Mustang Turbo

[LazerStang1999]

i need help with a turbo.....
does anyone know if this turbo is to big? or can I go bigger? suggestions?


0.96 A/R Turbine for Mid-High end Power
Billet Aluminum CNC Machined Back Plate

Computer Balanced
4" Air Inlet
3" V-band Outlet

Bearing Wet Floating Bearings
Cooling Oil
Flange Standard T4
Internal Wastegate None
Compressor 76mm Wheel Compressor
Turbine P Trim .96 A/R Turbine
Compressor Wheel 102.4mm/76.7
Turbine Wheel 74.1mm/64.6mm
Hot Side 3" V-band

 

[squeak93]

No need for multiple topics about the same thing......

 

[LazerStang1999]

i deleted the other one, but I wanted to change the title for easier answers

 

[billfisher]

ummm thats a 102mm turbo not a 76.

trim is...... .74 inducer is 76mm/exducer 102mm. a turbo like that will support oh 1000hp. or more. and be laggy as hell with a 74mm turbine.

 

[LazerStang1999]

So there would be alot of turbo lag... what would i have to look for different in order for it to work with my car?

 

[LazerStang1999]

Would this be more like it....



T70 600HP Turbocharger
APPLICATION
Universal, Fits all cars and trucks
DESCRIPTION
4" Inlet
Stage IV 4 Bolt
Wet Float Bearing
Divided T3 Flange
Oil Cooling
600 HP Capable
Compressor Wheel
.68 A/R
Ind: 52.76 mm
Exd: 75.46 mm
Trim: 48.9
Turbiner Wheel
.82 A/R
Ind: 57.75 mm
Exd: 73.35 mm
Trim: 61.9

 

[BurningRubber]

That would be more suited for a 4.6... that first one is freaking huge.

 

[billfisher]

yeah the second one is far better.

 

[billfisher]

if its a 48 trim its goin to flow less than a normal t-70. so 600hp? probably not.

 

[billfisher]

i would want a 56 or better trim for the compressor all the way up to 80mm.

 

[billfisher]

you see its just not as simple as looking for a turbo with a set hp rating.

the compressor map of that turbo is likely to be very narrow and tall. kinda like a diesel map.


the 'rating' it has is simply airflow at a set pressure ratio. in other words a turbo that flows 60lb/minute can have seriously different pressure ratios where that flow is achieved.

it has to match you engines airflow.

for example. a t-76 63 trim turbo will support about 800 hp. BUT its at a 1.88 presure ratio. or about 12.9psi idealized.

your motor at that manifold pressure has to match, to realize that hp rating.

a typical 4.6 4v at say 8psi will flow about 55 lb-minute ideally @6200 or about 450 crank hp(380rwhp). im fudging the numbers a tiny bit for illustration.

you need a turbo to match that on two sides. if a turbo has a narrow flow rating it will surge at low rpm/low flow rates. surging blows them up. and it onlt gets worse as pressure ratios rise, but engine flow doesnt increase as much.(4.6 2v)

so if a person sets the pressure ration to aviod low end surge, and that pressure ratio is very high say 2.0 or higher, suddenly things get dicey for the motor internal pressures.

it is difficult to pick the right turbo. you need lots of info for it to wirk right.

you need to calculate VE and airflow rates for YOUR engine. a dyno will help do that for u.

then select a turbo that matches your engine requirements and ho goals. lastly pick an exhaust housing that matches gas flow your rngine provides for lag reduction.

i simplified it a bunch. enough to where a good tech can pick it apart a little but the idea is the same. you can probably use that turbo. or a junkyard turbo at that. and it will most certainly do better than nothing. but you will spend a lot of money to fall short.

just my $.02

 

[LazerStang1999]

So in other words its gonna cost a ton and still not preform well.....

 

[eliteJAE]

So just go with a blower already made for our cars lol

 

[billfisher]

you have to match it to your engines airflow and rpm. but its far superior to ANY blower.

 

[billfisher]

theres a reason so many outlaws use turbo.

 

[Stan Weiss]

Once you get your mass air flow down

typical 4.6 4v at say 8 psi will flow about 55 lb-minute ideally @6200

I like to look at as 3300 lbs/hr. You can than start on fuel. At 11.5:1 you need 286.2 lbs/hr. Then you can look at inter coolers which finally brings up inlet charge temperature / density ratio the real number to tell how much HP you will make.

 

[slayr281]

Thank you billfisher for pretty much saying exactly what I've been wanting to say.

Figure out what you want that turbo to do, at what rpm and what boost level, and from that, you can calculate out your cfm, pr, lb/min flow. From there, look through the turbo manufacturers compressor maps to find one that has you in the sweet spot in the center of the map. For instance, I'm looking at a GT4088 54 trim with a .72 AR because it puts me at optimum efficiency at exactly the right boost levels I want them to be at. It took a couple hours of looking through various manufs maps to arrive at this, some were close, either too small, too big, or didn't scale when I'd be at different rpms and boosts. So often, we hear that somebody wants one because their buddy with a 351 runs a t-76 and hit 800rwhp, which is great for them, but they've likely got a significantly different setup, especially considering you've got a 281 and might not be full time drag racing it, or what have you.

Honestly, putting the turbo in and together is pretty easy, choosing the right one, is not. Once that's done, it's pretty easy (albeit expensive) to get the right motor, toss in a metric ton of fuel, and get the tuning done.

 

[billfisher]

4088 is good choice as is .72 exhaust. it sould be in full boost by 2500 or so. if you run an auto with stall ever sooner.

 

[billfisher]

those fellows who will pipe in with "just get a blower' need to find another thread. this isnt 'what should i do instead of a turbo'.

a turbo is superior in every way to a blower. and the'low end grunt' crap is just that.

a sequential twin is every bit as low-end as a blower.

at the same boost level a well designed turbo system will always kill an equal boosted blower. at 10lbs vs. 10lbs, turbo = kill.

well designed includes using aquick shifting automatic. and the right gearingstall cenverter. you talk about tons of torque off the line. shhheeeiiiittt.

 

[billfisher]

its a fact that iron cobra blocks break under drag conditions at ~700rwhp on a blower car. the cylinders are producing 1000hp because of blower losses.

a turbo motor keeps and uses that extra 300hp and uses it to go down the track not turn a blower.

tuning is where it gets tricky. let it go ~12.0:1 a.f or leaner - you will burn a hole through the best piston.