So confused about Turbos. Garrett, precision, BW.

[khezz]

I've posted questions about various turbo choices before and I'm more confused then ever. Goal is a street able GTR that will run on 98ron fuel 90% of its life. It will be a genuine daily with around 700awhp. When I do go drag racing I will switch to e85 and aim is around 1100awhp. Engine is a 3.2L 9:1 Nitto stroker built  by JHH with a ported head, oversized vlaves. Engine is sorted.

Turbo choice 1. BW EFR9280. Best response, probably the most fun as a daily. Worried about back pressure with smaller exhaust housing but could aid spool/torque, 1.45 housing may be too big, not a lot of real world data available yet, probably won't make the power im after on e85.

Turbo choice 2. Precision Gen2 7275. Proven performer on the strip and dyno both on e85 and straight petrol. Will make more then enough power. Same concern with small exhaust housing but could also aud spool/torque. 

Turbo choice 3. Garrett G42-1200 (1450 was considered but its too much for my needs).  Will make the power, easy to service/repair, good exhaust housing sizes. Still not allot of data.

Turbo choice 4. Twin BW EFR7163. Will make the power, rare/unique, save on engineering. Some amazing kits in US. Yet still by far the most expensive. Should be great all around. Almost no data available. Very limited if decide to upgrade.

Now I have been told that "you don't need an 1100hp gtr". No, I don't but I can and I will. 

This the last part of the build that I haven't decided on. If you were in my shoes, which way would you go and why?

Thank you

[GTSBoy]

Turbo choice 4, on a VR38

[khezz]

13 minutes ago, GTSBoy said:

Turbo choice 4, on a VR38

That was an actual consideration. The engine would have cost half as much to build and would have been a torque mo ster but fitting it into an R32 simply priced it out of the equation.

[Kinkstaah]

For dragstrip use, none of the turbo options truly matter. For daily driving, none of the options really matter one way or the other. Given the description you may as well go with the easiest thing that fits and one that sounds the best to you.

Realistically it's the new G Series Garrett. The BW EFR is a great turbo, worthy of consideration - but it's strengths and your use case just don't overlap.

[khezz]

2 hours ago, Kinkstaah said:

For dragstrip use, none of the turbo options truly matter. For daily driving, none of the options really matter one way or the other. Given the description you may as well go with the easiest thing that fits and one that sounds the best to you.

Realistically it's the new G Series Garrett. The BW EFR is a great turbo, worthy of consideration - but it's strengths and your use case just don't overlap.

These sensible answers are not going to be very helpful. I already have a wife who is sensible. I need some one here to convince me that rocket boosters are the way to go.

[BK]

1 hour ago, khezz said:

These sensible answers are not going to be very helpful. I already have a wife who is sensible. I need some one here to convince me that rocket boosters are the way to go.

Ok then - sounds like you need a Precision 7675 and turn it up to 40psi. It will make your power goals on your 3.2.

[khezz]

55 minutes ago, BK said:

Ok then - sounds like you need a Precision 7675 and turn it up to 40psi. It will make your power goals on your 3.2.

 

[Lithium]

17 hours ago, khezz said:

I've posted questions about various turbo choices before and I'm more confused then ever. Goal is a street able GTR that will run on 98ron fuel 90% of its life. It will be a genuine daily with around 700awhp. When I do go drag racing I will switch to e85 and aim is around 1100awhp. Engine is a 3.2L 9:1 Nitto stroker built  by JHH with a ported head, oversized vlaves. Engine is sorted.

Turbo choice 1. BW EFR9280. Best response, probably the most fun as a daily. Worried about back pressure with smaller exhaust housing but could aid spool/torque, 1.45 housing may be too big, not a lot of real world data available yet, probably won't make the power im after on e85.

Turbo choice 2. Precision Gen2 7275. Proven performer on the strip and dyno both on e85 and straight petrol. Will make more then enough power. Same concern with small exhaust housing but could also aud spool/torque. 

Turbo choice 3. Garrett G42-1200 (1450 was considered but its too much for my needs).  Will make the power, easy to service/repair, good exhaust housing sizes. Still not allot of data.

Turbo choice 4. Twin BW EFR7163. Will make the power, rare/unique, save on engineering. Some amazing kits in US. Yet still by far the most expensive. Should be great all around. Almost no data available. Very limited if decide to upgrade.

Now I have been told that "you don't need an 1100hp gtr". No, I don't but I can and I will. 

This the last part of the build that I haven't decided on. If you were in my shoes, which way would you go and why?

Thank you

Hi sir, this definitely feels like it could be wide open aside from the fact you seem to have stated the "1100hp GTR" thing as an absolute requirement.

I'm going to do my normal annoying thing and respond to your question with more questions, and bring in some philosophical yarns about it - not to talk you down as that might not be needed, but just in case they are things you've not thought about.

1) What kind of dyno are you looking for "1100whp" on?  Making that on a Dynojet in the US or a hub dyno anywhere vs making it on a Dyno Dynamics or even Mustang rolling road dyno are two quite different things.  We're talking the possibility of needing to make 15%+ more power to measure "1100whp".

2) Given that dyno numbers are so all over the place, do you have an idea of how ACTUAL fast you want it to be?  Have you experienced a car which would do sub tens, or driven a "BIG turbo car"?

3) What kind of transmission are you going to be running?   If you are going to be running a clutched/h-pattern gearbox predominantly on the road I'd definitely be biasing the more punchy things versus hoping for a full 1100whp personally.  I guess you are using a few cubes, but it can be pretty amazing how much boost you lose in shifts if you don't have no lift shifting or anything like that when using a large turbo.... there is probably a zone where if you are going to have some mechanical sympathy that a more responsive/lower powered turbo will be as quick or quicker EVEN on the 1/4mile.

I'll leave those questions and be interested to see what you say, but to give a general feeling from what you've said so far - what I'd go for if I were in your position:

1) If the 1100whp target is important and you are using a sequential/auto and especially if you have the option of no lift shifting when you are in race mode - I would actually go Gen2 7675, or even 7685.   The amount of lag you step up to when you try and aim for a legit 1100+hp starts blurring a bit, and if "crazy power" is important to you then you're going to want more anyway.   People don't seem to sit with 7275 sized turbos for too long, once you go past the solid 68mm things people just end up unhappy until they've gone ~76 from what I've seen.    If you really want 1100whp, just go straight here imho... don't f**k around.

2) Of the options you've provided, if the peak power isn't THAT important but you want it to be fast then if it were me and I wanted something that 90% of its life it was on 98 and road use and especially if you're using a more convention transmission etc then I'd use an EFR9280.  I don't think it will make 1100whp on E85, it may fall pretty well short - but it will be very fast, and very usable.   I'm not super blown away by what I've seen of these though, like I'm not certain that they are any better an option than the best 68mm turbos out there which makes me hesitant to suggest them given the price, intolerance to overspeed, and less than ideal packaging which brings me to:

3) If I'm answering #2, but casting a wider net to options you've not mentioned so that I'm just answering "this is what I would do in your shoes".   If it were ME then I'd go with a Xona Rotor XR9569S.  This is not because I have enough data to prove that its the best choice, or even that I am necessarily 100% sure that it is.   It's more that I have a hard on for Xona Rotor right now, I feel like the best 68mm turbos (so the Precision 6870 deserves an honorable mention here) offer a real nice in between for being a fun street turbo but also the potential to be real world FAST... often nipping on the heals of things running the bigger frame units despite being down on peak power, especially where conventional gear shifting is involved.   The Xonas are something different, very unique turbine wheel which have amazingly low EMAP for their size, very good transient response, have a TiAL v-band flange which is easier packaging and potential upgrade path wise I think, and you're not likely to make peak numbers any higher without going >70mm.    The two quickest A90 Supras in the world right now (well, last I checked) are running high 8s at >155mph with these turbos on 3.2litre straight 6s without nitrous - peak numbers aside they can make for a proper fast car but something that would be still really fun and real world fast "just" running on pump gas, you'd not need to have E85 and be revving it to the moon to be making it seem worthwhile.

In regards to the twins, imho you would have to REALLY want to go that way specifically.  PMC's G25-660 RB28 does seem like an epic combo for the power to be fair - probably the most impressed I have been with a twin-turbo RB setup that I can think of but as you said yourself, a lot of expense and not a very flexible point to build on if you decide you want to change in future.  

Just my NZ2c

 

Edited April 19, 2021 by Lithium

[Dose Pipe Sutututu]

I really hate talking in HP, please kW, this is an Australia forum and in Australia we use the metric system like most of the world.

If we want to talk in HP sure, please fk off to the US of A..

[Dose Pipe Sutututu]

Woooooooooooo

 

[GTSBoy]

MAGA in a single image.

[khezz]

2 hours ago, Lithium said:

Hi sir, this definitely feels like it could be wide open aside from the fact you seem to have stated the "1100hp GTR" thing as an absolute requirement.

I'm going to do my normal annoying thing and respond to your question with more questions, and bring in some philosophical yarns about it - not to talk you down as that might not be needed, but just in case they are things you've not thought about.

1) What kind of dyno are you looking for "1100whp" on?  Making that on a Dynojet in the US or a hub dyno anywhere vs making it on a Dyno Dynamics or even Mustang rolling road dyno are two quite different things.  We're talking the possibility of needing to make 15%+ more power to measure "1100whp".

2) Given that dyno numbers are so all over the place, do you have an idea of how ACTUAL fast you want it to be?  Have you experienced a car which would do sub tens, or driven a "BIG turbo car"?

3) What kind of transmission are you going to be running?   If you are going to be running a clutched/h-pattern gearbox predominantly on the road I'd definitely be biasing the more punchy things versus hoping for a full 1100whp personally.  I guess you are using a few cubes, but it can be pretty amazing how much boost you lose in shifts if you don't have no lift shifting or anything like that when using a large turbo.... there is probably a zone where if you are going to have some mechanical sympathy that a more responsive/lower powered turbo will be as quick or quicker EVEN on the 1/4mile.

I'll leave those questions and be interested to see what you say, but to give a general feeling from what you've said so far - what I'd go for if I were in your position:

1) If the 1100whp target is important and you are using a sequential/auto and especially if you have the option of no lift shifting when you are in race mode - I would actually go Gen2 7675, or even 7685.   The amount of lag you step up to when you try and aim for a legit 1100+hp starts blurring a bit, and if "crazy power" is important to you then you're going to want more anyway.   People don't seem to sit with 7275 sized turbos for too long, once you go past the solid 68mm things people just end up unhappy until they've gone ~76 from what I've seen.    If you really want 1100whp, just go straight here imho... don't f**k around.

2) Of the options you've provided, if the peak power isn't THAT important but you want it to be fast then if it were me and I wanted something that 90% of its life it was on 98 and road use and especially if you're using a more convention transmission etc then I'd use an EFR9280.  I don't think it will make 1100whp on E85, it may fall pretty well short - but it will be very fast, and very usable.   I'm not super blown away by what I've seen of these though, like I'm not certain that they are any better an option than the best 68mm turbos out there which makes me hesitant to suggest them given the price, intolerance to overspeed, and less than ideal packaging which brings me to:

3) If I'm answering #2, but casting a wider net to options you've not mentioned so that I'm just answering "this is what I would do in your shoes".   If it were ME then I'd go with a Xona Rotor XR9569S.  This is not because I have enough data to prove that its the best choice, or even that I am necessarily 100% sure that it is.   It's more that I have a hard on for Xona Rotor right now, I feel like the best 68mm turbos (so the Precision 6870 deserves an honorable mention here) offer a real nice in between for being a fun street turbo but also the potential to be real world FAST... often nipping on the heals of things running the bigger frame units despite being down on peak power, especially where conventional gear shifting is involved.   The Xonas are something different, very unique turbine wheel which have amazingly low EMAP for their size, very good transient response, have a TiAL v-band flange which is easier packaging and potential upgrade path wise I think, and you're not likely to make peak numbers any higher without going >70mm.    The two quickest A90 Supras in the world right now (well, last I checked) are running high 8s at >155mph with these turbos on 3.2litre straight 6s without nitrous - peak numbers aside they can make for a proper fast car but something that would be still really fun and real world fast "just" running on pump gas, you'd not need to have E85 and be revving it to the moon to be making it seem worthwhile.

In regards to the twins, imho you would have to REALLY want to go that way specifically.  PMC's G25-660 RB28 does seem like an epic combo for the power to be fair - probably the most impressed I have been with a twin-turbo RB setup that I can think of but as you said yourself, a lot of expense and not a very flexible point to build on if you decide you want to change in future.  

Just my NZ2c

 

Thank you for the informative reply. 

I will be using a DynoDynamics. The goal isn't strictly 1100awhp or nothing. If I get close consistently (1050-1100), I'll be ok with that. I know that it will be different every time. I would like to be able to be able to show up to a meet and no matter what the day bring's be able to reel off comfortable 1000-1100awhp+ on any dyno.

As for how fast I want it to be. 9 seconds on 98ron fuel and 8 seconds on e85. I had an early model XR6 turbo sedan (4L turbo 6 cyl) which got me oh so close to 10s. I have been in many of 10 second 6s and 8s. The R32 GTR is my unicorn car. Not a Ferrari or a Lambo or anything else. With the technology these days, you can have an 8 second 1100awhp and live with it on a daily basis. So, why not. It will probably be the last car I get to build.

I am pricing up a PPG dog box but leaning more towards a sequential with flat shift capabilities. NO AUTO!

I think logic is strongly pointing towards a Garrett or a Precision. Proven, well priced, easy to upgrade, plenty of support.

Efr seems like a ground braking product but like you said it will come up shy of my power goals and reliability is a concern. Especially if I am planning to push it to its limits.

Twins would be amazing g25-660 is an option also. Well spotted. There is an R34 that runs them for circuit work. Problem is if its done wrong it is very expensive to redo.

Maybe I should go the 7675/85 or a 1450 since. Push them less, less heat, more reliability and go sequential to limit any lag. Ill be honest I haven't heard of people using the Xona products here. So support and knowledge would be a very big factor.

 

[khezz]

2 hours ago, Dose Pipe Sutututu said:

I really hate talking in HP, please kW, this is an Australia forum and in Australia we use the metric system like most of the world.

If we want to talk in HP sure, please fk off to the US of A..

Well I am Russian born so my power goals are 1.1 Putin power. Or just devide hp by roughly one and a third. You know like we did in year 2.

Edited April 20, 2021 by khezz

[Lithium]

36 minutes ago, khezz said:

Thank you for the informative reply. 

As for how fast I want it to be. 9 seconds on 98ron fuel and 8 seconds on e85. I had an early model XR6 turbo sedan (4L turbo 6 cyl) which got me oh so close to 10s. I have been in many of 10 second 6s and 8s. The R32 GTR is my unicorn car. Not a Ferrari or a Lambo or anything else. With the technology these days, you can have an 8 second 1100awhp and live with it on a daily basis. So, why not. It will probably be the last car I get to build.

I am pricing up a PPG dog box but leaning more towards a sequential with flat shift capabilities. NO AUTO!

Maybe I should go the 7675/85 or a 1450 since. Push them less, less heat, more reliability and go sequential to limit any lag. Ill be honest I haven't heard of people using the Xona products here. So support and knowledge would be a very big factor.

 

No worries.  Based on what you've seen there, and if you've got the setup to hold it - I'd write off the G42-1200, the 7275 as well as the EFR.  I personally would go the Precision 76mm over the Garrett 79mm as well, the Precisions are just so proven at this kind of level on this kind of setup... just such a known quantity for offering a good balance of compressor flow, response, and backpressure.

If you haven't seen this then find some time to have a watch over it, it is very relevant to this discussion.  The TRC R32 GT-R runs an RB32 with a Precision 7685 Gen2....

Out of interest there are people running Xona products in Oz, Cartel in Oz (https://www.cartel-aus.com/product-category/turbos/xona-rotor/) sell them and have a few people running them to good effect.  They're also pretty proven in the US, but there are levels which different brands seem to have focussed on and the area you are looking (single turbo comfortably making >1000whp on a 2-4litre engine) is pretty well covered by Precision and I'd not suggest anything else.  The Xonas are best at the "700-1000whp per turbo with epic response and not epic backpressure" kind of deal - to the level that cars running them often are matching or beating things with bigger peak power numbers.

Edited April 20, 2021 by Lithium

[khezz]

1 hour ago, Lithium said:

No worries.  Based on what you've seen there, and if you've got the setup to hold it - I'd write off the G42-1200, the 7275 as well as the EFR.  I personally would go the Precision 76mm over the Garrett 79mm as well, the Precisions are just so proven at this kind of level on this kind of setup... just such a known quantity for offering a good balance of compressor flow, response, and backpressure.

If you haven't seen this then find some time to have a watch over it, it is very relevant to this discussion.  The TRC R32 GT-R runs an RB32 with a Precision 7685 Gen2....

Out of interest there are people running Xona products in Oz, Cartel in Oz (https://www.cartel-aus.com/product-category/turbos/xona-rotor/) sell them and have a few people running them to good effect.  They're also pretty proven in the US, but there are levels which different brands seem to have focussed on and the area you are looking (single turbo comfortably making >1000whp on a 2-4litre engine) is pretty well covered by Precision and I'd not suggest anything else.  The Xonas are best at the "700-1000whp per turbo with epic response and not epic backpressure" kind of deal - to the level that cars running them often are matching or beating things with bigger peak power numbers.

I have watched the videos of their build. Amazing result.

That's 3 for Precision. 

[Dose Pipe Sutututu]

2 hours ago, Lithium said:

Precisions are just so proven

Yep... I might too

[Lithium]

5 minutes ago, Dose Pipe Sutututu said:

Yep... I might too

At THAT kind of level, yes   EFRs have their place, as with Xona Rotors and Garretts..  The 6466 and 6870 are beasts as well, but I only really lean to them as being "the best" until you are looking at over 1000hp - realistically it seems that as much as you get people talking about EFRs being fragile, smoky Precisions seem more common than broken EFRs.  

Why not stick with your Garrett? They should have heaps more in it.

 

Edited April 20, 2021 by Lithium

[khezz]

45 minutes ago, Lithium said:

At THAT kind of level, yes   EFRs have their place, as with Xona Rotors and Garretts..  The 6466 and 6870 are beasts as well, but I only really lean to them as being "the best" until you are looking at over 1000hp - realistically it seems that as much as you get people talking about EFRs being fragile, smoky Precisions seem more common than broken EFRs.  

Why not stick with your Garrett? They should have heaps more in it.

 

At the end of the day, it's all me handicap it will all break. If misused or not looked after, it will break sooner.

[Dose Pipe Sutututu]

52 minutes ago, Lithium said:

Why not stick with your Garrett? They should have heaps more in it.

I will at first, to see if I can get what I want out of it.. I have a suspicion I "might" get there but all the SAU internet mechanic/tuner experts don't think I will get there. If not, then hello Precision lol.

[Lithium]

13 minutes ago, Dose Pipe Sutututu said:

I will at first, to see if I can get what I want out of it.. I have a suspicion I "might" get there but all the SAU internet mechanic/tuner experts don't think I will get there. If not, then hello Precision lol.

What is your power target?   I feel like I've said a few times that the 3576 should be capable of more than some may expect, or do I not count as an SAU internet mechach00ner?