Toysrme

Just because the IHI's come up all the ------- time, but noone ever has any info. I added the RHB52w VJ11 & RHB52w VJ16 compressor maps to the FAQ earlier in the week.




VJ11 (probe/mx6 turbo)









VJ16 (tbird)

Toysrme

A tbird @ 12-13 psi would be a great choice for most of the stock (read weak OEM parts) i4's common here. Fast spool, but not weak.

I've never been a fan of the VJ11's. They're only really useful in twin turbo setups on 6 cylinders where you can't afford to go all out on the engine (like a weak transmission, or driveline that isn't going to be preped). Otherwise they're just so small it's blaaaaaaaaaaah!!!

neil85ae86

Holy crap sick, I can't believe after seeing all the compressor maps posted that you still think that the probe/mx6 is only rated at 190cfm, it is you that cannot read a compressor map! As soon as you come up with 190 cfm it shouldn't be too hard to figure out that you are doing something wrong, it is impossible for 190 cfm to push your stock probe and mx6 to near and above 200 WHP and 250+ ft/lbs of torque, no possible way. Get the 190 out of your head.

The t-bird is definitely capable of pushing 350 cfm and stay within efficiency, even I can see that on the compressor map.

Please go and re-study how to read compressor maps. Please also remember that you need to plot your map according to the application engine so we are talking here about 16v small cc 4cyl engines, ie. I used 7200rpm and 1.6L for my calcs (250cfm at 12-13psi probe/mx6, 350+ cfm at 16 psi.

I agree you would never push the psi that thingyness suggested out of a probe/mx6, but if you could the cfm might not be too far off, although I would think it would be off the map.

Neil


Neil

Toysrme

My big thing is that the wastegate is 13-14 psi on the tbird. Every stock tbird I know of, and the few tbird turbo's I've had ALL hit 13-14psi.
Saying 190cfm is kinda dumb too, no offense, but how many bone stock mx6/probe's make more than the 130-140bhp worth of air you're talking about it can't move. Try all of them, they're underrated by 20-30bhp. They get their published bhp numbers in whp on a dyno. If your 190cfm was near correct, they'd all be 130-140bhp engine's dynoing in the 110whp range stock, not 140-150whp with 170-190ft/lb.
There are a few 100% stock 6-7psi f2t's making 145whp - 190 lb/ft.

I agree with the trim observations tho. I have NEVER seen a definitive rhb52 trim explanation. Every time you read one thing, you've got just as many other people saying it's something else. Who cares? They spool fast, all anyone needs to know LoL!


So 6 man, no offense, but you're still in left field on some issues.

97spydagst

hahah thread is so old guys i dont even have the turbo anymore some guy offer me good money for it so i sold it....! thanks anyways guys

sixsick6

Look at both compressor maps and you'll see that one is in cfm the VJ11 and pne is in cfm AND lbs per minute (T Bird)

If you know anything about converting CFM to to Lbs per minute, this will be easy for you, since you can't tell by looking, I gather that you don't know how. I'll leave the searching up to you.

Done searching? Good, now look at the 380 CFM mark on the T Bird and you'll see that it is barely on 60% efficiency. Now look at it's efficiency at a 2.1 pr, 76%. and this is with a 2.3 cu engine. Your calculations on your 1.6 are wrong as well as your calculations on a 2.2.

The VJ11 gets the F2T as close to 100% VE as possible with the Vj11. Do the calculations yourself and you'll see, unless you keep using that Type R calculator.

You're wrong my friend.

sixsick6

That doesn't matter. You can boost ANY wastegate past it's pre set level. The stock setting for the VJ11 and T Bird is 8.7 psi. If you're talking about the Garrett that also comes on the T Bird, then this is a different story. Don't confuse the Warner Ishi with a small T3 exhaust housing and the Garrett/aiResearch with a regular .48 or .63 as the same turbo with the same wastegate, they are not.

As per your question on F2 efficiency:

Temp at sea level 80.00
Intake CFM @ 100 efficiency would be 231.25 CFM
Engine RPM would be 6000
Pr (pressure ratio would be 8.7+14.7/14.7)=1.59

=231.25 cfm

if you wanted to figure out lbs/min multiply by .07
231.25 x .07= 16.19 lbs/min

BUT that is assuming that VE=100% which in reality, it doesn't.

So, 133.2 x 6000 rpm=799,200 x .5 (for 4 stroke breating every other revolution)=399,600 x .85 (VE for most OHC motors) = 339,660 / 1782 (converts cubic in to cubic feet) you'd get 190.61 cfm naturally aspirated.

So doing this again

You'd back at 190.61 cfm

Again to find lb/min x .07
190.61 x .07= 13.34 lbs/min

A good rule of thumb is that for every 10 hp a gasoline engine makes, it needs roughly a lb of air/min delivered to the intake manifold. Looking at 13.34 lb/min, you can easily see why the F2T is rated at 145 hp

Good thing I used a digital caliper, did calculations, and took pictures of both the VJ11 compressor wheel, T Bird compressor wheel, and both turbines (which are the same).

VJ11 compressor wheel would be a .47 because 36/52.5^2=47

T Bird would be .55 because 39/52.5^2= 55

The turbines are the same:



The turbines would be a .67 because 42.4/51.8^2=67




As to how I know so much, I own one.

Toysrme

You plainly said 190cfm.
190*.07 = 13.3 * 10 = 133bhp.
What's the compressor map say for 70% @ 1.6 bar? 6.7m^3/s blah blah blah 16.56 lb/m. You can try to spin it any way you want, you're still 3lb/m,42.8cfm, 1.21m^3/s, 30bhp off on where the power comes from on the F2T.Big difference between 133bhp, and the correct 165bhp. Maybe that doesn't seem like much for you, but when you're talking about small applications people are going to use a probe/mx6 turbo in, it does need to be good. That 30bhp makes a huge impact.

We're talking compressor output, and you're pulling in VE. That's funny LoL!


87-88 are the ihi's. There's nothing to be confused about.


Real cool beans on the trim. Props for doing that.

novtecdohc

i have a 48/60 on my B18b And i love this turbo.... It spools up at about 2100rp mand hold full boost till redline...

sixsick6

Dude are you f#%kin crazy? 1.6 bar is 8-9 psi lol

The way you'd figure out Pr is 14.7+23/14.2 giving you a Pr of 2.56. Look at where 2.56 is on the map, exactly, on the surge line and less than 60% efficiency

Who gives a f#%k what the total flow of the turbo is if all it is flowing at that point is hot air. Look at 18 lb/min/.07 giving you 257cfm max. This turbo gives you the best results on the stock settings at roughly 190 cfm. I bring VE into the equation because it most definately DOES matter. The VJ11 brings the F2T as close to 100% VE as possible on minimal boost (8.7-9.4psi) and is very well matched for the motor.

The only thing I do agree with is the fact that the T Bird pushes less at more and at 14 psi you'd be at a 1.95 Pr and in the 76% efficiency range.

It isn't my fault that you obviously don't know how to read a compressor map or suit a turbo to a motor. Maybe this is the reason some of you blow motors up so much, listening to guys like you say that you should push the turbo to its limit.

And while I'm at it, why did you write VJ16 on the bottom of the compressor map? QUIT MAKING THINGS UP. The T Bird is NOT a "VJ16" no matter who you heard it from. This is just another place that you are wrong.