Alfa Romeo GTV6 Forum: Performance: Capacity?
By euro2 on Unrecorded Date:

Could someone pls give me the excact capacity specs for my 85 GTV6? Thanks, Garth

Shopping for a couple of snails....

torque on tap

By Mats on Unrecorded Date:

Getting Turbos? Do not buy them based on displacement alone, that would be a mistake...

What kind of performance are you looking to get?

Turbo Cheers

By george on Unrecorded Date:

Good on ya euro,if you cant beat them get even.

By Julian on Unrecorded Date:

Mate- find a wrecked RB26 or Two Wrecked SR20s and pull the GT 28s off those for a budget build. They'll flow close on 300hp for your car at 15psi, but that's only with lowered comp ratio.

List what youre gonna do for us on site, and what you expect to pay, because the worst thing you can do is start doing something you cant finish, trust me.

Mats is right. Capacity has nothing to do with it. You can double power and nearly triple torque output EASILY with a real turbo setup.

If you wanna beat a japper turbo rice car then youre gonna have to change about 70% of what you have at the moment. Injectors, manifolds, ECU, fuelpump, oil cooler- you name it.

Unless youre happy to drive the thing around for two weeks- before it dies on you!

By george on Unrecorded Date:

Sorry fellas im gonna get of the topic here i just wanted to know did alfa romeo supply indy cars with there engines in the past im pretty sure they did does anybody know.

By euroxpress on Unrecorded Date:

Now thats a good question george? I know they did an old Brabbam F1 car, which wasnt that good, but Indy car..?

I want at least 250HP@the rear wheels. I realised I dont wont to stuff around anymore, I want to be able to blow the doors off just about anything, except an R34 or something like that. Can achieve this for around $10,000. Was going originally to just do a crazy N/A rebuild, but I know I would be tired with that power after awhile. Thinking of maybe going to the Rigoli Bro's in Sydney or the Goldcoast, they are turbo wizards! Did a crazy turbo job on a Fiat 131, and 124. Theres no other car I would rather modify, it has potential, outhandles just about everything, would like to give it the power it deserves and needs, also life is short, I want to do something crazy!! Would love to enter Targa Tasmania or something wild like that, go to Alfa Track days, shit like that, I'm out to give Alfa a reputation, street cred for me, hehe

I heard the stock managment can cope with turbo work? Does anyone know if this has been done in Australia? My car nearly looks like the Callaway in the web site, its begging me to up the performance. Yeah I could go a jap ride, S14 Nissan decked out with Trust gear, but it wont have the quality ride, class or character, I love my Alfas, I want something different, something to remember. Also it would be alot of fun! I'm going to finish this when I get back from overseas, but am looking for 2 snails in the meantime. Julian what you said is good mate, 15psi would be plenty, should be good for over 350HP @the engine, there abouts.

By Ben Bishop on Unrecorded Date:

Yep there was even an Alfa Romeo Indy car v8 on Ebay a while ago...$8,000 they wanted..hmmm, no management, turbo's or manifolding....wonder if it'll fit in a GTV6??


By Zamani on Unrecorded Date:

Rigoli! Now don't they have the SUPERFAST Subaru WRX with a custom stroker EJ"22"....

I know Julian simply love those Rexs, don't you Julian? hehe

BTW, Julian, I'm ordering Autronic this week. NA for now. I was thinking of a TS Turbo next year. Maybe in a 1.8 Alfetta body?

By Julian on Unrecorded Date:

Ha Zamani you crack me up! The pair are actually cousins- the Gold Coast Rigoli's did the rex, and Rigoli's out in Western Sydney do the Fiats.

Zamani- youre talking the goods now! That autronic is your ticket to controlling any modification you can dream of- Ive heard, and felt, the light load throttle repsonse of Bosch 500cc injectors on an injected 8v SOHC 2002 turbo making 400hp, and that sort of fidelity is not something easy to come by. There are stories of many lesser ECU's not being able to maintain an A/F ratio, even under full load with near stock injectors- the dyno operator tries to maintain say 12.1:1 and he can only manage 12.3:1 or 11.8:1- one too rich, one too lean, for optimum power. Autronic is good!

Euro, I know what youre going through- Im nearly finished with my first "street cred" alfa- all I need now is an oil cooler, spray my bonnet, and pay for it all- EVERYTHIHNG's DONE!!!!

Back to your dilemma- Rigoli are very well known for building those Fiats, and they got a Fiat blocked/Lancia16vhead Datoo 1200 ute into the VERY low 9s quarter bracket- yeah- they can do it no probs. I just wouldnt trust them to. SOOOOOOOOO many bad stories over the years ($7000 for a 75 1992 QV 12v 3.0 Engine rebuild- STOCK), plus many out at the illegal runs whose cars have had things done in, "Interesting" ways- like BOVs controlling boost (ie the turbo is free to spin as fast as it wants and spits out HOT air, while BOV spring is set to vent at certain pressure- Fine if youre running an old style F1 turbo and revving to 10,000rpm at 50psi, but not at 20psi). Ive heard of sandblasting pistons to clean them up. Budget pay- budget performance. It doesnt last long. I saw a GSR lancer spew its guts out all over the road. It was a Rigoli car apparently running 11s. Rods hadnt been done and turbo was huge- revs=boost. Bang!

Euro I tell you straight away- this is what is going to be ionvolved, as a minimum, to get 350hp out of a TT 2.5.
I realise you are on a budget. Good Pipework will allow you to move on from your first build at a later stage, and do things like forgies with lower comp and bigger turbos for even more power.

Fuel System: Porsche K Jetronic fuel pump flowing at around 90psi will do you just fine. Dont stuff around with Two VL turbo pumps. Get one POrker one. Use your stock GTV6 fuel tank. Its pretty good. Injectors will need to flow at least 70hp each. Do the maths- you want enough fuel in the rail that some is heading back to the tank all the time. That's why the higher pressure pump is better, so that you use less Duty Cycle on your Injectors. More growth potential. Forget about adjustable pressure regulators- theyre just there to make up for an inadequate base system.

Manifolds: Best you can afford, grouped in firing order to get best scavenging possible. Higher is better- longer pipe, in a smaller diameter- given volume of gas must accelerate to make its way through less cross sectional area. Faster spool up.

Intercooler: Forget about jap factory cores, unless you find a GTR one- you want to put two separate paths of compressed air through a single core, so get a proper bar and plate one made up. $2000 with piping. Maybe more- dont scrimp here, because Im assuming youre gonna use stock pistons. Anything goes wrong here and you WILL melt them. Even if you find a GTR one piping will cost close to 1100. Its essential you get this stuff done well, because you are really relying on externals to get you the power, and hoping your internals will take it.

Turbos- mid trim GT28s will do nicely. GTR/N14 turbos. Good flow @ 15psi, spool is nice. Dont be a dickhead and turn it up anymore than 15 though!

ECU- you know the choices- plenty of them. FORGET YOUR STOCK ECU! Youre kidding yourself if you think you will be able to get adequate control by tricking the factory AFM etc to run everything richer- bigger injectors puts it all out anyway, and ignition timing will most likely be WAY to advanced for 15psi at hi rpm. You'll detonate the thing to bits.

Just go a 3" exhaust. Id advise against O Rings with stock pistons- I have this little idea that if there is detonation, and you try and keep it all in with an O Ringed head then you'll really do some damage to pistons and combustion chambers and valves etc. If you leave it un o ringed and start blowing headgaskets then at least you know youre detonating, and you can back off the boost or retard ignition.

Im sure Ben and Mats will blow holes through my arguments, but that's what I like about this forum!

Listen to what they have to say too mate. And good luck!

By Julian on Unrecorded Date:

My pump cost $375.

By Ben Bishop on Unrecorded Date:

Erm, Jules, you pretty much hit the nail on the head... although, for a budget build, I recommend dropping the compression a little more with some copper head gastkets, they'll cost about $90 a gasket, and using as big an intercooler core as you can fit, using a modified truck core (I know Jules, but Colin Townsend is getting a lazy 600hp from his Valiant now, still with the 265Hemi 6, and its using a BIIIG truck core, its about as big as you can fit in the front of a VG valliant...and its a damn site cheaper...Another alternative would be a pair of second hand coolers exiting from the middle, side by side, each one fed by its own turbo) Aluminium or Stainless pipework for the intake charge is nice, but you can get away with powder coated mild steel or if you want, get it ceramic coated...
The factory intake manifold should do the biz with boost, The de Villiers in South Africa were getting 320hp on 1 bar boost through the factory intake manifold...

Check out:

You can actually glean a fair bit of info from the piccys...

Garth, I have now seen your bumper, It got primered today, I'll have it shipped on Monday...
Sorry about the wait, I feel pretty bad about how long its taken to get the thing out of this guy...

Ben Bishop

By euroxpress on Unrecorded Date:

Thats fine Ben, thanks for all your help, you came thru where other ppl could not, so well done, you made my day!

Thankyou Jules for all your help mate. That shit bout the Rigoli Bros is weird, but you live there and have seen what has happened so...

By euroxpress on Unrecorded Date:

My goodness that GTV6 was amazing!! With 14.7 psi it gave out easily over 300 rear wheel hp!!

Not looking at that much, but thats hair raising!!

Thanks for the link Ben!!

By Julian on Unrecorded Date:

Fucking Mack truck cores!- you sure the pressure drop isnt too much?

If you say its ok ben, it cant be too bad!

Sorting out my bonnet now!

8500rpm shift points here I come!

By Ben Bishop on Unrecorded Date:

The trick is to make them fairly deep so that you have a larger number of tubes to flow through. Theres a whole lot of thermodynamics stuff that can be applied to intercooler design (Its actually airconditioning design stuff, sort of...), i've got a text book floating around some where, It wouldn't take much to run some numbers on expected temperature and pressure drops across intercooler cores, but i don't really have access to the dimensions and some of the temperature data required...(ie expected turbo outlet temp, compressor side)
Anyway...all this talk about "pressure drops" get a pressure (Measured pressure, its still the same mass of air, just lower temp) drop accross the core simply from cooling the intake charge (the classic: heat air and it expands, cool it and it contracts; if the air cools and contracts, there is less pressure.) But the Pressure drop you're refering to needs to be measured on a flow bench or something similar. Just make it BIG!! It might not be as perfectly efficient, but if youre getting the intake temps you want, with the manifold pressures you want, who cares? (Okay the turbo itself might have to spool a litlle harder, but not much....)
But at the moment, all my time is split between slotting an electric start Suzuki RGV250 motor into a Cagiva Mito, messing with a Suzuki RG500 (fitting bigger brakes and a bigger rad), and getting my GTA project happening (anyone in Aus interested in a set of carbon bonnet/boot/doors for the 105 series coupes? I'm looking at making a set of moulds, carbon isn't quite as exspensive when you supply youre own moulds, boot lid would be about $500ish in carbon...which is what i got quoted for a glass one).... and theres this set of whacking great big Alcon 4 pot$ that I've got my eyes on....

Ben (need more hours in the day, this getting up at 6:30am and crashing at midnight crap is killing me....) Thank God for Bialetti Espresso Makers and good Coffee.........

By euroxpress on Unrecorded Date:

Haha, all that osunds good Ben, youll be popular with those carbon bits for 105 lovers in Melbourne, for they take their cars to the track often. I heard the size of intercooler shouldnt matter? What about getting one from a Jap wreckers that would suit a Supra or something?

By euroxpress on Unrecorded Date:

Jules, what da hell did you have done to your GTV6 to reach 8500RPM points? Thats wicked! You must have a strong driveline to cope with power like that? I changed into second at 5000Rpm and broke my coupling...

By Julian on Unrecorded Date:

Hey Euro, Mate, so did my four banger!

Flyin down a street near Cronulla Beach, racing a 253 HZ Pano (dont try to understand if youre not an Aussie), and beating him in first, and 2nd, then I flat changed third, and got the gear fine, but as the lever passed through neutral, all hell broke loose inside the cabin with this big bang, and two days later I heard a metal "rattle" at idle :) Guess I wouldve gone through about 6500 when I did that...

Balanced talishaft, really really light flywheel etc- I'll have sound clips as soon as Ive paid for the following:
Parts, Labour, Rego, Insurance, 2 x New rear Tyres (gotta love that LSD), maybe a little bit of dyno time to see what spot the Cams Should sit (adjustable cam gears). I want more torque than power on the street...

But you get the idea that nothing comes cheap when someone else is turning the spanners...

By Ben Bishop on Unrecorded Date:

Well, i had no problems turning over 5000rpm in fith (yes fith...175+km/h put the foot down and she still accelerates strongly..) for about 40km on the weekend........with a known to be cracked front donut... My donuts have seen 7000rpm resonably regulary, but not much flat shifting...
The Donuts are consumables, its just you consume them faster the harder you drive them (they have a fairly limited front one has lasted about 35,000km... about the same as the tires i just replaced...I'd forgotten what having grippy tires was like...)

Picking up some extra front uprights (2 pairs, i will wind up with a spare 2 pairs afterwards, anyone else want a set of 4cyl drop spindles??) this arvo for my drop spindles, and a set of extra 32mm Dellorto chokes for machining out to 36mm (my Webber 45s are going ont the GTA proj)

Euro, I didn't get to get the bumper away for you yet, it will definitly go next week (I'm really sorry about the delays!).


By euroxpress on Unrecorded Date:


Haha, thats fine Ben, as long as its comin, I'm content, interstate trip has been postponed, so all is good.

By Mats on Unrecorded Date:

I saw 5500 rpm i fifth this Saturday... Thats around 190 kph.
I didn't want to push it any further as I know that the engine goes a little lean over 5500. It was still accelerating like crazy though, I think I have to do some work on the bottom end during next winter so I can rev it to ~7500 or so, that should do it. ;-)

By Zamani on Unrecorded Date:

My friend turbocharged his 146 1.7 16V. Apparently his car is as quick as a Mitsubishi with the 4G93T engine (Lancer 1.8 GSR for you aussies). He was racing that guy, good fight apparently. But now, due to high compression (10:1), he blew his head gasket at 0.6 bar of boost. He's putting in new copper gaskets next week.

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