Garrett Turbo Selection,

[funkytown]

I've done a bit of searching about the place and havent found terribly much to help make an informed decision on which turbo to get.

A while back i was tossing up between the 2876 or 3071 or 76's from the Garrett range, and as im aware they come in a range of trim wheels and housings...

To be making a solid (read: comfortable) 250+ kw which would you suggest would get me there, with the earliest spool? Obviously its a trade off - i just want to avoid slapping on a big blower going overboard on power and losing spool time.

Any help would be appreciated, as it stands im leaning towards a GT3071r with 4" intake, i think this requires the larger front cover to do so.

Jon

[wrx_lou]

I recomend the following:

http://www.trademe.co.nz/Trade-Me-Motors/Car-parts-accessories/Performance/Turbos/auction-285679222.htm

;D

[funkytown]

a bit big eh ;D

i did see those earlier and the devil in me was tempted

[wrx_lou]

come on, its not that big. Thats one of those small cans of spaghetti :

[Guest]

mines a gt2876r and makes 245 kw at 18psi. engine still running good and the turbo is very responsive. not much difference in lag compared to a vf22

[Guest]

spoke to you about ths months ago dude

remember its not all about the the turbo size

The A/R's need to be correct to get the sppool at the correct time Prob 0.68 would suit your application dependant on turbo

Do the calc's with many online tables, go to the Garret web site and plot your airflows against their compressor/turbine maps

[Simon C]

+1 for compressor maps. Garrett are good in that there is a huge library of compressor maps on their site. I would have thought that a GT3071 would be a good turbo for you.

[Koom]

SquirrelPF Turbo Calculator

This site is pretty good for getting an idea of what turbo does what. Spool up rpm is best guessed off other peoples dyno charts if you want a quick easy way of seeing things.

[Guest crunchy]

Many things contribute to a turbos output

If your not making whats meant to be the turbo isnt always to blame, not may setups will max what the turbo can do.

Remember as with all turbos the maps you see are done based on a set size turbine housing and very few state what that was.

Experiance is something they wont tell you even with the calculators they offer, notice they dont offer turbine maps?

They are just as important as the cold end, turbo sizing is somewhat a black art and they only tell you what they want you to know 8)

The art of making good hp goes well beyond the turbo

[funkytown]

thanks guys,

have a bulk on conversation from yesterday on PM and have some informed ideas about where im headed.

Current thoughts are a GT3071r with the T2 flanged turbine side, runs a slightly smaller 56.5mm wheel (84 trim)but bigger than a GT28 series (53mm). (GT30 big wheel is 60mm). compressor side is the 71mm wheel (56 trim). Hope to run which end state with the large 4" intake twisted and flipped.

essentially this.

http://www.atpturbo.com/mm5/merchant.mvc?Screen=PROD&Store_Code=tp&Product_Code=GRT-TBO-025&Category_Code=GRT

 crunchy']

Many things contribute to a turbos output

Experiance is something they wont tell you even with the calculators they offer

i definately want the "real oil" on what people have experienced in this area - on that note - thanks capster for your input dude.

[quote name='Ichi Ban said:

spoke to you about ths months ago dude

remember its not all about the the turbo size

The A/R's need to be correct to get the sppool at the correct time Prob 0.68 would suit your application dependant on turbo

Do the calc's with many online tables, go to the Garret web site and plot your airflows against their compressor/turbine maps

we surely did and ive spent time thinking about it, and your dead right A/R's are very important - as is the housing they go into, A/R tells you nothing about the actual housing used.

0.68 you reckon - why so? They only do that in a T3 housing - which im picking will be too big? i thought a T2 (0.64 A/R) would suit better..

[Guest crunchy]

we surely did and ive spent time thinking about it, and your dead right A/R's are very important - as is the housing they go into, A/R tells you nothing about the actual housing used.

a/r doesnt tell you nothing about it? so what do you think it tells you?

It tells you everything about the involute size in relation to its frame verus turbine backpresure or compressor discharge.

Aspect ratio on any turbo helps determine the threshold point in relation to the nozzle area.

T3 t2 tbo4 to4e to05 etc all have different areas based on frame size even tho they can share the same a/r

Most info on the net is copy and pasted which is fine but theres too many things un said, those who make outstanding results dont post there findings and i dont blame them.

Ive done many simple setups that out perform cheque book/catologe setups, and how many times have people seen this at the drags.

This why i no longer give out generic setups the net seems to take care of that, i cover every detail it gives a greater result especialy when we all know sub heads alone flow varstly different from spec to spec along with headers etc etc etc.

Thus why thinking outside the sqaure is well worth the effort and can cost alot less.

[funkytown]

 crunchy said:

Aspect ratio on any turbo helps determine the threshold point in relation to the nozzle area.

T3 t2 tbo4 to4e to05 etc all have different areas based on frame size even tho they can share the same a/r

this is my understanding

edit: to clarify it doesnt tell you much when you talk about two different frames that share the same A/R (or very similar) as i understand it.. one can be wickedly bigger, i.e as i understood it a T3 in 0.64 vs say a T3 0.68 are quite a difference in "real/nominal" size.

 

those who make outstanding results dont post there findings and i dont blame them.

sure but im asking CS ppl that might share in the idea of being clubmates - good c*nts.. etc.. maybe not.

 

Ive done many simple setups that out perform cheque book/catologe setups, and how many times have people seen this at the drags.

what would you suggest - if you were to build me something? - seriously. the old turbo is off, i require the new one.

[Guest crunchy]

The power your after isnt hard to do even over stock so its basicly up to you either turbo you have meantioned will do the job, so will many other brands but again its your money that desides.

As ive said i wont give it out setups anymore as those who chose to try only do half what i say then bitch at me when it doesnt do what i said,good old kiwi tall poppy thing thus why i dont help out on alot of forums anymore.

[funkytown]

sorry but im very happy with my Steve Murch 1.0.

and i've come asking from professionals (like yourself) and those that have tried and tested the Garretts (in this instance).. I personally dont know - and am asking for help.

im trying to have a semi intelligent conversation about a making an informed decision and learn some (more) stuff along the way.

dont take it the wrong way but its hard to buy your service if you don't want to give it out ???

[Guest crunchy]

 funkytown said:

sorry but im very happy with my Steve Murch 1.0.

and i've come asking from professionals (like yourself) and those that have tried and tested the Garretts (in this instance).. I personally dont know - and am asking for help.

im trying to have a semi intelligent conversation about a making an informed decision and learn some (more) stuff along the way.

dont take it the wrong way but its hard to buy your service if you don't want to give it out ???

ok give me run down on what you have to date, specs head type headers other internals compression cam spec ecu top or from mount etc etc etc etc, and is the block pined and what rods ( stock rods i have found dont like to much over that power your after.

the main issue i find is people dont tell the truth about what they have and when i give them a spec sheet they go for the turbo only then abuse me when its turns to custard!!!

theres times when i wish i never helped

[funkytown]

il pm you some stuff.

happy to cross check it with Rick (ichi), he did the entire build.