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Discussion Starter · #1 ·
I'm an owner of alfa 155 Q4 and i would like to gain more power. I was thinking somewhere around 320 HP, and i would be very happy if you could help me with this.

I would like to know what exactly do i have to change to gain such power.
i was thinking about something like: turbocharger, intercooler, pistons, camshaft, injectors, fuel pump, pop-off valve. Did i forget anything?

The secon problem is that i dont know where to buy these parts.
I'm from Slovenia, but if you know ANY company that sels these stuff (doesnt matter where the company is from) please let me know.
I heard they have a lot of parts in Italy, but i dont know any companies there.

Keep it burnin' boyz! :cool:

Discussion Starter · #3 ·
yeah, i know this was asked before, but i have noticed and companies mentioned which made these parts.
I sincerely do hope some crazy Q4 dudes come along :) )

Discussion Starter · #4 ·
On my brother-in-laws Lancia Thema turbo they had swopped over the cams because the intergrale has them a certain way different to the Thema Turbo core did it go.

Discussion Starter · #5 ·
Hmmm 320bhp.. above 260-280 you'll need to start looking at a stronger clutch, diffs & gearbox as it's pretty hard on the transmission.

It should be pretty straight forward to get that sort of power though, head work, cams, exhaust manifold & exhaust, straighter intercooler path\larger intercooler, hybrid turbo, chip etc. There are a LOT of options - it all depends on what the car will be used for & if you wan out & out power or drivability\throttle responce.

Take a look at (& just about any other integrale tuner) - Guy croft can build these engines to 400hp for ~£6k the real pain is the transmission.


Discussion Starter · #6 ·
Thanx y'all for replies:)
Fade2gray, i have a list of what hings do i have to change to get 320HP, but i didnt know that transmision is SO bad? I was planning on inserting a different clutch, but do you think that the transmision itself should be replaced?
anyways, what i was intending on tuning was:

head bolts / head screws M12
head gasket
inlet valve
exhaust valve
valve springs

forged pistons
rod bolts M11
main bearrings
connecting rod bearrings
set of engine gaskets

turbo charger T3 / T4
air filter
metal intercooler
pop-off valve

fuel preassure control valve
fuel pump

brake lines - teflon

clutch plate sinter with springs
clutch bearring

Did i forget something?
Thanx again guys.
Keep it burnin' :cool:

Discussion Starter · #7 ·
I'm assuming there's an order for piston rings too to go with the new pistons :D

Also.. you may think i'm silly... reading Max Power and watching too much Fats and the Furious, but...... Nitrous is a viable option.

I know a few guys who use NOS on subaru impreza turbos. The have the firing linked into the ECUand use it to give more low down power b4 the turbo kicks in, as the turbo does kick in it fades away. A smooth transission from NOS to turbo is acheived by the ecu controlling the NOS levels, so in effect they are using it as a bit of an anti-lag device, and then the NOS comes back in as the turbo fades away top end and keeps some power for another 500 - 700 rpm or so.

Sounds silly and crazy, but can be used to a very good effect that way. Or you could just use it as well as the turbo and have silly power all the way through the rev range :D

If you use the NOS to the right power level you will not have any troubles at all... i.e. if you use 150bhp jets you'll have a fair chance of blowing the engine up - you see that a lot with NOS because people get power happy and just keep on upping up the jets untill it all goes bang.
You could use 75 bhp jets which is as high as I would take it on a standard engine internals.
I see you are uprating the internals so 120 it would handle... but reliability could be compromised. 100bhp jets would be the max I would use on an engine with those upgrades. (could get away with more.. but to be safe)

Allegedly the 'rule of thumb' with NOS is a max of 30-35% power gain on std engine internals and about 50-55% on modified engines (conrods/pistons/gaskets/bolts)

I honestly do think it's a viable option.

Now i will watch in anticipation of a huge queue of people taking the **** outta me for this one :D


Discussion Starter · #8 ·
Hey MG
because you can get big power & big torque the diffs are prone to damage - mainly because they were designed for a loose surface not super grippy rubber & tarmac. Should be OK as long as you are careful. A Sintered clutch might be a nightmare to drive with if it's a road car though.. have a look as the helix organic ones, a good compromise & should handle that sort of power\torque.

Your Valve springs should be OK but depends on how wild you go with the cams, the valves can be faced to increase flow. uprated con-rod bolts are well recommended if you are increasing rpm - ie by lightening things or changing cams.

The std intercooler is pretty good but the run to the inlet should be straightened if possible to improve responce. Also consider a charge-cooler - depends on what you use the car for though, the money might better be spent on something else.

Keep your re-circ wastegate, but there are better ones going - ie from TAS\Bailey etc. Fuel pressure should be set with the chip, ie 3.2 bar for Evocars ships, your std regulator should be fine for that. a Thema 8.32 fuel pump would be a good plan. Injectors & fueling will probably be decided with the chip, the std injectors may flow enough @ higher pressure for the power you want but it's worth checking.

Brakes, you'll need more than just new brake pipes.. Anything's possible from uprated pads & discs to full AP setups. Look at spending money on brakes & suspension so you can use the power unless you are after a drag car (which you won't be as the transmission is a bit crap wink )

enough to be going on with? :)


Discussion Starter · #9 ·
NOS is a good idea, but its a bit expensive. I'm not talkin' about equiptment or tuning, but the gas itself and you dont have it for a long time. If you wanna use that often you can have a cubic metre of it at home all the time to keep fillin' it when it empty:)
But maybe i'll nisert NOS, but after im done with tuning it to 320bhp :)
thanks 4 the tip;)

Hey F2G! wink
I dont think i can afford another transmission, so i'm gona have this one, until it fells apart:)

Helix organic clutches? Ive never heard of them.
Thanks, ill take a look.

Ive decided to change valves and springs, cuz i dont know in what condition are the present ones. Ive had a piston melting situation before, and ive changed the piston but i dont know if it affected the valves. It didnt seem it did so i didnt changed them at that time, so im planning on doing that now.

(what does ie mean?)

About the intecooler, if you mean the plastic run to the inlet, im intending on changing the intercooler because of that. But if you are thought about the rubber hoses, ive already replaced them with silicon ones.

Can you tell me what a charge-cooler is? What is it different than normal intercooler?

About waste gate, it comes with a turbo right?

Does evocars sell injectors with chip and instruction on how much should fuel preassure be set to?
If so, do you think this would be the best to buy?

Ive already have racing brakes, so im just replacing the old pipes with new ones.

thanx again dudes.

Discussion Starter · #10 ·
Hey MG..

Hopefully the transmission will hold together - it all depends on the use & abuse you give it..

If you are changing the valves (ouch!) Sodium ones are the way to go. You could use ti springs & retainers but it's probably over-kill. If you've had a piston melt, new valves may be a good idea though.

ie.. it means for example.

Intercooler - you can remove a number of tight elbows between the outlet of the intercooler & the throttle body by moving the battery to the boot & adjusting the pipe work. If you change the airbox side, make sure you are getting lots of cold air in. The consensus (spelling?) is that a std air box with holes drilled in the 'dirty' side is best. You may also be able to tilt or move the intercooler to facilitate the straigher path. An Charge-cooler is basically the same thing, but cooled by water & often it's own radiator - it reduces heat soak, particularly when at a stand still (eg traffic lights) in turn this improves throttle responce. The benifits once you are moving seem to be less noticable though. All in all, an uprated charge cooler would probably be better due to it being water cooled & having a higher performance core. Have a look on the Web for PACE.

Wastgate & it's actuator are on the turbo but can be unbolted & replaced.. take a look at the catalogue on for what's avalible off the shelf. The re-circ dump valve lives up at the air box end.

All of the Evocars chips are written for a 3.2 bar fuel pressure (higher than std), they provide instructios on how to increase this on your car. An off the shelf chip should be good for ~260bhp There are a few other places which make good chips too - Squadra are ones (I have one).

All in all, as a first step I would look for:
head work, exhaust & exhaust manifold, lightened flywheel, uprated gaskets & bolts (inc rod bolts), clutch, tipo inlet cam, chip, altered fuel pressure, air filter, hybrid Tb035 roller bearing turbo if funds allow.

That should be good for ~300bhp. beyond that, suspension, brakes etc etc etc :)

It all depends on if you haev won the lottery!


Discussion Starter · #11 ·
Thanks every1, especially F2G.
Now im going to dig in:) and then ill report, whats happening. Im intending on going to italy soon to buy all the parts and then open the hood and take HER heart out:)

Thanks again,
Keep it burnin' boyz;)

177 Posts
The way to go depends a lot of how you want the engine to behave, how much you want to modify, how much money you want to spend and of course how much work you’re ready to spend on the project.

If you degrade your goal to 300 hp you probably don’t have to do much about the transmission. Perhaps an uprated clutch would help and a serious control of the rest with a small modification of the central diff according to Evocars.

The injectors will do the job up to 300 hp as well as the turbine. The compressor impeller could be kept but the housing should be replaced for about 500 Euro. Tipo 16V inlet cam – Yes. Valves – No. Cyl. Head job? Well if you have the head of – Yes, do some flow improvements. Pistons – Yes, if you want high revs. Exhaust manifod – Yes, if you want better low rev characteristics and some extra hp’s on top. Inlet – Modify box with a pair of 3” bass refles ports from a Hifi-kit store. Intercooler – Yes. If you’re willing to sacrifice some of the front, go for a big one in front of the radiator, otherwise go for the chargecooler. Head bolts – No, only if you go for real big boost = torque.

This is the minimum – Go further if you want more.


Discussion Starter · #14 ·
Hi there!
Im back:)
I've been serching for parts lately a lot! And i've found some companies that have parts for Q4s, and the best of them is Gozzoli tuning (, which is in Modena and i'm going there probably next week to get everthing. But im not sure that im going to buy turbocharger there. It pretty expensive (about 1500 EU). But ive found Garret T4 turbo (for 400HP) in switzerland, its new, and it only costs 800 EU. ( ). Ive found other companies, but they are obviously not so interested in selling patrs, because they havent answered back.

But ive got one question. Is the camshaft from Fiat Tipo 16V really better then the one in Q4? Cuz if im going to Italy, i might stop by at some junkyard and buy this camshaft.


Discussion Starter · #15 ·
You need to be sure it's the right one.. by all accounts it's the fiat tipo 2.0 16v 5-door. Not the 3-door. If money's no object, C&B cam's are good but you don't really need them for 300hp.


177 Posts
I am not an Fiat Tipo Camshaft expert, but the one discussed should be good for another 1000 rpm on the top while loosing 300 rpm in the bottom. So, with the right exhaust manifold you should gain a lot on low revs and probably compensate for the camshaft loss.


Discussion Starter · #17 ·
I'm of the opinion you can get 300 without doing anything to the engine - mechanically that is - apart from different spark-plugs and - if you're really worried.. a better head gasket!

300 should be reachable with a decent exhaust (no cats of course wink , performance manifold, T38 turbo, chip, uprated intercooler (all alloy as opposed to standard plastic ended one :( ) Of course you will need a better clutch.

Remember.. if it ain't broke.. don't fix it and
if you don't need it.. don't touch it!!

PS What's all this raving on about the Tipo cams??? And what a difference is there between the 3 & 5 door cause it sounds a bit weird!

Discussion Starter · #19 ·

Does the name ZEGA ring a bell :D He will get the things you need and sort you out. And they did a competition car so they know what they're doin'.

The shop is located in Dutovlje (Sezana).

46 Posts
I'm using that certain Tipo inlet cam in my Q4.I have a custom chip(im running on 1.2 bar),decatted 60mm straight exhaust from turbo,and a big fat airfilter from a Mitsubishi L200(it has a much bigger surface than the stock airfilter,u can hear as the turbo sucks the air much freely) :) ) I'm using the standard clutch set,but I've removed the factory ferrodo surface and put some nice kevlar/ferrodo mixture on it.
My Q4 makes the 0 to 100 kmh in 5.5 seconds :)
So I havent't spent to much money on it,but it can't compared to a factory one.
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