) but boost response doesn't look overly impressive by these graphs. 130kmph is just under 4500 if the calcs are right (643mm rolling diam tyre, 4.11s, 4th gear 1:1)

I cant stand the waste gate cycling sound that the EBC and the screamer make. It sounds sooooo good on gate pressure with no pulsing so I might be back to sort something out soon.

Peak power was at 8000rpm. Retains factory 8200 rpm limiter

 

 

would you mind reposting your dyno chart with engine RPM as the lower axis?

...and if you are working to optimize the setup, a turbo speed sensor would be immensely helpful here to provide you feedback

3 hours ago, discopotato03 said:

I don't think we will realise the true potential of these G Series turbos until Garrett or whoever starts making twin scroll turbine housings for them . V band is a bit nowhere for the mass market .  

working on it!  may be a little while but making progress.  interestingly Full Race appears to be the only Garrett distributor pushing for this, everyone else just wants vband

[Butters]

The lack of data points and proper testing on these turbos makes me really suspicious. 

They show a before and after boost curves with no rpm or road speed line to compare  

Plus went a really big housing for the small 2.6 and didn't test the smaller one as suggested. 

 

 

 

[Stixbnr32]

I think the point of the video is to show the power it can make but they ran into some issues.  The way youtubers make money is to make it into different parts not one big video.  So that will come no doubt. 

I think the potential is there though.

[Lithium]

15 hours ago, Butters said:

The lack of data points and proper testing on these turbos makes me really suspicious. 

They show a before and after boost curves with no rpm or road speed line to compare  

Plus went a really big housing for the small 2.6 and didn't test the smaller one as suggested. 

 

 

Agreed.  The driving seemed pretty decent to be fair, and realistically that should be the best indicator but it would have been nice to have seen a pull in a gear where it doesn't go so fast that you can't tell what's happened - 3rd gear with a boost gauge or something that is meaningful when you aren't actually in the car would have been good, but not having that isn't necessarily being dodgy so much as I know myself that it can be hard to remember what will be helpful when you are out thrashing.

The fact that no dyno/boost plot or overlay without calibrated rpm is a LOT more suspicious.  That seems like the obvious thing to share if you are happy with the results, or what you'd omit if you really would rather not show it.

In regards to the smaller housing, Andrew has mentioned a few times on FB that he'd rather they had a bigger turbine wheel - seems a lot like they think exhaust back pressure is an issue and would probably explain why they didn't bother with the 1.01 in the end.

 

2 hours ago, Stixbnr32 said:

I think the point of the video is to show the power it can make but they ran into some issues.  The way youtubers make money is to make it into different parts not one big video.  So that will come no doubt. 

I think the potential is there though.

To be fair, the issues didn't seem to be ones which would affect spool.  The fact that they pushed it hard with the 1.21 with no filter does make it seem like this must be the upper realms of this turbo in a street(ish) setup.

[Myskyliner33]

Hi All

With my current setup (nitto 2.8 and cnc head) i was originally looking to go with a BW9174 or 9180.

I then changed my mind and decided i would go with a PTE 6870 as i did not think the BW would get me the top end i wanted. 

So now with the release of the g35-1050 i am thinking that this might be the turbo for me as it should make more then the BW and have more response then the PTE.

Looking at the video from Andrew, its hard to tell as it does not look as responsive as i would have thought it would be. do you guys think im on the money with putting it between the BW abd PTE?? 

 

CheersNeal  

[Dose Pipe Sutututu]

Also remember he has a 6 speed sequential in there too, much easier staying at the right RPM range.

[burn4005]

Flat shift means your transient response really isn't important for straight line punting which is what this car is about. 

[Lithium]

57 minutes ago, Myskyliner33 said:

Hi All

With my current setup (nitto 2.8 and cnc head) i was originally looking to go with a BW9174 or 9180.

I then changed my mind and decided i would go with a PTE 6870 as i did not think the BW would get me the top end i wanted. 

So now with the release of the g35-1050 i am thinking that this might be the turbo for me as it should make more then the BW and have more response then the PTE.

Looking at the video from Andrew, its hard to tell as it does not look as responsive as i would have thought it would be. do you guys think im on the money with putting it between the BW abd PTE?? 

 

Tbh it's hard to know what to say in response to this as you haven't actually specified your aims.  You've mentioned response, and mentioned power, but not really what you are looking for.   Andrews video really didn't give much info on response, stamping the throttle in 2nd at mid rpm with a car with a sequential gearbox doesn't tell you much.   It didn't seem like a lag monster, but what can you really tell watching a video - especially when the video isn't showing a boost gauge or tacho?

Fwiw from the little I've seen and the fact that he's basically said its laggier than a GTW3884R (which would be lucky to be over 20psi by 5000rpm) and the fact that the pulls in the video start at an rpm and a gear where it's going to rev out reasonably well even with almost no boost initially it's really hard to draw much from, I'd not be surprised if a 6870 didn't give anything perceptible away.

With so little information out I'd be deciding between an EFR9180 or a Precision 6870, both known quantities - the 9180 if you want more response or a 6870 if you want more power.   

People seem to have been having issues with poor quality housing castings with the EFRs so I am dubious of them atm, so the Precision arguably may be the best option - unless you are keen on taking a punt on the likes of a Xona Rotor XR9569S, the family of which seem to be given some epic results.   There are a couple of RBs in Oz due to be running with those in the relatively near future, I'd keep an eye out for results on those as I suspect they could be impressive.

 

 

Edited March 9, 2020 by Lithium

[Myskyliner33]

Hi Lith

 

Thanks for the response. I should have given a bit more information. 

The car is being built as a street car with roll racing in mind, with a 9.9sec pass on some mt as a goal I would like to active. It's not a dedicated drag car as I still want to go for family drives.

I am sticking with a manual (r34 getrag) and 4.1 diffs, so thinking this should help with response. I understand It won't help with the lag situation but once in the right rpm range it should be able to maintain boost. 

One of the other reasons I was looking to go Garrett is the relaiabilty fact. I have a gt3566 custom built thing on my other skyline and it has never let me down. Mind you it is an old Turbo and quality may have changed since 2006. 

I may just have to wait for more results. To male the final decision. 

 

[Full-Race Geoff]

3 hours ago, Myskyliner33 said:

One of the other reasons I was looking to go Garrett is the relaiabilty fact. I have a gt3566 custom built thing on my other skyline and it has never let me down. Mind you it is an old Turbo and quality may have changed since 2006. 

the Garrett quality went up with G-series compared to the older GT - no question about it.  The only debate seems to be about lag/response compared to their legacy turbos.. which will likely continue to be a debate until the G-series divided turbine housings become available

[Myskyliner33]

Hi Geoff

I contacted GCG who advised the turbo was on back order (30Days) and i asked how long till the t4 rear would be released as i did not mind waiting. I was told it wont ever be released. 

no sure if this is true but i think GCG would know what is going on.

 

[Full-Race Geoff]

GCG is fantastic, we have a good collaborative relationship with one another.  theyve been at the turbo game for longer than I've been alive. 

Re the G-series ... divided t4 will eventually happen, it may take a year or more.  So don't wait for it.  You can swap turbine housings once they are released if you choose.  Full Race has 1 or 2 G35s left in stock if you or gcg need one.  0.83 and 1.01 a/r 

 

 

[Piggaz]

1 hour ago, Full-Race Geoff said:

GCG is fantastic, we have a good collaborative relationship with one another.  theyve been at the turbo game for longer than I've been alive. 

Re the G-series ... divided t4 will eventually happen, it may take a year or more.  So don't wait for it.  You can swap turbine housings once they are released if you choose.  Full Race has 1 or 2 G35s left in stock if you or gcg need one.  0.83 and 1.01 a/r 

 

 

Wouldn’t be so bad if it was only just the turbine housing. Need the manifold to suit.

[IB_8229]

Here's My 2015 STI running a G35-900:

500 whp & 454 ft-lbs @ 24psi Pump Gas/Meth.
603 whp & 546 ft-lbs @ 32.5 psi Pump Gas/Meth.

 

 

 

 

 

[omnigear]

On 3/9/2020 at 5:25 PM, Full-Race Geoff said:

the Garrett quality went up with G-series compared to the older GT - no question about it.  The only debate seems to be about lag/response compared to their legacy turbos.. which will likely continue to be a debate until the G-series divided turbine housings become available

Hi turbo noob here, what benefits do the GTX2860R provide over the old hks2530's and do i need tyrion lanniaters hands to fit em in the car?  I would like a responsive bottom and 600hp on the ground along with keeping the twin configuration.