hey guys

no matter how much i try to read this thread https://honda-tech.com/zerothread?id=142398 over and over again i cant understand how to read these compressor maps one bit.

what i want to know is at what point does the garret t3/t04e 57 trim/.63ar turbo become most efficient. is it a certain boost level? or a engine RPM level? or am i totally out to lunch on this?

i would like to run anywhere from 14-18psi on a 2.0L engine with about a 8500rpm redline. so when/where will this turbo become most efficient? or when will it fall out of its efficiency range?

i guess it also sucks that this image i found isn't very good:



any help would be appreciated guys........thanks

 

well...

CID = 2000cc / 16.4 = 121.95cid

CFM = (121.95 x 8500 x .9 x .5) / (1728) = 269.941cfm

PR = @14.7 psi (14.7 + 14.7) / (14.7) = 2
@ 18 psi (18 + 14.7) / (14.7) = 2.22
@20psi 20 + 14.7) / (14.7) = 2.36

so CFM x PR =
@14.7 = 539.883 cfm
@18 = 599.27 cfm
@20 = 637.06 cfm

now lets convert to lb/min...(CFM x .0691)
@14.7 = 37.3059 lb/min
@18 = 41.4096 lb/min
@20 = 44.021 lb/min

just match the points...

 

BTW the to4e50 has a much better map

 

thanks for your help......still kinda makes no sense to me though........lol....im hopeless

50 vs. 57 how is the 50 map better than the 57 and why?

 

Ok first thing is first lets make sure you know how to use the numbers I gave you
Compressor maps are known as XY graphs you have a x coordinate (right to left), and a y coordinate (up and down)

you use each pair of numbers to find a singular point

for instance find 37(x) & 2(y) kinda like your playing battleship
now 41 & 2.2
now 44 & 2.3
It might help if you print the maps and use a pen drawing straight lines until they intersect.

the 2 is 14psi
2.2 is 18psi
2.3 is 20psi


If you plot those points (lines) on both the 57 map you provided and the 50 map below you will see that the 50 trim stays in the center island(s) for more of the rev range. That means cooler air for a longer period of time which means the knock threshold will be lower with the 50 trim than the 57 and you may/should make more power at a given boost, all things being equal.



understand?
if so you can plot maps all night long while your girlfriend lays in bed thinking your retarded.

 

ok i understand what you saying.....and i am following the points of intercestion on the maps provided.

but what makes no sense now is the 57 trim wheel is obviously larger (duh) but you say the 50 trim will make more power all thing being equal.

copied from cheapturbo.com:
50 trim flow: 46 lbs/min 588cfm
57 trim flow: 50 lbs/min 640cfm

how is that possible when the 57 trim can flow more air? there must be a point where the 57 trim will out perform the 50 trim? perhaps at really high boost levels? or really low boost levels?

or am i wrong?

 

the o4e50 will out perform the 04e57 in torque numbers since it spools faster and can maintain a lower average temperature through out the rev range. That means quicker acceleration, less shifting, and a all around more usable car.

When pushed the 04e57 will/ may make more power but at that point you should be looking at the 04e60 or maybe a nice 61mm compressor (see sc61 or the T61 compressor map)

notice how much larger the whole map is on the 50, take another look at the surge line as well. The 50 has far better surge characteristics than the 57.
The 04e50 can make 400whp at about 22psi on race fuel.

maybe we should start over?
what are your goals so that I can understand what it is you are looking for, and make better recommendations?

 

i would like to make about 350whp daily driven on pump gas with not to much lag.......but still make a good strong pull to the upper RPM.....i was told i should go with the 57 trim and it should do the trick pretty well......

also i already have a 57 trim but now it may seem that i may have picked the wrong one.........

https://honda-tech.com/zerothread?id=1011059

 

don't worry about it, just use it, I would if I had it laying around.
you should not have too much trouble getting the power you want out of it.
Worst case you turn up the wick and squeeze it for every last drop

Besides I tend to pick things apart and can be considered a extremist when it comes to engines.

what you have will work fine.

 

i have a spreadsheet that can help you.. but have no way to host it... anybody?

 

i have a server, you have PM

 

ask and thou shal recive
right click-save as
http://www.mrapg.net/hondatech/turbocalc-v1.xls

 

Thanks bud.



First off, i'm pretty new to this. flamming is more than welcome as i threw this together the other night pretty quickly. If someone with alot of experience can please compare this with their own calculations that would be great - i realize this is quite a watered down calculator.

Anyway. Everthing in blue can be modified. Just compare the pressure ratio to the RPM. I'm too damn tired to go into more detail.. maybe tomarrow

Again, flames welcome

 

one thing to think about is that the VE changes as RPM and boost changes, say you have 90% VE at 4000rpm and 10psi, then by 7000rpm you could be down to like 75% VE at 10psi. Not saying this is bad just something to think about.
edit: BTW does this output CFM or LB/M?

 

lbs/min

I think i remember reading that heat effects CFM more than lbs/min - which makes sense. lbs/min is better...

 

Wouldn't temperature effect lb/min rather than CFM?

A cubic foot of air is a cubic foot of air, no matter how dense the air is.
A lb of cold, dense air would be smaller (volume) than a lb of hot air.

And yes, lb/min is better because it takes temperature into the equation.

Correct me if I'm wrong, but that makes sense to me.

 

hey can u do mine to so i can do my compressor map? 1.8 liter 7000 red line

 

you can plug your numbers into the spreadsheet

 

sw20t, i just plotted my 2.0 liter motor with 8000 rpm redline on a t3 60-1 map.
was wonding what all this means:
"CFM = (121.95 x 8500 x .9 x .5) / (1728) = 269.941cfm"???
Obviously the 8500 is the redline since thats the redline he originally specified.
I used all the same numbers you did for CFM except the redline.
Heres my plot, what does it do for me besides telling me how efficent the compresor is for my set up?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by onePOINTsix &raquo;</TD></TR><TR><TD CLASS="quote">one thing to think about is that the VE changes as RPM and boost changes, say you have 90% VE at 4000rpm and 10psi, then by 7000rpm you could be down to like 75% VE at 10psi.</TD></TR></TABLE>

It's actually the other way around...on VTEC motors VE is low at lower RPM's and gets higher as the RPMs rise. Peak VE usually happens at or around <u>peak HP RPM</u>, and is usually around 100-112% depending on the motor. VTEC and similar valvetrain systems are the exception to the rule that max VE is reached at peak torque RPM.

On a different thread asked what the max VE was for a B18C and here was the reply I posted on that other thread.

People will say that in most cases peak VE occurs at peak torque RPM and it is around 70-80% VE, and in most cases that is correct. However VTEC motors are the exception, and they usually have peak VE happening at around peak HP RPM. According to http://www.autospeed.com the peak VE for an H22 is 102% occuring at 7000 RPMs, which is alsowhere the HP peaks at. And for an S2000, the peak VE is 112% which occurs at around 8000 RPM. The SAE did a paper on this and it was the engineers from Honda that found those VE numbers.

http://www.autospeed.com/cms/article.html?&A=1127

Now I know you asked about a B18C, but I'm sure the VE for the B18C is somewhere between 102% and 112% (probably closer to 102%).

HTH

 

on a B18B1 running 10 daily and 15psi at the most what would be better to use, 50 or 57 trim T3/to4e?