New member from France : 155 Q4 buyers guide required

[PtiSeb]

Hello everyone,

Let me introduce myself. My name's Sebastien, i live in France and i'm used to be called "PtiSeb" (little Seb in english). I'm 30 and a proud owner of an Alfa Romeo Gtv 3.0 v6 24v (nuvola and red momo leather). I already had an Alfa Romeo 164 Qv 233 bhp (unfortunatly sold because of road crash) and now i consider buying a 155 Q4 :!:

I would like to know more about this car, that's why i've joined this forum. I tried to read the buyers guide in the website but it's under construction...

Can you tell me what to look for ?
Strengths/Weaknesses...

No major problem with manifold (i think about fiat coupe turbo), no major problem with differential or clutch ? (i think about alfa romeo 164 q4), etc...etc...

Any feedbacks will be very useful :wink:
After spending some hours in this forum, i'm happy to see such beautiful models (Serge, wolf66, steve, and the other ones!)
I'm also pleased to see 155 Q4 performances are easy to upgrade with bigger turbo, performance camshafts and a remap to reach at least 250 bhp.

My project is to have a kind of trackday car.

2 pictures of my "garage" :

http://nuvola916.free.fr/Galerie/img/GTV2/gtv5.jpg http://nuvola916.free.fr/Photos/164r.jpg

[Steve Webb]

Hi Seb,

Sorry for the delay in getting back to you on this one, and apologies for the state of the buyers guide online, promise I'll get if finished one day.

Right a potted history of the strrengths/weaknesses of the 155 Q4. Firstly there are 3 different production runs of the Q4. The first run, or series 1 cars (@1500) have the intercooler waterspray, narrow bodys. These cars were made 1992/1993 . The Series 2 cars were made 1993/1994 narrow bodied, no waterspray and a couple of interior changes. S1+S2 cars both have the horrible 1/2 vinyl seats. Series 3 cars are the wide bodied cars and have a standard 155 16v interior.

Mechanically all 3 series of cars are pretty identical. All 155's were comprehensively galvanized so there should be very little body rust on even the early cars. Problem areas for rust are under the bottom edge of the wing mirrors, and at the wheel arches where the bumpers rub on the body. Its also worth mentioning that the 155 body is not that brilliant when it comes to torsional stiffness. Don't worry if you have trouble opening a front door if you have one of the front wheels jacked up off the ground. They all do that!!
On the subject of jacking the car up, take a look at the jacking points and the front footwell area in general, jacking points aren't that strong and can collapse if they are abused. And its not uncommon to see dents in the footwell area caused when the car is jacked up incorrectly.
Wheels - The black / Anthracite speedlines (There are two different colours so make sure they all match) look great but are soft so are easily buckled/dented. The S1+S2 original speedline (fake) split-rims are a real pain to refurbish because all the small 'bolts' are fake and plastic and will break when you try to remove them.

The drivetrain/4WD system is fairly bulletproof. Very very rare to hear of problems with any of the diff's. Can't remember the last time I heard of anyone breaking a driveshaft. And my car is even still running with its original wheel bearings. (145k Miles/232k Km's)
Clutches can struggle if you go for big power, but the standard clutch can cope upto about 300Lbsft torque and 260-270bhp.
3rd gear can be a weak point as well, but again only if you go for big power 300bhp+
The torque splitter can wear over time, and should be checked when you have the gearbox off to change the clutch.

Right now onto the engine. If well maintained the main components of the engine are fairly robust. Regular oil changes with a very good quality fully synthetic oil are a must. Selenia 10-60 / Motul / Agip racing 10-60 are the brands of choice. Never use Mobil 1 0-40, as its too thin when cold and drains away from the head.

The cambelt should be changed every 36,000 miles or 3 years. This is very important as if it snaps you will be looking at a very expensive engine rebuild.
The balance shaft belt can be removed if you really want to gain a couple of bhp. People who have removed it say you don't notice the difference.

[Steve Webb]

Right, part 2.

Starting at the airfilter, the airbox is in a pretty poor area, the opening is stuffed up against a structural part of the engine bay and so airflow into the airbox and across the filter is restricted.
The intercooler, at first glance looks very poor. Its got plastic endcaps for a start, but in reality it actually flows very well. There is very little pressure drop across the intercooler. Be careful when you tighten the clips holding the hoses onto the intercooler, it is possible to break the endcaps by over tightening. If you are going to run more than 1.4bar boost you will need a new intercooler and the plastic parts won't cope with this pressure.

The routing from the intercooler to the inlet plenum / collector is terrible because of the location of the battery. Moving the battery to the boot free's up loads of space to let you improve the routing.

The exhaust manifold is a huge piece of cast iron, and I've only ever heard of one break. Aftermarket ones are available, they are of better design, equal length primaries, more efficient diameters, better response and BHP. The average quote is @15bhp more.

Turbo design is an old one, Garrett T3, but it is reliable if treated well. 100K + miles no problem. Loads of upgrade options available. Base boost as standard is 0.7bar, with the overboost function pushing this up to 1.1bar for short periods. You can run upto 1.4bar with standard engine internals, but anymore than that and you will need to have an uprated head gasket, and possibly 12mm head bolts.

Now onto one of the biggest problems on the Q4, the exhaust. The OEM one consists of a pre-cat, main cat, 2 centre boxes and then a rear box.
Very heavy, and very restrictive. Remove it as soon as possible and get a new one. All you really need is a rear box. And maybe a cat if you have probs with MOT/CT . And make sure that the tube diameter is 2.5" /63mm at the very least.

The handling of the car is very safe, to the point of being boring. Turn-in can be vastly inproved by adding a strut brace and increasing the diameter of the front anti roll bar. The Dedra integrale front ARB is a bolt in option for an increase of @25% stiffness. Increasing front toe-in also improves things drastically.

[Steve Webb]

Right now onto the good points. It is a very very discrete Q car. Very few people know what they are, and with a few mods you can vastly improve the perfomance of the car.
Aftermarket airfilter, new manifold, free flowing exhaust, remap will see you well on your way to 250bhp.
At this point your 0-62 mph /0-100 kph will be somewhere around 6.5 seconds.
As I mentioned before the handling is very safe, this is true even on wet roads. When everyone else is slowing down due to the weather, you can carry on regardless.
The car is still comfortable, and big enough for 5 adults, the boot is huge! If you drive the car with a light right foot, you will see more than 25mpg.
The car hasn't dated that much to my eyes, still looks good, still looks aggressive.

So there you go my views on the Q4. I'm sure others on here will have something to add.

Steve