Turbo Basics 102... Advice welcome!!

[Archbish]

so...  I\'m looking to future proof the 1st gen, and bonus time is gonna be in Feb, so thinking about upgrading from the T2 turbo to something that would stand a ported 13b in the future...

Step 1 : choose the turbo.  Now I thought "simple T04 would be cool...".  Then I find out there are about 60 variants talking about compression ratio\'s and stuff.  So could do with advice about what variants there are, and what these numbers mean - and which would be ideal for this proj.  Or a GT3540?

Step 2 : wastegate & boost controller.  Presumably this will need to come after the Turbo choice, but any advice on choosing which one here would be great!

Step 3 : exhaust manifolds (in and out).  Anyone know where I can buy these for this sort of Turbo config on a 13bt in an s3?  I\'m assuming an oz import, as this is much more likely over there to be ready made than here, so any recommendations and contacts would be invaluable.

I am already looking to get bigger injectors (although size is yet to be decided), and a microtech for mapping purposes, but if there are other considerations to be made, please do offer advice!

Cheers guys

OJ

[sadgoth]

big question is what power/driveability are you after?

what sort of porting?

for e.g my 13bT which is a 1/2 bridge I\'m running a GT4088 (which is probably abou the same size as a T78 give or take) becuase the porting is quite substantial I should see boost from about 3k with full boost appearing at about the redline (ish) should be looking at 400 atw but who knows?

T04 come in all shapes and sizes, E, S, R and Z, but what you want is a decent A/R size (at least .96 ideally over 1) to get the most of the massive ammount of exhaust gasses the rotary produces.

GT35R is a nice mid sized turbo (or the GT3540)

Turbonetics T70 is a nice mid-large turbo

or if you have masses of funds spare the T51R KAI is a really nice bit of kit (but laggy due to its size)

Wastegate, I was advised to go for the biggest I could get so I went for a 60mm unbranded HKS copy which is the same as the one Chris Impey uses in his drag car

boost controller is up to you I\'ve got a Blitz SBC in mine

manifolds can be a problem mine is an HKS FC item but in the FB may not have the clearance so you may end up having to get one fabricated (talk to Tim at RX Motors, he has a guy who does all of his custom manifolds and they aren\'t stupidly priced)

[Archbish]

Good question, and what I really should have said... *slaps forehead*

I guess the phrase "well sorted" probably covers it.  Bearing in mind this will not be a stripped out racer, but rather more of the fun complete car, then something between street port and half bridge would be the kind of thing I\'d be looking for.  I guess the imagined target would be a comfy 350rwhp (once the gearbox and diff have crapped themselves and been replaced, etc) without massively stressing stuff.  A nice even power band between 3.5k and the red line would be cool.  Along with world peace, and kylie & danni turning up with a family pack of massage oil...

[clive]

I guess the imagined target would be a comfy 350rwhp

Look no further than the GT35/40 then:Thumbs-up

BTW, "s3" , real impressed, I knew you when you was a lad and could only recognise "s6" onward FD\'s (whoops me anorak just slipped)  http://plugin.smileycentral.com/http%253A%252F%252Fwww.smileycentral.com%252F%253Fpartner%253DZSzeb008%255FZNxuk101YYGB%2526i%253D4%252F4%255F1%255F219%2526feat%253Dprof/page.html" target="_blank">http://smileys.smileycentral.com/cat/4/4_1_219.gif" alt="SmileyCentral.com" border="0">http://plugin.smileycentral.com/http%253A%252F%252Fimgfarm%252Ecom%252Fimages%252Fnocache%252Ftr%252Ffw%252Fsmiley%252Fsocial%252Egif%253Fi%253D4%252F4_1_219/image.gif">

[Archbish]

"s3"

*GRIN* I\'m learning australian...

What\'s the difference between a GT35/40 and a T04 then??

[antnicuk]

i had a gt35/40 on my turbo 2.  0.96 hot side and it made 460 flywhp at 1.2 bar and spooled nice and early with a mildly ported T2 engine.  The GT range are a little more modern than the old T range (E,S&R) which were originally for lorrys (excluding the HKS ones).  The GT range were made for performance applications.  You will make 350 at the wheels easily with the right mods at about 1 bar.


Wastegate,  any 44 - 50 mm w/g will do the job,  I used an xs power HKS style racing one which worked ok but the diaphrams dont last as long as an original HKS one.

Manifold,    cast ones are a little quieter, HKS do one for the FC which is quite small and close fitting,  or, if you have room, you can fit an FD one,  you are just going have make sure the turbo misses the inlet manifolds and steering.  The GT35/40 is not big physically which will help

where can we find some pics of this little project then bish....

[Archbish]

Thanks Ant, just need to go hunting for a reasonably good second hand one... *hint hint*

where else but www.archbish.com

I do need to update it with some of the rad and intercooler mounting...

[shaunwil]

my god that thing will fly :Giggle Mine feels punchy with just 125bhp !

Have you thought of the old skool approach for the s3. You could have it setup with a blow through carb and not bother with the electronics.

As for turbo go for the GT35/40 for all round power.

The manifold is supposed to be quite hard because the steering box is in the way of the manifold. Not sure is A-spec do a FB kit for the GT3540. Add a reasonable streetport and your laughing.

Can\'t wait to see it running.

[Archbish]

OK, so lets assume I still don\'t quite get the price differentials between different turbos...

Why is this turbo so much cheaper than this one?

Cheers

OJ

[sadgoth]

The first one only has an A/R of .70 (small for a rotary) also the first one may well be an unknown brand rather than the original Garrett so maybe not as well made?

[BlitzBoy]

yeah sounds like the second ebay link you posted is selling  genuine Garrett turbos, so I would go with the second link, ask him to post a picture of the centre cartridge with S/N metal label, its should say Garrett

[Archbish]

OK, so I\'m taking an executive financial decision to NOT go with a named brand. I can\'t justify the 900 - 1200 quid cost when it\'s meant to be a budget project to keep me amused, and not really keen on a second hand tubby when I don\'t know what the poor lil\' blighters been through...

SO, the current idea is to go for a less regarded brand with similar spec. Because of the precision required for Ball Bearing turbo construction means I\'ll take something a little more uncouth. So something like this spec from OBX for about £350 delivered. The A/R seems large enough, but I am happy to be told why this would not be an appropriate one to buy...

T04R
Specification:
Compressor Wheel: 50 Trim - 65.5 Inducer / 92.0 Major.
Compressor Housing:105mm(4.0") Inlet / 65mm(2.5") Outlet -51mm(2.0") A/R.
Turbine Wheel: -76 Trim - 68.0 Major / 78.0 Exducer.
Turbine Housing-T04 inlet / 92.0 V-outlet -71mm(2.75") 1.01 A/R. .
Style:
OBX T04R.
Item Description:
4.0" Inlet.
3.629" V-Band Outlet.

[arrouk]

poss a bit big bish, do they do a to4s/to4e?

matt

[Archbish]

Not sure and which bit is the big bit?  The 1.01 A/R is based on the info above (.86 or bigger), but if there\'s another dimension that I should be worried about, which bit is it??

Thanks for the reply - so much learning with these damned things!! *grin*

[arrouk]

well the 68mm turbine wheel

to4r are a good tub capable of 500 fwhp on the right motor.
to4s are goog for 400-450 i think
and to4e is 350ish

hth

matt