Cummins 4BT & Diesel Conversions Forums banner

1 - 20 of 427 Posts

·
Super Moderator
Joined
·
8,728 Posts
Discussion Starter #1
Over the years I've built up some calculation spreadsheets to predict engine power and torque from air consumption, boost and efficiency (BSFC). I've had other spreadsheets to predict engine airflow from boost, volumetric efficiency and intercooling.

I had a burst of productivity last night and combined the two. I then set all the variables as close as I could to my 4BD1T using information from 4BD1T factory performance charts, observed boost and fuel pump settings.
These variables have all been set as close as I could estimate to my 4BD1T, it will also apply within reason to 4BD2T and 4BT engines.

Here are the basic variables:
RPM range from 800-3,600rpm in 100rpm steps.
VE starting at 0.9 at idle to 2000rpm, dropping to 0.8 at 3000rpm and 0.74 at 3,600rpm.
BSFC starting at 240g/kwh at idle, minimum of 215g/kwh at 2100-2200rpm and climbing to 257g/kwh at 3,600rpm.
Observed boost hitting 10psi at 1200rpm, 22psi at 2000rpm, 24psi at 2200rpm and dropping from there.
No intercooler, 20C intake temps, sea-level and 60% compressor efficiency.
A/F ratio used was 17:1.

Here are the results:








These aren't perfect, they don't include parasitics such as turbine drive pressure which are dropping more power at higher rpm than shown on the graphs. But they are a good indication. I think it's within 10% of reality at all points.
 

·
Super Moderator
Joined
·
8,728 Posts
Discussion Starter #2 (Edited)
Now here is where it gets very interesting. That loop shaped plot of PR vs Flow was done to overlay on available compressor maps.

Lets start with the smallest, the old T25 I was running.

Quite a good match.

T28 compressor on the DIY T2560 I'm currently running.

This is looking quite bad. I'm surprised to see it left of the surge line. It appears not all of the rough running I have been experiencing at low rpm and high boost is due to the flywheel. Compressor surge is a concern here.
This is obviously why Garrett don't sell a T28 turbo with a 0.49 A/R turbine housing. It lets you drive it into surge.

GT2259 Compressor. This is the closest to the Hino Turbo that some are running:

This is an excellent fit. It is also a very efficient compressor and the turbine is almost 10% more efficient also.

Holset small turbos. Including the HX25 and HE221:

We have an excellent fit for all of them. The HX25, HX27 and HE221 are perfectly suitable.

Holset large turbos. Including the HY35 and HX35:

None of those other tham the HX30 are a remotely good fit.
 

·
Registered
Joined
·
858 Posts
So the T2560 from the 4HE1 really is not a good match then, especially since its seems there are various differences in them.

Guess I'll see if I can track down a HE221W or a GT2259 from a Hino. Hopefully I can get my money back out of my 4HE1 turbo first.
 

·
Super Moderator
Joined
·
8,728 Posts
Discussion Starter #4
So the T2560 from the 4HE1 really is not a good match then, especially since its seems there are various differences in them.

Guess I'll see if I can track down a HE221W or a GT2259 from a Hino. Hopefully I can get my money back out of my 4HE1 turbo first.
When intercooled it starts to look much better. A large part of the surge line following is due to the very small exhaust housing I'm running.
I'll post those intercooled graphs next.

The GT2259 looks like it'll be able to max out our injection pumps stock. The HE221 has even more capacity to deal with altitude.
 

·
Registered
Joined
·
858 Posts
When intercooled it starts to look much better. A large part of the surge line following is due to the very small exhaust housing I'm running.
I'll post those intercooled graphs next.

The GT2259 looks like it'll be able to max out our injection pumps stock. The HE221 has even more capacity to deal with altitude.
Yeah the GT2259 and HE221W are looking like much better alternatives, if I get stuck with this 4HE1 turbo I will maybe try messing with it a bit, but its a hell of an odd ball from the looks of it.

I will be running an intercooler so maybe that changes things a bit, I'm also hoping to run a .64 A/R turbine (If I can find one) so that will move it away from the surge line a bit more too.
 

·
Super Moderator
Joined
·
8,728 Posts
Discussion Starter #6
I will be running an intercooler so maybe that changes things a bit, I'm also hoping to run a .64 A/R turbine (If I can find one) so that will move it away from the surge line a bit more too.
With a 0.64 and intercooler, it starts to look quite good. It's the combo of no intercooler and 0.49 that is driving mine too hard too soon.
 

·
Registered
Joined
·
858 Posts
With a 0.64 and intercooler, it starts to look quite good. It's the combo of no intercooler and 0.49 that is driving mine too hard too soon.
OK, I'll see if I can find that CA18 T25 turbine I know I have somewhere in hopes it can be made to fit.

I can live with more lag since I will be auto and have a converter that will lock up at 1600rpm. if it was manual I would be going for as fast spooling as I could get.
 

·
Registered
Joined
·
267 Posts
this is awesome. I am curious to see how an intercooler changes things.

How can you have multiple Air Pressures for the same airflow?
 

·
Super Moderator
Joined
·
8,728 Posts
Discussion Starter #9
Now for the Intercooled results. These are the same figures as above, just with 60% effective intercooling. This means the intercooler takes out 60% of the temperature difference between the compressor outlet and the engine intake.

Airflow vs RPM:

Total airflow is now up to 25 lb/min. Before we were around 21lb/min.

Pressure ratio vs density.
PR is the same as before (same boost), but the density increase has gone from 1.7 times to almost 2.2.


Pressure ratio vs airflow.
PR is the same as before, but the extra density pushes the airflow out to the right.


Predicted performance.
Big increase. Note the power scale has changed to fit it in.


T25 turbo map:
The demand line has now broken out to the right. This means the T25 is too small for maximum power.


T28 turbo map:
This one was in surge before, the extra flow from the charge cooling has made it work.


GT2259 turbo map:
This one is now knocking on the flow limits. Still a very good choice though.


Holset small frame:
The HX20, HX25 and HE221 are still looking very good.


Holset medium frame:
The HX30 is looking good, the rest are still far too big:
 

·
Super Moderator
Joined
·
8,728 Posts
Discussion Starter #10
this is awesome. I am curious to see how an intercooler changes things.

How can you have multiple Air Pressures for the same airflow?
Intercooled plots are now up.
Presuming with the multiple air pressures, you mean this plot?


As the engine rpm increases the VE drops so the flow drops and boost also drops. This is why it begins to tail in on itself.
 

·
Registered
Joined
·
267 Posts
oh ok, so the points are taken at different engine rpm...makes more sense now. What rpm has the highest airflow and pressure ratio? I am guessing it is around the same point where the torque peaks.

The other thing that I am seeing is the most fuel efficient place to operate the engine at is just above 2000 rpm where the torque maxes out as well....but I think that we knew that.

The intercooler giving you an extra 54 hp peak and 110 ftlbs peak is amazing. The extra 25cc/1000 shots....but that makes sense. All of those are about a 25% increase.

From your maps, any of the small frame holsets look the best, followed by the HX30, and then the GT2259....is that how you see it?
 

·
Super Moderator
Joined
·
8,728 Posts
Discussion Starter #12 (Edited)
oh ok, so the points are taken at different engine rpm...makes more sense now. What rpm has the highest airflow and pressure ratio? I am guessing it is around the same point where the torque peaks.

The other thing that I am seeing is the most fuel efficient place to operate the engine at is just above 2000 rpm where the torque maxes out as well....but I think that we knew that.

The intercooler giving you an extra 54 hp peak and 110 ftlbs peak is amazing. The extra 25cc/1000 shots....but that makes sense. All of those are about a 25% increase.

From your maps, any of the small frame holsets look the best, followed by the HX30, and then the GT2259....is that how you see it?
Yes it's showing max boost (24psi) between 2200 and 2500rpm. But the non-intercooled boost are based on my actual measurements. The intercooled will differ from those.
Interestingly, all these fuel quantities are below what you get from a maxed out stock pump. About 140cc is the limit. *edit* 180cc is the true limit of these pumps */edit*

My pick would be HE221 or TD04HL-19T (the HE221's step brother), then GT2259, then HX25, HX30 etc.
T25 and T28's suitability depend on your ultimate goals.

In a nutshell, a good honest 200hp is no problem. If you get everything perfect then over 250hp should be possible.
 

·
Super Moderator
Joined
·
8,728 Posts
Discussion Starter #13 (Edited)
And if we go to the Borg Warner site and plot in the same data. I get this:
http://www.turbodriven.com//performanceturbos/matchbot/index.html#version=1.2&displacement=3.9&CID=237.978&altitude=500&baro=14.502&aat=75&turboconfig=1&compressor=62k80&pt1_rpm=1500&pt1_ve=90&pt1_boost=14.5&pt1_ie=60&pt1_filres=0.08&pt1_ipd=0.2&pt1_mbp=0.5&pt1_ce=66&pt1_te=75&pt1_egt=1400&pt1_ter=1.58&pt1_pw=2.62&pt1_bsfc=0.37&pt1_afr=17&pt1_wts=300&pt1_wd=83&pt1_wd2=74&pt1_wrsin=69033&pt2_rpm=1800&pt2_ve=90&pt2_boost=19&pt2_ie=60&pt2_filres=0.1&pt2_ipd=0.2&pt2_mbp=1&pt2_ce=70&pt2_te=73&pt2_egt=1400&pt2_ter=1.8&pt2_pw=8.12&pt2_bsfc=0.36&pt2_afr=17&pt2_wts=320&pt2_wd=83&pt2_wd2=74&pt2_wrsin=73635&pt3_rpm=2100&pt3_ve=89&pt3_boost=23.5&pt3_ie=60&pt3_filres=0.12&pt3_ipd=0.3&pt3_mbp=1.3&pt3_ce=74&pt3_te=72&pt3_egt=1400&pt3_ter=2.04&pt3_pw=13.34&pt3_bsfc=0.35&pt3_afr=17&pt3_wts=340&pt3_wd=83&pt3_wd2=74&pt3_wrsin=78238&pt4_rpm=2500&pt4_ve=85&pt4_boost=24&pt4_ie=60&pt4_filres=0.15&pt4_ipd=0.3&pt4_mbp=1.5&pt4_ce=76&pt4_te=71&pt4_egt=1400&pt4_ter=2.16&pt4_pw=18.88&pt4_bsfc=0.36&pt4_afr=17&pt4_wts=368&pt4_wd=83&pt4_wd2=74&pt4_wrsin=84681&pt5_rpm=2800&pt5_ve=82&pt5_boost=22.5&pt5_ie=60&pt5_filres=0.18&pt5_ipd=0.3&pt5_mbp=1.8&pt5_ce=72&pt5_te=70&pt5_egt=1400&pt5_ter=2.2&pt5_pw=18.73&pt5_bsfc=0.37&pt5_afr=17&pt5_wts=400&pt5_wd=83&pt5_wd2=74&pt5_wrsin=92044&pt6_rpm=3100&pt6_ve=79&pt6_boost=20&pt6_ie=60&pt6_filres=0.2&pt6_ipd=0.3&pt6_mbp=2&pt6_ce=66&pt6_te=70&pt6_egt=1400&pt6_ter=2.18&pt6_pw=18.16&pt6_bsfc=0.38&pt6_afr=17&pt6_wts=400&pt6_wd=83&pt6_wd2=74&pt6_wrsin=92044&

Massive link, but it should take you to a "Matchbot" page all setup with similar data.
Their recommendation based on my figures is an EFR6258 turbo with a 0.65 A/R turbine housing. This is the one I would be fitting if I had the space and $$ for an EFR.
Here is a build thread for a 4BD1 being fitted with one: http://www.aulro.com/afvb/isuzu-landy-enthusiasts-section/167900-not-so-budget-turbo-install.html

To get to that forum you may need to sign up.

Here is another Borg Warner EFR6258-4BD1T match by our member Bush65: http://www.turbodriven.com//performanceturbos/matchbot/index.html#version=1.2&displacement=3.9&CID=237.978&altitude=500&baro=14.456&aat=80&turboconfig=1&compressor=62k80&pt1_rpm=1500&pt1_ve=80&pt1_boost=6&pt1_ie=80&pt1_filres=0.1&pt1_ipd=0.5&pt1_mbp=0.5&pt1_ce=60&pt1_te=72&pt1_egt=1250&pt1_ter=1.33&pt1_pw=1.99&pt1_bsfc=0.36&pt1_afr=19&pt1_wts=300&pt1_wd=83&pt1_wd2=74&pt1_wrsin=69033&pt2_rpm=2000&pt2_ve=85&pt2_boost=23&pt2_ie=75&pt2_filres=0.15&pt2_ipd=0.5&pt2_mbp=0.5&pt2_ce=65&pt2_te=72&pt2_egt=1250&pt2_ter=2.18&pt2_pw=0.05&pt2_bsfc=0.36&pt2_afr=19&pt2_wts=320&pt2_wd=83&pt2_wd2=74&pt2_wrsin=73635&pt3_rpm=2500&pt3_ve=85&pt3_boost=28&pt3_ie=75&pt3_filres=0.2&pt3_ipd=0.5&pt3_mbp=0.5&pt3_ce=70&pt3_te=72&pt3_egt=1250&pt3_ter=2.65&pt3_pw=12.46&pt3_bsfc=0.36&pt3_afr=19&pt3_wts=340&pt3_wd=83&pt3_wd2=74&pt3_wrsin=78238&pt4_rpm=3000&pt4_ve=80&pt4_boost=30&pt4_ie=70&pt4_filres=0.25&pt4_ipd=0.6&pt4_mbp=1.5&pt4_ce=73.5&pt4_te=72&pt4_egt=1250&pt4_ter=2.76&pt4_pw=15.25&pt4_bsfc=0.36&pt4_afr=19&pt4_wts=368&pt4_wd=83&pt4_wd2=74&pt4_wrsin=84681&pt5_rpm=3500&pt5_ve=75&pt5_boost=30&pt5_ie=70&pt5_filres=0.25&pt5_ipd=0.6&pt5_mbp=1.5&pt5_ce=74&pt5_te=72&pt5_egt=1250&pt5_ter=2.88&pt5_pw=18.79&pt5_bsfc=0.36&pt5_afr=19&pt5_wts=400&pt5_wd=83&pt5_wd2=74&pt5_wrsin=92044&pt6_rpm=4000&pt6_ve=75&pt6_boost=30&pt6_ie=70&pt6_filres=0.3&pt6_ipd=0.7&pt6_mbp=2&pt6_ce=70&pt6_te=72&pt6_egt=1250&pt6_ter=3.14&pt6_pw=19.42&pt6_bsfc=0.36&pt6_afr=19&pt6_wts=400&pt6_wd=83&pt6_wd2=74&pt6_wrsin=92044&

These BW turbos seem very very nice, but the price matches.

The power ratings calculated on the BW Matchbot match my own figures quite well. Big relief.

Here is the compressor map. You can see these with points plotted and turbine also in the links above.
 

·
Registered
Joined
·
858 Posts
I really like those EFR turbo's, I have seen a few cars with them and they have got to be the highest quality turbo out there bar none.

Even BW non EFR turbo's are top top quality, there castings make everyone else's looks like they they where done buy a 2 year old with playdough.

Really looking forward to see that the guys trying them think once they are running. Hopefully we can see some information that will confirm those maps.
 

·
Super Moderator
Joined
·
8,728 Posts
Discussion Starter #15
I really like those EFR turbo's, I have seen a few cars with them and they have got to be the highest quality turbo out there bar none.

Even BW non EFR turbo's are top top quality, there castings make everyone else's looks like they they where done buy a 2 year old with playdough.

Really looking forward to see that the guys trying them think once they are running. Hopefully we can see some information that will confirm those maps.
There appear to be only two downsides to those BW turbos.
They are physically very long and they are very expensive.

I agree on the playdough castings too.
 

·
Registered
Joined
·
858 Posts
There appear to be only two downsides to those BW turbos.
They are physically very long and they are very expensive.

I agree on the playdough castings too.
Yes agreed, my swap is more on the budget end this time so will be sticking to the more attainable turbo's for now. If I had a large turbo budget it would be a first and only choice.

I'm quite impressed by the power predictions of an intercooled 4BD1T with a proper sized turbo on it, 250hp and 500ft/lbs is no joke on the stock pump and would move most trucks along well. I hope to dyno my truck with the stock motor and again with the Isuzu 4BD1T when done, it will have an intercooler turbo and 3" exhaust. If I can match the stock motors HP and have a bunch more low end grunt I'm good.
 

·
Super Moderator
Joined
·
8,728 Posts
Discussion Starter #17
Yes agreed, my swap is more on the budget end this time so will be sticking to the more attainable turbo's for now. If I had a large turbo budget it would be a first and only choice.

I'm quite impressed by the power predictions of an intercooled 4BD1T with a proper sized turbo on it, 250hp and 500ft/lbs is no joke on the stock pump and would move most trucks along well. I hope to dyno my truck with the stock motor and again with the Isuzu 4BD1T when done, it will have an intercooler turbo and 3" exhaust. If I can match the stock motors HP and have a bunch more low end grunt I'm good.
250hp in a diesel feels a lot more impressive than 250hp in a petrol. Your torque and average power are higher across the board.
 

·
Registered
Joined
·
858 Posts
250hp in a diesel feels a lot more impressive than 250hp in a petrol. Your torque and average power are higher across the board.
Yep, looking forward to it and 2X the fuel economy I have now.
 

·
Registered
Joined
·
268 Posts
Question for you Dougal. What HP and torque would you estimate a HE221 would support? Looking at the intercooled chart, it seems there is a lot of flow left with that turbo...
 

·
Super Moderator
Joined
·
8,728 Posts
Discussion Starter #20
Question for you Dougal. What HP and torque would you estimate a HE221 would support? Looking at the intercooled chart, it seems there is a lot of flow left with that turbo...
The big unknown is the turbine and how that will handle a massive flow-range. The compressor is good past 35psi for pressure ratio and that only takes flow to around 30lb/min. Leaving plenty of flow capacity for altitude work.
Basically the compressor is good for 200kw on our engines. But we don't know how many of those 200kw will be choked off by the turbine. Are there any turbine maps for the MHI TD04HL turbine?
They also don't plot any efficiency ratings. The difference 60 vs 75% efficient makes in a compressor map will make a huge difference to air density and engine power at the same boost.
 
1 - 20 of 427 Posts
Top