Alfa romeo 156 3.0 V6 (the real GTA?)

[AlanV6]

Hello, i'm Alan and i come from Slovenia. I'm reading pistonheads for quite some time and have decided to join

I owned quite a few cars (ford fiesta xr 2i, vw scirocco, some ordinary daily drivers and a lot of alfas )

My latest project car is an alfa 156 with 3.0 V6 24v engine from GTV.

Firstly it was planned to use her daily and occasionally on track, well that didn't last long...

But let's go from the beginning

Stock 2.5 v6




Then i put on some ultraleggeras (less rotational weight)




Bushes for suspension




Koni sport (rebound adjustable)




to be continued

[AlanV6]

...

suspension done






she sits nicely




to stop the car we need brakes

rear disc 305mm from audi s5






front ap racing two piece 330 x 28 and alfa brembo caliper






caliper painted black so it's not too obvious

[AlanV6]

Today she weights around 1050kg so it the second thing
Will post more soon.

[AlanV6]

I'm sure you know what GTA means

engine(s)

[AlanV6]

I'll stick to 3.0, it has shorter stroke and i prefer it over the 3.2

Ofcourse it's not a stock unit




3.0 engine has destroyed a bearing so i went for full overhaul and some tuning:









ports are big enough from the factory, so a just cleaned them and made nice knife edge inside




heads were skimmed 1 mm for 11:1 CR




AHM cams (0,8mm bigger lift and longer duration)




shiny crank

[AlanV6]

Yes 2.5 is a lot shorter gearbox, around 250kph it reaches the limiter in 6. Great for trackdays

I had q2 and sell it to buy AHM race lsd. Expensive bit of kit but worth it!

[AlanV6]

Cnc lightened flywheel and cerametallic clutch



And because you cant just lighten the flywheel on a V6 (it has an imbalance) i weighted all assembly and made bobweights for proper balancng of the crank




I also reduced the main pulley size by 10% so i can spin the engine higher without water pump cavitating (and also the pulley is 600g lighter now)





random pic :P



weighting



bobweights

[AlanV6]

Yep Alegeritta

Lightened cam pulleys



255 fuel pump




liners mesured and honed with flexhone




some "ricambi originali"




crank balanced (quite a few new holes on the flywheel)




engine assembly




gapping the rings




"selfie"




torquing up




it's starting to look like an engine again

[AlanV6]

Thanks

Catless manifolds in titanium heat wrap






Some aluminium :P

Edited by AlanV6 on Thursday 31st July 16:07

[AlanV6]

Because stock plenum is a little on a small side and not the best shape, i made my own

And it has trumpets!


















stock vs maserati 82mm throttlebody

[AlanV6]

Well homemade is cheap and almost the only way as there isn't many alfa tuning related upgrades available...

something else will be homemade:

[AlanV6]

I wanted to change caster and camber at front to get more grip and get rid of understeer. I made my own lower arms and moved the wheels 4cm forward and 1.5cm out. Camber is now at -3°

Fixing for bushes






arms
















subframe was additionally welded on some places for more strenght






To further reduce the understeer and make the car more tailhappy (my kind of driving style )i made new rear arb that is 400% stiffer than stock

I used torsion bar from peugeot and welded some "blades"



testing stiffnes stock vs mine











a little jump into realtime

[AlanV6]

I'm trying

Let's go back to the engine, belt is on and cams dialed










sensors for oil temp and pressure





engine fitted





first test for oil pressure

http://youtu.be/QapxdAsBsA8


start

http://youtu.be/00-BMXYRxYY

[AlanV6]

Now about some unnecessary weight

I tried to lighten the front end as much as i could (serial weight distribution is around 65:35)



1.8kg lightweight 40cm fan



all of AC stuff removed ofcourse.

Lexan:



some cutting :P



seats:



steering wheel extended 20cm so i seat far back (wtcc style)





gauges




extended wheelbase (specially front wheels) it helps with weight distribution. I'm at 60:40 now




And she goes!!! (scary moment included as slicks were still cold)

https://www.youtube.com/watch?v=V1JkZHhNN4U

[AlanV6]

relocating the battery to the boot (later replaced with 4kg race version)






strenghtening plates for front subframe






in road trim




for trackday






some videos and photos from a litlle karting track

https://www.youtube.com/watch?v=MDlYsLFV1ys

http://youtu.be/8AkH4qGdgM8



i had the fastest time and i think she drives great for a heavy v6 fwd on such a closed track (second and third car are both at around 180bhp and under 800kg)

[AlanV6]

Thanks! I measure cam lift. Cams have to be dialed in as they arent stock, full lift is set at 107°.

[AlanV6]

Hehe well to make fwd go fast around a corner it has to have good roll control at rear and good grip on both front tyres. That's why thicker arb at front isnt the best solution. I have toe out at rear and just 1,5° negative camber so the car rotates nice and has almost no understeer (lsd helps too ofcourse)
It's a little twitchy but some softer rear slicks give quite good balance.

Future plan is some fibreglass and alu at front and maybe rear mounted water cooler to further improve weight distribution.

[AlanV6]

I started with further lighting the front, cutted all away and put some aluminium profile on M10 screws:








[/quote]

Around 10kg lighter than before.

And the whole car was weighted at 1140kg before that:

[AlanV6]

Alu brackets for radiator (rubber used on mounting holes)










Lot of space for big filter and cold air intake

[AlanV6]

done some measurements today




front camber is 3.5° negative, outside wheel on full lock goes to 5° negative (inner goes to 1° positive) ideal for corners Thats why she doesnt have understeer

Caster is 6°





another 2kg of brackets and screws was removed