starting my turbo build... advice? and what turbo? (again) gt17?
Turbo Mini Forums

Hey guys after a bit of looking around and searching i now plan to go turbo 5 port, and i'm seriously thinking of using the gt17 as lots have been using it with good results.

I just a bit of advice really, i'm aiming for about 150 bannanas and would like to keep it as drivable as possible, its going to be a weekend/track sort of build (not too many miles).

Another reason for the gt17 is that matty has now said about making some more mainifolds so it seemed like a plan, but i'm more than open to other turbo suggestions.

The spec i have at the min is:

+20 rebore 1293
worked crank
centre main strap
worked head, not sure whats size valves yet or chamber size.
pistons? not really sure but mini spares mega's are what i'm thinking atm.
gt17 on one of mattys manifolds hopefully
cam? really not sure on this one, phase 2 or 266?
gearbox is sorted already.
comp ratio between 8.5-9/1 seems about right?


So could anyone give me any advice that might help in general and as questioned above?

Also where abouts do you get your turbos from?

I'm bit of a turbo newbie and could do with pointing in the right direction.

Cheers, George.

Edited by george91 on 8th Oct, 2010.

center main strap isn't needed
valve size: generallity is 36/30, but as we are short on exhaust side 33/31; 33/32 is better at this power level.
piston wise omega/accralite 14/18cc will save you the hassle of enlarging your headchamber, will also aviod braking into water ways.
I'm using a set mega's turbo+40 enlarged to 16cc since some years and even if I sometimes heard a bit of click click. I'm rering and reuse them religiously ( Tdave ).
gt17/mattys combo will certainly become very popular,as Robert proved this turbo eat the dogs.(put on your compressor tube exit a bosch bov from a s3 8p part number 710n (cheap 16£ and higly rated)
camwise don't write of the mg n/a cam, though the pase2 will help to sort the last hps (at same boost aroud 140 mgna vs150/ phase2), mgna is upper from low to4500 rpm then the phase2 take the advantage up to 6500,.
cr:8.5 should be reliable and help to have a better ignition curve.
don't forget one of the most time consuming relocating oil filter/radiator/dizzy/alternator to fit a good IC set up.a bit of water injection (only used it to suppress a bit of det at high boost) is very worthwile and more if you use a bit of alcool with it..
to feed this you'll need to pass a new fuel line and use a high pressure fuel pomp (ie injection one)

fab thanks very much for your help, thanks for the tip on the bov, and i think i might go for the phase 2 in that case.

i'm going to be using megajolt and am thining about going for a compact alternator so that should give the the room for the IC but i might swap and have a front rad a side IC still not sure yet.

Also sorry but what do you mean by water injection? i will be using an alloy tank with a facet pump so that will be fine. and i think i'll be aiming for 8.5/1 in that case.

i saw the omega ones on meds site but there forged? so they cost £460 which might be a bit much but i could stretch that far if it was advised. also found the forged accralites with 18cc dish for £375 so i'll probably go for those instead of.

EDI: i've noticed a lot of interest in the gt2056 lately, would this be another option for what i'm aiming for?

Edited by george91 on 8th Oct, 2010.

Accralites £370 from Avonbar are a good piston choice

If something is worth doing, it's worth doing half of.

Cheerss john, yeah i was looking at those earlier they sound good, i wanted forged pistons but i aways thought they were out of budget until i found them.

also does anyone have any other cam suggestions?
i think i'll probably go for the phase 2 but still would like to know what everyone thinks or can suggest.

cheers :)

Edited by george91 on 8th Oct, 2010.

gt2056 have too much flow/pressure ratio for your power uotput, a gt 1752 will allready far exceed these, then still let you in efficient areas, allowing you to want more later.....

george , im using the cast omegas ,and have found them able to stand up to 16:1 air fuel ratio and 18 psi , so they seem to be pretty strong .

Edited by robert on 9th Oct, 2010.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

whats this about the s3 bosh bov? ive heard oh people using recirv bov's then filterin the recirc part... i dont want a chavvy tsssccccch just a nice sound.

it's the genuine audi s3 bov, quiet cheap and very effective 710n is the last digit number that differencie them

thanks for the help guys,

robert which pistons are you using? i thought the med omega fis pistons were forged?

now i think i'm going to go for the accalites as there a good price, and have been recommended a few times.

also don't really want a very loud bov either so i'll go for the s3 one.

is this the one fab?

http://www.stokeaudi-parts.co.uk/products....urbo-Dump-Valve

Edited by george91 on 9th Oct, 2010.

http://cgi.ebay.co.uk/Saab-9000-Turbo-Dump...=item45f042a747

im using cast omegas ,george , i think they used to be 230 quid a set , but i dont know now .they are plus 40 ,and 15 cc dish .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

oh right, where did you get the 15cc dish ones from? i know there asking round £300 for cast omegas atm.

unfortunately from a company that isnt in business any more . i think they may have been machined for me, starting with a 12cc piston .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

no ,best icould find was 11cc AT 275 POUNDS.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

yes it is this one,
you could ring your audi part dealer, don't know where's the receipt but I think last ones I bough were cheaper than this