s2 engine upgrade advice wanted

[wez 47]

hi everybody,im soon to be looking to upgrade my 3b s2 , firstly the engine. im new to the s2 my backround being in 205,s with mi16 engines etc.i was thinking of porting the head, triple cutting the valves+head inserts, double valve springs, steel rods, forged pistons, re shelling the bottom end, arp rod bolts, front mount intercooleretc,however my target is 320 bhp at the wheels, which i would guess is gonner be around 400bhp at the flywheel,what size garret turbo would be suitable as i dont want an on/off switch, its got to come in fairly early an hold all the way to the red line, more importantly i want at least 320-350 ft/lbs torque.also i donot know anything about how or what is available cam wise with regards to the s2 motor.and the integrity of the 3b gearbox, do quaiffe or ppg do straight cut gearsets for the 3b box?, any other advice on the way to proceed would be much appreciated, cheers wez.

[Animal Mother]

400bhp is easy without head or bottom end mods.

Bigger turbo, manifold (exhaust), filter, exhaust, injectors and remap/aftermarket management system should have you happy.

Pistons and bottom end mods would only be needed 450+bhp.

Others will be along with more advice shortly.

[macspring]

Not sure if double springs are necesarry?

Others will advise.

You suggested spec. sounds very like what one does to increase power on a N/A engine, but with theses engines it's as Animal Mother says, bigger turbo and remap etc., and also as he says, others will follow myself also.

Welcome and enjoy the grip of 4wd and the forum.

Kind regards.

[A80Avant]

Out of all the above comments,i might suggest that as a precaution, rods should be replaced because garrett turbos give good boost with good spool and that means lots of torgue very fast,which is what may cause your rods to bend.I have a friend who didnt change rods and used Gt3582 turbo to make 500whp but his power came on at 5500+rpm so no problems there.However for 400+hp if you get a Gt3071R like i have done,the rods will take a beating,and if something bad happens,you wont like the consequences.

On the other hand,if you reach for a nice RS2 setup which basically brings you close to 400hp but not above it,then you are safer.Mapping to bring the boost up a bit gradually should be addressed though

[S2central.net]

Welcome wez... There's lots to learn on the forum about the mighty I5T engine. Some grounding first -

400bhp is easy bolt on upgrade - no head porting or exotic internals required. Fiddling around with funky valve seats is not going to give you the bang for buck benefit as a good turbo upgrade. Sure with a turbo capable of high torque levels that careful measures for your conrods be made but lots of people run happily at 550Nm and beyond on stock bottom end. On a 3B it would be strongly recommended to upgrade big-end bearing. Biggest issue on the 3B is spark hop - thats the fundamental rod bender on that setup... Audi & Bosch didn't throw the dissy in the bin for no good reason. You can go with coilpacks if you aren't afraid of some wiring and an ECU swap (from AAN, ABY or ADU).

As stated here the RS2 setup will get you close to 400bhp but not quite and it carries more lag than a modern Garrett turbo.

My recommendation would be GT2871R (0.6 A/R 52 trim) on an RS2 EM. You'll need an RS2 intercooler (or bigger). RS2 metal head gasket. Stock cams. Oh and a 4bar FPR (from 7A for your 3B) along with 550cc injectors... I'm working with someone on that spec on an AAN and its running well - needs another software tweak to line it up. Makes 1bar at 3000rpm, building to wide mid-range peak of 1.7bar and dropping to 1.5bar on the redline. Runs AFR of 11ish for now but its over 300bhp at the wheels unfinished. You'd think it should surge in the lower revs but it doesn't - I really like it.

You could go bigger with GT3071R variants - that pushes the performance upwards but might impact the low end.

On a 3B you should look at uprated clutch and you might kill the 01A gearbox - get an 01E in there.

[wez 47]

thanks for the replies guys,keep em comin, with regards to A80Avant, would you say that the garret gt2871rs might be more suitible to my application?, also any suggestions or recomendations as far as the gearbox and clutch needs are concerned? the thought regarding going the route of steel rods and forged pistons was basically for security as i intend to do a few track days at oulton park next year and give my friend with a highly speced 02 bugeye a good kicking!cheers wez.

[macspring]

Paul,

Is this ANN in the the 32 or across the water?

Kind regards.

[S2central.net]

Its in 'the six'

Pulled nearly 0.9g on a 1st gear launch last week. Its NOT finished yet, but I'm going to real-time map that one just for kicks. We can talk more about it when its done (assuming all goes to plan).

[macspring]

At last, something on this side.

Small meet when it's done maybe?

Regards.

[S2central.net]

Sure - bring extra underpants though

[wez 47]

O1E gearbox wanted

on advice im looking to obtain an O1E gearbox, what sort of price should i be looking at for one?, anybody, cheers wez.

[DJones]

Its in 'the six'

Pulled nearly 0.9g on a 1st gear launch last week. Its NOT finished yet, but I'm going to real-time map that one just for kicks. We can talk more about it when its done (assuming all goes to plan).

I have attached my "g" graph would be interesting to see yours Paul. Perhaps in a different thread so as not to hijack this one.....

[newsh]

Wez you need a metal head gasket and the "rs2" big end shells.
Fit a Bosch Motorsport fuel pump and a 7A FPR.

[GazzaG60]

Wez

welcome. you have got the right ideas. the good thing about the audi is that it wont need those "heavy" mods for 400hp. problem is i personally thing you will need 500+ to see off a 400hp impreza thats well sorted. they handle so much better in every respect when it comes race day. you will be relying on stright line to an extent.

i run around 400-420 at present. im fuel pump limited. power is no greater since i upgraded the inlet, intercooler and cams as im fuel restricted.

400 is a turbo, manifold, 3" system, injectors and a map away. also budget for some gauges so you can get feedback.

remember a slightly bigger turbo will give less of a mid-range torque spike and will help it hold together. otehrwise budget to fit rods also.

the most important bit for track days will be suspension other driveline and brakes.