The best way to modify a Q4 : Engine

[Steve Webb]

There have been a few threads recently about the best way and in which order to do modifications to the Q4 motor.
I thought it might be an idea if there was a thread that discussed the best order in which to do things.

So assuming you have just gotten hold of a completely standard Q4 in good condition, what would you do first?

Paste the list into your reply so we keep all the details together.


Remove original exhaust with its cats (if possible) and replace with at least a 63mm system with single rear box.


Over to you guys. If this thread goes well, we can do another for the handling side of things.

[Varypodaros]

Remove original exhaust with its cats (if possible) and replace with at least a 63mm system with single rear box.
remove the original air filter and replace with a aftermarket one in the filter box.

[Brul(tm)]

Disconnect the EGR system. Use RON98 fuel, replace the original chip for one from Squadra-Tuning or something similar.

When I finally found the time, I will open a new topic and post my progress on my engine rebuild. There will be photo's of everything that's replaced or if somebody ask something specific and I am still able to take pictures from the requiested subject ;)
The first part of my project will be a forged bottem and I'll continue from there.
The other subjects will be the exhaust manifold + turbo and the cylinder head.

Regards,
Marc

[Steve Webb]

Paste the list into your reply so we keep all the details together.


:deal:



Remove original exhaust with its cats (if possible) and replace with at least a 63mm system with single rear box.
remove the original air filter and replace with a aftermarket one in the filter box.
Disconnect the EGR system. Use RON98 fuel, replace the original chip for one from Squadra-Tuning or something similar.

:thumb:

[1NRO]

At the beginning a high importance should be placed on a means to adjust the ecu to suit any modifications the furure might bring.

Not that sense ever prevailed when tuning engines! but really all tuning is chasing restriction through the entire engine, for that reason alone a sensible place to start is inside the engine. Let the engine breath better using either cams or cylinder head work (both ideally) and then follow the path along either side. A better head will show a weaker inlet/exhaust manifold and so the road unfolds.

Not sure how to add that to the threads instruction but IMO it's the way to do it if your serious. (I could pick the digits up in a copy so bombed the list off, someone better than me can maybe tidy it up?)

[Steve Webb]

The easiest way to add the existing list is to just quote the previous post, and remove the bits you don't need. You'll see in the quote how the list composed so should be able to add your bits with no probs.

Whilst I agree that if you are going to build the best engine you can, you would start inside the engine. In real world terms I don't think anyone, who is thinking about modifying an engine, would consider new cams or cylinder-head work as a first step.

[1NRO]

:smile: in that case concentrate on the electronics and get a modern roller bearing turbo with the biggest exhaust you can fit, its got to breath somehow.

With just a ported cylinder head I've seen .5 bar boost lost, thats before I had the pleasure of winding the boost back on :thumb: Boost is just a restriction. More air obviously needs more fuel, hence the importance of the electronic adjustment.

[Steve Webb]

Remove original exhaust with its cats (if possible) and replace with at least a 63mm system with single rear box.
remove the original air filter and replace with a aftermarket one in the filter box.
Disconnect the EGR system. Use RON98 fuel, replace the original chip for one from Squadra-Tuning or something similar.
Tubular manifold
Roller bearing turbo
Ported cylinder head

This still making sense to everyone?

[arguti]

I like the webpage from Richard Merrell who races 105 Alfas (nord engine) - gives you a good idea of potential benefits.

his rule of thumb is that in terms of purchasing lightweight racing parts, it costs approximately ?100 per kilo saved! :-)

http://www.alfa.me.uk/assessment.html

[WhizzMan]

A completely standard Q4 in good condition? I wouldn't change a single thing and keep it nice and dry stored. Only take it out with good weather and drive it relatively carefully. They are becoming rare and prices will go up soon for the pristine ones.

Regarding modifications I'd make on a Q4, if I were to make them:

- Take EGR off
- put squadra chip in
- put sports shocks on the rear
- put thicker ARB on rear
- street/sports brake pads and ATF blue fluid
- 145/146 turret tops for 1 deg negative camber on front
- "R" tires, like Toyo R888 or equivalent
- brake bias adjusted more to rear

Just these will get you a very fast road car that doesn't feel like the sluggish stock car at all. Way less understeer and over 240 BHP.

If that's not enough for you:

- Bigger air filter, like BMC-CDA
- ported turbo housing, inlet manifold, exhaust manifold
- de-cat
- bigger exhaust diameter and/or less dampers

If that's not enough for you (we're well over 250 bhp here, possibly 280 or even a bit more?):

- forged pistons, conrods
- ported head with inconel exhaust valves
- GT3072 turbo
- bespoke exhaust manifold with external waste gate
- sports clutch (springs, pads)
- reinforced gear box
- Intrax coil over kit
- 305 or 330mm front brake discs with 4 or more pot calipers
- matching wheels for those brakes

We 're at roughly 400 BHP and extremely track proven suspension setup here, if executed properly.

[markgq4]

is that correct that 145/6 strut top mounts give a neg camber? i havent heard that before?

[wrinx]

It's been mentioned a few times on 155.org, no idea if it's true or not but I bow to Whizz's knowledge.

wrinx

[mpampis_]

a good mod it is also to change the fuel pump. i have a walbro 255lt and i use a relay to have power directly from battery that i have in the trank (13,7 volts steadly) it can produce about 260 lt per hour.

[Steve Webb]

a good mod it is also to change the fuel pump. i have a walbro 255lt and i use a relay to have power directly from battery that i have in the trank (13,7 volts steadly) it can produce about 260 lt per hour.


Is that a straight swap for the original or do you need to modify anything, apart from the wiring.

[mpampis_]

It is something tha anyone can do by himself at home. I will post some pics when I will finish job and go home