Varying performance 2.0T

Hey Guys,

Like to pick your minds if I may...

I've been riding my bike to work for a few weeks (motor, not cycle) but as I've worn out the rear tyre in Germany this weekend I've been back in the car.

The thing I've noticed is that the performance seems to vary. Sometimes it's putting me in the seat, others it seems very luke warm. Airco on / off doesn't seem to do anything (goes fast / slow with airo on or off).

I was wondering: is there anything that could cause this? Am I just used to the blazing performance of my bike and expecting too much?

Any ideas much appriciated.

Stu

[Dan F]

Underbonnet temps have an awful lot to do with it. Why do you think that *serious* fast cars (i.e. cars that are designed to be driven hard ands fast all the time) have vents and holes all over the shop?

Performance can vary quite a bit with temp.
The other day my T5 made me smile a BIG smile, as it was a monster but the following day it seemed to be a different car. Best conditions are about 10C ambient if you ask me. No ice, but cool enough to let the turbo shine.

The next thing I would have done to my T4 was to be a scooby style bonnet vent, but I never got round to it.

Later,
Dan.

Cheers for that Dan,

I'll see what happens when the cool weather gets here (it did seem much faster when leaving the office, than after doing 30 miles to get home...)

Stu

[Ross9]

If you want to try and sort it out, you can focus your attention on the intake for the engine, the bay can be warm, and still you can have nice low intake temps, though it can take a bit of work.

Chargecooler systems can be plumbed in, this will be expensive I imagine, but one of the better ways of doing it, Intercooler sprays are also good, but not so much for on the road use, more so for drag racing as they run out quickly. Chargecooler works at all times, stationary or moving, and doesnt run out, U can use an IC spray at all times as well, it just wont last long on a drive, better saving it for a few seconds at a time after sitting in traffic.

Apart from that there's not much you can do. Heatsoak in traffic is where it will be most noticable, if you sit in a jam for a bit, or a queue at some traffic lights, the car will be lethargic afterwards. Vents etc wont really make much difference to this, some heat will come out, but theyre more designed to aid cooling when the car is moving, air comes in the front, and out the vents, creating a cool flow over the engine, apart from on Subarus, and Pulsars, which have top mounted intercoolers, their vent/scoop is designed to catch air, the IC sits under the scoop on a subaru, and the IC sits up inside the large cheesegrater vent on a Pulsar when the bonnet is closed.

All turbo cars have good and bad days, even those with big vents everywhere, as some of my Pulsar and Impreza owning friends will testify.

Personall I'm going for the DIY IC spray I've bodged together from some pumps and a second water bottle, just need to order the proper nozzles now.

PS, on leaving the office, remember and let it heat up first, it might have low intake temps due to the under bonnet temps not having gotten up yet, but your oil will be like syrup and the engine wont like being revved hard, nor will your turbo appreciate being spun while cold, your turbo will hgeat up a lot quicker than the oil though as the exhaust gases pass through it. 5mins should be fine before giving it any stick.

I don't 'use' the car 'till the neddle is horizontal. As you say it doesn't take long. I also wait for a few mins after starting to let some oil circulate to the turbo, and wait for a couple of mins when before turning off to wait for the turbo to relax a little.

As for the mods, my other half has made it clear that mods aren't allowed at the moment, as she is afraid of turning it into something she won't want to drive. So no bleed valves or panel filters for the time being. Working on it though :)

At least I have a nice new tyre for the bike now - that is quick, always!

Stu

[Dan F]

Hi Stu.

A panel filter and a bleed will not alter the normal road manners of the car.
My wife was against anything as well, however with persistence she 'agreed' ;-) and she now enjoys driving it more than I do, if that is possible!! :D

Hi Ross9. I was going to fit a scooby style vent to my T4 precisely *because* they are designed to catch air. It would have channelled a nice load of amibient air over the exhaust and compressor of the turbo! Have a look at where the turbo is mounted in a T4. It would have worked well. :)
The intercooler being at the front wouldn't need anymore air channelling towards it.

Later guys,
Dan.

Working on it, working on it.

The one good thing I have in my favour is that she loves driving the 2.0T more than the 440 1.8. I'm still trying to convince her the car will only go as quick as your right foot lets it, but it's hard going. With any luck, and alittle perseverance, I'll be able to convince her...

Stu

[Ross9]

Good point Dan, wasn't thinking it through at all or I'd have remembered the Turbo is down the back on a T4.

Do you reckon you would have gotten any gains from this? obviously it would help keep the turbo cool, but would it have managed to cool the actual charge temps any so close to the point of compression, rather than cooling the charge further after compression round at the intercooler with some other method, or even fitting the vent forther forward so it caught the air and channeled it onto the intake manifold etc at the front? I'm not saying it wouldn't, I dont know either way, just thinking out loud.

Not too sure how good a scooby vent would look on a T4, or any volvo, actually. I'm of the opinion it belongs on a Subaru and nowhere else, much like the Pulsars cheesegrater bulge/vent doesnt belogn anywhere but on a Pulsar, and a Cosworth Whale Tail looks ridiculous on anything but a Cosworth.

[Dan F]

Hi Ross9.

I don't know how much difference it would have made to the inlet temps, but with a T4 that isn't really the point.
On 2.0Ts and T4s the boost is calculated, not measured, so if you keep all temps down you can fool the ECU.

It calculates boost depending on the amount of air entering the system, the inlet temp and the exhaust temp.

Obviously if the exhaust temp goes way up then the turbine is working harder so the boost would be lowered after a certain point.
If you can keep it that bit cooler then the boost (even if it isn't increased) should be stronger and more stable for longer periods.
Obviously boost can only be increased to the point where the ECU deems its parameters have been exceeded or, in the best case scenario, the injectors simply cannot supply any more fuel regardless of temp.

In traffic the vent would also have the benefit of channelling hot air coming from the turbo directly out to atmosphere, thereby keeping it cooler even when standing still.

As for whether a scooby vent would look right, it doesn't have to be a genuine one, just a scooby 'style' vent would do, and I think it would look good if painted properly and it would be there for a purpose.
:-)
Later,
Dan.

[Dan F]

Hi Ross9.

I don't know how much difference it would have made to the inlet temps, but with a T4 that isn't really the point.
On 2.0Ts and T4s the boost is calculated, not measured, so if you keep all temps down you can fool the ECU.

It calculates boost depending on the amount of air entering the system, the inlet temp and the exhaust temp.

Obviously if the exhaust temp goes way up then the turbine is working harder so the boost would be lowered after a certain point.
If you can keep it that bit cooler then the boost (even if it isn't increased) should be stronger and more stable for longer periods.
Obviously boost can only be increased to the point where the ECU deems its parameters have been exceeded or, in the best case scenario, the injectors simply cannot supply any more fuel regardless of temp.

In traffic the vent would also have the benefit of channelling hot air coming from the turbo directly out to atmosphere, thereby keeping it cooler even when standing still.

As for whether a scooby vent would look right, it doesn't have to be a genuine one, just a scooby 'style' vent would do, and I think it would look good if painted properly and it would be there for a purpose.
:-)
Later,
Dan.