Understanding Turbo Lingo

[SKY 34]

Flanges,A/R, Trim, Compressor maps?

Split Pulse T4 Turbine Flange

Compressor

Inducer: 66.65

A/R: 0.7

Turbine

Exducer: 64.56

A/R

0.7

0.84

0.96

1

1.14

1.15

1.32

heya can anyone explain what the terms mean? I only understand the flange bit...

[RANDY]

lol! I'll have a go with my limited knowledge!

Flange - that bit with bolt-holes so you can put two pipes together!

A/R - air ratio?

Trim - or "type" of housing on a turbo

Split Pulse T4... - two channels. one for exhaust, one for wastegate, into a flange.

Inducer is prolly in relation to the compressor wheel side?

Exducer is prolly for the exhaust wheel side?

[MattSR]

Nup...

Flange - Yep

A/R - Area Radius ratio - determines the size of the housing

Trim - this is the size of the compressor and turbine wheels

Split pulse - lets you group the cylinders on an engine - ie on an RB six cylinder, the front three cylinders go down one channel, and the rear three go down the other. The wastegate must connect to BOTH channels or you will end up with serious problems.

Compressor inducer is the diameter of the wheel at the compressor inlet, Compressor exducer is the outside diameter of the wheel (the bigger bit)

Turbine inducer is the reverse - its the big bit of the wheel, and the exducer bore is the smaller diameter at the back of the turbo.

Hope this helps.

[djr81]

Flanges,A/R, Trim, Compressor maps?

Split Pulse T4 Turbine Flange

For anyone looking for these explanations (& alot more) the best starting point is the Garrett website www.turbobygarrett.com The site has a number of tutorials that leads you through the nomenclature of the various bits of the turbo & better still helps explain the effects of having, say, a larger A/R on the compressor wheel.

[RACESPEC]

Trim = (inducer/exducer)^2 x 100

Cheers

Tarek

RACESPEC

[MattSR]

Haha

is that for turbine or compressor - the eqns are different for both

[NXTIME]

that's for comp

turbine trim is (exducer/inducer)^2 x 100

[SKY 34]

thanks for reply

umm so what does the value really mean..like 0.7A/R is that good or bad? what figures do I need to look out for in turbos? larger housing means larger turbo lag? so I should be looking for a small housing with larger inducer exducer thingy?

"Split pulse - lets you group the cylinders on an engine - ie on an RB six cylinder, the front three cylinders go down one channel, and the rear three go down the other. The wastegate must connect to BOTH channels or you will end up with serious problems." <-- this applies to RB 26 only or all RBs??

um I'll post up a picture of turbo can please explain which bit is inducer which bit is the exducer ...use paint to mod or sumthing..

thanks

[SKY 34]

turbo pics

[R31Nismoid]

www.howstuffworks.com

cant beat it for the q's your asking

[MattSR]

so what does the value really mean..like 0.7A/R is that good or bad? what figures do I need to look out for in turbos? larger housing means larger turbo lag? so I should be looking for a small housing with larger inducer exducer thingy?

"Split pulse - lets you group the cylinders on an engine - ie on an RB six cylinder, the front three cylinders go down one channel, and the rear three go down the other. The wastegate must connect to BOTH channels or you will end up with serious problems." <-- this applies to RB 26 only or all RBs??

<{POST_SNAPBACK}>

SKY 34,

The value dictates how much the gas is going to be accelerated/deceleratedas it passes through the housing. generally speaking, larger turbine housings shift your power band up in the rev range, but not as much as people will have you believe. Going from a 0.63 to a 0.82 turbine housing will add maybe 5-600 rpm to your boost response.

Compressor housings are a totally different kettle of fish as they dont directly contribute to to lag. Going up in compressor housing size moves the efficiency island up and to the right which makes the compressor more resistant to surge and give slightly better performance when the turbo is sppoling very late in the RPM range as the engine will spool up and through peak efficency.

The split pulse configuration is for all 6 cylinder engines. With a split pulse turbo you want to time the exhaust pulses so that they fire alternately into each side of the housing.

Download the garrett catalog at this link, it has all the info you need plus some equations too. Also check out the tutorials on the garrett website, it will reveal all.

Catalog:-

http://www.turbobygarrett.com/turbobygarre...mon/catalog.pdf

Lessons:-

http://www.turbobygarrett.com/turbobygarre...bo_tech101.html

http://www.turbobygarrett.com/turbobygarre...bo_tech102.html

http://www.turbobygarrett.com/turbobygarre...bo_tech103.html

[SKY 34]

hiya Matt,

thanks a lot~~....Understoon more now~~

[Ezz35]

I was tryin to figure out te same questions about 2 weeks ago(yeah im new to the game) and the garret site was deffo worth the read :PBJ:

[T04GTR]

Flanges,A/R, Trim, Compressor maps?

THATS A T66

[SKY 34]

T66?

I've only heard of T3 and T4

[R31Nismoid]

ok, i think you got the answer you were after?

On actual turbos - goggle it

Or look @ Garrett website etc