Looking to improve the air intake a little pre turbo swap and came across this thread.

https://www.fiatforum.com/members-motors/265643-grande-punto-sporting-t-jet-2.html?p=2786109

Don't really want to do away with the airbox, not wanting an induction kit but thinking of increasing pipe diameter from the airbox to the turbo, and smoothing things out a little. I have the Esseesse intake in place of standard collector at the moment but even that seems rather small, thinking to replace this with a 76mm pipe running to similar location. You can feel air being pulled in hard at tick over through the intake, surely bigger could be better?

Anyone got any thoughts on this, waste of time or potential gains to be had?

Cheers

Ben

The fact I've had no response to this sort of tells me no one thinks it too ridiculous so I think I'm just going to do it. I'll get some pics up once the bits arrive. Only thing I can see being difficult is routing a larger diameter pipe from the air box to behind the light.

Cheers

Ben

Fact: each one of a 4 cylinder 4 stroke engine got a suction stroke every 2 turns, which means there is (kind of) a continuous suction through a quite small section (the admission valve opening); let's pretend it's dubled by the turbo action and we're still far from the section that's offered by the original piping...
I think you won't feel any benefit (other than the Placebo/self-suggesting effect), but at least it wouldn't hurt.
BTW: the fressher the air, the better, so no KN near engine etc.

BRs, Bernie

I don't think you'll see any gain either.

I don't own a t-jet but my Corsa intake is 70mm and that'll will happily support up to 240/250 brake...i.e. that diameter is in no way a limiting factor/performance bottleneck so unless your cars intake pipe is the size of a straw you won't see any horsepower gain.

Does the t-jet have an intercooler?

Surely you'd be better spending the money upgrading that? Again i don't own a t-jet but standard coolers are usually woeful weak and soon become overpowered.

I have to disagree with the bernies last comment about open cones as well; heat soak on turbo cars isn't a real issue as the air gets ran over a red hot turbo so a few extra degrees temperature/"fresher air" isn't going to make any difference in the grand scheme of things.

You should do an intercooler upgrade - you will feel feel that benefit even on a standard car, and moreso when you get remapped.

I have one 3/4 times the size of standard on the Corsa for only a couple hundred quid.

u33db said:

...I have to disagree with the bernies last comment about open cones as well; heat soak on turbo cars isn't a real issue as the air gets ran over a red hot turbo so a few extra degrees temperature/"fresher air" isn't going to make any difference in the grand scheme of things ...

Click to expand...

it's not realy the temperature, but the amount of oxygen in a given (sucked-in) air volume ! So as the air expands with temperature: the less dense (hoter) the air, the less oxygen, the less fuel that can be burnt ...
I haven't said don't use KN's or whatever cones, just manage to feed 'hem with FRESH air ;-)

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)

I'm talking temperature and you're talking density but really it amounts to the same thing, because as you state hotter air = less dense = less power and colder air = more dense = more power.

I'm just saying that if you have 2 turbo cars with the same engine, one fed with cold "fresh" air from outside the car and one fed with warm air from under the bonnet you will not see any difference in overall power between the 2.

Why?

The air will be compressed via the turbo and heated, and will also be heated by the fact the turbo is powered by hot exhaust gasses - so any benefit of the colder/fresher air from outside the engine bay will be eradicated due to this.

It would be different on a normally aspirated car, where the air temperate (fresh or not) is the only thing to control the air density.

On a turbo car the turbo, and ultimately the inetrcooler decide how dense the actual air ingested is, nothing else will really matter.

u33db:
That example is not true!
-you cannot compress hot air as well as cold air ( an extreme example of that is trying to compress air at high altitudes where there's a lot less air).
-let's assume you have 2 turbo cars with one compressing air that is 10 degrees hotter, after the air is compressed by the turbo to 1 bar, it will be 20 degrees hotter + the heat from the inefficiency of the turbo. That is why air-air intercoolers work. but that is also why they are more inefficient as temperatures go up, they also get heat soaked (cannot dissipate enough heat)

It is true that a bigger intercooler will help, but only to some extent.
In reality any intake temperature drop is useful.

I am generalizing the issue so i am not talking about extremes of altitude or temperature.

In your example it wouldn't be 20 degrees hotter unless your intercooler was completely inadequate to begin with - if both cars have a good intercooler design then there'd be no noticable power difference between one sucking under bonnet temps and one sucking outside temp.

I stress the world "noticeable" - on a thermometer yes the car fed from outside may get a slighter cooler air feed by a few degrees at the TB. Will you feel this though? No.

Its like comparing 2 cars where one has an extra 5-10bhp. Yes its technically more powerful but you're not going to notice any difference in the real world.

Any reduction in air temperature has to be a good thing but the main motivation is an increase in flow, the stock piping is definitely on the small side particularly feed into airbox. Feed comes in from behind headlight.

I'm seeing about 12 degrees difference between ambient and TB (IAT) when on the open road and not booting it. In traffic or when driving hard the difference can be up to 35 degrees. So stock IC is not that great, moving slowly it heats up quickly. It is definitely not as quick when hot, I could feel it before I was watching it.

I'm still going to do it if for no other reason than it'll be fun to do!

Think getting the cat out of the engine bay can only be a good thing too.

Cheers

Ben

Must somehow agree one wouldn't feel a real difference by sucking fresh vs engine-bay warmed air; as U33b says it's gonna be cooled down by the IC anyway... ONLY if this IC has been correctly designed and is freshly cooled itself (have seen reg plate in front of it on this forum !!).

Anyway, if you don't notice a difference, the average mpg, hence your wallet, will :-D

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)

Definately.

I know the chassis is the same as the corsa but looking at pictures of your standard intercooler it looks virtually indentical to the corsa one too and thats known to be rubbish.

I guess you can get the likes of an Airtec/Forge for your car which would be a vast improvement? I managed to get a semi universal one for mine which is almost the exact height and width of the radiator and its been excellent, not fade in power after repeatedly hammering it.

Consensus on the corsa forums is ANY aftermarket one would be better so you don't need to speed hundreds to get a known brand.

BTW i've used these guys for custom silicone hoses before;

http://stores.ebay.co.uk/Auto-Silicone-Hoses-Outlet?_trksid=p2047675.l2563

Cheap and fast postage if helps!

I'd also recommend buy a proper hose cutter off ebay for a tenner as well rather than going at it with a stanley knife...makes the job a whole lot neater.

Intercooler is on the list, will probably go for airtec as I know it will go straight on with no issues.
That's exactly where I'll be getting them from, all sat in my eBay cart, just need to figure out how or if I can run a 76mm pipe to same location as current intake before I get it all bought. Will have a look at the cutter, was going to use jubilee clip and scalpel for the hoses and a grinder for the piping.

will not hurt to run a larger pipe though !


BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)

So whilst looking at the best way to route a pipe from the airbox to behind the bumper under the light, a Forge induction came up cheap so I bought it against my be judgement.

First run I hated the noise but hardly notice it now. Intake temps are about the same as factory box and it does seem to review a little more freely and took no more than 30 mins to fit.

Cheers

Ben