Lets talk turbos. T4 big singles

MorganY · Jan 30, 2014

dzlpwr said:
More worried about more airflow. Spool is always nice. Like I said my 75 spools very well so if I can go to a bigger, easier spooling charger and keep spool time similar to how it is now, but flow more air I would be a happy camper

GTX4508 with a tight turbine housing.

Josh@DirtyDiesels · Jan 30, 2014

MorganY said:
GTX4508 with a tight turbine housing.

word. Time to do some research.

Josh@DirtyDiesels · Jan 30, 2014

What about even a garrett 4202 vs the 475? The 4508 looks a bit on the large side

sleeps · Jan 30, 2014

BW has an fmw 80mm, i dont have a big turbo setup on my truck just spit balling.
http://www.full-race.com/store/turb...borgwarner-s400sx-80mm-1-25-a-r-t4-turbo.html

MorganY · Jan 30, 2014

dzlpwr said:
What about even a garrett 4202 vs the 475? The 4508 looks a bit on the large side

You said large lol. 4202 will spool better than a 475.

Look into the EFRs too.

The 4508 accelerates faster than my 478 with the same amount of volume introduced into the volutes. 4508 had a 1.28 housing vs. The 1.10 on my 478.

Josh@DirtyDiesels · Jan 30, 2014

MorganY said:
You said large lol. 4202 will spool better than a 475.

Look into the EFRs too.

The 4508 accelerates faster than my 478 with the same amount of volume introduced into the volutes. 4508 had a 1.28 housing vs. The 1.10 on my 478.

True... the 4202 seems to be very similar to what I'm running now. I wonder how the 4508 would spool on my setup. It's a tough call to make because that's a lot of $$ to drop on a charger just to see if it works lol.

KCTurbos · Jan 30, 2014

Seems like the gt4508r would be right at the limit of what you could run. It is riding the surge line. Depending on the volumetric efficiency of your motor and what exhaust housing your run... It looks like 700hp is possible.

I made up a quick compressor map for reference.

BlueWaffle · Jan 30, 2014

if you want more flow, aren't worried about spool up, and don't want to spend a fortune...just throw a cast 80 in there. 120 lb/min for $1000 aint bad!

Extended Power · Jan 30, 2014

BlueWaffle said:
if you want more flow, aren't worried about spool up, and don't want to spend a fortune...just throw a cast 80 in there. 120 lb/min for $1000 aint bad!

I think Cutting Edge has a couple used 80mm for sale right now...give em a shout.

MorganY · Jan 30, 2014

BlueWaffle said:
if you want more flow, aren't worried about spool up, and don't want to spend a fortune...just throw a cast 80 in there. 120 lb/min for $1000 aint bad!

I dont think a journal that size will spool on a 6.0. Need a 2700 stall at the minimum.

Josh@DirtyDiesels · Jan 30, 2014

MorganY said:
I dont think a journal that size will spool on a 6.0. Need a 2700 stall at the minimum.

I agree with this. Don't know how well that would work or if it would even light at all. Been there, done that with a 2700 stall. Screw that!

smoker00 · Jan 30, 2014

I know im not running a 6.0 but I have run a 7675BB and a 7685BB and now this GTX4294.. I have liked this GTX the best ..I am going to move up to a GTX4202.. because how fast this 94 spool.. even with a lower than stock TC.. I like the BB stuff I have run some different S400's too.. But ill stick with my BB chargers..

How about A precision 7675/7685 DBB, GTX4202 flows like a 80mm spools like a 70mm or a GTX4508.

Josh@DirtyDiesels · Jan 30, 2014

smoker00 said:
I know im not running a 6.0 but I have run a 7675BB and a 7685BB and now this GTX4294.. I have liked this GTX the best ..I am going to move up to a GTX4202.. because how fast this 94 spool.. even with a lower than stock TC.. I like the BB stuff I have run some different S400's too.. But ill stick with my BB chargers..

How about A precision 7675/7685 DBB, GTX4202 flows like a 80mm spools like a 70mm or a GTX4508.

I still need to read more about the PT chargers. The 4202 interests me quite a bit, just curious if it will flow that much better than my 475. The 4508 is also very intriguing but I wonder if it will spool halfway decent...

KCTurbos · Jan 30, 2014

Not to start any huge battle or argument so take this with a grain of salt.

I would say 99% of 6.0 owners running fuel only with a large single are not going to flow 120lbs of air out of an 80mm cast turbo. That is the maximum that turbo can flow if you were even able to spin the rpms up high enough. You would be lucky to get 90lbs of air out of it. To get 120lbs of air out of a 6.0 you would have to be pushing 100psi of boost or run it up past 5000rpms. IMO too many people look at a compressor map and look to see what the maximum air flow of the compressor is without even taking into account the volumetric efficiency of the motor, rpm band, air flow, surge line, efficiency islands, etc... those are the more important parts of it for us 6.0 guys. Most people are not hitting the right side of the compressor map unless you are running a tiny turbo. Most of us are going to be riding the surge line and maxing out at the top of the compressor map. The only way to get more power out of our motors is to increase the pressure ratio... but once you reach the top of the compressor map and the end of the rpm band then you have tapped out the flowing ability of the turbo.

Just a little food for thought

Josh@DirtyDiesels · Jan 30, 2014

KCTurbos said:
Not to start any huge battle or argument so take this with a grain of salt.

I would say 99% of 6.0 owners running fuel only with a large single are not going to flow 120lbs of air out of an 80mm cast turbo. That is the maximum that turbo can flow if you were even able to spin the rpms up high enough. You would be lucky to get 90lbs of air out of it. To get 120lbs of air out of a 6.0 you would have to be pushing 100psi of boost or run it up past 5000rpms. IMO too many people look at a compressor map and look to see what the maximum air flow of the compressor is without even taking into account the voumetric efficiency of the motor, rpm band, air flow, surge line, efficiency islands, etc... those are the more important parts of it for us 6.0 guys. Most people are not hitting the right side of the compressor map unless you are running a tiny turbo. Most of us are going to be riding the surge line and maxing out at the top of the compressor map. The only way to get more power out of our motors is to increase the pressure ratio... but once you reach the top of the compressor map and the end of the rpm band then you have tapped out the flowing ability of the turbo.

Just a little food for thought

Interesting info.

MorganY · Jan 30, 2014

KCTurbos said:
Not to start any huge battle or argument so take this with a grain of salt.

I would say 99% of 6.0 owners running fuel only with a large single are not going to flow 120lbs of air out of an 80mm cast turbo. That is the maximum that turbo can flow if you were even able to spin the rpms up high enough. You would be lucky to get 90lbs of air out of it. To get 120lbs of air out of a 6.0 you would have to be pushing 100psi of boost or run it up past 5000rpms. IMO too many people look at a compressor map and look to see what the maximum air flow of the compressor is without even taking into account the volumetric efficiency of the motor, rpm band, air flow, surge line, efficiency islands, etc... those are the more important parts of it for us 6.0 guys. Most people are not hitting the right side of the compressor map unless you are running a tiny turbo. Most of us are going to be riding the surge line and maxing out at the top of the compressor map. The only way to get more power out of our motors is to increase the pressure ratio... but once you reach the top of the compressor map and the end of the rpm band then you have tapped out the flowing ability of the turbo.

Just a little food for thought

Good post. That's why compounds work so well.

KCTurbos · Jan 30, 2014

MorganY said:
Good post. That's why compounds work so well.

Yep... you can only go so far on a single. This is also why you don't want the little turbo to spool up and then gate around it to let the lp turbo run... that defeats the purpose of comounds IMO... you need to use the hp turbo to re-compress/compound the lp turbo air to increase the pressure ratio at which you can run the system

Josh@DirtyDiesels · Jan 30, 2014

KCTurbos said:
Yep... you can only go so far on a single. This is also why you don't want the little turbo to spool up and then gate around it to let the lp turbo run... that defeats the purpose of comounds IMO... you need to use the hp turbo to re-compress/compound the lp turbo air to increase the pressure ratio at which you can run the system

As much as I love the simplicity, posts like this and what Morgan said almost make me want to do a nasty set of compounds

smoker00 · Jan 30, 2014

KCTurbos said:
Yep... you can only go so far on a single. This is also why you don't want the little turbo to spool up and then gate around it to let the lp turbo run... that defeats the purpose of comounds IMO... you need to use the hp turbo to re-compress/compound the lp turbo air to increase the pressure ratio at which you can run the system

So are you saying sized right no gate?

KCTurbos · Jan 30, 2014

smoker00 said:
So are you saying sized right no gate?

Kinda... you could theoretically size them right and not need a gate. But I think gating to maximize the efficiency of the system by using a gate would be the best. But not to shut down completely one turbo... Hope that makes sense.

Sorry for the derail... I will try to stay out of the thread a little and let other people comment. Threads like this usually bring out a lot of good info. :thumbsup: