Gtx4202 or g42-1450 turbo? Wanting 700hp street car
On a Bridgeport we were making 30psi by 4200rpm
On a street port we were making 30psi by around 4600rpm both cars are making good transient boost as well, with the twin scroll setup done properly boost is very linear, it does not feel like a light switch
On a street port we were making 30psi by around 4600rpm both cars are making good transient boost as well, with the twin scroll setup done properly boost is very linear, it does not feel like a light switch
and you state your personal experience as the end-all of end-alls, when clearly that isn’t the case
and actually I was stating some direct personal experience, just as I have put a lot of time into studying and assessing what others are doing as well. Yourself included.
I’m not a fan of BP, but whatever floats somebody else’s boat is their own deal.
I also don’t have any problem with what you’re saying, I simply disagree for the very reasons you stated; the variables involved. That can go both ways.
.
and actually I was stating some direct personal experience, just as I have put a lot of time into studying and assessing what others are doing as well. Yourself included.
I’m not a fan of BP, but whatever floats somebody else’s boat is their own deal.
I also don’t have any problem with what you’re saying, I simply disagree for the very reasons you stated; the variables involved. That can go both ways.
.
Last edited by TeamRX8; Jan 28, 2023 at 04:18 PM.
maybe this will add some context, because the OP is from down under and the following quote is where he was at when the thread started with the request. Which is not using pump gasoline fuel and is maxed out on compressor, likely as responsive as that turbo can possibly be:
If he ran that on your dyno my bet is the number would be lower, and this was what he decided on for the GTX4202R turbine:
which matches up with a G40-1150 0.94. He never posted again on this forum, so maybe he never followed through on it.
but it’s roughly equivalent to the lower end of the BW S400SXE range with 0.90 A/R. I wouldn’t disagree that a larger turbine might be better for certain conditions, but to say it absolutely won’t work goes against the many results on this forum. Of which there are AU results as well.
When I said it can go both ways, I meant that your engine might be making even more equivalent hp than you fully realize. You might consider going away from a BP to a semi-PP for a better overall result.
.
Thanks guys. I have a street port with a t04z running 550hp on e85 at the wheels. I know the gtx42 has been around a while and interested in the results of the g42 as it's a new turbo. I see the BW is big in America but I would prefer to still to garett. Looks like it might be the gtx42 I may go with. But now the problem of which rear housing?
If he ran that on your dyno my bet is the number would be lower, and this was what he decided on for the GTX4202R turbine:
which matches up with a G40-1150 0.94. He never posted again on this forum, so maybe he never followed through on it.
but it’s roughly equivalent to the lower end of the BW S400SXE range with 0.90 A/R. I wouldn’t disagree that a larger turbine might be better for certain conditions, but to say it absolutely won’t work goes against the many results on this forum. Of which there are AU results as well.
When I said it can go both ways, I meant that your engine might be making even more equivalent hp than you fully realize. You might consider going away from a BP to a semi-PP for a better overall result.
.
Senior Member
Joined: Jun 2010
Posts: 476
Likes: 240
From: Instagram - Copyninja_FD
Thread Starter
Junior Member
Joined: Jul 2019
Posts: 15
Likes: 2
From: Gold coast
maybe this will add some context, because the OP is from down under and the following quote is where he was at when the thread started with the request. Which is not using pump gasoline fuel and is maxed out on compressor, likely as responsive as that turbo can possibly be:
If he ran that on your dyno my bet is the number would be lower, and this was what he decided on for the GTX4202R turbine:
which matches up with a G40-1150 0.94. He never posted again on this forum, so maybe he never followed through on it.
but it’s roughly equivalent to the lower end of the BW S400SXE range with 0.90 A/R. I wouldn’t disagree that a larger turbine might be better for certain conditions, but to say it absolutely won’t work goes against the many results on this forum. Of which there are AU results as well.
When I said it can go both ways, I meant that your engine might be making even more equivalent hp than you fully realize. You might consider going away from a BP to a semi-PP for a better overall result.
.
If he ran that on your dyno my bet is the number would be lower, and this was what he decided on for the GTX4202R turbine:
which matches up with a G40-1150 0.94. He never posted again on this forum, so maybe he never followed through on it.
but it’s roughly equivalent to the lower end of the BW S400SXE range with 0.90 A/R. I wouldn’t disagree that a larger turbine might be better for certain conditions, but to say it absolutely won’t work goes against the many results on this forum. Of which there are AU results as well.
When I said it can go both ways, I meant that your engine might be making even more equivalent hp than you fully realize. You might consider going away from a BP to a semi-PP for a better overall result.
.
Went a different avenue. Went the gtx3584rs. 1.01 rear housing . 24psi dynoed 542hp. Using full potential of the turbo from 2800rpm right through no drop in power. Will always wonder if the bigger turbo would be worth it but can't be bothered with lag. If anything I may look at a bigger rear housing but unsure if that would change the hp by much.
Cheers
nice. as expected for the choice 
thanks for taking the time to let us know and congratulations on a successful result.
would agree with your assessment that the 1.06 will breathe better up high, but it’s a bit of a jump in turbine flow potential (3-4 lbs/min peak) and will likely impact low end response. It’s also already pushing out in the less efficient area of the compressor map. Better safe than sorry.
.
thanks for taking the time to let us know and congratulations on a successful result.
would agree with your assessment that the 1.06 will breathe better up high, but it’s a bit of a jump in turbine flow potential (3-4 lbs/min peak) and will likely impact low end response. It’s also already pushing out in the less efficient area of the compressor map. Better safe than sorry.
.
Last edited by TeamRX8; Mar 6, 2023 at 01:12 PM.
Senior Member
Joined: Oct 2006
Posts: 439
Likes: 337
From: SoCal
Gents
Went a different avenue. Went the gtx3584rs. 1.01 rear housing . 24psi dynoed 542hp. Using full potential of the turbo from 2800rpm right through no drop in power. Will always wonder if the bigger turbo would be worth it but can't be bothered with lag. If anything I may look at a bigger rear housing but unsure if that would change the hp by much.
Cheers
Went a different avenue. Went the gtx3584rs. 1.01 rear housing . 24psi dynoed 542hp. Using full potential of the turbo from 2800rpm right through no drop in power. Will always wonder if the bigger turbo would be worth it but can't be bothered with lag. If anything I may look at a bigger rear housing but unsure if that would change the hp by much.
Cheers
Thread Starter
Junior Member
Joined: Jul 2019
Posts: 15
Likes: 2
From: Gold coast
nice. as expected for the choice
thanks for taking the time to let us know and congratulations on a successful result.
would agree with your assessment that the 1.06 will breathe better up high, but it’s a bit of a jump in turbine flow potential (3-4 lbs/min peak) and will likely impact low end response. It’s also already pushing out in the less efficient area of the compressor map. Better safe than sorry.
.
thanks for taking the time to let us know and congratulations on a successful result.
would agree with your assessment that the 1.06 will breathe better up high, but it’s a bit of a jump in turbine flow potential (3-4 lbs/min peak) and will likely impact low end response. It’s also already pushing out in the less efficient area of the compressor map. Better safe than sorry.
.
maybe you missed the “better safe than sorry” part of the comment?
but if you decide to push your luck further, then the 1.06 A/R or higher is a better/safer choice.
Probably should confirm what type of turbine housing inlet you have; V-band, T3 or T4?
.
but if you decide to push your luck further, then the 1.06 A/R or higher is a better/safer choice.
Probably should confirm what type of turbine housing inlet you have; V-band, T3 or T4?
.
Last edited by TeamRX8; Mar 8, 2023 at 01:38 AM.
Thread Starter
Junior Member
Joined: Jul 2019
Posts: 15
Likes: 2
From: Gold coast
Also. I didn't think there was a 1.06. I think the next size up was the 1.21
Last edited by Broadbeach; Mar 8, 2023 at 02:48 AM.
in the V-band that’s correct, which is why I asked.
as far as I know, your only larger V-band options would either be the Garrett 1.21 A/R or Tial 1.03 A/R housings.
There is a 1.01 T3 and a 1.06 div T4
edit: found an offbrand name 1.06 v-band on the web:
https://arashidynamics.com/products/...sing-stainless
as far as I know, your only larger V-band options would either be the Garrett 1.21 A/R or Tial 1.03 A/R housings.
There is a 1.01 T3 and a 1.06 div T4
edit: found an offbrand name 1.06 v-band on the web:
https://arashidynamics.com/products/...sing-stainless
Last edited by TeamRX8; Mar 8, 2023 at 05:13 AM.
Thread Starter
Junior Member
Joined: Jul 2019
Posts: 15
Likes: 2
From: Gold coast
in the V-band that’s correct, which is why I asked.
as far as I know, your only larger V-band options would either be the Garrett 1.21 A/R or Tial 1.03 A/R housings.
There is a 1.01 T3 and a 1.06 div T4
edit: found an offbrand name 1.06 v-band on the web:
https://arashidynamics.com/products/...sing-stainless
as far as I know, your only larger V-band options would either be the Garrett 1.21 A/R or Tial 1.03 A/R housings.
There is a 1.01 T3 and a 1.06 div T4
edit: found an offbrand name 1.06 v-band on the web:
https://arashidynamics.com/products/...sing-stainless
got nothing to offer you on a Precision.
imo the GTX3584RS was the predecessor of the current G-series, or at least the turbine in terms of continuing development in that direction.
Based on where you’re at, I’d suggest a G40-1150 with 0.85 A/R. It’s a balanced jump up in compressor (+20 lbs/min) and turbine flow (+6 lbs/min). Which gives you some margin to go higher still, going to cost you though.
but you could also consider a G35-1050 1.01 A/R; + 10 lbs/min compressor and +3 lbs/min turbine over the GTX3584RS 1.01.
.
imo the GTX3584RS was the predecessor of the current G-series, or at least the turbine in terms of continuing development in that direction.
Based on where you’re at, I’d suggest a G40-1150 with 0.85 A/R. It’s a balanced jump up in compressor (+20 lbs/min) and turbine flow (+6 lbs/min). Which gives you some margin to go higher still, going to cost you though.
but you could also consider a G35-1050 1.01 A/R; + 10 lbs/min compressor and +3 lbs/min turbine over the GTX3584RS 1.01.
.
Last edited by TeamRX8; Mar 9, 2023 at 12:42 AM.
Thread Starter
Junior Member
Joined: Jul 2019
Posts: 15
Likes: 2
From: Gold coast
got nothing to offer you on a Precision.
imo the GTX3584RS was the predecessor of the current G-series, or at least the turbine in terms of continuing development in that direction.
Based on where you’re at, I’d suggest a G40-1150 with 0.85 A/R. It’s a balanced jump up in compressor (+20 lbs/min) and turbine flow (+6 lbs/min). Which gives you some margin to go higher still, going to cost you though.
but you could also consider a G35-1050 1.01 A/R; + 10 lbs/min compressor and +3 lbs/min turbine over the GTX3584RS 1.01.
.
imo the GTX3584RS was the predecessor of the current G-series, or at least the turbine in terms of continuing development in that direction.
Based on where you’re at, I’d suggest a G40-1150 with 0.85 A/R. It’s a balanced jump up in compressor (+20 lbs/min) and turbine flow (+6 lbs/min). Which gives you some margin to go higher still, going to cost you though.
but you could also consider a G35-1050 1.01 A/R; + 10 lbs/min compressor and +3 lbs/min turbine over the GTX3584RS 1.01.
.
Thread Starter
Junior Member
Joined: Jul 2019
Posts: 15
Likes: 2
From: Gold coast
got nothing to offer you on a Precision.
imo the GTX3584RS was the predecessor of the current G-series, or at least the turbine in terms of continuing development in that direction.
Based on where you’re at, I’d suggest a G40-1150 with 0.85 A/R. It’s a balanced jump up in compressor (+20 lbs/min) and turbine flow (+6 lbs/min). Which gives you some margin to go higher still, going to cost you though.
but you could also consider a G35-1050 1.01 A/R; + 10 lbs/min compressor and +3 lbs/min turbine over the GTX3584RS 1.01.
.
imo the GTX3584RS was the predecessor of the current G-series, or at least the turbine in terms of continuing development in that direction.
Based on where you’re at, I’d suggest a G40-1150 with 0.85 A/R. It’s a balanced jump up in compressor (+20 lbs/min) and turbine flow (+6 lbs/min). Which gives you some margin to go higher still, going to cost you though.
but you could also consider a G35-1050 1.01 A/R; + 10 lbs/min compressor and +3 lbs/min turbine over the GTX3584RS 1.01.
.
You can’t just pick any A/R number, or at least not unless you’re a high stakes roller and like taking wild chances. It needs to be understood that A/R is only dimensional relationship that applies to the specific turbo model being looked at. When a turbine flow map is available then it needs to be referenced to figure out what the potential flow values are for making a selection to somewhat match the intention and get you in the ballpark to achieve that. It’d possibly need to be refined from there with testing and data collection.
The 1.01 A/R turbine flow map rate on your current turbo is indicating ~28 lbs/min @2.25 PR
The G40 1.06 A/R turbine at 2.25 PR is indicating ~39 lbs/min. This is a substantial increase from where you presently are.
To emphasize the point, the 1.06 A/R turbine for the GTX3584RS that you have now is indicating ~32.5 lbs/min there.
The G40 0.91 A/R is indicating ~36 lbs/min there and the G35 1.01 A/R is indicating ~30 lbs/min. I was being a bit conservative on the G40 0.91 A/R selection; the 0.85 A/R is indicating ~34 lbs/min and should be more responsive.
It’s not that you can’t use the G40 1.06 A/R, but the response the current setup has now and was stated as being important to you will likely be sacrificed. Because the G40 1.06 would support quite a bit more power than the current turbo is making. Unless you intend to shoot for substantially more.
Looking at it again closer, the G35 1.01 turbine map curve flattens out some in the PR range it’d likely be operating in. So I’d refine it to either the G40 0.85 or 0.91 depending on the power/response goal.
.
The 1.01 A/R turbine flow map rate on your current turbo is indicating ~28 lbs/min @2.25 PR
The G40 1.06 A/R turbine at 2.25 PR is indicating ~39 lbs/min. This is a substantial increase from where you presently are.
To emphasize the point, the 1.06 A/R turbine for the GTX3584RS that you have now is indicating ~32.5 lbs/min there.
The G40 0.91 A/R is indicating ~36 lbs/min there and the G35 1.01 A/R is indicating ~30 lbs/min. I was being a bit conservative on the G40 0.91 A/R selection; the 0.85 A/R is indicating ~34 lbs/min and should be more responsive.
It’s not that you can’t use the G40 1.06 A/R, but the response the current setup has now and was stated as being important to you will likely be sacrificed. Because the G40 1.06 would support quite a bit more power than the current turbo is making. Unless you intend to shoot for substantially more.
Looking at it again closer, the G35 1.01 turbine map curve flattens out some in the PR range it’d likely be operating in. So I’d refine it to either the G40 0.85 or 0.91 depending on the power/response goal.
.
Last edited by TeamRX8; Mar 10, 2023 at 08:48 PM.
Junior Member
Joined: Jul 2016
Posts: 16
Likes: 0
From: Burlington
Lots of great info on this thread.
Wondering if anyone has thoughts or confirmation on what a G42-1450 with a 1.15 AR would be like for a street driven street ported 20B FD?
Currently have an older PT76 with a .96 AR
Car is only street driven and plan to run max 15 lbs of boost. Would like to hit ~600 rwhp on pump gas and have good low rpm response.
Wondering if anyone has thoughts or confirmation on what a G42-1450 with a 1.15 AR would be like for a street driven street ported 20B FD?
Currently have an older PT76 with a .96 AR
Car is only street driven and plan to run max 15 lbs of boost. Would like to hit ~600 rwhp on pump gas and have good low rpm response.
Arrogant Wankeler
Joined: Nov 2006
Posts: 1,008
Likes: 231
From: Hunter Valley NSW Australia
Lots of great info on this thread.
Wondering if anyone has thoughts or confirmation on what a G42-1450 with a 1.15 AR would be like for a street driven street ported 20B FD?
Currently have an older PT76 with a .96 AR
Car is only street driven and plan to run max 15 lbs of boost. Would like to hit ~600 rwhp on pump gas and have good low rpm response.
Wondering if anyone has thoughts or confirmation on what a G42-1450 with a 1.15 AR would be like for a street driven street ported 20B FD?
Currently have an older PT76 with a .96 AR
Car is only street driven and plan to run max 15 lbs of boost. Would like to hit ~600 rwhp on pump gas and have good low rpm response.
Joined: Oct 2001
Posts: 6,279
Likes: 728
From: Florence, Alabama
"G40-1150 should do 600 at 1 Bar and respond much faster."
i am still running my G40-1150 off the spring... about 15.9 psi. i am seeing 515-520 at 2600 ft elevation on a very conservative tune.. this was 3rd gear and road limited to 7250. probably a bit more power if i was able to run it out to 9000.
if you are looking for 700 i certainly wouldn't go bigger than the G40-1150.
i am still running my G40-1150 off the spring... about 15.9 psi. i am seeing 515-520 at 2600 ft elevation on a very conservative tune.. this was 3rd gear and road limited to 7250. probably a bit more power if i was able to run it out to 9000.
if you are looking for 700 i certainly wouldn't go bigger than the G40-1150.
Last edited by Howard Coleman; Apr 9, 2023 at 08:00 AM.
