Researching more about the perfect turbo trim.......

i came across the SCC article on how to read compressor maps, and thus, i used their equations to plot these points.

I had to assume a few things to make these work, such as the VOLUMETRIC EFFICIENCY, INTAKE TEMPERATURE (I am pretty close to it, and +/-20 degrees doesn't make a HUGE difference), and MASS FLOW RATE.

Volumetric efficiency was set to .9, as suggested by SCC. MASS FLOR RATE was derrived by using volumetric efficiency, so you see the problem there.

Anyway, at 8psi, PR is 1.64 and CMF is 25.09 lb/Min.

This is for an h22a4 motor.

heres what i plotted for the t04E trims, tell me what you think is the most advisable trim.
geocities sucks so you might have to copy and paste it.
http://www.geocities.com/timn_1/t4e-50.gif
http://www.geocities.com/timn_1/t4e-54.gif
http://www.geocities.com/timn_1/t4e-57.gif
http://www.geocities.com/timn_1/t4e-60.gif

to me, it looks like the .54 trim is most efficient.


[Modified by Purelude, 7:11 PM 8/16/2001]

 

wouldn't the .60 trim be a much better choice then?

 

I would lean toward the 54 or 57 as both of them will allow you to increase boost up to about 1 bar without losing any efficiency.

 

good idea dbman, almost slipped my mind about boosting past 8psi.

does anyone know the cfm's for integras? atleast its something to compare to, to see if my #'s are even close to correct.

 

Just some factual numbers...

I know a Miata that dynoed 400whp with a .46-trim T04E. He has run a high 10.

Our racecar uses a "Super" .50 T04E and dynoed 486whp. Ran a 10.0.

I wouldn't get bigger than a .50. The bigger wheels lag a lot more.

 

I did the exaxct same **** when i got the mag
at 10 psi my pr is 1.782 and cmf is 22.3. Now its not 100% accurate but pretty close. I also did one for 18psi which is what i hope to run later. PR=2.32 and CMF =29.58
thats for a b16 engine.
if someone has diff numbers for the same motor let me now i couldve made an error.
btw the pics dont work.


[Modified by SiRkid, 7:43 PM 8/17/2001]

 

you have to remove the www. form the url




[Modified by Strng1dah, 1:31 PM 8/17/2001]

 

oh ****.
thanks
Id say the 60 trim is the best on for you.
for me I think 50 or 54 is good.
what do you think?

 

hey... check this out!!!
http://www.turbofast.com.au/turbomap.html

my setting for h22a4 was as follows:
pt 3: 2500 1 90 60
pt 2: 4000 20 90 75
pt 1: 7500 20 90 60

bore: 3.48
stroke: 3.628
num of cylinder: 4
air temp: 30
inter efficiency: 75

from those graph, seems like t04e "50" trim was the best since pt 2 was on surge line, and pt 1 was right on the sweet spot... any suggestion?

 

you don't want to be on the surge line !

whoa, 20psi...hows that feel?


[Modified by Purelude, 4:42 PM 8/17/2001]

 

You said you wouldnt go over .50 trim. Remeber this is a prelude. Maybe bigger is better?

 

Purelude, i was just following the example on the site, that the pt 2 should be near to the surge line for maximum efficiency...

i was just planning ahead for 20psi.... don't want to buy a new turbo for 7psi, 15psi and 20psi....

turbolude... so what trim to use??????

 

its hard to say what trim to use, but don't get it too big of course.

also, Volumetric Efficiency changes with rpms. I assume that that page calculates air flow correctly.

I think i'm going to go w/ a .54 stage 2 to4e.

 

Mark, he is now upgrading to a .57 the last time I talked to him. Dont forget to mention this is also on a stock Miata block.

art


[Modified by Arturbo, 6:54 AM 8/18/2001]

 

All i was saying before was that the prelude motor doesnt seem to react like any other honda motor. So i wouldnt take to much information from other motors and try to incorporate that into your descision.

I dont know which one to get, from talking to Purelude it sounded like the .63 trim stage 3 t3/t4e was the way to go. Its seems the people making power have the .63 trim...apexii and G and some other dude with a ball bearing .63.

To bad WE dont have the money to do some testing and find out which one suits the prelude motor.

By the way, shouldnt the people at Turbonetics or Majestic no the exact turbo trim and size that we should need?