A classic example of how not to do it

[old-git]

Went to the Dick Turpin, on the A127 near Benfleet in Essex last Wednesday as it is the regular meeting place for the local modding fraternity. Mainly American but also a diverse mixture of English and Jap machinery.

The point of this thread is that a Skyline pulled into the car park - loud with the standard shopping list on the side. Looked the part. Parked up with lots of revving and immediately opened the bonnet for his admirers. When the crowds had dispersed I wandered over to have a looksee. Normal stuff; chrome everywhere and a large turbo.

However, what caught my eye was the air filter. A large cone filter was stuck in the front right side (when looking from the front) of the engine bay with no heat shield. A 5 inch chromed duct took the already hot air to the turbo. I touched the duct and couldn't keep my hand on it!

Made me wonder what he (or more probably his builder) actually knows about building for performance? However, as he was rather a large guy with lots of followers, I decided not to ask him about it

[turbonutter69]

Wimp.

[pgarner]

come on steve

[Loz]

Lol @ PG!

Blimey he must be losing a lot of power, surely he must notice when everything's warmed up?
Don't some ecu's throw lots of petrol in, to try & cool the combustion chamber when the air is too hot? Am I right in thinking that leads to the bores being 'washed' as well?

[old-git]

Originally Posted by turbonutter69

Wimp.

Yup

[old-git]

Originally Posted by pgarner

come on steve

But there was more than one of them and slingshots are one-shot wonders!

[Loz]

Get your car finished & you could out run 'im!

[waynne]

OG! It is a well known fact that cars are more economical when you have hot air coming into your intake. It would appear that ECO tuning is taking off then!

Who needs performance when you have a Skyline to pose around in!


Or perhaps it is just another clueless wannabe without much of an idea!

[old-git]

Originally Posted by Loz

Get your car finished & you could out run 'im!

I wouldn't even bother, not playing with toy cars

[Loz]

Good point, I could probably out run him on hot day in my little Rover!

[pgarner]

thats no way to talk about the elan

[old-git]

Originally Posted by pgarner

thats no way to talk about the elan

I wondered how long it would take you

Actually, sizewise, it is a toy compared to most cars.

[pgarner]

well somebody had to say it

[Loz]

I dunno, twist my words why don't you!

[danzul]

i apologise as i am limited on time but spotted this thread so read the first post and am now commenting, but bugger me with a fork sideways! surly every one knows that one of the basic points of engine tuning is to keep the air being fed into the engine relatively cold! he must be losing a lot of power and economy as the ecu will be pumping extra fuel into the engine to cool it!

[claymore]

Right, here goes (puts on flack jacket and helmet) I have been monitoring temperatures around my engine in 4 different places (engine bay, intake at the air filter, boost temp after turbo and intake temp after the intercooler).

On my Volvo with just a cone filter in the hot engine bay the temp would drop to ambient temp within about two miles of driving,

With the filter shielded and a cold air feed, it would drop to ambient temp within about a quarter of a mile.

So what I'm saying is it made no difference weather the air filter was shielded or not within about two miles.

[turbonutter69]

Originally Posted by danzul

i apologise as i am limited on time but spotted this thread so read the first post and am now commenting, but bugger me with a fork sideways! surly every one knows that one of the basic points of engine tuning is to keep the air being fed into the engine relatively cold! he must be losing a lot of power and economy as the ecu will be pumping extra fuel into the engine to cool it!

If everyone knew that then they'd be wrong. Hotter air will make the car more economical because the fuel will be sparse and not dense.

[old-git]

Originally Posted by claymore

Right, here goes (puts on flack jacket and helmet) I have been monitoring temperatures around my engine in 4 different places (engine bay, intake at the air filter, boost temp after turbo and intake temp after the intercooler).

On my Volvo with just a cone filter in the hot engine bay the temp would drop to ambient temp within about two miles of driving,

With the filter shielded and a cold air feed, it would drop to ambient temp within about a quarter of a mile.

So what I'm saying is it made no difference weather the air filter was shielded or not within about two miles.

That's interesting CM. Is the filter only getting its air from under the bonnet or is there an outside feed as well?

If there is no outside feed, I can't understand how the intake temp can be at ambient when it must be hotter than that under the bonnet.

I can understand how shielding will make no real difference as the filter is still drawing air around it from the engine bay. All the shielding will do is protect the filter from direct radiated heat.

[turbonutter69]

Originally Posted by old-git

All the shielding will do is protect the filter from direct radiated heat.

Now this is something I don't understand?
If you use a metal heat shield for the air filter then surely the metal of the heat shield will get just as hot as the engine and still radiate heat to the filter.

[herb]

Originally Posted by turbonutter69

Now this is something I don't understand?
If you use a metal heat shield for the air filter then surely the metal of the heat shield will get just as hot as the engine and still radiate heat to the filter.

this is true use aluminum, a heat shield wont 100% get rid of the heat but it does help alot!!
a correctly set up heat shield should be able to dissipate (?maybe wrong word not sure?)(been out drinking)away from the source you are trying to protect!!!

[old-git]

Originally Posted by turbonutter69

Now this is something I don't understand?
If you use a metal heat shield for the air filter then surely the metal of the heat shield will get just as hot as the engine and still radiate heat to the filter.

Agreed, if you use plain steel. By shielding I am assuming that proper heat reflecting materials are being used.

[claymore]

Originally Posted by old-git

That's interesting CM. Is the filter only getting its air from under the bonnet or is there an outside feed as well?

Interestingly, the air temp in the engine bay also goes down to nearly ambient temp after a couple of miles, so I assume that once the car is on the move (on an open road and not in traffic) the hot engine air is replaced by cold air from under and around the engine bay. also once the car is stationary the un-shielded filter gets hot very quickly. the problem I found was that for drag racing there is a lot of waiting around in the staging area before you take off. my solution is to put one of those electric "superchargers" in the cold air feed to send ambient temp to the filter before the race.

[indiaman]

Hot or not, its a pretty fast car, maybe the filter is in the airstream when motoring fast on the highway

[waynne]

Interesting post, thanks for doing the research and scotching another myth (or proving that a shield is more effective than open filters on short runs.)

[danzul]

Originally Posted by turbonutter69

If everyone knew that then they'd be wrong. Hotter air will make the car more economical because the fuel will be sparse and not dense.

i did say relatively cold lol