cold air induction

[Pooh]

My 400SE gets pretty hot under the bonnet after a decently long run and the power seems to drop off quite a bit which I assume is down to it drawing in hot air.
I would like to try and modify the car to get cold air to the filter, I have a few ideas but I thought that this must be a common problem and wondered does anybody who has done this themselves have any advice or even pics of what they have done?
I had thought about boxing in the air-filter so that it draws air from the vent in the front LH corner of the bonnet but I thought this might reduce airflow through the engine bay and increase under-bonnet temperatures even further.
I had also thought of doing a similar thing but using the cold air hoses to the interior air vents to supply air to the filter.
Any ideas please?

[Number 7]

I'm surprised that the power is dropping off noticeably - does the engine run hot, and is the cooling system ok? I've not experienced this, even on 80 deg.F trackdays.

As for a cold air intake, I've run flexible trunking (2" dia.approx) from each of the intakes next to the driving lights to the underside of the air filter. I couldn't be bothered to figure out a way of boxing it in though, it just didn't seem worth it. As for the fresh air supply to the cabin - take the roof off!

7.

[Pooh]

Number 7 said:

I'm surprised that the power is dropping off noticeably - does the engine run hot, and is the cooling system ok? I've not experienced this, even on 80 deg.F trackdays.

As for a cold air intake, I've run flexible trunking (2" dia.approx) from each of the intakes next to the driving lights to the underside of the air filter. I couldn't be bothered to figure out a way of boxing it in though, it just didn't seem worth it. As for the fresh air supply to the cabin - take the roof off!

7.

I have fitted a new aluminium radiator but it still seems to run with the fan on most of the time and everything under the bonnet does seem to get very hot, maybe it is not running correctly, I need to get it set up properly on a rolling road.
The power drop off is most noticeable if the car has been moving slowly in traffic, I am happy to sacrifice the air supply to the cabin because I try to never use the roof and I would rather have more power than more air.

[rev-erend]

The point is - is it really power drop off or fuel vapourisation in the fuel rail.. ?

[Number 7]

Pooh said:

I have fitted a new aluminium radiator but it still seems to run with the fan on most of the time and everything under the bonnet does seem to get very hot, maybe it is not running correctly, I need to get it set up properly on a rolling road.
The power drop off is most noticeable if the car has been moving slowly in traffic, I am happy to sacrifice the air supply to the cabin because I try to never use the roof and I would rather have more power than more air.

Is it running hotter with the new rad than it was before? They can be tricky to refill with coolant, and therefore end up with an air lock. Does the heater put out hot air?

When you initially said a power drop-off after a run, I didn't think you meant whilst sitting in traffic. Mine has a tendency to sometimes pink a bit after sitting in a long traffic jam, but after a few minutes of cooler air it's fine. Your fan definitely shouldn't be on most of the time. What's the idle like and does it use / lose any water?

7.

Edited by Number 7 on Tuesday 12th January 16:37

[lancia4wd]

Hi,

I have a ali surround with my cone filter in it, that clamps around the afm, is them piped to a ali collector, flat on the bottom.

It was quite expensive to make, its not fitted now, but i could try to sort some photos out in near future, designed as a Ram / cold air.

Regards


Nick

[combine]

Number 7 said:

Pooh said:

I have fitted a new aluminium radiator but it still seems to run with the fan on most of the time and everything under the bonnet does seem to get very hot, maybe it is not running correctly, I need to get it set up properly on a rolling road.
The power drop off is most noticeable if the car has been moving slowly in traffic, I am happy to sacrifice the air supply to the cabin because I try to never use the roof and I would rather have more power than more air.

Is it running hotter with the new rad than it was before? They can be tricky to refill with coolant, and therefore end up with an air lock. Does the heater put out hot air?

When you initially said a power drop-off after a run, I didn't think you meant whilst sitting in traffic. Mine has a tendency to sometimes pink a bit after sitting in a long traffic jam, but after a few minutes of cooler air it's fine. Your fan definitely shouldn't be on most of the time. What's the idle like and does it use / lose any water?

7.

Edited by Number 7 on Tuesday 12th January 16:37

Sounds more like an airlock issue if you've just changed the rad , I got mine fixed recently( slight leak ) and have had no problems with cooling so far .

[Pooh]

Number 7 said:

Pooh said:

I have fitted a new aluminium radiator but it still seems to run with the fan on most of the time and everything under the bonnet does seem to get very hot, maybe it is not running correctly, I need to get it set up properly on a rolling road.
The power drop off is most noticeable if the car has been moving slowly in traffic, I am happy to sacrifice the air supply to the cabin because I try to never use the roof and I would rather have more power than more air.

Is it running hotter with the new rad than it was before? They can be tricky to refill with coolant, and therefore end up with an air lock. Does the heater put out hot air?

When you initially said a power drop-off after a run, I didn't think you meant whilst sitting in traffic. Mine has a tendency to sometimes pink a bit after sitting in a long traffic jam, but after a few minutes of cooler air it's fine. Your fan definitely shouldn't be on most of the time. What's the idle like and does it use / lose any water?

7.

Edited by Number 7 on Tuesday 12th January 16:37

Thanks for the help.
I got the car cheap because it needed a new radiator so I cannot compare it to before, the heater takes a while to heat up but does blow hot air. The idle is a bit lumpy and it does not always idle at the same revs, a quick blip of the throttle usually results in a lower idle speed than just coming gently of the throttle, it does not use/lose any water.

[Pooh]

rev-erend said:

The point is - is it really power drop off or fuel vapourisation in the fuel rail.. ?

I did have a problem with that, the fuel pressure regulator was stuck shut causing no/very little fuel flow round the rail, fuel vaporisation and a mega rich mixture but I have freed it off and it seems OK now.
I may be confusing my symptoms a bit because I haven't driven it for a while but it does seem to get slower after the engine bay heats up due to traffic/length of trip.

[C O Jones]

I think Richard Thorpe did some work on this - brought the car along to Zolder I seem to recall.

I don't know how much it improved things but RT may be able to give you more info.

Be careful fitting the air intake too low as it could suck up water in very wet conditions.

Russ

[Pooh]

lancia4wd said:

Hi,

I have a ali surround with my cone filter in it, that clamps around the afm, is them piped to a ali collector, flat on the bottom.

It was quite expensive to make, its not fitted now, but i could try to sort some photos out in near future, designed as a Ram / cold air.

Regards


Nick

This sounds like the sort of solution I am looking for, photos would be good.
Have you had it fitted and did it make a noticeable difference?

[Number 7]

I think you need to establish why the fan is on so much (how do you know when driving though - is there an indicator light fitted?). When you put the new rad in, what did you do about the otter switch - maybe you have the wrong switch which is set at too low a temperature? I'm no expert, but I think a lean fuel mixture could cause an engine to run hotter than normal - maybe connected to the fuel pressure regulator issue? Have you pulled the plkugs and checked condition? I wouldn't be concerned about a cold air feed (at this stage), as plenty of these cars (standard and tuned) don't use anything like that.

7.

[Pooh]

Number 7 said:

I think you need to establish why the fan is on so much (how do you know when driving though - is there an indicator light fitted?). When you put the new rad in, what did you do about the otter switch - maybe you have the wrong switch which is set at too low a temperature? I'm no expert, but I think a lean fuel mixture could cause an engine to run hotter than normal - maybe connected to the fuel pressure regulator issue? Have you pulled the plkugs and checked condition? I wouldn't be concerned about a cold air feed (at this stage), as plenty of these cars (standard and tuned) don't use anything like that.

7.

The otter switch came from TVR car parts and I was told it was correct, I think the fan is on quite a bit because for a while I had wiring problem which meant the otter switch was not working, I had to turn the fan on and off with the manual override switch and the fan needed to be on even at 70 mph to stop it from overheating.
The cool air supply was a project for the winter, I was hoping that it would make the car a bit quicker because it is not as quick as I expected it to be.
I need to get the car set up properly on a rolling road and see what happens, I have hardly driven it since I fixed the fuel regulator.

[2mad]

Check the tension on the water pump belt as this could be loose causing the engine to get hot also the otter switches are not very reliable. i fitted an electronic one with adjustable temp setting to stop excesssive heat build up purchased from burton race engines about £50.00 works a treat also on the air filter best to buy a k& n filter with smooth bore inlet pipe from act etc.

[grahamw48]

Apart from faults in the cooling system itself, I think you may have basic engine set-up issues...fuelling (weak),timing (too advanced), possibly wrong plugs fitted, even headgasket ?

The fan should only rarely cut in, and then only when standing in traffic on a hot day.
That's been my experience anyway.

[honestjohntoo]

Pooh said:

I got the car cheap because it needed a new radiator so I cannot compare it to before, the heater takes a while to heat up but does blow hot air. The idle is a bit lumpy and it does not always idle at the same revs, a quick blip of the throttle usually results in a lower idle speed than just coming gently of the throttle, it does not use/lose any water.

Pooh. Drawing in hot air has nothing to do with the problems you describe and changing things to get cold air instead will improve nothing.

1. All your problems are identified in the above quote:

1. Your car needed a new radiator when you acquired it cheap, but it prolly also needed flushing and reverse flushing of the engine block and heater matrix.

1. That accounts for why the cabin heater is so slow to get going.

1. The same thing also accounts for why the cooling system is inefficient and the whole engine is overheating due to impaired water flow.

1. Contributing to the over-heating problem will be airlocks in your cooling system which can be very difficult to eliminate. Such airlocks would also contribute to tardy cabin heating.

1. Your lumpy idle "might" be due due to maladjusted Efi system setup, but bearing in mind the possibility of engine neglect - before you got the car - to go along with a crudded coolant system, I'd bet a shilling to an old boot that your plenum innards are also filthy dirty.

1. Dirty goo inside the plenum defo accounts for your "idle speed hang-up" which, if its a single plenum, hardly ever occurs due to maladjusted throttle mechanism, but is "odds on" down to crud. Hence the need to blip the throttle.

1. Going full circle, lumpy idle is invariably caused by an impaired crankcase ventilation system so you may also find your plenum breather and idle galleries are partially blocked.

1. You'll need some reading material for resolving these issues but unfortunately I know nothing about your 400SE engine and can only recommend trawling through these three links for clues how you might proceed.

Airlocks - http://www.vintagemodelairplane.com/pages/TipsAndT...

Plenum - http://www.vintagemodelairplane.com/pages/TipsAndT...

Idle Speed Hang-up - http://www.vintagemodelairplane.com/pages/Download...

There is also loadsa other stuff on all Efi components in the same archive.

“Look after your Plenum and your Plenum will look after you!”

Edited by honestjohntoo on Wednesday 13th January 01:11

[BadRed]

I am sure that cold air induction is not the answer as the above posts, but for info this is Gandalfs 450 ( ex Richard Thorpe ) as mentioned by Mr Jones the air filter enclosure is feed by a large pipe and a scoop under the front splitter.



This is the set up on my old 450 with the air filter moved and vent holes drilled in the top skin of the wheel arch, I believe that sone SEACs have this set up as standard, or may have been modified early in there lives. In theory ! cooler air travels from the front of the car in the cavity between the inner and outer skin of the wheel arch and creates a cool (er) area in the corner of the engine bay

Edited by BadRed on Wednesday 13th January 07:59

[Pooh]

honestjohntoo said:

Pooh said:

I got the car cheap because it needed a new radiator so I cannot compare it to before, the heater takes a while to heat up but does blow hot air. The idle is a bit lumpy and it does not always idle at the same revs, a quick blip of the throttle usually results in a lower idle speed than just coming gently of the throttle, it does not use/lose any water.

Pooh. Drawing in hot air has nothing to do with the problems you describe and changing things to get cold air instead will improve nothing.

1. All your problems are identified in the above quote:

1. Your car needed a new radiator when you acquired it cheap, but it prolly also needed flushing and reverse flushing of the engine block and heater matrix.

1. That accounts for why the cabin heater is so slow to get going.

1. The same thing also accounts for why the cooling system is inefficient and the whole engine is overheating due to impaired water flow.

1. Contributing to the over-heating problem will be airlocks in your cooling system which can be very difficult to eliminate. Such airlocks would also contribute to tardy cabin heating.

1. Your lumpy idle "might" be due due to maladjusted Efi system setup, but bearing in mind the possibility of engine neglect - before you got the car - to go along with a crudded coolant system, I'd bet a shilling to an old boot that your plenum innards are also filthy dirty.

1. Dirty goo inside the plenum defo accounts for your "idle speed hang-up" which, if its a single plenum, hardly ever occurs due to maladjusted throttle mechanism, but is "odds on" down to crud. Hence the need to blip the throttle.

1. Going full circle, lumpy idle is invariably caused by an impaired crankcase ventilation system so you may also find your plenum breather and idle galleries are partially blocked.

1. You'll need some reading material for resolving these issues but unfortunately I know nothing about your 400SE engine and can only recommend trawling through these three links for clues how you might proceed.

Airlocks - http://www.vintagemodelairplane.com/pages/TipsAndT...

Plenum - http://www.vintagemodelairplane.com/pages/TipsAndT...

Idle Speed Hang-up - http://www.vintagemodelairplane.com/pages/Download...

There is also loadsa other stuff on all Efi components in the same archive.

“Look after your Plenum and your Plenum will look after you!”

Edited by honestjohntoo on Wednesday 13th January 01:11

Thanks

Loads of stuff to look at/fiddle with, I will have a go at flushing the cooling system once the snow/ice melts enough for me to get the car out of the garage.

[Pooh]

BadRed said:

I am sure that cold air induction is not the answer as the above posts, but for info this is Gandalfs 450 ( ex Richard Thorpe ) as mentioned by Mr Jones the air filter enclosure is feed by a large pipe and a scoop under the front splitter.



This is the set up on my old 450 with the air filter moved and vent holes drilled in the top skin of the wheel arch, I believe that sone SEACs have this set up as standard, or may have been modified early in there lives. In theory ! cooler air travels from the front of the car in the cavity between the inner and outer skin of the wheel arch and creates a cool (er) area in the corner of the engine bay

Edited by BadRed on Wednesday 13th January 07:59

Those are the sorts of pictures I was after, the bottom one in particular looks like a good solution.

[jmorgan]

My intake is the same as that bottom pic.