Air Research turbo (450hp) - Need help ASAP!!!

GT4TOY

New member
Hi guys,

I'm trying to find out about an Air Research Turbo. I don't know much about it except that it has:
3" inlet
exhaust hsg A/R .96,comp hsg A/R .60.
VWM11 written on the compressor hsg ( I think the model is M11, I found info on a M10 and it was simular to a Garret T2)
exhaust port: Inner Dia70mm/outer Dia95mm

I've been able to find out that Air Research is part of Garret (I think??)

The guy says it will flow 450hp, but I can't find out anything on this turbo to support this (well can't find out anything at all to be honest)

I've got until tomorrow to give the guy my answer. Its $500 NZD (prob around $300 USD) so its quite cheap.

heres the link: http://www.trademe.co.nz/structure/auct ... d=15661743
and heres a pic:
airresearchTurbo.jpg


any help would be great.

Thanks Guys!!!!
 

gearhead313

New member
get the compressor housing off and measure the major and minor diameters of the trim wheel. That will get you somewhere.

My guess is a to4b....
 

GT4TOY

New member
unfortunaltly I can't, as the turbo is in the South Island (about 15hrs drive).

yeah, if it was a to4b it would be good. They are rated at the same HP level as what the guy is telling me.

thanks for the answer.
 

MrWOT

New member
gt4toy":26873cx8 said:
Hi guys,

I'm trying to find out about an Air Research Turbo. I don't know much about it except that it has:
3" inlet
exhaust hsg A/R .96,comp hsg A/R .60.
VWM11 written on the compressor hsg ( I think the model is M11, I found info on a M10 and it was simular to a Garret T2)
exhaust port: Inner Dia70mm/outer Dia95mm

I've been able to find out that Air Research is part of Garret (I think??)

The guy says it will flow 450hp, but I can't find out anything on this turbo to support this (well can't find out anything at all to be honest)

I've got until tomorrow to give the guy my answer. Its $500 NZD (prob around $300 USD) so its quite cheap.

heres the link: http://www.trademe.co.nz/structure/auct ... d=15661743
and heres a pic:
airresearchTurbo.jpg


any help would be great.

Thanks Guys!!!!

I can tell you right now in no uncertain terms that unless it is a pure drag racing car, don't touch that thing with a 10' ft pole. With the size of it plus the .96 exh A/R it won't even spool until above 4000 rpm, it's would be a total dog on the street.
 

lhoy12

New member
Thats what most people would call "Unstreetable" :crazy: I wouldn't use it something you plan to drive on the streets due to the lag you will have.
 

GT4TOY

New member
oh.....bugger!!!! :doh:
When you say the size of it, to big I presume? I thought 3" would be average for a 450hp turbo.
Also what does the .96 a/r on the exhaust cause it to spool very late?
sorry if I sound dumb, but when it comes to turbo numbers I am!! :oops:
And thanks for answering, I was just about to get it off him!!!
p.s. it is my project car that I'm going to be dragging/weekend monster type stuff with.

Thanks!!
 

alltracman78

Active member
a/r is area of the scroll ( the outer piece that gets smaller as it wraps around the turbo) divided by the radius of the turbo to the center of the scroll (as the scroll (area) gets smaller, the radius will too, so the a/r ratio will stay the same no matter where you measure it).
a=area
r=radius

For example: Say we have a turbo that has a area of 2" at a given point. The radius from the turbo shaft to the CENTER of this point is 4". Your a/r ratio will be 0.5.

Think of it kinda like a compression ratio. The higher the ratio (this turbo is 0.96 to 1.00), the more power (potential), but the more lag. The lower the ratio, the quicker the response, but the lower the power potential. That is a general rule to go by. There will always be exceptions.

I hope this explains it for you.

*it's too big 'cause the radius is almost as big as the area of the scroll, which will cause the turbine (exhaust blades) to accelerate slowly. Once they are up to speed, they will produce alot of boost, it just takes a while to get there. Like accelerating with a mountain bike, and then doing the same acceleration with a road race bike. Smaller wheel accelerates faster, but has a lower top speed.*
 

GT4TOY

New member
ok, getting how it works now.
Would most turbos with that HP range take that long to spool up? I am looking for about 500hp within the next year ( I have a standing challenge from a mate who has a S4 RX7 turbo, and we are doing them up togeather) so if they are all going to be the same anyway, it would be best for me to get this one as it is cheap.
(p.s. ignoring the latest Garrett GT series turbos as I know they spool very quick for the flow they can produce, but $500 vs $2500, this looks like a good option)

Thanks guys!!
 

MrWOT

New member
First to clear up a bit of a misconception. The problem with a large a/r isnt lag, it's boost threshold, boost threshold is at what RPM at WOT the turbo will produce full boost, turbo lag is the length of the delay when you at that rpm when you depress the pedal that it takes the turbine to accelerate. In english, threshold = minumum RPM at full PSI, lag = delay from 0-max psi when at WOT at boost threshold.

To make thinking of a/r in a more simple manner think of it this way, the larger the a/r the more exhaust is allowed to flow around the turbine without accelerating it. You get much reduced backpressure so you achieve better flow at high rpm, but at the same time, you will have a high boost threshold because the exhaust would rather flow around an object, then give up it's inertial energy to move one. The smaller the a/r housing the lower your boost threshold, but too small will choke the top end horsepower.

Also, there is no such thing as a 450, 500, or 600hp turbo. A turbo is rated by flow (cfm) and pressure (psi). You want to select a turbo that will meet the required cfm for the engine at your desired pressure ratio. Remember that horsepower is just a measure of torque over time, horsepower comes with RPM, but the increase you really want is lower torque since our motors aren't real revvy as is. If you want a good streetable motor, you want the efficiency curve to peak at about 4000rpm in our case, and you will want an a/r housing to match the impeller.

If you really want to learn the nitty gritty mechanics of turbocharging (and I highly recommend you do if you are serious about performance, since off the shelf turbos can be greatly improved if you know what you're doing) check this book out http://www.amazon.com/exec/obidos/t...102-0634395-7206544?v=glance&s=books&n=507846 , it's about $35 but I guarentee that if you read through it at least twice you will have a good working knowledge of how to design and build a good turbo system for whatever you want.
 

BayAreaAT

Active member
how much lag did you get from the turbo?

didnt get a chance to install it...Im going for GT2540 thats why i sold the turbo.
 

GT4TOY

New member
Well I got the turbo, decided that it was what I wanted.
Now all I have todo is get all the other parts made up and I should (never, never say that :shoots: ) be away laughing!!
Thanks for the help guys.

Gus.
 
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